// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
pragma abicoder v2;
import "./GPv2VaultRelayer.sol";
import "./interfaces/GPv2Authentication.sol";
import "./interfaces/IERC20.sol";
import "./interfaces/IVault.sol";
import "./libraries/GPv2Interaction.sol";
import "./libraries/GPv2Order.sol";
import "./libraries/GPv2Trade.sol";
import "./libraries/GPv2Transfer.sol";
import "./libraries/SafeCast.sol";
import "./libraries/SafeMath.sol";
import "./mixins/GPv2Signing.sol";
import "./mixins/ReentrancyGuard.sol";
import "./mixins/StorageAccessible.sol";
/// @title Gnosis Protocol v2 Settlement Contract
/// @author Gnosis Developers
contract GPv2Settlement is GPv2Signing, ReentrancyGuard, StorageAccessible {
    using GPv2Order for bytes;
    using GPv2Transfer for IVault;
    using SafeCast for int256;
    using SafeCast for uint256;
    using SafeMath for uint256;
    /// @dev The authenticator is used to determine who can call the settle function.
    /// That is, only authorised solvers have the ability to invoke settlements.
    /// Any valid authenticator implements an isSolver method called by the onlySolver
    /// modifier below.
    GPv2Authentication public immutable authenticator;
    /// @dev The Balancer Vault the protocol uses for managing user funds.
    IVault public immutable vault;
    /// @dev The Balancer Vault relayer which can interact on behalf of users.
    /// This contract is created during deployment
    GPv2VaultRelayer public immutable vaultRelayer;
    /// @dev Map each user order by UID to the amount that has been filled so
    /// far. If this amount is larger than or equal to the amount traded in the
    /// order (amount sold for sell orders, amount bought for buy orders) then
    /// the order cannot be traded anymore. If the order is fill or kill, then
    /// this value is only used to determine whether the order has already been
    /// executed.
    mapping(bytes => uint256) public filledAmount;
    /// @dev Event emitted for each executed trade.
    event Trade(
        address indexed owner,
        IERC20 sellToken,
        IERC20 buyToken,
        uint256 sellAmount,
        uint256 buyAmount,
        uint256 feeAmount,
        bytes orderUid
    );
    /// @dev Event emitted for each executed interaction.
    ///
    /// For gas effeciency, only the interaction calldata selector (first 4
    /// bytes) is included in the event. For interactions without calldata or
    /// whose calldata is shorter than 4 bytes, the selector will be `0`.
    event Interaction(address indexed target, uint256 value, bytes4 selector);
    /// @dev Event emitted when a settlement complets
    event Settlement(address indexed solver);
    /// @dev Event emitted when an order is invalidated.
    event OrderInvalidated(address indexed owner, bytes orderUid);
    constructor(GPv2Authentication authenticator_, IVault vault_) {
        authenticator = authenticator_;
        vault = vault_;
        vaultRelayer = new GPv2VaultRelayer(vault_);
    }
    // solhint-disable-next-line no-empty-blocks
    receive() external payable {
        // NOTE: Include an empty receive function so that the settlement
        // contract can receive Ether from contract interactions.
    }
    /// @dev This modifier is called by settle function to block any non-listed
    /// senders from settling batches.
    modifier onlySolver {
        require(authenticator.isSolver(msg.sender), "GPv2: not a solver");
        _;
    }
    /// @dev Modifier to ensure that an external function is only callable as a
    /// settlement interaction.
    modifier onlyInteraction {
        require(address(this) == msg.sender, "GPv2: not an interaction");
        _;
    }
    /// @dev Settle the specified orders at a clearing price. Note that it is
    /// the responsibility of the caller to ensure that all GPv2 invariants are
    /// upheld for the input settlement, otherwise this call will revert.
    /// Namely:
    /// - All orders are valid and signed
    /// - Accounts have sufficient balance and approval.
    /// - Settlement contract has sufficient balance to execute trades. Note
    ///   this implies that the accumulated fees held in the contract can also
    ///   be used for settlement. This is OK since:
    ///   - Solvers need to be authorized
    ///   - Misbehaving solvers will be slashed for abusing accumulated fees for
    ///     settlement
    ///   - Critically, user orders are entirely protected
    ///
    /// @param tokens An array of ERC20 tokens to be traded in the settlement.
    /// Trades encode tokens as indices into this array.
    /// @param clearingPrices An array of clearing prices where the `i`-th price
    /// is for the `i`-th token in the [`tokens`] array.
    /// @param trades Trades for signed orders.
    /// @param interactions Smart contract interactions split into three
    /// separate lists to be run before the settlement, during the settlement
    /// and after the settlement respectively.
    function settle(
        IERC20[] calldata tokens,
        uint256[] calldata clearingPrices,
        GPv2Trade.Data[] calldata trades,
        GPv2Interaction.Data[][3] calldata interactions
    ) external nonReentrant onlySolver {
        executeInteractions(interactions[0]);
        (
            GPv2Transfer.Data[] memory inTransfers,
            GPv2Transfer.Data[] memory outTransfers
        ) = computeTradeExecutions(tokens, clearingPrices, trades);
        vaultRelayer.transferFromAccounts(inTransfers);
        executeInteractions(interactions[1]);
        vault.transferToAccounts(outTransfers);
        executeInteractions(interactions[2]);
        emit Settlement(msg.sender);
    }
    /// @dev Settle an order directly against Balancer V2 pools.
    ///
    /// @param swaps The Balancer V2 swap steps to use for trading.
    /// @param tokens An array of ERC20 tokens to be traded in the settlement.
    /// Swaps and the trade encode tokens as indices into this array.
    /// @param trade The trade to match directly against Balancer liquidity. The
    /// order will always be fully executed, so the trade's `executedAmount`
    /// field is used to represent a swap limit amount.
    function swap(
        IVault.BatchSwapStep[] calldata swaps,
        IERC20[] calldata tokens,
        GPv2Trade.Data calldata trade
    ) external nonReentrant onlySolver {
        RecoveredOrder memory recoveredOrder = allocateRecoveredOrder();
        GPv2Order.Data memory order = recoveredOrder.data;
        recoverOrderFromTrade(recoveredOrder, tokens, trade);
        IVault.SwapKind kind =
            order.kind == GPv2Order.KIND_SELL
                ? IVault.SwapKind.GIVEN_IN
                : IVault.SwapKind.GIVEN_OUT;
        IVault.FundManagement memory funds;
        funds.sender = recoveredOrder.owner;
        funds.fromInternalBalance =
            order.sellTokenBalance == GPv2Order.BALANCE_INTERNAL;
        funds.recipient = payable(recoveredOrder.receiver);
        funds.toInternalBalance =
            order.buyTokenBalance == GPv2Order.BALANCE_INTERNAL;
        int256[] memory limits = new int256[](tokens.length);
        uint256 limitAmount = trade.executedAmount;
        // NOTE: Array allocation initializes elements to 0, so we only need to
        // set the limits we care about. This ensures that the swap will respect
        // the order's limit price.
        if (order.kind == GPv2Order.KIND_SELL) {
            require(limitAmount >= order.buyAmount, "GPv2: limit too low");
            limits[trade.sellTokenIndex] = order.sellAmount.toInt256();
            limits[trade.buyTokenIndex] = -limitAmount.toInt256();
        } else {
            require(limitAmount <= order.sellAmount, "GPv2: limit too high");
            limits[trade.sellTokenIndex] = limitAmount.toInt256();
            limits[trade.buyTokenIndex] = -order.buyAmount.toInt256();
        }
        GPv2Transfer.Data memory feeTransfer;
        feeTransfer.account = recoveredOrder.owner;
        feeTransfer.token = order.sellToken;
        feeTransfer.amount = order.feeAmount;
        feeTransfer.balance = order.sellTokenBalance;
        int256[] memory tokenDeltas =
            vaultRelayer.batchSwapWithFee(
                kind,
                swaps,
                tokens,
                funds,
                limits,
                // NOTE: Specify a deadline to ensure that an expire order
                // cannot be used to trade.
                order.validTo,
                feeTransfer
            );
        bytes memory orderUid = recoveredOrder.uid;
        uint256 executedSellAmount =
            tokenDeltas[trade.sellTokenIndex].toUint256();
        uint256 executedBuyAmount =
            (-tokenDeltas[trade.buyTokenIndex]).toUint256();
        // NOTE: Check that the orders were completely filled and update their
        // filled amounts to avoid replaying them. The limit price and order
        // validity have already been verified when executing the swap through
        // the `limit` and `deadline` parameters.
        require(filledAmount[orderUid] == 0, "GPv2: order filled");
        if (order.kind == GPv2Order.KIND_SELL) {
            require(
                executedSellAmount == order.sellAmount,
                "GPv2: sell amount not respected"
            );
            filledAmount[orderUid] = order.sellAmount;
        } else {
            require(
                executedBuyAmount == order.buyAmount,
                "GPv2: buy amount not respected"
            );
            filledAmount[orderUid] = order.buyAmount;
        }
        emit Trade(
            recoveredOrder.owner,
            order.sellToken,
            order.buyToken,
            executedSellAmount,
            executedBuyAmount,
            order.feeAmount,
            orderUid
        );
        emit Settlement(msg.sender);
    }
    /// @dev Invalidate onchain an order that has been signed offline.
    ///
    /// @param orderUid The unique identifier of the order that is to be made
    /// invalid after calling this function. The user that created the order
    /// must be the the sender of this message. See [`extractOrderUidParams`]
    /// for details on orderUid.
    function invalidateOrder(bytes calldata orderUid) external {
        (, address owner, ) = orderUid.extractOrderUidParams();
        require(owner == msg.sender, "GPv2: caller does not own order");
        filledAmount[orderUid] = uint256(-1);
        emit OrderInvalidated(owner, orderUid);
    }
    /// @dev Free storage from the filled amounts of **expired** orders to claim
    /// a gas refund. This method can only be called as an interaction.
    ///
    /// @param orderUids The unique identifiers of the expired order to free
    /// storage for.
    function freeFilledAmountStorage(bytes[] calldata orderUids)
        external
        onlyInteraction
    {
        freeOrderStorage(filledAmount, orderUids);
    }
    /// @dev Free storage from the pre signatures of **expired** orders to claim
    /// a gas refund. This method can only be called as an interaction.
    ///
    /// @param orderUids The unique identifiers of the expired order to free
    /// storage for.
    function freePreSignatureStorage(bytes[] calldata orderUids)
        external
        onlyInteraction
    {
        freeOrderStorage(preSignature, orderUids);
    }
    /// @dev Process all trades one at a time returning the computed net in and
    /// out transfers for the trades.
    ///
    /// This method reverts if processing of any single trade fails. See
    /// [`computeTradeExecution`] for more details.
    ///
    /// @param tokens An array of ERC20 tokens to be traded in the settlement.
    /// @param clearingPrices An array of token clearing prices.
    /// @param trades Trades for signed orders.
    /// @return inTransfers Array of in transfers of executed sell amounts.
    /// @return outTransfers Array of out transfers of executed buy amounts.
    function computeTradeExecutions(
        IERC20[] calldata tokens,
        uint256[] calldata clearingPrices,
        GPv2Trade.Data[] calldata trades
    )
        internal
        returns (
            GPv2Transfer.Data[] memory inTransfers,
            GPv2Transfer.Data[] memory outTransfers
        )
    {
        RecoveredOrder memory recoveredOrder = allocateRecoveredOrder();
        inTransfers = new GPv2Transfer.Data[](trades.length);
        outTransfers = new GPv2Transfer.Data[](trades.length);
        for (uint256 i = 0; i < trades.length; i++) {
            GPv2Trade.Data calldata trade = trades[i];
            recoverOrderFromTrade(recoveredOrder, tokens, trade);
            computeTradeExecution(
                recoveredOrder,
                clearingPrices[trade.sellTokenIndex],
                clearingPrices[trade.buyTokenIndex],
                trade.executedAmount,
                inTransfers[i],
                outTransfers[i]
            );
        }
    }
    /// @dev Compute the in and out transfer amounts for a single trade.
    /// This function reverts if:
    /// - The order has expired
    /// - The order's limit price is not respected
    /// - The order gets over-filled
    /// - The fee discount is larger than the executed fee
    ///
    /// @param recoveredOrder The recovered order to process.
    /// @param sellPrice The price of the order's sell token.
    /// @param buyPrice The price of the order's buy token.
    /// @param executedAmount The portion of the order to execute. This will be
    /// ignored for fill-or-kill orders.
    /// @param inTransfer Memory location for computed executed sell amount
    /// transfer.
    /// @param outTransfer Memory location for computed executed buy amount
    /// transfer.
    function computeTradeExecution(
        RecoveredOrder memory recoveredOrder,
        uint256 sellPrice,
        uint256 buyPrice,
        uint256 executedAmount,
        GPv2Transfer.Data memory inTransfer,
        GPv2Transfer.Data memory outTransfer
    ) internal {
        GPv2Order.Data memory order = recoveredOrder.data;
        bytes memory orderUid = recoveredOrder.uid;
        // solhint-disable-next-line not-rely-on-time
        require(order.validTo >= block.timestamp, "GPv2: order expired");
        // NOTE: The following computation is derived from the equation:
        // ```
        // amount_x * price_x = amount_y * price_y
        // ```
        // Intuitively, if a chocolate bar is 0,50€ and a beer is 4€, 1 beer
        // is roughly worth 8 chocolate bars (`1 * 4 = 8 * 0.5`). From this
        // equation, we can derive:
        // - The limit price for selling `x` and buying `y` is respected iff
        // ```
        // limit_x * price_x >= limit_y * price_y
        // ```
        // - The executed amount of token `y` given some amount of `x` and
        //   clearing prices is:
        // ```
        // amount_y = amount_x * price_x / price_y
        // ```
        require(
            order.sellAmount.mul(sellPrice) >= order.buyAmount.mul(buyPrice),
            "GPv2: limit price not respected"
        );
        uint256 executedSellAmount;
        uint256 executedBuyAmount;
        uint256 executedFeeAmount;
        uint256 currentFilledAmount;
        if (order.kind == GPv2Order.KIND_SELL) {
            if (order.partiallyFillable) {
                executedSellAmount = executedAmount;
                executedFeeAmount = order.feeAmount.mul(executedSellAmount).div(
                    order.sellAmount
                );
            } else {
                executedSellAmount = order.sellAmount;
                executedFeeAmount = order.feeAmount;
            }
            executedBuyAmount = executedSellAmount.mul(sellPrice).ceilDiv(
                buyPrice
            );
            currentFilledAmount = filledAmount[orderUid].add(
                executedSellAmount
            );
            require(
                currentFilledAmount <= order.sellAmount,
                "GPv2: order filled"
            );
        } else {
            if (order.partiallyFillable) {
                executedBuyAmount = executedAmount;
                executedFeeAmount = order.feeAmount.mul(executedBuyAmount).div(
                    order.buyAmount
                );
            } else {
                executedBuyAmount = order.buyAmount;
                executedFeeAmount = order.feeAmount;
            }
            executedSellAmount = executedBuyAmount.mul(buyPrice).div(sellPrice);
            currentFilledAmount = filledAmount[orderUid].add(executedBuyAmount);
            require(
                currentFilledAmount <= order.buyAmount,
                "GPv2: order filled"
            );
        }
        executedSellAmount = executedSellAmount.add(executedFeeAmount);
        filledAmount[orderUid] = currentFilledAmount;
        emit Trade(
            recoveredOrder.owner,
            order.sellToken,
            order.buyToken,
            executedSellAmount,
            executedBuyAmount,
            executedFeeAmount,
            orderUid
        );
        inTransfer.account = recoveredOrder.owner;
        inTransfer.token = order.sellToken;
        inTransfer.amount = executedSellAmount;
        inTransfer.balance = order.sellTokenBalance;
        outTransfer.account = recoveredOrder.receiver;
        outTransfer.token = order.buyToken;
        outTransfer.amount = executedBuyAmount;
        outTransfer.balance = order.buyTokenBalance;
    }
    /// @dev Execute a list of arbitrary contract calls from this contract.
    /// @param interactions The list of interactions to execute.
    function executeInteractions(GPv2Interaction.Data[] calldata interactions)
        internal
    {
        for (uint256 i; i < interactions.length; i++) {
            GPv2Interaction.Data calldata interaction = interactions[i];
            // To prevent possible attack on user funds, we explicitly disable
            // any interactions with the vault relayer contract.
            require(
                interaction.target != address(vaultRelayer),
                "GPv2: forbidden interaction"
            );
            GPv2Interaction.execute(interaction);
            emit Interaction(
                interaction.target,
                interaction.value,
                GPv2Interaction.selector(interaction)
            );
        }
    }
    /// @dev Claims refund for the specified storage and order UIDs.
    ///
    /// This method reverts if any of the orders are still valid.
    ///
    /// @param orderUids Order refund data for freeing storage.
    /// @param orderStorage Order storage mapped on a UID.
    function freeOrderStorage(
        mapping(bytes => uint256) storage orderStorage,
        bytes[] calldata orderUids
    ) internal {
        for (uint256 i = 0; i < orderUids.length; i++) {
            bytes calldata orderUid = orderUids[i];
            (, , uint32 validTo) = orderUid.extractOrderUidParams();
            // solhint-disable-next-line not-rely-on-time
            require(validTo < block.timestamp, "GPv2: order still valid");
            orderStorage[orderUid] = 0;
        }
    }
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
pragma abicoder v2;
import "./interfaces/IERC20.sol";
import "./interfaces/IVault.sol";
import "./libraries/GPv2Transfer.sol";
/// @title Gnosis Protocol v2 Vault Relayer Contract
/// @author Gnosis Developers
contract GPv2VaultRelayer {
    using GPv2Transfer for IVault;
    /// @dev The creator of the contract which has special permissions. This
    /// value is set at creation time and cannot change.
    address private immutable creator;
    /// @dev The vault this relayer is for.
    IVault private immutable vault;
    constructor(IVault vault_) {
        creator = msg.sender;
        vault = vault_;
    }
    /// @dev Modifier that ensures that a function can only be called by the
    /// creator of this contract.
    modifier onlyCreator {
        require(msg.sender == creator, "GPv2: not creator");
        _;
    }
    /// @dev Transfers all sell amounts for the executed trades from their
    /// owners to the caller.
    ///
    /// This function reverts if:
    /// - The caller is not the creator of the vault relayer
    /// - Any ERC20 transfer fails
    ///
    /// @param transfers The transfers to execute.
    function transferFromAccounts(GPv2Transfer.Data[] calldata transfers)
        external
        onlyCreator
    {
        vault.transferFromAccounts(transfers, msg.sender);
    }
    /// @dev Performs a Balancer batched swap on behalf of a user and sends a
    /// fee to the caller.
    ///
    /// This function reverts if:
    /// - The caller is not the creator of the vault relayer
    /// - The swap fails
    /// - The fee transfer fails
    ///
    /// @param kind The Balancer swap kind, this can either be `GIVEN_IN` for
    /// sell orders or `GIVEN_OUT` for buy orders.
    /// @param swaps The swaps to perform.
    /// @param tokens The tokens for the swaps. Swaps encode to and from tokens
    /// as indices into this array.
    /// @param funds The fund management settings, specifying the user the swap
    /// is being performed for as well as the recipient of the proceeds.
    /// @param limits Swap limits for encoding limit prices.
    /// @param deadline The deadline for the swap.
    /// @param feeTransfer The transfer data for the caller fee.
    /// @return tokenDeltas The executed swap amounts.
    function batchSwapWithFee(
        IVault.SwapKind kind,
        IVault.BatchSwapStep[] calldata swaps,
        IERC20[] memory tokens,
        IVault.FundManagement memory funds,
        int256[] memory limits,
        uint256 deadline,
        GPv2Transfer.Data calldata feeTransfer
    ) external onlyCreator returns (int256[] memory tokenDeltas) {
        tokenDeltas = vault.batchSwap(
            kind,
            swaps,
            tokens,
            funds,
            limits,
            deadline
        );
        vault.fastTransferFromAccount(feeTransfer, msg.sender);
    }
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
/// @title Gnosis Protocol v2 Authentication Interface
/// @author Gnosis Developers
interface GPv2Authentication {
    /// @dev determines whether the provided address is an authenticated solver.
    /// @param prospectiveSolver the address of prospective solver.
    /// @return true when prospectiveSolver is an authenticated solver, otherwise false.
    function isSolver(address prospectiveSolver) external view returns (bool);
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
library GPv2EIP1271 {
    /// @dev Value returned by a call to `isValidSignature` if the signature
    /// was verified successfully. The value is defined in EIP-1271 as:
    /// bytes4(keccak256("isValidSignature(bytes32,bytes)"))
    bytes4 internal constant MAGICVALUE = 0x1626ba7e;
}
/// @title EIP1271 Interface
/// @dev Standardized interface for an implementation of smart contract
/// signatures as described in EIP-1271. The code that follows is identical to
/// the code in the standard with the exception of formatting and syntax
/// changes to adapt the code to our Solidity version.
interface EIP1271Verifier {
    /// @dev Should return whether the signature provided is valid for the
    /// provided data
    /// @param _hash      Hash of the data to be signed
    /// @param _signature Signature byte array associated with _data
    ///
    /// MUST return the bytes4 magic value 0x1626ba7e when function passes.
    /// MUST NOT modify state (using STATICCALL for solc < 0.5, view modifier for
    /// solc > 0.5)
    /// MUST allow external calls
    ///
    function isValidSignature(bytes32 _hash, bytes memory _signature)
        external
        view
        returns (bytes4 magicValue);
}
// SPDX-License-Identifier: MIT
// Vendored from OpenZeppelin contracts with minor modifications:
// - Modified Solidity version
// - Formatted code
// - Added `name`, `symbol` and `decimals` function declarations
// <https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v3.4.0/contracts/token/ERC20/IERC20.sol>
pragma solidity ^0.7.6;
/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);
    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);
    /**
     * @dev Returns the number of decimals the token uses.
     */
    function decimals() external view returns (uint8);
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);
    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);
    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount)
        external
        returns (bool);
    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender)
        external
        view
        returns (uint256);
    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);
    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external returns (bool);
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);
    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(
        address indexed owner,
        address indexed spender,
        uint256 value
    );
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.6;
pragma abicoder v2;
import "./IERC20.sol";
/**
 * @dev Minimal interface for the Vault core contract only containing methods
 * used by Gnosis Protocol V2. Original source:
 * <https://github.com/balancer-labs/balancer-core-v2/blob/v1.0.0/contracts/vault/interfaces/IVault.sol>
 */
interface IVault {
    // Internal Balance
    //
    // Users can deposit tokens into the Vault, where they are allocated to their Internal Balance, and later
    // transferred or withdrawn. It can also be used as a source of tokens when joining Pools, as a destination
    // when exiting them, and as either when performing swaps. This usage of Internal Balance results in greatly reduced
    // gas costs when compared to relying on plain ERC20 transfers, leading to large savings for frequent users.
    //
    // Internal Balance management features batching, which means a single contract call can be used to perform multiple
    // operations of different kinds, with different senders and recipients, at once.
    /**
     * @dev Performs a set of user balance operations, which involve Internal Balance (deposit, withdraw or transfer)
     * and plain ERC20 transfers using the Vault's allowance. This last feature is particularly useful for relayers, as
     * it lets integrators reuse a user's Vault allowance.
     *
     * For each operation, if the caller is not `sender`, it must be an authorized relayer for them.
     */
    function manageUserBalance(UserBalanceOp[] memory ops) external payable;
    /**
     * @dev Data for `manageUserBalance` operations, which include the possibility for ETH to be sent and received
     without manual WETH wrapping or unwrapping.
     */
    struct UserBalanceOp {
        UserBalanceOpKind kind;
        IERC20 asset;
        uint256 amount;
        address sender;
        address payable recipient;
    }
    // There are four possible operations in `manageUserBalance`:
    //
    // - DEPOSIT_INTERNAL
    // Increases the Internal Balance of the `recipient` account by transferring tokens from the corresponding
    // `sender`. The sender must have allowed the Vault to use their tokens via `IERC20.approve()`.
    //
    // ETH can be used by passing the ETH sentinel value as the asset and forwarding ETH in the call: it will be wrapped
    // and deposited as WETH. Any ETH amount remaining will be sent back to the caller (not the sender, which is
    // relevant for relayers).
    //
    // Emits an `InternalBalanceChanged` event.
    //
    //
    // - WITHDRAW_INTERNAL
    // Decreases the Internal Balance of the `sender` account by transferring tokens to the `recipient`.
    //
    // ETH can be used by passing the ETH sentinel value as the asset. This will deduct WETH instead, unwrap it and send
    // it to the recipient as ETH.
    //
    // Emits an `InternalBalanceChanged` event.
    //
    //
    // - TRANSFER_INTERNAL
    // Transfers tokens from the Internal Balance of the `sender` account to the Internal Balance of `recipient`.
    //
    // Reverts if the ETH sentinel value is passed.
    //
    // Emits an `InternalBalanceChanged` event.
    //
    //
    // - TRANSFER_EXTERNAL
    // Transfers tokens from `sender` to `recipient`, using the Vault's ERC20 allowance. This is typically used by
    // relayers, as it lets them reuse a user's Vault allowance.
    //
    // Reverts if the ETH sentinel value is passed.
    //
    // Emits an `ExternalBalanceTransfer` event.
    enum UserBalanceOpKind {
        DEPOSIT_INTERNAL,
        WITHDRAW_INTERNAL,
        TRANSFER_INTERNAL,
        TRANSFER_EXTERNAL
    }
    // Swaps
    //
    // Users can swap tokens with Pools by calling the `swap` and `batchSwap` functions. To do this,
    // they need not trust Pool contracts in any way: all security checks are made by the Vault. They must however be
    // aware of the Pools' pricing algorithms in order to estimate the prices Pools will quote.
    //
    // The `swap` function executes a single swap, while `batchSwap` can perform multiple swaps in sequence.
    // In each individual swap, tokens of one kind are sent from the sender to the Pool (this is the 'token in'),
    // and tokens of another kind are sent from the Pool to the recipient in exchange (this is the 'token out').
    // More complex swaps, such as one token in to multiple tokens out can be achieved by batching together
    // individual swaps.
    //
    // There are two swap kinds:
    //  - 'given in' swaps, where the amount of tokens in (sent to the Pool) is known, and the Pool determines (via the
    // `onSwap` hook) the amount of tokens out (to send to the recipient).
    //  - 'given out' swaps, where the amount of tokens out (received from the Pool) is known, and the Pool determines
    // (via the `onSwap` hook) the amount of tokens in (to receive from the sender).
    //
    // Additionally, it is possible to chain swaps using a placeholder input amount, which the Vault replaces with
    // the calculated output of the previous swap. If the previous swap was 'given in', this will be the calculated
    // tokenOut amount. If the previous swap was 'given out', it will use the calculated tokenIn amount. These extended
    // swaps are known as 'multihop' swaps, since they 'hop' through a number of intermediate tokens before arriving at
    // the final intended token.
    //
    // In all cases, tokens are only transferred in and out of the Vault (or withdrawn from and deposited into Internal
    // Balance) after all individual swaps have been completed, and the net token balance change computed. This makes
    // certain swap patterns, such as multihops, or swaps that interact with the same token pair in multiple Pools, cost
    // much less gas than they would otherwise.
    //
    // It also means that under certain conditions it is possible to perform arbitrage by swapping with multiple
    // Pools in a way that results in net token movement out of the Vault (profit), with no tokens being sent in (only
    // updating the Pool's internal accounting).
    //
    // To protect users from front-running or the market changing rapidly, they supply a list of 'limits' for each token
    // involved in the swap, where either the maximum number of tokens to send (by passing a positive value) or the
    // minimum amount of tokens to receive (by passing a negative value) is specified.
    //
    // Additionally, a 'deadline' timestamp can also be provided, forcing the swap to fail if it occurs after
    // this point in time (e.g. if the transaction failed to be included in a block promptly).
    //
    // If interacting with Pools that hold WETH, it is possible to both send and receive ETH directly: the Vault will do
    // the wrapping and unwrapping. To enable this mechanism, the IAsset sentinel value (the zero address) must be
    // passed in the `assets` array instead of the WETH address. Note that it is possible to combine ETH and WETH in the
    // same swap. Any excess ETH will be sent back to the caller (not the sender, which is relevant for relayers).
    //
    // Finally, Internal Balance can be used when either sending or receiving tokens.
    enum SwapKind {GIVEN_IN, GIVEN_OUT}
    /**
     * @dev Performs a swap with a single Pool.
     *
     * If the swap is 'given in' (the number of tokens to send to the Pool is known), it returns the amount of tokens
     * taken from the Pool, which must be greater than or equal to `limit`.
     *
     * If the swap is 'given out' (the number of tokens to take from the Pool is known), it returns the amount of tokens
     * sent to the Pool, which must be less than or equal to `limit`.
     *
     * Internal Balance usage and the recipient are determined by the `funds` struct.
     *
     * Emits a `Swap` event.
     */
    function swap(
        SingleSwap memory singleSwap,
        FundManagement memory funds,
        uint256 limit,
        uint256 deadline
    ) external payable returns (uint256);
    /**
     * @dev Data for a single swap executed by `swap`. `amount` is either `amountIn` or `amountOut` depending on
     * the `kind` value.
     *
     * `assetIn` and `assetOut` are either token addresses, or the IAsset sentinel value for ETH (the zero address).
     * Note that Pools never interact with ETH directly: it will be wrapped to or unwrapped from WETH by the Vault.
     *
     * The `userData` field is ignored by the Vault, but forwarded to the Pool in the `onSwap` hook, and may be
     * used to extend swap behavior.
     */
    struct SingleSwap {
        bytes32 poolId;
        SwapKind kind;
        IERC20 assetIn;
        IERC20 assetOut;
        uint256 amount;
        bytes userData;
    }
    /**
     * @dev Performs a series of swaps with one or multiple Pools. In each individual swap, the caller determines either
     * the amount of tokens sent to or received from the Pool, depending on the `kind` value.
     *
     * Returns an array with the net Vault asset balance deltas. Positive amounts represent tokens (or ETH) sent to the
     * Vault, and negative amounts represent tokens (or ETH) sent by the Vault. Each delta corresponds to the asset at
     * the same index in the `assets` array.
     *
     * Swaps are executed sequentially, in the order specified by the `swaps` array. Each array element describes a
     * Pool, the token to be sent to this Pool, the token to receive from it, and an amount that is either `amountIn` or
     * `amountOut` depending on the swap kind.
     *
     * Multihop swaps can be executed by passing an `amount` value of zero for a swap. This will cause the amount in/out
     * of the previous swap to be used as the amount in for the current one. In a 'given in' swap, 'tokenIn' must equal
     * the previous swap's `tokenOut`. For a 'given out' swap, `tokenOut` must equal the previous swap's `tokenIn`.
     *
     * The `assets` array contains the addresses of all assets involved in the swaps. These are either token addresses,
     * or the IAsset sentinel value for ETH (the zero address). Each entry in the `swaps` array specifies tokens in and
     * out by referencing an index in `assets`. Note that Pools never interact with ETH directly: it will be wrapped to
     * or unwrapped from WETH by the Vault.
     *
     * Internal Balance usage, sender, and recipient are determined by the `funds` struct. The `limits` array specifies
     * the minimum or maximum amount of each token the vault is allowed to transfer.
     *
     * `batchSwap` can be used to make a single swap, like `swap` does, but doing so requires more gas than the
     * equivalent `swap` call.
     *
     * Emits `Swap` events.
     */
    function batchSwap(
        SwapKind kind,
        BatchSwapStep[] memory swaps,
        IERC20[] memory assets,
        FundManagement memory funds,
        int256[] memory limits,
        uint256 deadline
    ) external payable returns (int256[] memory);
    /**
     * @dev Data for each individual swap executed by `batchSwap`. The asset in and out fields are indexes into the
     * `assets` array passed to that function, and ETH assets are converted to WETH.
     *
     * If `amount` is zero, the multihop mechanism is used to determine the actual amount based on the amount in/out
     * from the previous swap, depending on the swap kind.
     *
     * The `userData` field is ignored by the Vault, but forwarded to the Pool in the `onSwap` hook, and may be
     * used to extend swap behavior.
     */
    struct BatchSwapStep {
        bytes32 poolId;
        uint256 assetInIndex;
        uint256 assetOutIndex;
        uint256 amount;
        bytes userData;
    }
    /**
     * @dev All tokens in a swap are either sent from the `sender` account to the Vault, or from the Vault to the
     * `recipient` account.
     *
     * If the caller is not `sender`, it must be an authorized relayer for them.
     *
     * If `fromInternalBalance` is true, the `sender`'s Internal Balance will be preferred, performing an ERC20
     * transfer for the difference between the requested amount and the User's Internal Balance (if any). The `sender`
     * must have allowed the Vault to use their tokens via `IERC20.approve()`. This matches the behavior of
     * `joinPool`.
     *
     * If `toInternalBalance` is true, tokens will be deposited to `recipient`'s internal balance instead of
     * transferred. This matches the behavior of `exitPool`.
     *
     * Note that ETH cannot be deposited to or withdrawn from Internal Balance: attempting to do so will trigger a
     * revert.
     */
    struct FundManagement {
        address sender;
        bool fromInternalBalance;
        address payable recipient;
        bool toInternalBalance;
    }
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
/// @title Gnosis Protocol v2 Interaction Library
/// @author Gnosis Developers
library GPv2Interaction {
    /// @dev Interaction data for performing arbitrary contract interactions.
    /// Submitted to [`GPv2Settlement.settle`] for code execution.
    struct Data {
        address target;
        uint256 value;
        bytes callData;
    }
    /// @dev Execute an arbitrary contract interaction.
    ///
    /// @param interaction Interaction data.
    function execute(Data calldata interaction) internal {
        address target = interaction.target;
        uint256 value = interaction.value;
        bytes calldata callData = interaction.callData;
        // NOTE: Use assembly to call the interaction instead of a low level
        // call for two reasons:
        // - We don't want to copy the return data, since we discard it for
        // interactions.
        // - Solidity will under certain conditions generate code to copy input
        // calldata twice to memory (the second being a "memcopy loop").
        // <https://github.com/gnosis/gp-v2-contracts/pull/417#issuecomment-775091258>
        // solhint-disable-next-line no-inline-assembly
        assembly {
            let freeMemoryPointer := mload(0x40)
            calldatacopy(freeMemoryPointer, callData.offset, callData.length)
            if iszero(
                call(
                    gas(),
                    target,
                    value,
                    freeMemoryPointer,
                    callData.length,
                    0,
                    0
                )
            ) {
                returndatacopy(0, 0, returndatasize())
                revert(0, returndatasize())
            }
        }
    }
    /// @dev Extracts the Solidity ABI selector for the specified interaction.
    ///
    /// @param interaction Interaction data.
    /// @return result The 4 byte function selector of the call encoded in
    /// this interaction.
    function selector(Data calldata interaction)
        internal
        pure
        returns (bytes4 result)
    {
        bytes calldata callData = interaction.callData;
        if (callData.length >= 4) {
            // NOTE: Read the first word of the interaction's calldata. The
            // value does not need to be shifted since `bytesN` values are left
            // aligned, and the value does not need to be masked since masking
            // occurs when the value is accessed and not stored:
            // <https://docs.soliditylang.org/en/v0.7.6/abi-spec.html#encoding-of-indexed-event-parameters>
            // <https://docs.soliditylang.org/en/v0.7.6/assembly.html#access-to-external-variables-functions-and-libraries>
            // solhint-disable-next-line no-inline-assembly
            assembly {
                result := calldataload(callData.offset)
            }
        }
    }
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
import "../interfaces/IERC20.sol";
/// @title Gnosis Protocol v2 Order Library
/// @author Gnosis Developers
library GPv2Order {
    /// @dev The complete data for a Gnosis Protocol order. This struct contains
    /// all order parameters that are signed for submitting to GP.
    struct Data {
        IERC20 sellToken;
        IERC20 buyToken;
        address receiver;
        uint256 sellAmount;
        uint256 buyAmount;
        uint32 validTo;
        bytes32 appData;
        uint256 feeAmount;
        bytes32 kind;
        bool partiallyFillable;
        bytes32 sellTokenBalance;
        bytes32 buyTokenBalance;
    }
    /// @dev The order EIP-712 type hash for the [`GPv2Order.Data`] struct.
    ///
    /// This value is pre-computed from the following expression:
    /// ```
    /// keccak256(
    ///     "Order(" +
    ///         "address sellToken," +
    ///         "address buyToken," +
    ///         "address receiver," +
    ///         "uint256 sellAmount," +
    ///         "uint256 buyAmount," +
    ///         "uint32 validTo," +
    ///         "bytes32 appData," +
    ///         "uint256 feeAmount," +
    ///         "string kind," +
    ///         "bool partiallyFillable" +
    ///         "string sellTokenBalance" +
    ///         "string buyTokenBalance" +
    ///     ")"
    /// )
    /// ```
    bytes32 internal constant TYPE_HASH =
        hex"d5a25ba2e97094ad7d83dc28a6572da797d6b3e7fc6663bd93efb789fc17e489";
    /// @dev The marker value for a sell order for computing the order struct
    /// hash. This allows the EIP-712 compatible wallets to display a
    /// descriptive string for the order kind (instead of 0 or 1).
    ///
    /// This value is pre-computed from the following expression:
    /// ```
    /// keccak256("sell")
    /// ```
    bytes32 internal constant KIND_SELL =
        hex"f3b277728b3fee749481eb3e0b3b48980dbbab78658fc419025cb16eee346775";
    /// @dev The OrderKind marker value for a buy order for computing the order
    /// struct hash.
    ///
    /// This value is pre-computed from the following expression:
    /// ```
    /// keccak256("buy")
    /// ```
    bytes32 internal constant KIND_BUY =
        hex"6ed88e868af0a1983e3886d5f3e95a2fafbd6c3450bc229e27342283dc429ccc";
    /// @dev The TokenBalance marker value for using direct ERC20 balances for
    /// computing the order struct hash.
    ///
    /// This value is pre-computed from the following expression:
    /// ```
    /// keccak256("erc20")
    /// ```
    bytes32 internal constant BALANCE_ERC20 =
        hex"5a28e9363bb942b639270062aa6bb295f434bcdfc42c97267bf003f272060dc9";
    /// @dev The TokenBalance marker value for using Balancer Vault external
    /// balances (in order to re-use Vault ERC20 approvals) for computing the
    /// order struct hash.
    ///
    /// This value is pre-computed from the following expression:
    /// ```
    /// keccak256("external")
    /// ```
    bytes32 internal constant BALANCE_EXTERNAL =
        hex"abee3b73373acd583a130924aad6dc38cfdc44ba0555ba94ce2ff63980ea0632";
    /// @dev The TokenBalance marker value for using Balancer Vault internal
    /// balances for computing the order struct hash.
    ///
    /// This value is pre-computed from the following expression:
    /// ```
    /// keccak256("internal")
    /// ```
    bytes32 internal constant BALANCE_INTERNAL =
        hex"4ac99ace14ee0a5ef932dc609df0943ab7ac16b7583634612f8dc35a4289a6ce";
    /// @dev Marker address used to indicate that the receiver of the trade
    /// proceeds should the owner of the order.
    ///
    /// This is chosen to be `address(0)` for gas efficiency as it is expected
    /// to be the most common case.
    address internal constant RECEIVER_SAME_AS_OWNER = address(0);
    /// @dev The byte length of an order unique identifier.
    uint256 internal constant UID_LENGTH = 56;
    /// @dev Returns the actual receiver for an order. This function checks
    /// whether or not the [`receiver`] field uses the marker value to indicate
    /// it is the same as the order owner.
    ///
    /// @return receiver The actual receiver of trade proceeds.
    function actualReceiver(Data memory order, address owner)
        internal
        pure
        returns (address receiver)
    {
        if (order.receiver == RECEIVER_SAME_AS_OWNER) {
            receiver = owner;
        } else {
            receiver = order.receiver;
        }
    }
    /// @dev Return the EIP-712 signing hash for the specified order.
    ///
    /// @param order The order to compute the EIP-712 signing hash for.
    /// @param domainSeparator The EIP-712 domain separator to use.
    /// @return orderDigest The 32 byte EIP-712 struct hash.
    function hash(Data memory order, bytes32 domainSeparator)
        internal
        pure
        returns (bytes32 orderDigest)
    {
        bytes32 structHash;
        // NOTE: Compute the EIP-712 order struct hash in place. As suggested
        // in the EIP proposal, noting that the order struct has 10 fields, and
        // including the type hash `(12 + 1) * 32 = 416` bytes to hash.
        // <https://github.com/ethereum/EIPs/blob/master/EIPS/eip-712.md#rationale-for-encodedata>
        // solhint-disable-next-line no-inline-assembly
        assembly {
            let dataStart := sub(order, 32)
            let temp := mload(dataStart)
            mstore(dataStart, TYPE_HASH)
            structHash := keccak256(dataStart, 416)
            mstore(dataStart, temp)
        }
        // NOTE: Now that we have the struct hash, compute the EIP-712 signing
        // hash using scratch memory past the free memory pointer. The signing
        // hash is computed from `"\\x19\\x01" || domainSeparator || structHash`.
        // <https://docs.soliditylang.org/en/v0.7.6/internals/layout_in_memory.html#layout-in-memory>
        // <https://github.com/ethereum/EIPs/blob/master/EIPS/eip-712.md#specification>
        // solhint-disable-next-line no-inline-assembly
        assembly {
            let freeMemoryPointer := mload(0x40)
            mstore(freeMemoryPointer, "\\x19\\x01")
            mstore(add(freeMemoryPointer, 2), domainSeparator)
            mstore(add(freeMemoryPointer, 34), structHash)
            orderDigest := keccak256(freeMemoryPointer, 66)
        }
    }
    /// @dev Packs order UID parameters into the specified memory location. The
    /// result is equivalent to `abi.encodePacked(...)` with the difference that
    /// it allows re-using the memory for packing the order UID.
    ///
    /// This function reverts if the order UID buffer is not the correct size.
    ///
    /// @param orderUid The buffer pack the order UID parameters into.
    /// @param orderDigest The EIP-712 struct digest derived from the order
    /// parameters.
    /// @param owner The address of the user who owns this order.
    /// @param validTo The epoch time at which the order will stop being valid.
    function packOrderUidParams(
        bytes memory orderUid,
        bytes32 orderDigest,
        address owner,
        uint32 validTo
    ) internal pure {
        require(orderUid.length == UID_LENGTH, "GPv2: uid buffer overflow");
        // NOTE: Write the order UID to the allocated memory buffer. The order
        // parameters are written to memory in **reverse order** as memory
        // operations write 32-bytes at a time and we want to use a packed
        // encoding. This means, for example, that after writing the value of
        // `owner` to bytes `20:52`, writing the `orderDigest` to bytes `0:32`
        // will **overwrite** bytes `20:32`. This is desirable as addresses are
        // only 20 bytes and `20:32` should be `0`s:
        //
        //        |           1111111111222222222233333333334444444444555555
        //   byte | 01234567890123456789012345678901234567890123456789012345
        // -------+---------------------------------------------------------
        //  field | [.........orderDigest..........][......owner.......][vT]
        // -------+---------------------------------------------------------
        // mstore |                         [000000000000000000000000000.vT]
        //        |                     [00000000000.......owner.......]
        //        | [.........orderDigest..........]
        //
        // Additionally, since Solidity `bytes memory` are length prefixed,
        // 32 needs to be added to all the offsets.
        //
        // solhint-disable-next-line no-inline-assembly
        assembly {
            mstore(add(orderUid, 56), validTo)
            mstore(add(orderUid, 52), owner)
            mstore(add(orderUid, 32), orderDigest)
        }
    }
    /// @dev Extracts specific order information from the standardized unique
    /// order id of the protocol.
    ///
    /// @param orderUid The unique identifier used to represent an order in
    /// the protocol. This uid is the packed concatenation of the order digest,
    /// the validTo order parameter and the address of the user who created the
    /// order. It is used by the user to interface with the contract directly,
    /// and not by calls that are triggered by the solvers.
    /// @return orderDigest The EIP-712 signing digest derived from the order
    /// parameters.
    /// @return owner The address of the user who owns this order.
    /// @return validTo The epoch time at which the order will stop being valid.
    function extractOrderUidParams(bytes calldata orderUid)
        internal
        pure
        returns (
            bytes32 orderDigest,
            address owner,
            uint32 validTo
        )
    {
        require(orderUid.length == UID_LENGTH, "GPv2: invalid uid");
        // Use assembly to efficiently decode packed calldata.
        // solhint-disable-next-line no-inline-assembly
        assembly {
            orderDigest := calldataload(orderUid.offset)
            owner := shr(96, calldataload(add(orderUid.offset, 32)))
            validTo := shr(224, calldataload(add(orderUid.offset, 52)))
        }
    }
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
import "../interfaces/IERC20.sol";
/// @title Gnosis Protocol v2 Safe ERC20 Transfer Library
/// @author Gnosis Developers
/// @dev Gas-efficient version of Openzeppelin's SafeERC20 contract that notably
/// does not revert when calling a non-contract.
library GPv2SafeERC20 {
    /// @dev Wrapper around a call to the ERC20 function `transfer` that reverts
    /// also when the token returns `false`.
    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        bytes4 selector_ = token.transfer.selector;
        // solhint-disable-next-line no-inline-assembly
        assembly {
            let freeMemoryPointer := mload(0x40)
            mstore(freeMemoryPointer, selector_)
            mstore(
                add(freeMemoryPointer, 4),
                and(to, 0xffffffffffffffffffffffffffffffffffffffff)
            )
            mstore(add(freeMemoryPointer, 36), value)
            if iszero(call(gas(), token, 0, freeMemoryPointer, 68, 0, 0)) {
                returndatacopy(0, 0, returndatasize())
                revert(0, returndatasize())
            }
        }
        require(getLastTansferResult(token), "GPv2: failed transfer");
    }
    /// @dev Wrapper around a call to the ERC20 function `transferFrom` that
    /// reverts also when the token returns `false`.
    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        bytes4 selector_ = token.transferFrom.selector;
        // solhint-disable-next-line no-inline-assembly
        assembly {
            let freeMemoryPointer := mload(0x40)
            mstore(freeMemoryPointer, selector_)
            mstore(
                add(freeMemoryPointer, 4),
                and(from, 0xffffffffffffffffffffffffffffffffffffffff)
            )
            mstore(
                add(freeMemoryPointer, 36),
                and(to, 0xffffffffffffffffffffffffffffffffffffffff)
            )
            mstore(add(freeMemoryPointer, 68), value)
            if iszero(call(gas(), token, 0, freeMemoryPointer, 100, 0, 0)) {
                returndatacopy(0, 0, returndatasize())
                revert(0, returndatasize())
            }
        }
        require(getLastTansferResult(token), "GPv2: failed transferFrom");
    }
    /// @dev Verifies that the last return was a successful `transfer*` call.
    /// This is done by checking that the return data is either empty, or
    /// is a valid ABI encoded boolean.
    function getLastTansferResult(IERC20 token)
        private
        view
        returns (bool success)
    {
        // NOTE: Inspecting previous return data requires assembly. Note that
        // we write the return data to memory 0 in the case where the return
        // data size is 32, this is OK since the first 64 bytes of memory are
        // reserved by Solidy as a scratch space that can be used within
        // assembly blocks.
        // <https://docs.soliditylang.org/en/v0.7.6/internals/layout_in_memory.html>
        // solhint-disable-next-line no-inline-assembly
        assembly {
            /// @dev Revert with an ABI encoded Solidity error with a message
            /// that fits into 32-bytes.
            ///
            /// An ABI encoded Solidity error has the following memory layout:
            ///
            /// ------------+----------------------------------
            ///  byte range | value
            /// ------------+----------------------------------
            ///  0x00..0x04 |        selector("Error(string)")
            ///  0x04..0x24 |      string offset (always 0x20)
            ///  0x24..0x44 |                    string length
            ///  0x44..0x64 | string value, padded to 32-bytes
            function revertWithMessage(length, message) {
                mstore(0x00, "\\x08\\xc3\\x79\\xa0")
                mstore(0x04, 0x20)
                mstore(0x24, length)
                mstore(0x44, message)
                revert(0x00, 0x64)
            }
            switch returndatasize()
                // Non-standard ERC20 transfer without return.
                case 0 {
                    // NOTE: When the return data size is 0, verify that there
                    // is code at the address. This is done in order to maintain
                    // compatibility with Solidity calling conventions.
                    // <https://docs.soliditylang.org/en/v0.7.6/control-structures.html#external-function-calls>
                    if iszero(extcodesize(token)) {
                        revertWithMessage(20, "GPv2: not a contract")
                    }
                    success := 1
                }
                // Standard ERC20 transfer returning boolean success value.
                case 32 {
                    returndatacopy(0, 0, returndatasize())
                    // NOTE: For ABI encoding v1, any non-zero value is accepted
                    // as `true` for a boolean. In order to stay compatible with
                    // OpenZeppelin's `SafeERC20` library which is known to work
                    // with the existing ERC20 implementation we care about,
                    // make sure we return success for any non-zero return value
                    // from the `transfer*` call.
                    success := iszero(iszero(mload(0)))
                }
                default {
                    revertWithMessage(31, "GPv2: malformed transfer result")
                }
        }
    }
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
import "../interfaces/IERC20.sol";
import "../mixins/GPv2Signing.sol";
import "./GPv2Order.sol";
/// @title Gnosis Protocol v2 Trade Library.
/// @author Gnosis Developers
library GPv2Trade {
    using GPv2Order for GPv2Order.Data;
    using GPv2Order for bytes;
    /// @dev A struct representing a trade to be executed as part a batch
    /// settlement.
    struct Data {
        uint256 sellTokenIndex;
        uint256 buyTokenIndex;
        address receiver;
        uint256 sellAmount;
        uint256 buyAmount;
        uint32 validTo;
        bytes32 appData;
        uint256 feeAmount;
        uint256 flags;
        uint256 executedAmount;
        bytes signature;
    }
    /// @dev Extracts the order data and signing scheme for the specified trade.
    ///
    /// @param trade The trade.
    /// @param tokens The list of tokens included in the settlement. The token
    /// indices in the trade parameters map to tokens in this array.
    /// @param order The memory location to extract the order data to.
    function extractOrder(
        Data calldata trade,
        IERC20[] calldata tokens,
        GPv2Order.Data memory order
    ) internal pure returns (GPv2Signing.Scheme signingScheme) {
        order.sellToken = tokens[trade.sellTokenIndex];
        order.buyToken = tokens[trade.buyTokenIndex];
        order.receiver = trade.receiver;
        order.sellAmount = trade.sellAmount;
        order.buyAmount = trade.buyAmount;
        order.validTo = trade.validTo;
        order.appData = trade.appData;
        order.feeAmount = trade.feeAmount;
        (
            order.kind,
            order.partiallyFillable,
            order.sellTokenBalance,
            order.buyTokenBalance,
            signingScheme
        ) = extractFlags(trade.flags);
    }
    /// @dev Decodes trade flags.
    ///
    /// Trade flags are used to tightly encode information on how to decode
    /// an order. Examples that directly affect the structure of an order are
    /// the kind of order (either a sell or a buy order) as well as whether the
    /// order is partially fillable or if it is a "fill-or-kill" order. It also
    /// encodes the signature scheme used to validate the order. As the most
    /// likely values are fill-or-kill sell orders by an externally owned
    /// account, the flags are chosen such that `0x00` represents this kind of
    /// order. The flags byte uses the following format:
    ///
    /// ```
    /// bit | 31 ...   | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
    /// ----+----------+---+---+-------+---+---+
    ///     | reserved | *   * | * | *   * | * | * |
    ///                  |   |   |   |   |   |   |
    ///                  |   |   |   |   |   |   +---- order kind bit, 0 for a sell order
    ///                  |   |   |   |   |   |         and 1 for a buy order
    ///                  |   |   |   |   |   |
    ///                  |   |   |   |   |   +-------- order fill bit, 0 for fill-or-kill
    ///                  |   |   |   |   |             and 1 for a partially fillable order
    ///                  |   |   |   |   |
    ///                  |   |   |   +---+------------ use internal sell token balance bit:
    ///                  |   |   |                     0x: ERC20 token balance
    ///                  |   |   |                     10: external Balancer Vault balance
    ///                  |   |   |                     11: internal Balancer Vault balance
    ///                  |   |   |
    ///                  |   |   +-------------------- use buy token balance bit
    ///                  |   |                         0: ERC20 token balance
    ///                  |   |                         1: internal Balancer Vault balance
    ///                  |   |
    ///                  +---+------------------------ signature scheme bits:
    ///                                                00: EIP-712
    ///                                                01: eth_sign
    ///                                                10: EIP-1271
    ///                                                11: pre_sign
    /// ```
    function extractFlags(uint256 flags)
        internal
        pure
        returns (
            bytes32 kind,
            bool partiallyFillable,
            bytes32 sellTokenBalance,
            bytes32 buyTokenBalance,
            GPv2Signing.Scheme signingScheme
        )
    {
        if (flags & 0x01 == 0) {
            kind = GPv2Order.KIND_SELL;
        } else {
            kind = GPv2Order.KIND_BUY;
        }
        partiallyFillable = flags & 0x02 != 0;
        if (flags & 0x08 == 0) {
            sellTokenBalance = GPv2Order.BALANCE_ERC20;
        } else if (flags & 0x04 == 0) {
            sellTokenBalance = GPv2Order.BALANCE_EXTERNAL;
        } else {
            sellTokenBalance = GPv2Order.BALANCE_INTERNAL;
        }
        if (flags & 0x10 == 0) {
            buyTokenBalance = GPv2Order.BALANCE_ERC20;
        } else {
            buyTokenBalance = GPv2Order.BALANCE_INTERNAL;
        }
        // NOTE: Take advantage of the fact that Solidity will revert if the
        // following expression does not produce a valid enum value. This means
        // we check here that the leading reserved bits must be 0.
        signingScheme = GPv2Signing.Scheme(flags >> 5);
    }
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
pragma abicoder v2;
import "../interfaces/IERC20.sol";
import "../interfaces/IVault.sol";
import "./GPv2Order.sol";
import "./GPv2SafeERC20.sol";
/// @title Gnosis Protocol v2 Transfers
/// @author Gnosis Developers
library GPv2Transfer {
    using GPv2SafeERC20 for IERC20;
    /// @dev Transfer data.
    struct Data {
        address account;
        IERC20 token;
        uint256 amount;
        bytes32 balance;
    }
    /// @dev Ether marker address used to indicate an Ether transfer.
    address internal constant BUY_ETH_ADDRESS =
        0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
    /// @dev Execute the specified transfer from the specified account to a
    /// recipient. The recipient will either receive internal Vault balances or
    /// ERC20 token balances depending on whether the account is using internal
    /// balances or not.
    ///
    /// This method is used for transferring fees to the settlement contract
    /// when settling a single order directly with Balancer.
    ///
    /// Note that this method is subtly different from `transferFromAccounts`
    /// with a single transfer with respect to how it deals with internal
    /// balances. Specifically, this method will perform an **internal balance
    /// transfer to the settlement contract instead of a withdrawal to the
    /// external balance of the settlement contract** for trades that specify
    /// trading with internal balances. This is done as a gas optimization in
    /// the single order "fast-path".
    ///
    /// @param vault The Balancer vault to use.
    /// @param transfer The transfer to perform specifying the sender account.
    /// @param recipient The recipient for the transfer.
    function fastTransferFromAccount(
        IVault vault,
        Data calldata transfer,
        address recipient
    ) internal {
        require(
            address(transfer.token) != BUY_ETH_ADDRESS,
            "GPv2: cannot transfer native ETH"
        );
        if (transfer.balance == GPv2Order.BALANCE_ERC20) {
            transfer.token.safeTransferFrom(
                transfer.account,
                recipient,
                transfer.amount
            );
        } else {
            IVault.UserBalanceOp[] memory balanceOps =
                new IVault.UserBalanceOp[](1);
            IVault.UserBalanceOp memory balanceOp = balanceOps[0];
            balanceOp.kind = transfer.balance == GPv2Order.BALANCE_EXTERNAL
                ? IVault.UserBalanceOpKind.TRANSFER_EXTERNAL
                : IVault.UserBalanceOpKind.TRANSFER_INTERNAL;
            balanceOp.asset = transfer.token;
            balanceOp.amount = transfer.amount;
            balanceOp.sender = transfer.account;
            balanceOp.recipient = payable(recipient);
            vault.manageUserBalance(balanceOps);
        }
    }
    /// @dev Execute the specified transfers from the specified accounts to a
    /// single recipient. The recipient will receive all transfers as ERC20
    /// token balances, regardless of whether or not the accounts are using
    /// internal Vault balances.
    ///
    /// This method is used for accumulating user balances into the settlement
    /// contract.
    ///
    /// @param vault The Balancer vault to use.
    /// @param transfers The batched transfers to perform specifying the
    /// sender accounts.
    /// @param recipient The single recipient for all the transfers.
    function transferFromAccounts(
        IVault vault,
        Data[] calldata transfers,
        address recipient
    ) internal {
        // NOTE: Allocate buffer of Vault balance operations large enough to
        // hold all GP transfers. This is done to avoid re-allocations (which
        // are gas inefficient) while still allowing all transfers to be batched
        // into a single Vault call.
        IVault.UserBalanceOp[] memory balanceOps =
            new IVault.UserBalanceOp[](transfers.length);
        uint256 balanceOpCount = 0;
        for (uint256 i = 0; i < transfers.length; i++) {
            Data calldata transfer = transfers[i];
            require(
                address(transfer.token) != BUY_ETH_ADDRESS,
                "GPv2: cannot transfer native ETH"
            );
            if (transfer.balance == GPv2Order.BALANCE_ERC20) {
                transfer.token.safeTransferFrom(
                    transfer.account,
                    recipient,
                    transfer.amount
                );
            } else {
                IVault.UserBalanceOp memory balanceOp =
                    balanceOps[balanceOpCount++];
                balanceOp.kind = transfer.balance == GPv2Order.BALANCE_EXTERNAL
                    ? IVault.UserBalanceOpKind.TRANSFER_EXTERNAL
                    : IVault.UserBalanceOpKind.WITHDRAW_INTERNAL;
                balanceOp.asset = transfer.token;
                balanceOp.amount = transfer.amount;
                balanceOp.sender = transfer.account;
                balanceOp.recipient = payable(recipient);
            }
        }
        if (balanceOpCount > 0) {
            truncateBalanceOpsArray(balanceOps, balanceOpCount);
            vault.manageUserBalance(balanceOps);
        }
    }
    /// @dev Execute the specified transfers to their respective accounts.
    ///
    /// This method is used for paying out trade proceeds from the settlement
    /// contract.
    ///
    /// @param vault The Balancer vault to use.
    /// @param transfers The batched transfers to perform.
    function transferToAccounts(IVault vault, Data[] memory transfers)
        internal
    {
        IVault.UserBalanceOp[] memory balanceOps =
            new IVault.UserBalanceOp[](transfers.length);
        uint256 balanceOpCount = 0;
        for (uint256 i = 0; i < transfers.length; i++) {
            Data memory transfer = transfers[i];
            if (address(transfer.token) == BUY_ETH_ADDRESS) {
                require(
                    transfer.balance != GPv2Order.BALANCE_INTERNAL,
                    "GPv2: unsupported internal ETH"
                );
                payable(transfer.account).transfer(transfer.amount);
            } else if (transfer.balance == GPv2Order.BALANCE_ERC20) {
                transfer.token.safeTransfer(transfer.account, transfer.amount);
            } else {
                IVault.UserBalanceOp memory balanceOp =
                    balanceOps[balanceOpCount++];
                balanceOp.kind = IVault.UserBalanceOpKind.DEPOSIT_INTERNAL;
                balanceOp.asset = transfer.token;
                balanceOp.amount = transfer.amount;
                balanceOp.sender = address(this);
                balanceOp.recipient = payable(transfer.account);
            }
        }
        if (balanceOpCount > 0) {
            truncateBalanceOpsArray(balanceOps, balanceOpCount);
            vault.manageUserBalance(balanceOps);
        }
    }
    /// @dev Truncate a Vault balance operation array to its actual size.
    ///
    /// This method **does not** check whether or not the new length is valid,
    /// and specifying a size that is larger than the array's actual length is
    /// undefined behaviour.
    ///
    /// @param balanceOps The memory array of balance operations to truncate.
    /// @param newLength The new length to set.
    function truncateBalanceOpsArray(
        IVault.UserBalanceOp[] memory balanceOps,
        uint256 newLength
    ) private pure {
        // NOTE: Truncate the vault transfers array to the specified length.
        // This is done by setting the array's length which occupies the first
        // word in memory pointed to by the `balanceOps` memory variable.
        // <https://docs.soliditylang.org/en/v0.7.6/internals/layout_in_memory.html>
        // solhint-disable-next-line no-inline-assembly
        assembly {
            mstore(balanceOps, newLength)
        }
    }
}
// SPDX-License-Identifier: MIT
// Vendored from OpenZeppelin contracts with minor modifications:
// - Modified Solidity version
// - Formatted code
// - Shortened revert messages
// - Removed unused methods
// - Convert to `type(*).*` notation
// <https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v3.4.0/contracts/utils/SafeCast.sol>
pragma solidity ^0.7.6;
/**
 * @dev Wrappers over Solidity's uintXX/intXX casting operators with added overflow
 * checks.
 *
 * Downcasting from uint256/int256 in Solidity does not revert on overflow. This can
 * easily result in undesired exploitation or bugs, since developers usually
 * assume that overflows raise errors. `SafeCast` restores this intuition by
 * reverting the transaction when such an operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 *
 * Can be combined with {SafeMath} and {SignedSafeMath} to extend it to smaller types, by performing
 * all math on `uint256` and `int256` and then downcasting.
 */
library SafeCast {
    /**
     * @dev Converts a signed int256 into an unsigned uint256.
     *
     * Requirements:
     *
     * - input must be greater than or equal to 0.
     */
    function toUint256(int256 value) internal pure returns (uint256) {
        require(value >= 0, "SafeCast: not positive");
        return uint256(value);
    }
    /**
     * @dev Converts an unsigned uint256 into a signed int256.
     *
     * Requirements:
     *
     * - input must be less than or equal to maxInt256.
     */
    function toInt256(uint256 value) internal pure returns (int256) {
        require(
            value <= uint256(type(int256).max),
            "SafeCast: int256 overflow"
        );
        return int256(value);
    }
}
// SPDX-License-Identifier: MIT
// Vendored from OpenZeppelin contracts with minor modifications:
// - Modified Solidity version
// - Formatted code
// - Shortened some revert messages
// - Removed unused methods
// - Added `ceilDiv` method
// <https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v3.4.0/contracts/math/SafeMath.sol>
pragma solidity ^0.7.6;
/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");
        return c;
    }
    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SafeMath: subtraction overflow");
        return a - b;
    }
    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) return 0;
        uint256 c = a * b;
        require(c / a == b, "SafeMath: mul overflow");
        return c;
    }
    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: division by 0");
        return a / b;
    }
    /**
     * @dev Returns the ceiling integer division of two unsigned integers,
     * reverting on division by zero. The result is rounded towards up the
     * nearest integer, instead of truncating the fractional part.
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     * - The sum of the dividend and divisor cannot overflow.
     */
    function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: ceiling division by 0");
        return a / b + (a % b == 0 ? 0 : 1);
    }
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
import "../interfaces/GPv2EIP1271.sol";
import "../libraries/GPv2Order.sol";
import "../libraries/GPv2Trade.sol";
/// @title Gnosis Protocol v2 Signing Library.
/// @author Gnosis Developers
abstract contract GPv2Signing {
    using GPv2Order for GPv2Order.Data;
    using GPv2Order for bytes;
    /// @dev Recovered trade data containing the extracted order and the
    /// recovered owner address.
    struct RecoveredOrder {
        GPv2Order.Data data;
        bytes uid;
        address owner;
        address receiver;
    }
    /// @dev Signing scheme used for recovery.
    enum Scheme {Eip712, EthSign, Eip1271, PreSign}
    /// @dev The EIP-712 domain type hash used for computing the domain
    /// separator.
    bytes32 private constant DOMAIN_TYPE_HASH =
        keccak256(
            "EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"
        );
    /// @dev The EIP-712 domain name used for computing the domain separator.
    bytes32 private constant DOMAIN_NAME = keccak256("Gnosis Protocol");
    /// @dev The EIP-712 domain version used for computing the domain separator.
    bytes32 private constant DOMAIN_VERSION = keccak256("v2");
    /// @dev Marker value indicating an order is pre-signed.
    uint256 private constant PRE_SIGNED =
        uint256(keccak256("GPv2Signing.Scheme.PreSign"));
    /// @dev The domain separator used for signing orders that gets mixed in
    /// making signatures for different domains incompatible. This domain
    /// separator is computed following the EIP-712 standard and has replay
    /// protection mixed in so that signed orders are only valid for specific
    /// GPv2 contracts.
    bytes32 public immutable domainSeparator;
    /// @dev Storage indicating whether or not an order has been signed by a
    /// particular address.
    mapping(bytes => uint256) public preSignature;
    /// @dev Event that is emitted when an account either pre-signs an order or
    /// revokes an existing pre-signature.
    event PreSignature(address indexed owner, bytes orderUid, bool signed);
    constructor() {
        // NOTE: Currently, the only way to get the chain ID in solidity is
        // using assembly.
        uint256 chainId;
        // solhint-disable-next-line no-inline-assembly
        assembly {
            chainId := chainid()
        }
        domainSeparator = keccak256(
            abi.encode(
                DOMAIN_TYPE_HASH,
                DOMAIN_NAME,
                DOMAIN_VERSION,
                chainId,
                address(this)
            )
        );
    }
    /// @dev Sets a presignature for the specified order UID.
    ///
    /// @param orderUid The unique identifier of the order to pre-sign.
    function setPreSignature(bytes calldata orderUid, bool signed) external {
        (, address owner, ) = orderUid.extractOrderUidParams();
        require(owner == msg.sender, "GPv2: cannot presign order");
        if (signed) {
            preSignature[orderUid] = PRE_SIGNED;
        } else {
            preSignature[orderUid] = 0;
        }
        emit PreSignature(owner, orderUid, signed);
    }
    /// @dev Returns an empty recovered order with a pre-allocated buffer for
    /// packing the unique identifier.
    ///
    /// @return recoveredOrder The empty recovered order data.
    function allocateRecoveredOrder()
        internal
        pure
        returns (RecoveredOrder memory recoveredOrder)
    {
        recoveredOrder.uid = new bytes(GPv2Order.UID_LENGTH);
    }
    /// @dev Extracts order data and recovers the signer from the specified
    /// trade.
    ///
    /// @param recoveredOrder Memory location used for writing the recovered order data.
    /// @param tokens The list of tokens included in the settlement. The token
    /// indices in the trade parameters map to tokens in this array.
    /// @param trade The trade data to recover the order data from.
    function recoverOrderFromTrade(
        RecoveredOrder memory recoveredOrder,
        IERC20[] calldata tokens,
        GPv2Trade.Data calldata trade
    ) internal view {
        GPv2Order.Data memory order = recoveredOrder.data;
        Scheme signingScheme = GPv2Trade.extractOrder(trade, tokens, order);
        (bytes32 orderDigest, address owner) =
            recoverOrderSigner(order, signingScheme, trade.signature);
        recoveredOrder.uid.packOrderUidParams(
            orderDigest,
            owner,
            order.validTo
        );
        recoveredOrder.owner = owner;
        recoveredOrder.receiver = order.actualReceiver(owner);
    }
    /// @dev The length of any signature from an externally owned account.
    uint256 private constant ECDSA_SIGNATURE_LENGTH = 65;
    /// @dev Recovers an order's signer from the specified order and signature.
    ///
    /// @param order The order to recover a signature for.
    /// @param signingScheme The signing scheme.
    /// @param signature The signature bytes.
    /// @return orderDigest The computed order hash.
    /// @return owner The recovered address from the specified signature.
    function recoverOrderSigner(
        GPv2Order.Data memory order,
        Scheme signingScheme,
        bytes calldata signature
    ) internal view returns (bytes32 orderDigest, address owner) {
        orderDigest = order.hash(domainSeparator);
        if (signingScheme == Scheme.Eip712) {
            owner = recoverEip712Signer(orderDigest, signature);
        } else if (signingScheme == Scheme.EthSign) {
            owner = recoverEthsignSigner(orderDigest, signature);
        } else if (signingScheme == Scheme.Eip1271) {
            owner = recoverEip1271Signer(orderDigest, signature);
        } else {
            // signingScheme == Scheme.PreSign
            owner = recoverPreSigner(orderDigest, signature, order.validTo);
        }
    }
    /// @dev Perform an ECDSA recover for the specified message and calldata
    /// signature.
    ///
    /// The signature is encoded by tighyly packing the following struct:
    /// ```
    /// struct EncodedSignature {
    ///     bytes32 r;
    ///     bytes32 s;
    ///     uint8 v;
    /// }
    /// ```
    ///
    /// @param message The signed message.
    /// @param encodedSignature The encoded signature.
    function ecdsaRecover(bytes32 message, bytes calldata encodedSignature)
        internal
        pure
        returns (address signer)
    {
        require(
            encodedSignature.length == ECDSA_SIGNATURE_LENGTH,
            "GPv2: malformed ecdsa signature"
        );
        bytes32 r;
        bytes32 s;
        uint8 v;
        // NOTE: Use assembly to efficiently decode signature data.
        // solhint-disable-next-line no-inline-assembly
        assembly {
            // r = uint256(encodedSignature[0:32])
            r := calldataload(encodedSignature.offset)
            // s = uint256(encodedSignature[32:64])
            s := calldataload(add(encodedSignature.offset, 32))
            // v = uint8(encodedSignature[64])
            v := shr(248, calldataload(add(encodedSignature.offset, 64)))
        }
        signer = ecrecover(message, v, r, s);
        require(signer != address(0), "GPv2: invalid ecdsa signature");
    }
    /// @dev Decodes signature bytes originating from an EIP-712-encoded
    /// signature.
    ///
    /// EIP-712 signs typed data. The specifications are described in the
    /// related EIP (<https://eips.ethereum.org/EIPS/eip-712>).
    ///
    /// EIP-712 signatures are encoded as standard ECDSA signatures as described
    /// in the corresponding decoding function [`ecdsaRecover`].
    ///
    /// @param orderDigest The EIP-712 signing digest derived from the order
    /// parameters.
    /// @param encodedSignature Calldata pointing to tightly packed signature
    /// bytes.
    /// @return owner The address of the signer.
    function recoverEip712Signer(
        bytes32 orderDigest,
        bytes calldata encodedSignature
    ) internal pure returns (address owner) {
        owner = ecdsaRecover(orderDigest, encodedSignature);
    }
    /// @dev Decodes signature bytes originating from the output of the eth_sign
    /// RPC call.
    ///
    /// The specifications are described in the Ethereum documentation
    /// (<https://eth.wiki/json-rpc/API#eth_sign>).
    ///
    /// eth_sign signatures are encoded as standard ECDSA signatures as
    /// described in the corresponding decoding function
    /// [`ecdsaRecover`].
    ///
    /// @param orderDigest The EIP-712 signing digest derived from the order
    /// parameters.
    /// @param encodedSignature Calldata pointing to tightly packed signature
    /// bytes.
    /// @return owner The address of the signer.
    function recoverEthsignSigner(
        bytes32 orderDigest,
        bytes calldata encodedSignature
    ) internal pure returns (address owner) {
        // The signed message is encoded as:
        // `"\\x19Ethereum Signed Message:\
" || length || data`, where
        // the length is a constant (32 bytes) and the data is defined as:
        // `orderDigest`.
        bytes32 ethsignDigest =
            keccak256(
                abi.encodePacked(
                    "\\x19Ethereum Signed Message:\
32",
                    orderDigest
                )
            );
        owner = ecdsaRecover(ethsignDigest, encodedSignature);
    }
    /// @dev Verifies the input calldata as an EIP-1271 contract signature and
    /// returns the address of the signer.
    ///
    /// The encoded signature tightly packs the following struct:
    ///
    /// ```
    /// struct EncodedEip1271Signature {
    ///     address owner;
    ///     bytes signature;
    /// }
    /// ```
    ///
    /// This function enforces that the encoded data stores enough bytes to
    /// cover the full length of the decoded signature.
    ///
    /// @param encodedSignature The encoded EIP-1271 signature.
    /// @param orderDigest The EIP-712 signing digest derived from the order
    /// parameters.
    /// @return owner The address of the signer.
    function recoverEip1271Signer(
        bytes32 orderDigest,
        bytes calldata encodedSignature
    ) internal view returns (address owner) {
        // NOTE: Use assembly to read the verifier address from the encoded
        // signature bytes.
        // solhint-disable-next-line no-inline-assembly
        assembly {
            // owner = address(encodedSignature[0:20])
            owner := shr(96, calldataload(encodedSignature.offset))
        }
        // NOTE: Configure prettier to ignore the following line as it causes
        // a panic in the Solidity plugin.
        // prettier-ignore
        bytes calldata signature = encodedSignature[20:];
        require(
            EIP1271Verifier(owner).isValidSignature(orderDigest, signature) ==
                GPv2EIP1271.MAGICVALUE,
            "GPv2: invalid eip1271 signature"
        );
    }
    /// @dev Verifies the order has been pre-signed. The signature is the
    /// address of the signer of the order.
    ///
    /// @param orderDigest The EIP-712 signing digest derived from the order
    /// parameters.
    /// @param encodedSignature The pre-sign signature reprenting the order UID.
    /// @param validTo The order expiry timestamp.
    /// @return owner The address of the signer.
    function recoverPreSigner(
        bytes32 orderDigest,
        bytes calldata encodedSignature,
        uint32 validTo
    ) internal view returns (address owner) {
        require(encodedSignature.length == 20, "GPv2: malformed presignature");
        // NOTE: Use assembly to read the owner address from the encoded
        // signature bytes.
        // solhint-disable-next-line no-inline-assembly
        assembly {
            // owner = address(encodedSignature[0:20])
            owner := shr(96, calldataload(encodedSignature.offset))
        }
        bytes memory orderUid = new bytes(GPv2Order.UID_LENGTH);
        orderUid.packOrderUidParams(orderDigest, owner, validTo);
        require(
            preSignature[orderUid] == PRE_SIGNED,
            "GPv2: order not presigned"
        );
    }
}
// SPDX-License-Identifier: MIT
// Vendored from OpenZeppelin contracts with minor modifications:
// - Modified Solidity version
// - Formatted code
// <https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v3.4.0/contracts/utils/ReentrancyGuard.sol>
pragma solidity ^0.7.6;
/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuard {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.
    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;
    uint256 private _status;
    constructor() {
        _status = _NOT_ENTERED;
    }
    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and make it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;
        _;
        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
}
// SPDX-License-Identifier: LGPL-3.0-only
// Vendored from Gnosis utility contracts with minor modifications:
// - Modified Solidity version
// - Formatted code
// - Added linter directives to ignore low level call and assembly warnings
// <https://github.com/gnosis/util-contracts/blob/v3.1.0-solc-7/contracts/StorageAccessible.sol>
pragma solidity ^0.7.6;
/// @title ViewStorageAccessible - Interface on top of StorageAccessible base class to allow simulations from view functions
interface ViewStorageAccessible {
    /**
     * @dev Same as `simulateDelegatecall` on StorageAccessible. Marked as view so that it can be called from external contracts
     * that want to run simulations from within view functions. Will revert if the invoked simulation attempts to change state.
     */
    function simulateDelegatecall(
        address targetContract,
        bytes memory calldataPayload
    ) external view returns (bytes memory);
    /**
     * @dev Same as `getStorageAt` on StorageAccessible. This method allows reading aribtrary ranges of storage.
     */
    function getStorageAt(uint256 offset, uint256 length)
        external
        view
        returns (bytes memory);
}
/// @title StorageAccessible - generic base contract that allows callers to access all internal storage.
contract StorageAccessible {
    /**
     * @dev Reads `length` bytes of storage in the currents contract
     * @param offset - the offset in the current contract's storage in words to start reading from
     * @param length - the number of words (32 bytes) of data to read
     * @return the bytes that were read.
     */
    function getStorageAt(uint256 offset, uint256 length)
        external
        view
        returns (bytes memory)
    {
        bytes memory result = new bytes(length * 32);
        for (uint256 index = 0; index < length; index++) {
            // solhint-disable-next-line no-inline-assembly
            assembly {
                let word := sload(add(offset, index))
                mstore(add(add(result, 0x20), mul(index, 0x20)), word)
            }
        }
        return result;
    }
    /**
     * @dev Performs a delegetecall on a targetContract in the context of self.
     * Internally reverts execution to avoid side effects (making it static). Catches revert and returns encoded result as bytes.
     * @param targetContract Address of the contract containing the code to execute.
     * @param calldataPayload Calldata that should be sent to the target contract (encoded method name and arguments).
     */
    function simulateDelegatecall(
        address targetContract,
        bytes memory calldataPayload
    ) public returns (bytes memory response) {
        bytes memory innerCall =
            abi.encodeWithSelector(
                this.simulateDelegatecallInternal.selector,
                targetContract,
                calldataPayload
            );
        // solhint-disable-next-line avoid-low-level-calls
        (, response) = address(this).call(innerCall);
        bool innerSuccess = response[response.length - 1] == 0x01;
        setLength(response, response.length - 1);
        if (innerSuccess) {
            return response;
        } else {
            revertWith(response);
        }
    }
    /**
     * @dev Performs a delegetecall on a targetContract in the context of self.
     * Internally reverts execution to avoid side effects (making it static). Returns encoded result as revert message
     * concatenated with the success flag of the inner call as a last byte.
     * @param targetContract Address of the contract containing the code to execute.
     * @param calldataPayload Calldata that should be sent to the target contract (encoded method name and arguments).
     */
    function simulateDelegatecallInternal(
        address targetContract,
        bytes memory calldataPayload
    ) external returns (bytes memory response) {
        bool success;
        // solhint-disable-next-line avoid-low-level-calls
        (success, response) = targetContract.delegatecall(calldataPayload);
        revertWith(abi.encodePacked(response, success));
    }
    function revertWith(bytes memory response) internal pure {
        // solhint-disable-next-line no-inline-assembly
        assembly {
            revert(add(response, 0x20), mload(response))
        }
    }
    function setLength(bytes memory buffer, uint256 length) internal pure {
        // solhint-disable-next-line no-inline-assembly
        assembly {
            mstore(buffer, length)
        }
    }
}

pragma solidity ^0.4.24;

// File: zos-lib/contracts/upgradeability/Proxy.sol

/**
 * @title Proxy
 * @dev Implements delegation of calls to other contracts, with proper
 * forwarding of return values and bubbling of failures.
 * It defines a fallback function that delegates all calls to the address
 * returned by the abstract _implementation() internal function.
 */
contract Proxy {
  /**
   * @dev Fallback function.
   * Implemented entirely in `_fallback`.
   */
  function () payable external {
    _fallback();
  }

  /**
   * @return The Address of the implementation.
   */
  function _implementation() internal view returns (address);

  /**
   * @dev Delegates execution to an implementation contract.
   * This is a low level function that doesn't return to its internal call site.
   * It will return to the external caller whatever the implementation returns.
   * @param implementation Address to delegate.
   */
  function _delegate(address implementation) internal {
    assembly {
      // Copy msg.data. We take full control of memory in this inline assembly
      // block because it will not return to Solidity code. We overwrite the
      // Solidity scratch pad at memory position 0.
      calldatacopy(0, 0, calldatasize)

      // Call the implementation.
      // out and outsize are 0 because we don't know the size yet.
      let result := delegatecall(gas, implementation, 0, calldatasize, 0, 0)

      // Copy the returned data.
      returndatacopy(0, 0, returndatasize)

      switch result
      // delegatecall returns 0 on error.
      case 0 { revert(0, returndatasize) }
      default { return(0, returndatasize) }
    }
  }

  /**
   * @dev Function that is run as the first thing in the fallback function.
   * Can be redefined in derived contracts to add functionality.
   * Redefinitions must call super._willFallback().
   */
  function _willFallback() internal {
  }

  /**
   * @dev fallback implementation.
   * Extracted to enable manual triggering.
   */
  function _fallback() internal {
    _willFallback();
    _delegate(_implementation());
  }
}

// File: openzeppelin-solidity/contracts/AddressUtils.sol

/**
 * Utility library of inline functions on addresses
 */
library AddressUtils {

  /**
   * Returns whether the target address is a contract
   * @dev This function will return false if invoked during the constructor of a contract,
   * as the code is not actually created until after the constructor finishes.
   * @param addr address to check
   * @return whether the target address is a contract
   */
  function isContract(address addr) internal view returns (bool) {
    uint256 size;
    // XXX Currently there is no better way to check if there is a contract in an address
    // than to check the size of the code at that address.
    // See https://ethereum.stackexchange.com/a/14016/36603
    // for more details about how this works.
    // TODO Check this again before the Serenity release, because all addresses will be
    // contracts then.
    // solium-disable-next-line security/no-inline-assembly
    assembly { size := extcodesize(addr) }
    return size > 0;
  }

}

// File: zos-lib/contracts/upgradeability/UpgradeabilityProxy.sol

/**
 * @title UpgradeabilityProxy
 * @dev This contract implements a proxy that allows to change the
 * implementation address to which it will delegate.
 * Such a change is called an implementation upgrade.
 */
contract UpgradeabilityProxy is Proxy {
  /**
   * @dev Emitted when the implementation is upgraded.
   * @param implementation Address of the new implementation.
   */
  event Upgraded(address implementation);

  /**
   * @dev Storage slot with the address of the current implementation.
   * This is the keccak-256 hash of "org.zeppelinos.proxy.implementation", and is
   * validated in the constructor.
   */
  bytes32 private constant IMPLEMENTATION_SLOT = 0x7050c9e0f4ca769c69bd3a8ef740bc37934f8e2c036e5a723fd8ee048ed3f8c3;

  /**
   * @dev Contract constructor.
   * @param _implementation Address of the initial implementation.
   */
  constructor(address _implementation) public {
    assert(IMPLEMENTATION_SLOT == keccak256("org.zeppelinos.proxy.implementation"));

    _setImplementation(_implementation);
  }

  /**
   * @dev Returns the current implementation.
   * @return Address of the current implementation
   */
  function _implementation() internal view returns (address impl) {
    bytes32 slot = IMPLEMENTATION_SLOT;
    assembly {
      impl := sload(slot)
    }
  }

  /**
   * @dev Upgrades the proxy to a new implementation.
   * @param newImplementation Address of the new implementation.
   */
  function _upgradeTo(address newImplementation) internal {
    _setImplementation(newImplementation);
    emit Upgraded(newImplementation);
  }

  /**
   * @dev Sets the implementation address of the proxy.
   * @param newImplementation Address of the new implementation.
   */
  function _setImplementation(address newImplementation) private {
    require(AddressUtils.isContract(newImplementation), "Cannot set a proxy implementation to a non-contract address");

    bytes32 slot = IMPLEMENTATION_SLOT;

    assembly {
      sstore(slot, newImplementation)
    }
  }
}

// File: zos-lib/contracts/upgradeability/AdminUpgradeabilityProxy.sol

/**
 * @title AdminUpgradeabilityProxy
 * @dev This contract combines an upgradeability proxy with an authorization
 * mechanism for administrative tasks.
 * All external functions in this contract must be guarded by the
 * `ifAdmin` modifier. See ethereum/solidity#3864 for a Solidity
 * feature proposal that would enable this to be done automatically.
 */
contract AdminUpgradeabilityProxy is UpgradeabilityProxy {
  /**
   * @dev Emitted when the administration has been transferred.
   * @param previousAdmin Address of the previous admin.
   * @param newAdmin Address of the new admin.
   */
  event AdminChanged(address previousAdmin, address newAdmin);

  /**
   * @dev Storage slot with the admin of the contract.
   * This is the keccak-256 hash of "org.zeppelinos.proxy.admin", and is
   * validated in the constructor.
   */
  bytes32 private constant ADMIN_SLOT = 0x10d6a54a4754c8869d6886b5f5d7fbfa5b4522237ea5c60d11bc4e7a1ff9390b;

  /**
   * @dev Modifier to check whether the `msg.sender` is the admin.
   * If it is, it will run the function. Otherwise, it will delegate the call
   * to the implementation.
   */
  modifier ifAdmin() {
    if (msg.sender == _admin()) {
      _;
    } else {
      _fallback();
    }
  }

  /**
   * Contract constructor.
   * It sets the `msg.sender` as the proxy administrator.
   * @param _implementation address of the initial implementation.
   */
  constructor(address _implementation) UpgradeabilityProxy(_implementation) public {
    assert(ADMIN_SLOT == keccak256("org.zeppelinos.proxy.admin"));

    _setAdmin(msg.sender);
  }

  /**
   * @return The address of the proxy admin.
   */
  function admin() external view ifAdmin returns (address) {
    return _admin();
  }

  /**
   * @return The address of the implementation.
   */
  function implementation() external view ifAdmin returns (address) {
    return _implementation();
  }

  /**
   * @dev Changes the admin of the proxy.
   * Only the current admin can call this function.
   * @param newAdmin Address to transfer proxy administration to.
   */
  function changeAdmin(address newAdmin) external ifAdmin {
    require(newAdmin != address(0), "Cannot change the admin of a proxy to the zero address");
    emit AdminChanged(_admin(), newAdmin);
    _setAdmin(newAdmin);
  }

  /**
   * @dev Upgrade the backing implementation of the proxy.
   * Only the admin can call this function.
   * @param newImplementation Address of the new implementation.
   */
  function upgradeTo(address newImplementation) external ifAdmin {
    _upgradeTo(newImplementation);
  }

  /**
   * @dev Upgrade the backing implementation of the proxy and call a function
   * on the new implementation.
   * This is useful to initialize the proxied contract.
   * @param newImplementation Address of the new implementation.
   * @param data Data to send as msg.data in the low level call.
   * It should include the signature and the parameters of the function to be
   * called, as described in
   * https://solidity.readthedocs.io/en/develop/abi-spec.html#function-selector-and-argument-encoding.
   */
  function upgradeToAndCall(address newImplementation, bytes data) payable external ifAdmin {
    _upgradeTo(newImplementation);
    require(address(this).call.value(msg.value)(data));
  }

  /**
   * @return The admin slot.
   */
  function _admin() internal view returns (address adm) {
    bytes32 slot = ADMIN_SLOT;
    assembly {
      adm := sload(slot)
    }
  }

  /**
   * @dev Sets the address of the proxy admin.
   * @param newAdmin Address of the new proxy admin.
   */
  function _setAdmin(address newAdmin) internal {
    bytes32 slot = ADMIN_SLOT;

    assembly {
      sstore(slot, newAdmin)
    }
  }

  /**
   * @dev Only fall back when the sender is not the admin.
   */
  function _willFallback() internal {
    require(msg.sender != _admin(), "Cannot call fallback function from the proxy admin");
    super._willFallback();
  }
}

// File: contracts/FiatTokenProxy.sol

/**
* Copyright CENTRE SECZ 2018
*
* Permission is hereby granted, free of charge, to any person obtaining a copy 
* of this software and associated documentation files (the "Software"), to deal 
* in the Software without restriction, including without limitation the rights 
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 
* copies of the Software, and to permit persons to whom the Software is furnished to 
* do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all 
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/

pragma solidity ^0.4.24;


/**
 * @title FiatTokenProxy
 * @dev This contract proxies FiatToken calls and enables FiatToken upgrades
*/ 
contract FiatTokenProxy is AdminUpgradeabilityProxy {
    constructor(address _implementation) public AdminUpgradeabilityProxy(_implementation) {
    }
}

pragma solidity ^0.4.17;

/**
 * @title SafeMath
 * @dev Math operations with safety checks that throw on error
 */
library SafeMath {
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }
        uint256 c = a * b;
        assert(c / a == b);
        return c;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        // assert(b > 0); // Solidity automatically throws when dividing by 0
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold
        return c;
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        assert(b <= a);
        return a - b;
    }

    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        assert(c >= a);
        return c;
    }
}

/**
 * @title Ownable
 * @dev The Ownable contract has an owner address, and provides basic authorization control
 * functions, this simplifies the implementation of "user permissions".
 */
contract Ownable {
    address public owner;

    /**
      * @dev The Ownable constructor sets the original `owner` of the contract to the sender
      * account.
      */
    function Ownable() public {
        owner = msg.sender;
    }

    /**
      * @dev Throws if called by any account other than the owner.
      */
    modifier onlyOwner() {
        require(msg.sender == owner);
        _;
    }

    /**
    * @dev Allows the current owner to transfer control of the contract to a newOwner.
    * @param newOwner The address to transfer ownership to.
    */
    function transferOwnership(address newOwner) public onlyOwner {
        if (newOwner != address(0)) {
            owner = newOwner;
        }
    }

}

/**
 * @title ERC20Basic
 * @dev Simpler version of ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/20
 */
contract ERC20Basic {
    uint public _totalSupply;
    function totalSupply() public constant returns (uint);
    function balanceOf(address who) public constant returns (uint);
    function transfer(address to, uint value) public;
    event Transfer(address indexed from, address indexed to, uint value);
}

/**
 * @title ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/20
 */
contract ERC20 is ERC20Basic {
    function allowance(address owner, address spender) public constant returns (uint);
    function transferFrom(address from, address to, uint value) public;
    function approve(address spender, uint value) public;
    event Approval(address indexed owner, address indexed spender, uint value);
}

/**
 * @title Basic token
 * @dev Basic version of StandardToken, with no allowances.
 */
contract BasicToken is Ownable, ERC20Basic {
    using SafeMath for uint;

    mapping(address => uint) public balances;

    // additional variables for use if transaction fees ever became necessary
    uint public basisPointsRate = 0;
    uint public maximumFee = 0;

    /**
    * @dev Fix for the ERC20 short address attack.
    */
    modifier onlyPayloadSize(uint size) {
        require(!(msg.data.length < size + 4));
        _;
    }

    /**
    * @dev transfer token for a specified address
    * @param _to The address to transfer to.
    * @param _value The amount to be transferred.
    */
    function transfer(address _to, uint _value) public onlyPayloadSize(2 * 32) {
        uint fee = (_value.mul(basisPointsRate)).div(10000);
        if (fee > maximumFee) {
            fee = maximumFee;
        }
        uint sendAmount = _value.sub(fee);
        balances[msg.sender] = balances[msg.sender].sub(_value);
        balances[_to] = balances[_to].add(sendAmount);
        if (fee > 0) {
            balances[owner] = balances[owner].add(fee);
            Transfer(msg.sender, owner, fee);
        }
        Transfer(msg.sender, _to, sendAmount);
    }

    /**
    * @dev Gets the balance of the specified address.
    * @param _owner The address to query the the balance of.
    * @return An uint representing the amount owned by the passed address.
    */
    function balanceOf(address _owner) public constant returns (uint balance) {
        return balances[_owner];
    }

}

/**
 * @title Standard ERC20 token
 *
 * @dev Implementation of the basic standard token.
 * @dev https://github.com/ethereum/EIPs/issues/20
 * @dev Based oncode by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
 */
contract StandardToken is BasicToken, ERC20 {

    mapping (address => mapping (address => uint)) public allowed;

    uint public constant MAX_UINT = 2**256 - 1;

    /**
    * @dev Transfer tokens from one address to another
    * @param _from address The address which you want to send tokens from
    * @param _to address The address which you want to transfer to
    * @param _value uint the amount of tokens to be transferred
    */
    function transferFrom(address _from, address _to, uint _value) public onlyPayloadSize(3 * 32) {
        var _allowance = allowed[_from][msg.sender];

        // Check is not needed because sub(_allowance, _value) will already throw if this condition is not met
        // if (_value > _allowance) throw;

        uint fee = (_value.mul(basisPointsRate)).div(10000);
        if (fee > maximumFee) {
            fee = maximumFee;
        }
        if (_allowance < MAX_UINT) {
            allowed[_from][msg.sender] = _allowance.sub(_value);
        }
        uint sendAmount = _value.sub(fee);
        balances[_from] = balances[_from].sub(_value);
        balances[_to] = balances[_to].add(sendAmount);
        if (fee > 0) {
            balances[owner] = balances[owner].add(fee);
            Transfer(_from, owner, fee);
        }
        Transfer(_from, _to, sendAmount);
    }

    /**
    * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
    * @param _spender The address which will spend the funds.
    * @param _value The amount of tokens to be spent.
    */
    function approve(address _spender, uint _value) public onlyPayloadSize(2 * 32) {

        // To change the approve amount you first have to reduce the addresses`
        //  allowance to zero by calling `approve(_spender, 0)` if it is not
        //  already 0 to mitigate the race condition described here:
        //  https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
        require(!((_value != 0) && (allowed[msg.sender][_spender] != 0)));

        allowed[msg.sender][_spender] = _value;
        Approval(msg.sender, _spender, _value);
    }

    /**
    * @dev Function to check the amount of tokens than an owner allowed to a spender.
    * @param _owner address The address which owns the funds.
    * @param _spender address The address which will spend the funds.
    * @return A uint specifying the amount of tokens still available for the spender.
    */
    function allowance(address _owner, address _spender) public constant returns (uint remaining) {
        return allowed[_owner][_spender];
    }

}


/**
 * @title Pausable
 * @dev Base contract which allows children to implement an emergency stop mechanism.
 */
contract Pausable is Ownable {
  event Pause();
  event Unpause();

  bool public paused = false;


  /**
   * @dev Modifier to make a function callable only when the contract is not paused.
   */
  modifier whenNotPaused() {
    require(!paused);
    _;
  }

  /**
   * @dev Modifier to make a function callable only when the contract is paused.
   */
  modifier whenPaused() {
    require(paused);
    _;
  }

  /**
   * @dev called by the owner to pause, triggers stopped state
   */
  function pause() onlyOwner whenNotPaused public {
    paused = true;
    Pause();
  }

  /**
   * @dev called by the owner to unpause, returns to normal state
   */
  function unpause() onlyOwner whenPaused public {
    paused = false;
    Unpause();
  }
}

contract BlackList is Ownable, BasicToken {

    /////// Getters to allow the same blacklist to be used also by other contracts (including upgraded Tether) ///////
    function getBlackListStatus(address _maker) external constant returns (bool) {
        return isBlackListed[_maker];
    }

    function getOwner() external constant returns (address) {
        return owner;
    }

    mapping (address => bool) public isBlackListed;
    
    function addBlackList (address _evilUser) public onlyOwner {
        isBlackListed[_evilUser] = true;
        AddedBlackList(_evilUser);
    }

    function removeBlackList (address _clearedUser) public onlyOwner {
        isBlackListed[_clearedUser] = false;
        RemovedBlackList(_clearedUser);
    }

    function destroyBlackFunds (address _blackListedUser) public onlyOwner {
        require(isBlackListed[_blackListedUser]);
        uint dirtyFunds = balanceOf(_blackListedUser);
        balances[_blackListedUser] = 0;
        _totalSupply -= dirtyFunds;
        DestroyedBlackFunds(_blackListedUser, dirtyFunds);
    }

    event DestroyedBlackFunds(address _blackListedUser, uint _balance);

    event AddedBlackList(address _user);

    event RemovedBlackList(address _user);

}

contract UpgradedStandardToken is StandardToken{
    // those methods are called by the legacy contract
    // and they must ensure msg.sender to be the contract address
    function transferByLegacy(address from, address to, uint value) public;
    function transferFromByLegacy(address sender, address from, address spender, uint value) public;
    function approveByLegacy(address from, address spender, uint value) public;
}

contract TetherToken is Pausable, StandardToken, BlackList {

    string public name;
    string public symbol;
    uint public decimals;
    address public upgradedAddress;
    bool public deprecated;

    //  The contract can be initialized with a number of tokens
    //  All the tokens are deposited to the owner address
    //
    // @param _balance Initial supply of the contract
    // @param _name Token Name
    // @param _symbol Token symbol
    // @param _decimals Token decimals
    function TetherToken(uint _initialSupply, string _name, string _symbol, uint _decimals) public {
        _totalSupply = _initialSupply;
        name = _name;
        symbol = _symbol;
        decimals = _decimals;
        balances[owner] = _initialSupply;
        deprecated = false;
    }

    // Forward ERC20 methods to upgraded contract if this one is deprecated
    function transfer(address _to, uint _value) public whenNotPaused {
        require(!isBlackListed[msg.sender]);
        if (deprecated) {
            return UpgradedStandardToken(upgradedAddress).transferByLegacy(msg.sender, _to, _value);
        } else {
            return super.transfer(_to, _value);
        }
    }

    // Forward ERC20 methods to upgraded contract if this one is deprecated
    function transferFrom(address _from, address _to, uint _value) public whenNotPaused {
        require(!isBlackListed[_from]);
        if (deprecated) {
            return UpgradedStandardToken(upgradedAddress).transferFromByLegacy(msg.sender, _from, _to, _value);
        } else {
            return super.transferFrom(_from, _to, _value);
        }
    }

    // Forward ERC20 methods to upgraded contract if this one is deprecated
    function balanceOf(address who) public constant returns (uint) {
        if (deprecated) {
            return UpgradedStandardToken(upgradedAddress).balanceOf(who);
        } else {
            return super.balanceOf(who);
        }
    }

    // Forward ERC20 methods to upgraded contract if this one is deprecated
    function approve(address _spender, uint _value) public onlyPayloadSize(2 * 32) {
        if (deprecated) {
            return UpgradedStandardToken(upgradedAddress).approveByLegacy(msg.sender, _spender, _value);
        } else {
            return super.approve(_spender, _value);
        }
    }

    // Forward ERC20 methods to upgraded contract if this one is deprecated
    function allowance(address _owner, address _spender) public constant returns (uint remaining) {
        if (deprecated) {
            return StandardToken(upgradedAddress).allowance(_owner, _spender);
        } else {
            return super.allowance(_owner, _spender);
        }
    }

    // deprecate current contract in favour of a new one
    function deprecate(address _upgradedAddress) public onlyOwner {
        deprecated = true;
        upgradedAddress = _upgradedAddress;
        Deprecate(_upgradedAddress);
    }

    // deprecate current contract if favour of a new one
    function totalSupply() public constant returns (uint) {
        if (deprecated) {
            return StandardToken(upgradedAddress).totalSupply();
        } else {
            return _totalSupply;
        }
    }

    // Issue a new amount of tokens
    // these tokens are deposited into the owner address
    //
    // @param _amount Number of tokens to be issued
    function issue(uint amount) public onlyOwner {
        require(_totalSupply + amount > _totalSupply);
        require(balances[owner] + amount > balances[owner]);

        balances[owner] += amount;
        _totalSupply += amount;
        Issue(amount);
    }

    // Redeem tokens.
    // These tokens are withdrawn from the owner address
    // if the balance must be enough to cover the redeem
    // or the call will fail.
    // @param _amount Number of tokens to be issued
    function redeem(uint amount) public onlyOwner {
        require(_totalSupply >= amount);
        require(balances[owner] >= amount);

        _totalSupply -= amount;
        balances[owner] -= amount;
        Redeem(amount);
    }

    function setParams(uint newBasisPoints, uint newMaxFee) public onlyOwner {
        // Ensure transparency by hardcoding limit beyond which fees can never be added
        require(newBasisPoints < 20);
        require(newMaxFee < 50);

        basisPointsRate = newBasisPoints;
        maximumFee = newMaxFee.mul(10**decimals);

        Params(basisPointsRate, maximumFee);
    }

    // Called when new token are issued
    event Issue(uint amount);

    // Called when tokens are redeemed
    event Redeem(uint amount);

    // Called when contract is deprecated
    event Deprecate(address newAddress);

    // Called if contract ever adds fees
    event Params(uint feeBasisPoints, uint maxFee);
}

/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/LibBytesV06.sol";
import "./migrations/LibBootstrap.sol";
import "./features/Bootstrap.sol";
import "./storage/LibProxyStorage.sol";
import "./errors/LibProxyRichErrors.sol";
/// @dev An extensible proxy contract that serves as a universal entry point for
///      interacting with the 0x protocol.
contract ZeroEx {
    // solhint-disable separate-by-one-line-in-contract,indent,var-name-mixedcase
    using LibBytesV06 for bytes;
    /// @dev Construct this contract and register the `Bootstrap` feature.
    ///      After constructing this contract, `bootstrap()` should be called
    ///      to seed the initial feature set.
    constructor() public {
        // Temporarily create and register the bootstrap feature.
        // It will deregister itself after `bootstrap()` has been called.
        Bootstrap bootstrap = new Bootstrap(msg.sender);
        LibProxyStorage.getStorage().impls[bootstrap.bootstrap.selector] =
            address(bootstrap);
    }
    // solhint-disable state-visibility
    /// @dev Forwards calls to the appropriate implementation contract.
    fallback() external payable {
        bytes4 selector = msg.data.readBytes4(0);
        address impl = getFunctionImplementation(selector);
        if (impl == address(0)) {
            _revertWithData(LibProxyRichErrors.NotImplementedError(selector));
        }
        (bool success, bytes memory resultData) = impl.delegatecall(msg.data);
        if (!success) {
            _revertWithData(resultData);
        }
        _returnWithData(resultData);
    }
    /// @dev Fallback for just receiving ether.
    receive() external payable {}
    // solhint-enable state-visibility
    /// @dev Get the implementation contract of a registered function.
    /// @param selector The function selector.
    /// @return impl The implementation contract address.
    function getFunctionImplementation(bytes4 selector)
        public
        view
        returns (address impl)
    {
        return LibProxyStorage.getStorage().impls[selector];
    }
    /// @dev Revert with arbitrary bytes.
    /// @param data Revert data.
    function _revertWithData(bytes memory data) private pure {
        assembly { revert(add(data, 32), mload(data)) }
    }
    /// @dev Return with arbitrary bytes.
    /// @param data Return data.
    function _returnWithData(bytes memory data) private pure {
        assembly { return(add(data, 32), mload(data)) }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
import "./errors/LibBytesRichErrorsV06.sol";
import "./errors/LibRichErrorsV06.sol";
library LibBytesV06 {
    using LibBytesV06 for bytes;
    /// @dev Gets the memory address for a byte array.
    /// @param input Byte array to lookup.
    /// @return memoryAddress Memory address of byte array. This
    ///         points to the header of the byte array which contains
    ///         the length.
    function rawAddress(bytes memory input)
        internal
        pure
        returns (uint256 memoryAddress)
    {
        assembly {
            memoryAddress := input
        }
        return memoryAddress;
    }
    /// @dev Gets the memory address for the contents of a byte array.
    /// @param input Byte array to lookup.
    /// @return memoryAddress Memory address of the contents of the byte array.
    function contentAddress(bytes memory input)
        internal
        pure
        returns (uint256 memoryAddress)
    {
        assembly {
            memoryAddress := add(input, 32)
        }
        return memoryAddress;
    }
    /// @dev Copies `length` bytes from memory location `source` to `dest`.
    /// @param dest memory address to copy bytes to.
    /// @param source memory address to copy bytes from.
    /// @param length number of bytes to copy.
    function memCopy(
        uint256 dest,
        uint256 source,
        uint256 length
    )
        internal
        pure
    {
        if (length < 32) {
            // Handle a partial word by reading destination and masking
            // off the bits we are interested in.
            // This correctly handles overlap, zero lengths and source == dest
            assembly {
                let mask := sub(exp(256, sub(32, length)), 1)
                let s := and(mload(source), not(mask))
                let d := and(mload(dest), mask)
                mstore(dest, or(s, d))
            }
        } else {
            // Skip the O(length) loop when source == dest.
            if (source == dest) {
                return;
            }
            // For large copies we copy whole words at a time. The final
            // word is aligned to the end of the range (instead of after the
            // previous) to handle partial words. So a copy will look like this:
            //
            //  ####
            //      ####
            //          ####
            //            ####
            //
            // We handle overlap in the source and destination range by
            // changing the copying direction. This prevents us from
            // overwriting parts of source that we still need to copy.
            //
            // This correctly handles source == dest
            //
            if (source > dest) {
                assembly {
                    // We subtract 32 from `sEnd` and `dEnd` because it
                    // is easier to compare with in the loop, and these
                    // are also the addresses we need for copying the
                    // last bytes.
                    length := sub(length, 32)
                    let sEnd := add(source, length)
                    let dEnd := add(dest, length)
                    // Remember the last 32 bytes of source
                    // This needs to be done here and not after the loop
                    // because we may have overwritten the last bytes in
                    // source already due to overlap.
                    let last := mload(sEnd)
                    // Copy whole words front to back
                    // Note: the first check is always true,
                    // this could have been a do-while loop.
                    // solhint-disable-next-line no-empty-blocks
                    for {} lt(source, sEnd) {} {
                        mstore(dest, mload(source))
                        source := add(source, 32)
                        dest := add(dest, 32)
                    }
                    // Write the last 32 bytes
                    mstore(dEnd, last)
                }
            } else {
                assembly {
                    // We subtract 32 from `sEnd` and `dEnd` because those
                    // are the starting points when copying a word at the end.
                    length := sub(length, 32)
                    let sEnd := add(source, length)
                    let dEnd := add(dest, length)
                    // Remember the first 32 bytes of source
                    // This needs to be done here and not after the loop
                    // because we may have overwritten the first bytes in
                    // source already due to overlap.
                    let first := mload(source)
                    // Copy whole words back to front
                    // We use a signed comparisson here to allow dEnd to become
                    // negative (happens when source and dest < 32). Valid
                    // addresses in local memory will never be larger than
                    // 2**255, so they can be safely re-interpreted as signed.
                    // Note: the first check is always true,
                    // this could have been a do-while loop.
                    // solhint-disable-next-line no-empty-blocks
                    for {} slt(dest, dEnd) {} {
                        mstore(dEnd, mload(sEnd))
                        sEnd := sub(sEnd, 32)
                        dEnd := sub(dEnd, 32)
                    }
                    // Write the first 32 bytes
                    mstore(dest, first)
                }
            }
        }
    }
    /// @dev Returns a slices from a byte array.
    /// @param b The byte array to take a slice from.
    /// @param from The starting index for the slice (inclusive).
    /// @param to The final index for the slice (exclusive).
    /// @return result The slice containing bytes at indices [from, to)
    function slice(
        bytes memory b,
        uint256 from,
        uint256 to
    )
        internal
        pure
        returns (bytes memory result)
    {
        // Ensure that the from and to positions are valid positions for a slice within
        // the byte array that is being used.
        if (from > to) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.FromLessThanOrEqualsToRequired,
                from,
                to
            ));
        }
        if (to > b.length) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.ToLessThanOrEqualsLengthRequired,
                to,
                b.length
            ));
        }
        // Create a new bytes structure and copy contents
        result = new bytes(to - from);
        memCopy(
            result.contentAddress(),
            b.contentAddress() + from,
            result.length
        );
        return result;
    }
    /// @dev Returns a slice from a byte array without preserving the input.
    ///      When `from == 0`, the original array will match the slice.
    ///      In other cases its state will be corrupted.
    /// @param b The byte array to take a slice from. Will be destroyed in the process.
    /// @param from The starting index for the slice (inclusive).
    /// @param to The final index for the slice (exclusive).
    /// @return result The slice containing bytes at indices [from, to)
    function sliceDestructive(
        bytes memory b,
        uint256 from,
        uint256 to
    )
        internal
        pure
        returns (bytes memory result)
    {
        // Ensure that the from and to positions are valid positions for a slice within
        // the byte array that is being used.
        if (from > to) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.FromLessThanOrEqualsToRequired,
                from,
                to
            ));
        }
        if (to > b.length) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.ToLessThanOrEqualsLengthRequired,
                to,
                b.length
            ));
        }
        // Create a new bytes structure around [from, to) in-place.
        assembly {
            result := add(b, from)
            mstore(result, sub(to, from))
        }
        return result;
    }
    /// @dev Pops the last byte off of a byte array by modifying its length.
    /// @param b Byte array that will be modified.
    /// @return result The byte that was popped off.
    function popLastByte(bytes memory b)
        internal
        pure
        returns (bytes1 result)
    {
        if (b.length == 0) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.LengthGreaterThanZeroRequired,
                b.length,
                0
            ));
        }
        // Store last byte.
        result = b[b.length - 1];
        assembly {
            // Decrement length of byte array.
            let newLen := sub(mload(b), 1)
            mstore(b, newLen)
        }
        return result;
    }
    /// @dev Tests equality of two byte arrays.
    /// @param lhs First byte array to compare.
    /// @param rhs Second byte array to compare.
    /// @return equal True if arrays are the same. False otherwise.
    function equals(
        bytes memory lhs,
        bytes memory rhs
    )
        internal
        pure
        returns (bool equal)
    {
        // Keccak gas cost is 30 + numWords * 6. This is a cheap way to compare.
        // We early exit on unequal lengths, but keccak would also correctly
        // handle this.
        return lhs.length == rhs.length && keccak256(lhs) == keccak256(rhs);
    }
    /// @dev Reads an address from a position in a byte array.
    /// @param b Byte array containing an address.
    /// @param index Index in byte array of address.
    /// @return result address from byte array.
    function readAddress(
        bytes memory b,
        uint256 index
    )
        internal
        pure
        returns (address result)
    {
        if (b.length < index + 20) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.LengthGreaterThanOrEqualsTwentyRequired,
                b.length,
                index + 20 // 20 is length of address
            ));
        }
        // Add offset to index:
        // 1. Arrays are prefixed by 32-byte length parameter (add 32 to index)
        // 2. Account for size difference between address length and 32-byte storage word (subtract 12 from index)
        index += 20;
        // Read address from array memory
        assembly {
            // 1. Add index to address of bytes array
            // 2. Load 32-byte word from memory
            // 3. Apply 20-byte mask to obtain address
            result := and(mload(add(b, index)), 0xffffffffffffffffffffffffffffffffffffffff)
        }
        return result;
    }
    /// @dev Writes an address into a specific position in a byte array.
    /// @param b Byte array to insert address into.
    /// @param index Index in byte array of address.
    /// @param input Address to put into byte array.
    function writeAddress(
        bytes memory b,
        uint256 index,
        address input
    )
        internal
        pure
    {
        if (b.length < index + 20) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.LengthGreaterThanOrEqualsTwentyRequired,
                b.length,
                index + 20 // 20 is length of address
            ));
        }
        // Add offset to index:
        // 1. Arrays are prefixed by 32-byte length parameter (add 32 to index)
        // 2. Account for size difference between address length and 32-byte storage word (subtract 12 from index)
        index += 20;
        // Store address into array memory
        assembly {
            // The address occupies 20 bytes and mstore stores 32 bytes.
            // First fetch the 32-byte word where we'll be storing the address, then
            // apply a mask so we have only the bytes in the word that the address will not occupy.
            // Then combine these bytes with the address and store the 32 bytes back to memory with mstore.
            // 1. Add index to address of bytes array
            // 2. Load 32-byte word from memory
            // 3. Apply 12-byte mask to obtain extra bytes occupying word of memory where we'll store the address
            let neighbors := and(
                mload(add(b, index)),
                0xffffffffffffffffffffffff0000000000000000000000000000000000000000
            )
            // Make sure input address is clean.
            // (Solidity does not guarantee this)
            input := and(input, 0xffffffffffffffffffffffffffffffffffffffff)
            // Store the neighbors and address into memory
            mstore(add(b, index), xor(input, neighbors))
        }
    }
    /// @dev Reads a bytes32 value from a position in a byte array.
    /// @param b Byte array containing a bytes32 value.
    /// @param index Index in byte array of bytes32 value.
    /// @return result bytes32 value from byte array.
    function readBytes32(
        bytes memory b,
        uint256 index
    )
        internal
        pure
        returns (bytes32 result)
    {
        if (b.length < index + 32) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.LengthGreaterThanOrEqualsThirtyTwoRequired,
                b.length,
                index + 32
            ));
        }
        // Arrays are prefixed by a 256 bit length parameter
        index += 32;
        // Read the bytes32 from array memory
        assembly {
            result := mload(add(b, index))
        }
        return result;
    }
    /// @dev Writes a bytes32 into a specific position in a byte array.
    /// @param b Byte array to insert <input> into.
    /// @param index Index in byte array of <input>.
    /// @param input bytes32 to put into byte array.
    function writeBytes32(
        bytes memory b,
        uint256 index,
        bytes32 input
    )
        internal
        pure
    {
        if (b.length < index + 32) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.LengthGreaterThanOrEqualsThirtyTwoRequired,
                b.length,
                index + 32
            ));
        }
        // Arrays are prefixed by a 256 bit length parameter
        index += 32;
        // Read the bytes32 from array memory
        assembly {
            mstore(add(b, index), input)
        }
    }
    /// @dev Reads a uint256 value from a position in a byte array.
    /// @param b Byte array containing a uint256 value.
    /// @param index Index in byte array of uint256 value.
    /// @return result uint256 value from byte array.
    function readUint256(
        bytes memory b,
        uint256 index
    )
        internal
        pure
        returns (uint256 result)
    {
        result = uint256(readBytes32(b, index));
        return result;
    }
    /// @dev Writes a uint256 into a specific position in a byte array.
    /// @param b Byte array to insert <input> into.
    /// @param index Index in byte array of <input>.
    /// @param input uint256 to put into byte array.
    function writeUint256(
        bytes memory b,
        uint256 index,
        uint256 input
    )
        internal
        pure
    {
        writeBytes32(b, index, bytes32(input));
    }
    /// @dev Reads an unpadded bytes4 value from a position in a byte array.
    /// @param b Byte array containing a bytes4 value.
    /// @param index Index in byte array of bytes4 value.
    /// @return result bytes4 value from byte array.
    function readBytes4(
        bytes memory b,
        uint256 index
    )
        internal
        pure
        returns (bytes4 result)
    {
        if (b.length < index + 4) {
            LibRichErrorsV06.rrevert(LibBytesRichErrorsV06.InvalidByteOperationError(
                LibBytesRichErrorsV06.InvalidByteOperationErrorCodes.LengthGreaterThanOrEqualsFourRequired,
                b.length,
                index + 4
            ));
        }
        // Arrays are prefixed by a 32 byte length field
        index += 32;
        // Read the bytes4 from array memory
        assembly {
            result := mload(add(b, index))
            // Solidity does not require us to clean the trailing bytes.
            // We do it anyway
            result := and(result, 0xFFFFFFFF00000000000000000000000000000000000000000000000000000000)
        }
        return result;
    }
    /// @dev Writes a new length to a byte array.
    ///      Decreasing length will lead to removing the corresponding lower order bytes from the byte array.
    ///      Increasing length may lead to appending adjacent in-memory bytes to the end of the byte array.
    /// @param b Bytes array to write new length to.
    /// @param length New length of byte array.
    function writeLength(bytes memory b, uint256 length)
        internal
        pure
    {
        assembly {
            mstore(b, length)
        }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibBytesRichErrorsV06 {
    enum InvalidByteOperationErrorCodes {
        FromLessThanOrEqualsToRequired,
        ToLessThanOrEqualsLengthRequired,
        LengthGreaterThanZeroRequired,
        LengthGreaterThanOrEqualsFourRequired,
        LengthGreaterThanOrEqualsTwentyRequired,
        LengthGreaterThanOrEqualsThirtyTwoRequired,
        LengthGreaterThanOrEqualsNestedBytesLengthRequired,
        DestinationLengthGreaterThanOrEqualSourceLengthRequired
    }
    // bytes4(keccak256("InvalidByteOperationError(uint8,uint256,uint256)"))
    bytes4 internal constant INVALID_BYTE_OPERATION_ERROR_SELECTOR =
        0x28006595;
    // solhint-disable func-name-mixedcase
    function InvalidByteOperationError(
        InvalidByteOperationErrorCodes errorCode,
        uint256 offset,
        uint256 required
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            INVALID_BYTE_OPERATION_ERROR_SELECTOR,
            errorCode,
            offset,
            required
        );
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibRichErrorsV06 {
    // bytes4(keccak256("Error(string)"))
    bytes4 internal constant STANDARD_ERROR_SELECTOR = 0x08c379a0;
    // solhint-disable func-name-mixedcase
    /// @dev ABI encode a standard, string revert error payload.
    ///      This is the same payload that would be included by a `revert(string)`
    ///      solidity statement. It has the function signature `Error(string)`.
    /// @param message The error string.
    /// @return The ABI encoded error.
    function StandardError(string memory message)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            STANDARD_ERROR_SELECTOR,
            bytes(message)
        );
    }
    // solhint-enable func-name-mixedcase
    /// @dev Reverts an encoded rich revert reason `errorData`.
    /// @param errorData ABI encoded error data.
    function rrevert(bytes memory errorData)
        internal
        pure
    {
        assembly {
            revert(add(errorData, 0x20), mload(errorData))
        }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "../errors/LibProxyRichErrors.sol";
library LibBootstrap {
    /// @dev Magic bytes returned by the bootstrapper to indicate success.
    ///      This is `keccack('BOOTSTRAP_SUCCESS')`.
    bytes4 internal constant BOOTSTRAP_SUCCESS = 0xd150751b;
    using LibRichErrorsV06 for bytes;
    /// @dev Perform a delegatecall and ensure it returns the magic bytes.
    /// @param target The call target.
    /// @param data The call data.
    function delegatecallBootstrapFunction(
        address target,
        bytes memory data
    )
        internal
    {
        (bool success, bytes memory resultData) = target.delegatecall(data);
        if (!success ||
            resultData.length != 32 ||
            abi.decode(resultData, (bytes4)) != BOOTSTRAP_SUCCESS)
        {
            LibProxyRichErrors.BootstrapCallFailedError(target, resultData).rrevert();
        }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibProxyRichErrors {
    // solhint-disable func-name-mixedcase
    function NotImplementedError(bytes4 selector)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("NotImplementedError(bytes4)")),
            selector
        );
    }
    function InvalidBootstrapCallerError(address actual, address expected)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("InvalidBootstrapCallerError(address,address)")),
            actual,
            expected
        );
    }
    function InvalidDieCallerError(address actual, address expected)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("InvalidDieCallerError(address,address)")),
            actual,
            expected
        );
    }
    function BootstrapCallFailedError(address target, bytes memory resultData)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("BootstrapCallFailedError(address,bytes)")),
            target,
            resultData
        );
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "../migrations/LibBootstrap.sol";
import "../storage/LibProxyStorage.sol";
import "./IBootstrap.sol";
/// @dev Detachable `bootstrap()` feature.
contract Bootstrap is
    IBootstrap
{
    // solhint-disable state-visibility,indent
    /// @dev The ZeroEx contract.
    ///      This has to be immutable to persist across delegatecalls.
    address immutable private _deployer;
    /// @dev The implementation address of this contract.
    ///      This has to be immutable to persist across delegatecalls.
    address immutable private _implementation;
    /// @dev The deployer.
    ///      This has to be immutable to persist across delegatecalls.
    address immutable private _bootstrapCaller;
    // solhint-enable state-visibility,indent
    using LibRichErrorsV06 for bytes;
    /// @dev Construct this contract and set the bootstrap migration contract.
    ///      After constructing this contract, `bootstrap()` should be called
    ///      to seed the initial feature set.
    /// @param bootstrapCaller The allowed caller of `bootstrap()`.
    constructor(address bootstrapCaller) public {
        _deployer = msg.sender;
        _implementation = address(this);
        _bootstrapCaller = bootstrapCaller;
    }
    /// @dev Bootstrap the initial feature set of this contract by delegatecalling
    ///      into `target`. Before exiting the `bootstrap()` function will
    ///      deregister itself from the proxy to prevent being called again.
    /// @param target The bootstrapper contract address.
    /// @param callData The call data to execute on `target`.
    function bootstrap(address target, bytes calldata callData) external override {
        // Only the bootstrap caller can call this function.
        if (msg.sender != _bootstrapCaller) {
            LibProxyRichErrors.InvalidBootstrapCallerError(
                msg.sender,
                _bootstrapCaller
            ).rrevert();
        }
        // Deregister.
        LibProxyStorage.getStorage().impls[this.bootstrap.selector] = address(0);
        // Self-destruct.
        Bootstrap(_implementation).die();
        // Call the bootstrapper.
        LibBootstrap.delegatecallBootstrapFunction(target, callData);
    }
    /// @dev Self-destructs this contract.
    ///      Can only be called by the deployer.
    function die() external {
        if (msg.sender != _deployer) {
            LibProxyRichErrors.InvalidDieCallerError(msg.sender, _deployer).rrevert();
        }
        selfdestruct(msg.sender);
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "./LibStorage.sol";
/// @dev Storage helpers for the proxy contract.
library LibProxyStorage {
    /// @dev Storage bucket for proxy contract.
    struct Storage {
        // Mapping of function selector -> function implementation
        mapping(bytes4 => address) impls;
        // The owner of the proxy contract.
        address owner;
    }
    /// @dev Get the storage bucket for this contract.
    function getStorage() internal pure returns (Storage storage stor) {
        uint256 storageSlot = LibStorage.getStorageSlot(
            LibStorage.StorageId.Proxy
        );
        // Dip into assembly to change the slot pointed to by the local
        // variable `stor`.
        // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
        assembly { stor_slot := storageSlot }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
/// @dev Common storage helpers
library LibStorage {
    /// @dev What to bit-shift a storage ID by to get its slot.
    ///      This gives us a maximum of 2**128 inline fields in each bucket.
    uint256 private constant STORAGE_SLOT_EXP = 128;
    /// @dev Storage IDs for feature storage buckets.
    ///      WARNING: APPEND-ONLY.
    enum StorageId {
        Proxy,
        SimpleFunctionRegistry,
        Ownable,
        TokenSpender,
        TransformERC20
    }
    /// @dev Get the storage slot given a storage ID. We assign unique, well-spaced
    ///     slots to storage bucket variables to ensure they do not overlap.
    ///     See: https://solidity.readthedocs.io/en/v0.6.6/assembly.html#access-to-external-variables-functions-and-libraries
    /// @param storageId An entry in `StorageId`
    /// @return slot The storage slot.
    function getStorageSlot(StorageId storageId)
        internal
        pure
        returns (uint256 slot)
    {
        // This should never overflow with a reasonable `STORAGE_SLOT_EXP`
        // because Solidity will do a range check on `storageId` during the cast.
        return (uint256(storageId) + 1) << STORAGE_SLOT_EXP;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
/// @dev Detachable `bootstrap()` feature.
interface IBootstrap {
    /// @dev Bootstrap the initial feature set of this contract by delegatecalling
    ///      into `target`. Before exiting the `bootstrap()` function will
    ///      deregister itself from the proxy to prevent being called again.
    /// @param target The bootstrapper contract address.
    /// @param callData The call data to execute on `target`.
    function bootstrap(address target, bytes calldata callData) external;
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibCommonRichErrors {
    // solhint-disable func-name-mixedcase
    function OnlyCallableBySelfError(address sender)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("OnlyCallableBySelfError(address)")),
            sender
        );
    }
    function IllegalReentrancyError()
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("IllegalReentrancyError()"))
        );
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibOwnableRichErrors {
    // solhint-disable func-name-mixedcase
    function OnlyOwnerError(
        address sender,
        address owner
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("OnlyOwnerError(address,address)")),
            sender,
            owner
        );
    }
    function TransferOwnerToZeroError()
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("TransferOwnerToZeroError()"))
        );
    }
    function MigrateCallFailedError(address target, bytes memory resultData)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("MigrateCallFailedError(address,bytes)")),
            target,
            resultData
        );
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibSimpleFunctionRegistryRichErrors {
    // solhint-disable func-name-mixedcase
    function NotInRollbackHistoryError(bytes4 selector, address targetImpl)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("NotInRollbackHistoryError(bytes4,address)")),
            selector,
            targetImpl
        );
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibSpenderRichErrors {
    // solhint-disable func-name-mixedcase
    function SpenderERC20TransferFromFailedError(
        address token,
        address owner,
        address to,
        uint256 amount,
        bytes memory errorData
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("SpenderERC20TransferFromFailedError(address,address,address,uint256,bytes)")),
            token,
            owner,
            to,
            amount,
            errorData
        );
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibTransformERC20RichErrors {
    // solhint-disable func-name-mixedcase,separate-by-one-line-in-contract
    function InsufficientEthAttachedError(
        uint256 ethAttached,
        uint256 ethNeeded
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("InsufficientEthAttachedError(uint256,uint256)")),
            ethAttached,
            ethNeeded
        );
    }
    function IncompleteTransformERC20Error(
        address outputToken,
        uint256 outputTokenAmount,
        uint256 minOutputTokenAmount
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("IncompleteTransformERC20Error(address,uint256,uint256)")),
            outputToken,
            outputTokenAmount,
            minOutputTokenAmount
        );
    }
    function NegativeTransformERC20OutputError(
        address outputToken,
        uint256 outputTokenLostAmount
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("NegativeTransformERC20OutputError(address,uint256)")),
            outputToken,
            outputTokenLostAmount
        );
    }
    function TransformerFailedError(
        address transformer,
        bytes memory transformerData,
        bytes memory resultData
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("TransformerFailedError(address,bytes,bytes)")),
            transformer,
            transformerData,
            resultData
        );
    }
    // Common Transformer errors ///////////////////////////////////////////////
    function OnlyCallableByDeployerError(
        address caller,
        address deployer
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("OnlyCallableByDeployerError(address,address)")),
            caller,
            deployer
        );
    }
    function InvalidExecutionContextError(
        address actualContext,
        address expectedContext
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("InvalidExecutionContextError(address,address)")),
            actualContext,
            expectedContext
        );
    }
    enum InvalidTransformDataErrorCode {
        INVALID_TOKENS,
        INVALID_ARRAY_LENGTH
    }
    function InvalidTransformDataError(
        InvalidTransformDataErrorCode errorCode,
        bytes memory transformData
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("InvalidTransformDataError(uint8,bytes)")),
            errorCode,
            transformData
        );
    }
    // FillQuoteTransformer errors /////////////////////////////////////////////
    function IncompleteFillSellQuoteError(
        address sellToken,
        uint256 soldAmount,
        uint256 sellAmount
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("IncompleteFillSellQuoteError(address,uint256,uint256)")),
            sellToken,
            soldAmount,
            sellAmount
        );
    }
    function IncompleteFillBuyQuoteError(
        address buyToken,
        uint256 boughtAmount,
        uint256 buyAmount
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("IncompleteFillBuyQuoteError(address,uint256,uint256)")),
            buyToken,
            boughtAmount,
            buyAmount
        );
    }
    function InsufficientTakerTokenError(
        uint256 tokenBalance,
        uint256 tokensNeeded
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("InsufficientTakerTokenError(uint256,uint256)")),
            tokenBalance,
            tokensNeeded
        );
    }
    function InsufficientProtocolFeeError(
        uint256 ethBalance,
        uint256 ethNeeded
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("InsufficientProtocolFeeError(uint256,uint256)")),
            ethBalance,
            ethNeeded
        );
    }
    function InvalidERC20AssetDataError(
        bytes memory assetData
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("InvalidERC20AssetDataError(bytes)")),
            assetData
        );
    }
    function InvalidTakerFeeTokenError(
        address token
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("InvalidTakerFeeTokenError(address)")),
            token
        );
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibWalletRichErrors {
    // solhint-disable func-name-mixedcase
    function WalletExecuteCallFailedError(
        address wallet,
        address callTarget,
        bytes memory callData,
        uint256 callValue,
        bytes memory errorData
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("WalletExecuteCallFailedError(address,address,bytes,uint256,bytes)")),
            wallet,
            callTarget,
            callData,
            callValue,
            errorData
        );
    }
    function WalletExecuteDelegateCallFailedError(
        address wallet,
        address callTarget,
        bytes memory callData,
        bytes memory errorData
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("WalletExecuteDelegateCallFailedError(address,address,bytes,bytes)")),
            wallet,
            callTarget,
            callData,
            errorData
        );
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "@0x/contracts-utils/contracts/src/v06/AuthorizableV06.sol";
import "../errors/LibSpenderRichErrors.sol";
import "./IAllowanceTarget.sol";
/// @dev The allowance target for the TokenSpender feature.
contract AllowanceTarget is
    IAllowanceTarget,
    AuthorizableV06
{
    // solhint-disable no-unused-vars,indent,no-empty-blocks
    using LibRichErrorsV06 for bytes;
    /// @dev Execute an arbitrary call. Only an authority can call this.
    /// @param target The call target.
    /// @param callData The call data.
    /// @return resultData The data returned by the call.
    function executeCall(
        address payable target,
        bytes calldata callData
    )
        external
        override
        onlyAuthorized
        returns (bytes memory resultData)
    {
        bool success;
        (success, resultData) = target.call(callData);
        if (!success) {
            resultData.rrevert();
        }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
import "./interfaces/IAuthorizableV06.sol";
import "./errors/LibRichErrorsV06.sol";
import "./errors/LibAuthorizableRichErrorsV06.sol";
import "./OwnableV06.sol";
// solhint-disable no-empty-blocks
contract AuthorizableV06 is
    OwnableV06,
    IAuthorizableV06
{
    /// @dev Only authorized addresses can invoke functions with this modifier.
    modifier onlyAuthorized {
        _assertSenderIsAuthorized();
        _;
    }
    // @dev Whether an address is authorized to call privileged functions.
    // @param 0 Address to query.
    // @return 0 Whether the address is authorized.
    mapping (address => bool) public override authorized;
    // @dev Whether an address is authorized to call privileged functions.
    // @param 0 Index of authorized address.
    // @return 0 Authorized address.
    address[] public override authorities;
    /// @dev Initializes the `owner` address.
    constructor()
        public
        OwnableV06()
    {}
    /// @dev Authorizes an address.
    /// @param target Address to authorize.
    function addAuthorizedAddress(address target)
        external
        override
        onlyOwner
    {
        _addAuthorizedAddress(target);
    }
    /// @dev Removes authorizion of an address.
    /// @param target Address to remove authorization from.
    function removeAuthorizedAddress(address target)
        external
        override
        onlyOwner
    {
        if (!authorized[target]) {
            LibRichErrorsV06.rrevert(LibAuthorizableRichErrorsV06.TargetNotAuthorizedError(target));
        }
        for (uint256 i = 0; i < authorities.length; i++) {
            if (authorities[i] == target) {
                _removeAuthorizedAddressAtIndex(target, i);
                break;
            }
        }
    }
    /// @dev Removes authorizion of an address.
    /// @param target Address to remove authorization from.
    /// @param index Index of target in authorities array.
    function removeAuthorizedAddressAtIndex(
        address target,
        uint256 index
    )
        external
        override
        onlyOwner
    {
        _removeAuthorizedAddressAtIndex(target, index);
    }
    /// @dev Gets all authorized addresses.
    /// @return Array of authorized addresses.
    function getAuthorizedAddresses()
        external
        override
        view
        returns (address[] memory)
    {
        return authorities;
    }
    /// @dev Reverts if msg.sender is not authorized.
    function _assertSenderIsAuthorized()
        internal
        view
    {
        if (!authorized[msg.sender]) {
            LibRichErrorsV06.rrevert(LibAuthorizableRichErrorsV06.SenderNotAuthorizedError(msg.sender));
        }
    }
    /// @dev Authorizes an address.
    /// @param target Address to authorize.
    function _addAuthorizedAddress(address target)
        internal
    {
        // Ensure that the target is not the zero address.
        if (target == address(0)) {
            LibRichErrorsV06.rrevert(LibAuthorizableRichErrorsV06.ZeroCantBeAuthorizedError());
        }
        // Ensure that the target is not already authorized.
        if (authorized[target]) {
            LibRichErrorsV06.rrevert(LibAuthorizableRichErrorsV06.TargetAlreadyAuthorizedError(target));
        }
        authorized[target] = true;
        authorities.push(target);
        emit AuthorizedAddressAdded(target, msg.sender);
    }
    /// @dev Removes authorizion of an address.
    /// @param target Address to remove authorization from.
    /// @param index Index of target in authorities array.
    function _removeAuthorizedAddressAtIndex(
        address target,
        uint256 index
    )
        internal
    {
        if (!authorized[target]) {
            LibRichErrorsV06.rrevert(LibAuthorizableRichErrorsV06.TargetNotAuthorizedError(target));
        }
        if (index >= authorities.length) {
            LibRichErrorsV06.rrevert(LibAuthorizableRichErrorsV06.IndexOutOfBoundsError(
                index,
                authorities.length
            ));
        }
        if (authorities[index] != target) {
            LibRichErrorsV06.rrevert(LibAuthorizableRichErrorsV06.AuthorizedAddressMismatchError(
                authorities[index],
                target
            ));
        }
        delete authorized[target];
        authorities[index] = authorities[authorities.length - 1];
        authorities.pop();
        emit AuthorizedAddressRemoved(target, msg.sender);
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
import "./IOwnableV06.sol";
interface IAuthorizableV06 is
    IOwnableV06
{
    // Event logged when a new address is authorized.
    event AuthorizedAddressAdded(
        address indexed target,
        address indexed caller
    );
    // Event logged when a currently authorized address is unauthorized.
    event AuthorizedAddressRemoved(
        address indexed target,
        address indexed caller
    );
    /// @dev Authorizes an address.
    /// @param target Address to authorize.
    function addAuthorizedAddress(address target)
        external;
    /// @dev Removes authorizion of an address.
    /// @param target Address to remove authorization from.
    function removeAuthorizedAddress(address target)
        external;
    /// @dev Removes authorizion of an address.
    /// @param target Address to remove authorization from.
    /// @param index Index of target in authorities array.
    function removeAuthorizedAddressAtIndex(
        address target,
        uint256 index
    )
        external;
    /// @dev Gets all authorized addresses.
    /// @return authorizedAddresses Array of authorized addresses.
    function getAuthorizedAddresses()
        external
        view
        returns (address[] memory authorizedAddresses);
    /// @dev Whether an adderss is authorized to call privileged functions.
    /// @param addr Address to query.
    /// @return isAuthorized Whether the address is authorized.
    function authorized(address addr) external view returns (bool isAuthorized);
    /// @dev All addresseses authorized to call privileged functions.
    /// @param idx Index of authorized address.
    /// @return addr Authorized address.
    function authorities(uint256 idx) external view returns (address addr);
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
interface IOwnableV06 {
    /// @dev Emitted by Ownable when ownership is transferred.
    /// @param previousOwner The previous owner of the contract.
    /// @param newOwner The new owner of the contract.
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    /// @dev Transfers ownership of the contract to a new address.
    /// @param newOwner The address that will become the owner.
    function transferOwnership(address newOwner) external;
    /// @dev The owner of this contract.
    /// @return ownerAddress The owner address.
    function owner() external view returns (address ownerAddress);
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibAuthorizableRichErrorsV06 {
    // bytes4(keccak256("AuthorizedAddressMismatchError(address,address)"))
    bytes4 internal constant AUTHORIZED_ADDRESS_MISMATCH_ERROR_SELECTOR =
        0x140a84db;
    // bytes4(keccak256("IndexOutOfBoundsError(uint256,uint256)"))
    bytes4 internal constant INDEX_OUT_OF_BOUNDS_ERROR_SELECTOR =
        0xe9f83771;
    // bytes4(keccak256("SenderNotAuthorizedError(address)"))
    bytes4 internal constant SENDER_NOT_AUTHORIZED_ERROR_SELECTOR =
        0xb65a25b9;
    // bytes4(keccak256("TargetAlreadyAuthorizedError(address)"))
    bytes4 internal constant TARGET_ALREADY_AUTHORIZED_ERROR_SELECTOR =
        0xde16f1a0;
    // bytes4(keccak256("TargetNotAuthorizedError(address)"))
    bytes4 internal constant TARGET_NOT_AUTHORIZED_ERROR_SELECTOR =
        0xeb5108a2;
    // bytes4(keccak256("ZeroCantBeAuthorizedError()"))
    bytes internal constant ZERO_CANT_BE_AUTHORIZED_ERROR_BYTES =
        hex"57654fe4";
    // solhint-disable func-name-mixedcase
    function AuthorizedAddressMismatchError(
        address authorized,
        address target
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            AUTHORIZED_ADDRESS_MISMATCH_ERROR_SELECTOR,
            authorized,
            target
        );
    }
    function IndexOutOfBoundsError(
        uint256 index,
        uint256 length
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            INDEX_OUT_OF_BOUNDS_ERROR_SELECTOR,
            index,
            length
        );
    }
    function SenderNotAuthorizedError(address sender)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            SENDER_NOT_AUTHORIZED_ERROR_SELECTOR,
            sender
        );
    }
    function TargetAlreadyAuthorizedError(address target)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            TARGET_ALREADY_AUTHORIZED_ERROR_SELECTOR,
            target
        );
    }
    function TargetNotAuthorizedError(address target)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            TARGET_NOT_AUTHORIZED_ERROR_SELECTOR,
            target
        );
    }
    function ZeroCantBeAuthorizedError()
        internal
        pure
        returns (bytes memory)
    {
        return ZERO_CANT_BE_AUTHORIZED_ERROR_BYTES;
    }
}
/*
  Copyright 2019 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
import "./interfaces/IOwnableV06.sol";
import "./errors/LibRichErrorsV06.sol";
import "./errors/LibOwnableRichErrorsV06.sol";
contract OwnableV06 is
    IOwnableV06
{
    /// @dev The owner of this contract.
    /// @return 0 The owner address.
    address public override owner;
    constructor() public {
        owner = msg.sender;
    }
    modifier onlyOwner() {
        _assertSenderIsOwner();
        _;
    }
    /// @dev Change the owner of this contract.
    /// @param newOwner New owner address.
    function transferOwnership(address newOwner)
        public
        override
        onlyOwner
    {
        if (newOwner == address(0)) {
            LibRichErrorsV06.rrevert(LibOwnableRichErrorsV06.TransferOwnerToZeroError());
        } else {
            owner = newOwner;
            emit OwnershipTransferred(msg.sender, newOwner);
        }
    }
    function _assertSenderIsOwner()
        internal
        view
    {
        if (msg.sender != owner) {
            LibRichErrorsV06.rrevert(LibOwnableRichErrorsV06.OnlyOwnerError(
                msg.sender,
                owner
            ));
        }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibOwnableRichErrorsV06 {
    // bytes4(keccak256("OnlyOwnerError(address,address)"))
    bytes4 internal constant ONLY_OWNER_ERROR_SELECTOR =
        0x1de45ad1;
    // bytes4(keccak256("TransferOwnerToZeroError()"))
    bytes internal constant TRANSFER_OWNER_TO_ZERO_ERROR_BYTES =
        hex"e69edc3e";
    // solhint-disable func-name-mixedcase
    function OnlyOwnerError(
        address sender,
        address owner
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            ONLY_OWNER_ERROR_SELECTOR,
            sender,
            owner
        );
    }
    function TransferOwnerToZeroError()
        internal
        pure
        returns (bytes memory)
    {
        return TRANSFER_OWNER_TO_ZERO_ERROR_BYTES;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/interfaces/IAuthorizableV06.sol";
/// @dev The allowance target for the TokenSpender feature.
interface IAllowanceTarget is
    IAuthorizableV06
{
    /// @dev Execute an arbitrary call. Only an authority can call this.
    /// @param target The call target.
    /// @param callData The call data.
    /// @return resultData The data returned by the call.
    function executeCall(
        address payable target,
        bytes calldata callData
    )
        external
        returns (bytes memory resultData);
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "@0x/contracts-utils/contracts/src/v06/errors/LibOwnableRichErrorsV06.sol";
import "../errors/LibWalletRichErrors.sol";
import "./IFlashWallet.sol";
/// @dev A contract that can execute arbitrary calls from its owner.
contract FlashWallet is
    IFlashWallet
{
    // solhint-disable no-unused-vars,indent,no-empty-blocks
    using LibRichErrorsV06 for bytes;
    // solhint-disable
    /// @dev Store the owner/deployer as an immutable to make this contract stateless.
    address public override immutable owner;
    // solhint-enable
    constructor() public {
        // The deployer is the owner.
        owner = msg.sender;
    }
    /// @dev Allows only the (immutable) owner to call a function.
    modifier onlyOwner() virtual {
        if (msg.sender != owner) {
            LibOwnableRichErrorsV06.OnlyOwnerError(
                msg.sender,
                owner
            ).rrevert();
        }
        _;
    }
    /// @dev Execute an arbitrary call. Only an authority can call this.
    /// @param target The call target.
    /// @param callData The call data.
    /// @param value Ether to attach to the call.
    /// @return resultData The data returned by the call.
    function executeCall(
        address payable target,
        bytes calldata callData,
        uint256 value
    )
        external
        payable
        override
        onlyOwner
        returns (bytes memory resultData)
    {
        bool success;
        (success, resultData) = target.call{value: value}(callData);
        if (!success) {
            LibWalletRichErrors
                .WalletExecuteCallFailedError(
                    address(this),
                    target,
                    callData,
                    value,
                    resultData
                )
                .rrevert();
        }
    }
    /// @dev Execute an arbitrary delegatecall, in the context of this puppet.
    ///      Only an authority can call this.
    /// @param target The call target.
    /// @param callData The call data.
    /// @return resultData The data returned by the call.
    function executeDelegateCall(
        address payable target,
        bytes calldata callData
    )
        external
        payable
        override
        onlyOwner
        returns (bytes memory resultData)
    {
        bool success;
        (success, resultData) = target.delegatecall(callData);
        if (!success) {
            LibWalletRichErrors
                .WalletExecuteDelegateCallFailedError(
                    address(this),
                    target,
                    callData,
                    resultData
                )
                .rrevert();
        }
    }
    // solhint-disable
    /// @dev Allows this contract to receive ether.
    receive() external override payable {}
    // solhint-enable
    /// @dev Signal support for receiving ERC1155 tokens.
    /// @param interfaceID The interface ID, as per ERC-165 rules.
    /// @return hasSupport `true` if this contract supports an ERC-165 interface.
    function supportsInterface(bytes4 interfaceID)
        external
        pure
        returns (bool hasSupport)
    {
        return  interfaceID == this.supportsInterface.selector ||
                interfaceID == this.onERC1155Received.selector ^ this.onERC1155BatchReceived.selector ||
                interfaceID == this.tokenFallback.selector;
    }
    ///  @dev Allow this contract to receive ERC1155 tokens.
    ///  @return success  `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))`
    function onERC1155Received(
        address, // operator,
        address, // from,
        uint256, // id,
        uint256, // value,
        bytes calldata //data
    )
        external
        pure
        returns (bytes4 success)
    {
        return this.onERC1155Received.selector;
    }
    ///  @dev Allow this contract to receive ERC1155 tokens.
    ///  @return success  `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))`
    function onERC1155BatchReceived(
        address, // operator,
        address, // from,
        uint256[] calldata, // ids,
        uint256[] calldata, // values,
        bytes calldata // data
    )
        external
        pure
        returns (bytes4 success)
    {
        return this.onERC1155BatchReceived.selector;
    }
    /// @dev Allows this contract to receive ERC223 tokens.
    function tokenFallback(
        address, // from,
        uint256, // value,
        bytes calldata // value
    )
        external
        pure
    {}
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/interfaces/IOwnableV06.sol";
/// @dev A contract that can execute arbitrary calls from its owner.
interface IFlashWallet {
    /// @dev Execute an arbitrary call. Only an authority can call this.
    /// @param target The call target.
    /// @param callData The call data.
    /// @param value Ether to attach to the call.
    /// @return resultData The data returned by the call.
    function executeCall(
        address payable target,
        bytes calldata callData,
        uint256 value
    )
        external
        payable
        returns (bytes memory resultData);
    /// @dev Execute an arbitrary delegatecall, in the context of this puppet.
    ///      Only an authority can call this.
    /// @param target The call target.
    /// @param callData The call data.
    /// @return resultData The data returned by the call.
    function executeDelegateCall(
        address payable target,
        bytes calldata callData
    )
        external
        payable
        returns (bytes memory resultData);
    /// @dev Allows the puppet to receive ETH.
    receive() external payable;
    /// @dev Fetch the immutable owner/deployer of this contract.
    /// @return owner_ The immutable owner/deployer/
    function owner() external view returns (address owner_);
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/AuthorizableV06.sol";
/// @dev A contract with a `die()` function.
interface IKillable {
    function die() external;
}
/// @dev Deployer contract for ERC20 transformers.
///      Only authorities may call `deploy()` and `kill()`.
contract TransformerDeployer is
    AuthorizableV06
{
    /// @dev Emitted when a contract is deployed via `deploy()`.
    /// @param deployedAddress The address of the deployed contract.
    /// @param nonce The deployment nonce.
    /// @param sender The caller of `deploy()`.
    event Deployed(address deployedAddress, uint256 nonce, address sender);
    /// @dev Emitted when a contract is killed via `kill()`.
    /// @param target The address of the contract being killed..
    /// @param sender The caller of `kill()`.
    event Killed(address target, address sender);
    // @dev The current nonce of this contract.
    uint256 public nonce = 1;
    // @dev Mapping of deployed contract address to deployment nonce.
    mapping (address => uint256) public toDeploymentNonce;
    /// @dev Create this contract and register authorities.
    constructor(address[] memory authorities) public {
        for (uint256 i = 0; i < authorities.length; ++i) {
            _addAuthorizedAddress(authorities[i]);
        }
    }
    /// @dev Deploy a new contract. Only callable by an authority.
    ///      Any attached ETH will also be forwarded.
    function deploy(bytes memory bytecode)
        public
        payable
        onlyAuthorized
        returns (address deployedAddress)
    {
        uint256 deploymentNonce = nonce;
        nonce += 1;
        assembly {
            deployedAddress := create(callvalue(), add(bytecode, 32), mload(bytecode))
        }
        toDeploymentNonce[deployedAddress] = deploymentNonce;
        emit Deployed(deployedAddress, deploymentNonce, msg.sender);
    }
    /// @dev Call `die()` on a contract. Only callable by an authority.
    function kill(IKillable target)
        public
        onlyAuthorized
    {
        target.die();
        emit Killed(address(target), msg.sender);
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
/// @dev Basic interface for a feature contract.
interface IFeature {
    // solhint-disable func-name-mixedcase
    /// @dev The name of this feature set.
    function FEATURE_NAME() external view returns (string memory name);
    /// @dev The version of this feature set.
    function FEATURE_VERSION() external view returns (uint256 version);
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/interfaces/IOwnableV06.sol";
// solhint-disable no-empty-blocks
/// @dev Owner management and migration features.
interface IOwnable is
    IOwnableV06
{
    /// @dev Emitted when `migrate()` is called.
    /// @param caller The caller of `migrate()`.
    /// @param migrator The migration contract.
    /// @param newOwner The address of the new owner.
    event Migrated(address caller, address migrator, address newOwner);
    /// @dev Execute a migration function in the context of the ZeroEx contract.
    ///      The result of the function being called should be the magic bytes
    ///      0x2c64c5ef (`keccack('MIGRATE_SUCCESS')`). Only callable by the owner.
    ///      The owner will be temporarily set to `address(this)` inside the call.
    ///      Before returning, the owner will be set to `newOwner`.
    /// @param target The migrator contract address.
    /// @param newOwner The address of the new owner.
    /// @param data The call data.
    function migrate(address target, bytes calldata data, address newOwner) external;
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
/// @dev Basic registry management features.
interface ISimpleFunctionRegistry {
    /// @dev A function implementation was updated via `extend()` or `rollback()`.
    /// @param selector The function selector.
    /// @param oldImpl The implementation contract address being replaced.
    /// @param newImpl The replacement implementation contract address.
    event ProxyFunctionUpdated(bytes4 indexed selector, address oldImpl, address newImpl);
    /// @dev Roll back to a prior implementation of a function.
    /// @param selector The function selector.
    /// @param targetImpl The address of an older implementation of the function.
    function rollback(bytes4 selector, address targetImpl) external;
    /// @dev Register or replace a function.
    /// @param selector The function selector.
    /// @param impl The implementation contract for the function.
    function extend(bytes4 selector, address impl) external;
    /// @dev Retrieve the length of the rollback history for a function.
    /// @param selector The function selector.
    /// @return rollbackLength The number of items in the rollback history for
    ///         the function.
    function getRollbackLength(bytes4 selector)
        external
        view
        returns (uint256 rollbackLength);
    /// @dev Retrieve an entry in the rollback history for a function.
    /// @param selector The function selector.
    /// @param idx The index in the rollback history.
    /// @return impl An implementation address for the function at
    ///         index `idx`.
    function getRollbackEntryAtIndex(bytes4 selector, uint256 idx)
        external
        view
        returns (address impl);
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
/// @dev Feature that allows spending token allowances.
interface ITokenSpender {
    /// @dev Transfers ERC20 tokens from `owner` to `to`.
    ///      Only callable from within.
    /// @param token The token to spend.
    /// @param owner The owner of the tokens.
    /// @param to The recipient of the tokens.
    /// @param amount The amount of `token` to transfer.
    function _spendERC20Tokens(
        IERC20TokenV06 token,
        address owner,
        address to,
        uint256 amount
    )
        external;
    /// @dev Gets the maximum amount of an ERC20 token `token` that can be
    ///      pulled from `owner`.
    /// @param token The token to spend.
    /// @param owner The owner of the tokens.
    /// @return amount The amount of tokens that can be pulled.
    function getSpendableERC20BalanceOf(IERC20TokenV06 token, address owner)
        external
        view
        returns (uint256 amount);
    /// @dev Get the address of the allowance target.
    /// @return target The target of token allowances.
    function getAllowanceTarget() external view returns (address target);
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
interface IERC20TokenV06 {
    // solhint-disable no-simple-event-func-name
    event Transfer(
        address indexed from,
        address indexed to,
        uint256 value
    );
    event Approval(
        address indexed owner,
        address indexed spender,
        uint256 value
    );
    /// @dev send `value` token to `to` from `msg.sender`
    /// @param to The address of the recipient
    /// @param value The amount of token to be transferred
    /// @return True if transfer was successful
    function transfer(address to, uint256 value)
        external
        returns (bool);
    /// @dev send `value` token to `to` from `from` on the condition it is approved by `from`
    /// @param from The address of the sender
    /// @param to The address of the recipient
    /// @param value The amount of token to be transferred
    /// @return True if transfer was successful
    function transferFrom(
        address from,
        address to,
        uint256 value
    )
        external
        returns (bool);
    /// @dev `msg.sender` approves `spender` to spend `value` tokens
    /// @param spender The address of the account able to transfer the tokens
    /// @param value The amount of wei to be approved for transfer
    /// @return Always true if the call has enough gas to complete execution
    function approve(address spender, uint256 value)
        external
        returns (bool);
    /// @dev Query total supply of token
    /// @return Total supply of token
    function totalSupply()
        external
        view
        returns (uint256);
    /// @dev Get the balance of `owner`.
    /// @param owner The address from which the balance will be retrieved
    /// @return Balance of owner
    function balanceOf(address owner)
        external
        view
        returns (uint256);
    /// @dev Get the allowance for `spender` to spend from `owner`.
    /// @param owner The address of the account owning tokens
    /// @param spender The address of the account able to transfer the tokens
    /// @return Amount of remaining tokens allowed to spent
    function allowance(address owner, address spender)
        external
        view
        returns (uint256);
    /// @dev Get the number of decimals this token has.
    function decimals()
        external
        view
        returns (uint8);
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
import "../transformers/IERC20Transformer.sol";
import "../external/IFlashWallet.sol";
/// @dev Feature to composably transform between ERC20 tokens.
interface ITransformERC20 {
    /// @dev Defines a transformation to run in `transformERC20()`.
    struct Transformation {
        // The deployment nonce for the transformer.
        // The address of the transformer contract will be derived from this
        // value.
        uint32 deploymentNonce;
        // Arbitrary data to pass to the transformer.
        bytes data;
    }
    /// @dev Raised upon a successful `transformERC20`.
    /// @param taker The taker (caller) address.
    /// @param inputToken The token being provided by the taker.
    ///        If `0xeee...`, ETH is implied and should be provided with the call.`
    /// @param outputToken The token to be acquired by the taker.
    ///        `0xeee...` implies ETH.
    /// @param inputTokenAmount The amount of `inputToken` to take from the taker.
    /// @param outputTokenAmount The amount of `outputToken` received by the taker.
    event TransformedERC20(
        address indexed taker,
        address inputToken,
        address outputToken,
        uint256 inputTokenAmount,
        uint256 outputTokenAmount
    );
    /// @dev Raised when `setTransformerDeployer()` is called.
    /// @param transformerDeployer The new deployer address.
    event TransformerDeployerUpdated(address transformerDeployer);
    /// @dev Replace the allowed deployer for transformers.
    ///      Only callable by the owner.
    /// @param transformerDeployer The address of the trusted deployer for transformers.
    function setTransformerDeployer(address transformerDeployer)
        external;
    /// @dev Deploy a new flash wallet instance and replace the current one with it.
    ///      Useful if we somehow break the current wallet instance.
    ///      Anyone can call this.
    /// @return wallet The new wallet instance.
    function createTransformWallet()
        external
        returns (IFlashWallet wallet);
    /// @dev Executes a series of transformations to convert an ERC20 `inputToken`
    ///      to an ERC20 `outputToken`.
    /// @param inputToken The token being provided by the sender.
    ///        If `0xeee...`, ETH is implied and should be provided with the call.`
    /// @param outputToken The token to be acquired by the sender.
    ///        `0xeee...` implies ETH.
    /// @param inputTokenAmount The amount of `inputToken` to take from the sender.
    /// @param minOutputTokenAmount The minimum amount of `outputToken` the sender
    ///        must receive for the entire transformation to succeed.
    /// @param transformations The transformations to execute on the token balance(s)
    ///        in sequence.
    /// @return outputTokenAmount The amount of `outputToken` received by the sender.
    function transformERC20(
        IERC20TokenV06 inputToken,
        IERC20TokenV06 outputToken,
        uint256 inputTokenAmount,
        uint256 minOutputTokenAmount,
        Transformation[] calldata transformations
    )
        external
        payable
        returns (uint256 outputTokenAmount);
    /// @dev Internal version of `transformERC20()`. Only callable from within.
    /// @param callDataHash Hash of the ingress calldata.
    /// @param taker The taker address.
    /// @param inputToken The token being provided by the taker.
    ///        If `0xeee...`, ETH is implied and should be provided with the call.`
    /// @param outputToken The token to be acquired by the taker.
    ///        `0xeee...` implies ETH.
    /// @param inputTokenAmount The amount of `inputToken` to take from the taker.
    /// @param minOutputTokenAmount The minimum amount of `outputToken` the taker
    ///        must receive for the entire transformation to succeed.
    /// @param transformations The transformations to execute on the token balance(s)
    ///        in sequence.
    /// @return outputTokenAmount The amount of `outputToken` received by the taker.
    function _transformERC20(
        bytes32 callDataHash,
        address payable taker,
        IERC20TokenV06 inputToken,
        IERC20TokenV06 outputToken,
        uint256 inputTokenAmount,
        uint256 minOutputTokenAmount,
        Transformation[] calldata transformations
    )
        external
        payable
        returns (uint256 outputTokenAmount);
    /// @dev Return the current wallet instance that will serve as the execution
    ///      context for transformations.
    /// @return wallet The wallet instance.
    function getTransformWallet()
        external
        view
        returns (IFlashWallet wallet);
    /// @dev Return the allowed deployer for transformers.
    /// @return deployer The transform deployer address.
    function getTransformerDeployer()
        external
        view
        returns (address deployer);
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
/// @dev A transformation callback used in `TransformERC20.transformERC20()`.
interface IERC20Transformer {
    /// @dev Called from `TransformERC20.transformERC20()`. This will be
    ///      delegatecalled in the context of the FlashWallet instance being used.
    /// @param callDataHash The hash of the `TransformERC20.transformERC20()` calldata.
    /// @param taker The taker address (caller of `TransformERC20.transformERC20()`).
    /// @param data Arbitrary data to pass to the transformer.
    /// @return success The success bytes (`LibERC20Transformer.TRANSFORMER_SUCCESS`).
    function transform(
        bytes32 callDataHash,
        address payable taker,
        bytes calldata data
    )
        external
        returns (bytes4 success);
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "../fixins/FixinCommon.sol";
import "../errors/LibOwnableRichErrors.sol";
import "../storage/LibOwnableStorage.sol";
import "../migrations/LibBootstrap.sol";
import "../migrations/LibMigrate.sol";
import "./IFeature.sol";
import "./IOwnable.sol";
import "./SimpleFunctionRegistry.sol";
/// @dev Owner management features.
contract Ownable is
    IFeature,
    IOwnable,
    FixinCommon
{
    // solhint-disable
    /// @dev Name of this feature.
    string public constant override FEATURE_NAME = "Ownable";
    /// @dev Version of this feature.
    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 0, 0);
    /// @dev The deployed address of this contract.
    address immutable private _implementation;
    // solhint-enable
    using LibRichErrorsV06 for bytes;
    constructor() public {
        _implementation = address(this);
    }
    /// @dev Initializes this feature. The intial owner will be set to this (ZeroEx)
    ///      to allow the bootstrappers to call `extend()`. Ownership should be
    ///      transferred to the real owner by the bootstrapper after
    ///      bootstrapping is complete.
    /// @return success Magic bytes if successful.
    function bootstrap() external returns (bytes4 success) {
        // Set the owner to ourselves to allow bootstrappers to call `extend()`.
        LibOwnableStorage.getStorage().owner = address(this);
        // Register feature functions.
        SimpleFunctionRegistry(address(this))._extendSelf(this.transferOwnership.selector, _implementation);
        SimpleFunctionRegistry(address(this))._extendSelf(this.owner.selector, _implementation);
        SimpleFunctionRegistry(address(this))._extendSelf(this.migrate.selector, _implementation);
        return LibBootstrap.BOOTSTRAP_SUCCESS;
    }
    /// @dev Change the owner of this contract.
    ///      Only directly callable by the owner.
    /// @param newOwner New owner address.
    function transferOwnership(address newOwner)
        external
        override
        onlyOwner
    {
        LibOwnableStorage.Storage storage proxyStor = LibOwnableStorage.getStorage();
        if (newOwner == address(0)) {
            LibOwnableRichErrors.TransferOwnerToZeroError().rrevert();
        } else {
            proxyStor.owner = newOwner;
            emit OwnershipTransferred(msg.sender, newOwner);
        }
    }
    /// @dev Execute a migration function in the context of the ZeroEx contract.
    ///      The result of the function being called should be the magic bytes
    ///      0x2c64c5ef (`keccack('MIGRATE_SUCCESS')`). Only callable by the owner.
    ///      Temporarily sets the owner to ourselves so we can perform admin functions.
    ///      Before returning, the owner will be set to `newOwner`.
    /// @param target The migrator contract address.
    /// @param data The call data.
    /// @param newOwner The address of the new owner.
    function migrate(address target, bytes calldata data, address newOwner)
        external
        override
        onlyOwner
    {
        if (newOwner == address(0)) {
            LibOwnableRichErrors.TransferOwnerToZeroError().rrevert();
        }
        LibOwnableStorage.Storage storage stor = LibOwnableStorage.getStorage();
        // The owner will be temporarily set to `address(this)` inside the call.
        stor.owner = address(this);
        // Perform the migration.
        LibMigrate.delegatecallMigrateFunction(target, data);
        // Update the owner.
        stor.owner = newOwner;
        emit Migrated(msg.sender, target, newOwner);
    }
    /// @dev Get the owner of this contract.
    /// @return owner_ The owner of this contract.
    function owner() external override view returns (address owner_) {
        return LibOwnableStorage.getStorage().owner;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "../errors/LibCommonRichErrors.sol";
import "../errors/LibOwnableRichErrors.sol";
import "../features/IOwnable.sol";
/// @dev Common feature utilities.
contract FixinCommon {
    using LibRichErrorsV06 for bytes;
    /// @dev The caller must be this contract.
    modifier onlySelf() virtual {
        if (msg.sender != address(this)) {
            LibCommonRichErrors.OnlyCallableBySelfError(msg.sender).rrevert();
        }
        _;
    }
    /// @dev The caller of this function must be the owner.
    modifier onlyOwner() virtual {
        {
            address owner = IOwnable(address(this)).owner();
            if (msg.sender != owner) {
                LibOwnableRichErrors.OnlyOwnerError(
                    msg.sender,
                    owner
                ).rrevert();
            }
        }
        _;
    }
    /// @dev Encode a feature version as a `uint256`.
    /// @param major The major version number of the feature.
    /// @param minor The minor version number of the feature.
    /// @param revision The revision number of the feature.
    /// @return encodedVersion The encoded version number.
    function _encodeVersion(uint32 major, uint32 minor, uint32 revision)
        internal
        pure
        returns (uint256 encodedVersion)
    {
        return (major << 64) | (minor << 32) | revision;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "./LibStorage.sol";
/// @dev Storage helpers for the `Ownable` feature.
library LibOwnableStorage {
    /// @dev Storage bucket for this feature.
    struct Storage {
        // The owner of this contract.
        address owner;
    }
    /// @dev Get the storage bucket for this contract.
    function getStorage() internal pure returns (Storage storage stor) {
        uint256 storageSlot = LibStorage.getStorageSlot(
            LibStorage.StorageId.Ownable
        );
        // Dip into assembly to change the slot pointed to by the local
        // variable `stor`.
        // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
        assembly { stor_slot := storageSlot }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "../errors/LibOwnableRichErrors.sol";
library LibMigrate {
    /// @dev Magic bytes returned by a migrator to indicate success.
    ///      This is `keccack('MIGRATE_SUCCESS')`.
    bytes4 internal constant MIGRATE_SUCCESS = 0x2c64c5ef;
    using LibRichErrorsV06 for bytes;
    /// @dev Perform a delegatecall and ensure it returns the magic bytes.
    /// @param target The call target.
    /// @param data The call data.
    function delegatecallMigrateFunction(
        address target,
        bytes memory data
    )
        internal
    {
        (bool success, bytes memory resultData) = target.delegatecall(data);
        if (!success ||
            resultData.length != 32 ||
            abi.decode(resultData, (bytes4)) != MIGRATE_SUCCESS)
        {
            LibOwnableRichErrors.MigrateCallFailedError(target, resultData).rrevert();
        }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "../fixins/FixinCommon.sol";
import "../storage/LibProxyStorage.sol";
import "../storage/LibSimpleFunctionRegistryStorage.sol";
import "../errors/LibSimpleFunctionRegistryRichErrors.sol";
import "../migrations/LibBootstrap.sol";
import "./IFeature.sol";
import "./ISimpleFunctionRegistry.sol";
/// @dev Basic registry management features.
contract SimpleFunctionRegistry is
    IFeature,
    ISimpleFunctionRegistry,
    FixinCommon
{
    // solhint-disable
    /// @dev Name of this feature.
    string public constant override FEATURE_NAME = "SimpleFunctionRegistry";
    /// @dev Version of this feature.
    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 0, 0);
    /// @dev The deployed address of this contract.
    address private immutable _implementation;
    // solhint-enable
    using LibRichErrorsV06 for bytes;
    constructor() public {
        _implementation = address(this);
    }
    /// @dev Initializes this feature, registering its own functions.
    /// @return success Magic bytes if successful.
    function bootstrap()
        external
        returns (bytes4 success)
    {
        // Register the registration functions (inception vibes).
        _extend(this.extend.selector, _implementation);
        _extend(this._extendSelf.selector, _implementation);
        // Register the rollback function.
        _extend(this.rollback.selector, _implementation);
        // Register getters.
        _extend(this.getRollbackLength.selector, _implementation);
        _extend(this.getRollbackEntryAtIndex.selector, _implementation);
        return LibBootstrap.BOOTSTRAP_SUCCESS;
    }
    /// @dev Roll back to a prior implementation of a function.
    ///      Only directly callable by an authority.
    /// @param selector The function selector.
    /// @param targetImpl The address of an older implementation of the function.
    function rollback(bytes4 selector, address targetImpl)
        external
        override
        onlyOwner
    {
        (
            LibSimpleFunctionRegistryStorage.Storage storage stor,
            LibProxyStorage.Storage storage proxyStor
        ) = _getStorages();
        address currentImpl = proxyStor.impls[selector];
        if (currentImpl == targetImpl) {
            // Do nothing if already at targetImpl.
            return;
        }
        // Walk history backwards until we find the target implementation.
        address[] storage history = stor.implHistory[selector];
        uint256 i = history.length;
        for (; i > 0; --i) {
            address impl = history[i - 1];
            history.pop();
            if (impl == targetImpl) {
                break;
            }
        }
        if (i == 0) {
            LibSimpleFunctionRegistryRichErrors.NotInRollbackHistoryError(
                selector,
                targetImpl
            ).rrevert();
        }
        proxyStor.impls[selector] = targetImpl;
        emit ProxyFunctionUpdated(selector, currentImpl, targetImpl);
    }
    /// @dev Register or replace a function.
    ///      Only directly callable by an authority.
    /// @param selector The function selector.
    /// @param impl The implementation contract for the function.
    function extend(bytes4 selector, address impl)
        external
        override
        onlyOwner
    {
        _extend(selector, impl);
    }
    /// @dev Register or replace a function.
    ///      Only callable from within.
    ///      This function is only used during the bootstrap process and
    ///      should be deregistered by the deployer after bootstrapping is
    ///      complete.
    /// @param selector The function selector.
    /// @param impl The implementation contract for the function.
    function _extendSelf(bytes4 selector, address impl)
        external
        onlySelf
    {
        _extend(selector, impl);
    }
    /// @dev Retrieve the length of the rollback history for a function.
    /// @param selector The function selector.
    /// @return rollbackLength The number of items in the rollback history for
    ///         the function.
    function getRollbackLength(bytes4 selector)
        external
        override
        view
        returns (uint256 rollbackLength)
    {
        return LibSimpleFunctionRegistryStorage.getStorage().implHistory[selector].length;
    }
    /// @dev Retrieve an entry in the rollback history for a function.
    /// @param selector The function selector.
    /// @param idx The index in the rollback history.
    /// @return impl An implementation address for the function at
    ///         index `idx`.
    function getRollbackEntryAtIndex(bytes4 selector, uint256 idx)
        external
        override
        view
        returns (address impl)
    {
        return LibSimpleFunctionRegistryStorage.getStorage().implHistory[selector][idx];
    }
    /// @dev Register or replace a function.
    /// @param selector The function selector.
    /// @param impl The implementation contract for the function.
    function _extend(bytes4 selector, address impl)
        private
    {
        (
            LibSimpleFunctionRegistryStorage.Storage storage stor,
            LibProxyStorage.Storage storage proxyStor
        ) = _getStorages();
        address oldImpl = proxyStor.impls[selector];
        address[] storage history = stor.implHistory[selector];
        history.push(oldImpl);
        proxyStor.impls[selector] = impl;
        emit ProxyFunctionUpdated(selector, oldImpl, impl);
    }
    /// @dev Get the storage buckets for this feature and the proxy.
    /// @return stor Storage bucket for this feature.
    /// @return proxyStor age bucket for the proxy.
    function _getStorages()
        private
        pure
        returns (
            LibSimpleFunctionRegistryStorage.Storage storage stor,
            LibProxyStorage.Storage storage proxyStor
        )
    {
        return (
            LibSimpleFunctionRegistryStorage.getStorage(),
            LibProxyStorage.getStorage()
        );
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "./LibStorage.sol";
/// @dev Storage helpers for the `SimpleFunctionRegistry` feature.
library LibSimpleFunctionRegistryStorage {
    /// @dev Storage bucket for this feature.
    struct Storage {
        // Mapping of function selector -> implementation history.
        mapping(bytes4 => address[]) implHistory;
    }
    /// @dev Get the storage bucket for this contract.
    function getStorage() internal pure returns (Storage storage stor) {
        uint256 storageSlot = LibStorage.getStorageSlot(
            LibStorage.StorageId.SimpleFunctionRegistry
        );
        // Dip into assembly to change the slot pointed to by the local
        // variable `stor`.
        // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
        assembly { stor_slot := storageSlot }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
import "@0x/contracts-erc20/contracts/src/v06/LibERC20TokenV06.sol";
import "../errors/LibSpenderRichErrors.sol";
import "../fixins/FixinCommon.sol";
import "../migrations/LibMigrate.sol";
import "../external/IAllowanceTarget.sol";
import "../storage/LibTokenSpenderStorage.sol";
import "./ITokenSpender.sol";
import "./IFeature.sol";
import "./ISimpleFunctionRegistry.sol";
/// @dev Feature that allows spending token allowances.
contract TokenSpender is
    IFeature,
    ITokenSpender,
    FixinCommon
{
    // solhint-disable
    /// @dev Name of this feature.
    string public constant override FEATURE_NAME = "TokenSpender";
    /// @dev Version of this feature.
    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 0, 0);
    /// @dev The implementation address of this feature.
    address private immutable _implementation;
    // solhint-enable
    using LibRichErrorsV06 for bytes;
    constructor() public {
        _implementation = address(this);
    }
    /// @dev Initialize and register this feature. Should be delegatecalled
    ///      into during a `Migrate.migrate()`.
    /// @param allowanceTarget An `allowanceTarget` instance, configured to have
    ///        the ZeroeEx contract as an authority.
    /// @return success `MIGRATE_SUCCESS` on success.
    function migrate(IAllowanceTarget allowanceTarget) external returns (bytes4 success) {
        LibTokenSpenderStorage.getStorage().allowanceTarget = allowanceTarget;
        ISimpleFunctionRegistry(address(this))
            .extend(this.getAllowanceTarget.selector, _implementation);
        ISimpleFunctionRegistry(address(this))
            .extend(this._spendERC20Tokens.selector, _implementation);
        ISimpleFunctionRegistry(address(this))
            .extend(this.getSpendableERC20BalanceOf.selector, _implementation);
        return LibMigrate.MIGRATE_SUCCESS;
    }
    /// @dev Transfers ERC20 tokens from `owner` to `to`. Only callable from within.
    /// @param token The token to spend.
    /// @param owner The owner of the tokens.
    /// @param to The recipient of the tokens.
    /// @param amount The amount of `token` to transfer.
    function _spendERC20Tokens(
        IERC20TokenV06 token,
        address owner,
        address to,
        uint256 amount
    )
        external
        override
        onlySelf
    {
        IAllowanceTarget spender = LibTokenSpenderStorage.getStorage().allowanceTarget;
        // Have the allowance target execute an ERC20 `transferFrom()`.
        (bool didSucceed, bytes memory resultData) = address(spender).call(
            abi.encodeWithSelector(
                IAllowanceTarget.executeCall.selector,
                address(token),
                abi.encodeWithSelector(
                    IERC20TokenV06.transferFrom.selector,
                    owner,
                    to,
                    amount
                )
            )
        );
        if (didSucceed) {
            resultData = abi.decode(resultData, (bytes));
        }
        if (!didSucceed || !LibERC20TokenV06.isSuccessfulResult(resultData)) {
            LibSpenderRichErrors.SpenderERC20TransferFromFailedError(
                address(token),
                owner,
                to,
                amount,
                resultData
            ).rrevert();
        }
    }
    /// @dev Gets the maximum amount of an ERC20 token `token` that can be
    ///      pulled from `owner` by the token spender.
    /// @param token The token to spend.
    /// @param owner The owner of the tokens.
    /// @return amount The amount of tokens that can be pulled.
    function getSpendableERC20BalanceOf(IERC20TokenV06 token, address owner)
        external
        override
        view
        returns (uint256 amount)
    {
        return LibSafeMathV06.min256(
            token.allowance(owner, address(LibTokenSpenderStorage.getStorage().allowanceTarget)),
            token.balanceOf(owner)
        );
    }
    /// @dev Get the address of the allowance target.
    /// @return target The target of token allowances.
    function getAllowanceTarget()
        external
        override
        view
        returns (address target)
    {
        return address(LibTokenSpenderStorage.getStorage().allowanceTarget);
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
import "./errors/LibRichErrorsV06.sol";
import "./errors/LibSafeMathRichErrorsV06.sol";
library LibSafeMathV06 {
    function safeMul(uint256 a, uint256 b)
        internal
        pure
        returns (uint256)
    {
        if (a == 0) {
            return 0;
        }
        uint256 c = a * b;
        if (c / a != b) {
            LibRichErrorsV06.rrevert(LibSafeMathRichErrorsV06.Uint256BinOpError(
                LibSafeMathRichErrorsV06.BinOpErrorCodes.MULTIPLICATION_OVERFLOW,
                a,
                b
            ));
        }
        return c;
    }
    function safeDiv(uint256 a, uint256 b)
        internal
        pure
        returns (uint256)
    {
        if (b == 0) {
            LibRichErrorsV06.rrevert(LibSafeMathRichErrorsV06.Uint256BinOpError(
                LibSafeMathRichErrorsV06.BinOpErrorCodes.DIVISION_BY_ZERO,
                a,
                b
            ));
        }
        uint256 c = a / b;
        return c;
    }
    function safeSub(uint256 a, uint256 b)
        internal
        pure
        returns (uint256)
    {
        if (b > a) {
            LibRichErrorsV06.rrevert(LibSafeMathRichErrorsV06.Uint256BinOpError(
                LibSafeMathRichErrorsV06.BinOpErrorCodes.SUBTRACTION_UNDERFLOW,
                a,
                b
            ));
        }
        return a - b;
    }
    function safeAdd(uint256 a, uint256 b)
        internal
        pure
        returns (uint256)
    {
        uint256 c = a + b;
        if (c < a) {
            LibRichErrorsV06.rrevert(LibSafeMathRichErrorsV06.Uint256BinOpError(
                LibSafeMathRichErrorsV06.BinOpErrorCodes.ADDITION_OVERFLOW,
                a,
                b
            ));
        }
        return c;
    }
    function max256(uint256 a, uint256 b)
        internal
        pure
        returns (uint256)
    {
        return a >= b ? a : b;
    }
    function min256(uint256 a, uint256 b)
        internal
        pure
        returns (uint256)
    {
        return a < b ? a : b;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibSafeMathRichErrorsV06 {
    // bytes4(keccak256("Uint256BinOpError(uint8,uint256,uint256)"))
    bytes4 internal constant UINT256_BINOP_ERROR_SELECTOR =
        0xe946c1bb;
    // bytes4(keccak256("Uint256DowncastError(uint8,uint256)"))
    bytes4 internal constant UINT256_DOWNCAST_ERROR_SELECTOR =
        0xc996af7b;
    enum BinOpErrorCodes {
        ADDITION_OVERFLOW,
        MULTIPLICATION_OVERFLOW,
        SUBTRACTION_UNDERFLOW,
        DIVISION_BY_ZERO
    }
    enum DowncastErrorCodes {
        VALUE_TOO_LARGE_TO_DOWNCAST_TO_UINT32,
        VALUE_TOO_LARGE_TO_DOWNCAST_TO_UINT64,
        VALUE_TOO_LARGE_TO_DOWNCAST_TO_UINT96
    }
    // solhint-disable func-name-mixedcase
    function Uint256BinOpError(
        BinOpErrorCodes errorCode,
        uint256 a,
        uint256 b
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            UINT256_BINOP_ERROR_SELECTOR,
            errorCode,
            a,
            b
        );
    }
    function Uint256DowncastError(
        DowncastErrorCodes errorCode,
        uint256 a
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            UINT256_DOWNCAST_ERROR_SELECTOR,
            errorCode,
            a
        );
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "@0x/contracts-utils/contracts/src/v06/LibBytesV06.sol";
import "./IERC20TokenV06.sol";
library LibERC20TokenV06 {
    bytes constant private DECIMALS_CALL_DATA = hex"313ce567";
    /// @dev Calls `IERC20TokenV06(token).approve()`.
    ///      Reverts if the result fails `isSuccessfulResult()` or the call reverts.
    /// @param token The address of the token contract.
    /// @param spender The address that receives an allowance.
    /// @param allowance The allowance to set.
    function compatApprove(
        IERC20TokenV06 token,
        address spender,
        uint256 allowance
    )
        internal
    {
        bytes memory callData = abi.encodeWithSelector(
            token.approve.selector,
            spender,
            allowance
        );
        _callWithOptionalBooleanResult(address(token), callData);
    }
    /// @dev Calls `IERC20TokenV06(token).approve()` and sets the allowance to the
    ///      maximum if the current approval is not already >= an amount.
    ///      Reverts if the result fails `isSuccessfulResult()` or the call reverts.
    /// @param token The address of the token contract.
    /// @param spender The address that receives an allowance.
    /// @param amount The minimum allowance needed.
    function approveIfBelow(
        IERC20TokenV06 token,
        address spender,
        uint256 amount
    )
        internal
    {
        if (token.allowance(address(this), spender) < amount) {
            compatApprove(token, spender, uint256(-1));
        }
    }
    /// @dev Calls `IERC20TokenV06(token).transfer()`.
    ///      Reverts if the result fails `isSuccessfulResult()` or the call reverts.
    /// @param token The address of the token contract.
    /// @param to The address that receives the tokens
    /// @param amount Number of tokens to transfer.
    function compatTransfer(
        IERC20TokenV06 token,
        address to,
        uint256 amount
    )
        internal
    {
        bytes memory callData = abi.encodeWithSelector(
            token.transfer.selector,
            to,
            amount
        );
        _callWithOptionalBooleanResult(address(token), callData);
    }
    /// @dev Calls `IERC20TokenV06(token).transferFrom()`.
    ///      Reverts if the result fails `isSuccessfulResult()` or the call reverts.
    /// @param token The address of the token contract.
    /// @param from The owner of the tokens.
    /// @param to The address that receives the tokens
    /// @param amount Number of tokens to transfer.
    function compatTransferFrom(
        IERC20TokenV06 token,
        address from,
        address to,
        uint256 amount
    )
        internal
    {
        bytes memory callData = abi.encodeWithSelector(
            token.transferFrom.selector,
            from,
            to,
            amount
        );
        _callWithOptionalBooleanResult(address(token), callData);
    }
    /// @dev Retrieves the number of decimals for a token.
    ///      Returns `18` if the call reverts.
    /// @param token The address of the token contract.
    /// @return tokenDecimals The number of decimals places for the token.
    function compatDecimals(IERC20TokenV06 token)
        internal
        view
        returns (uint8 tokenDecimals)
    {
        tokenDecimals = 18;
        (bool didSucceed, bytes memory resultData) = address(token).staticcall(DECIMALS_CALL_DATA);
        if (didSucceed && resultData.length == 32) {
            tokenDecimals = uint8(LibBytesV06.readUint256(resultData, 0));
        }
    }
    /// @dev Retrieves the allowance for a token, owner, and spender.
    ///      Returns `0` if the call reverts.
    /// @param token The address of the token contract.
    /// @param owner The owner of the tokens.
    /// @param spender The address the spender.
    /// @return allowance_ The allowance for a token, owner, and spender.
    function compatAllowance(IERC20TokenV06 token, address owner, address spender)
        internal
        view
        returns (uint256 allowance_)
    {
        (bool didSucceed, bytes memory resultData) = address(token).staticcall(
            abi.encodeWithSelector(
                token.allowance.selector,
                owner,
                spender
            )
        );
        if (didSucceed && resultData.length == 32) {
            allowance_ = LibBytesV06.readUint256(resultData, 0);
        }
    }
    /// @dev Retrieves the balance for a token owner.
    ///      Returns `0` if the call reverts.
    /// @param token The address of the token contract.
    /// @param owner The owner of the tokens.
    /// @return balance The token balance of an owner.
    function compatBalanceOf(IERC20TokenV06 token, address owner)
        internal
        view
        returns (uint256 balance)
    {
        (bool didSucceed, bytes memory resultData) = address(token).staticcall(
            abi.encodeWithSelector(
                token.balanceOf.selector,
                owner
            )
        );
        if (didSucceed && resultData.length == 32) {
            balance = LibBytesV06.readUint256(resultData, 0);
        }
    }
    /// @dev Check if the data returned by a non-static call to an ERC20 token
    ///      is a successful result. Supported functions are `transfer()`,
    ///      `transferFrom()`, and `approve()`.
    /// @param resultData The raw data returned by a non-static call to the ERC20 token.
    /// @return isSuccessful Whether the result data indicates success.
    function isSuccessfulResult(bytes memory resultData)
        internal
        pure
        returns (bool isSuccessful)
    {
        if (resultData.length == 0) {
            return true;
        }
        if (resultData.length == 32) {
            uint256 result = LibBytesV06.readUint256(resultData, 0);
            if (result == 1) {
                return true;
            }
        }
    }
    /// @dev Executes a call on address `target` with calldata `callData`
    ///      and asserts that either nothing was returned or a single boolean
    ///      was returned equal to `true`.
    /// @param target The call target.
    /// @param callData The abi-encoded call data.
    function _callWithOptionalBooleanResult(
        address target,
        bytes memory callData
    )
        private
    {
        (bool didSucceed, bytes memory resultData) = target.call(callData);
        if (didSucceed && isSuccessfulResult(resultData)) {
            return;
        }
        LibRichErrorsV06.rrevert(resultData);
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "./LibStorage.sol";
import "../external/IAllowanceTarget.sol";
/// @dev Storage helpers for the `TokenSpender` feature.
library LibTokenSpenderStorage {
    /// @dev Storage bucket for this feature.
    struct Storage {
        // Allowance target contract.
        IAllowanceTarget allowanceTarget;
    }
    /// @dev Get the storage bucket for this contract.
    function getStorage() internal pure returns (Storage storage stor) {
        uint256 storageSlot = LibStorage.getStorageSlot(
            LibStorage.StorageId.TokenSpender
        );
        // Dip into assembly to change the slot pointed to by the local
        // variable `stor`.
        // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
        assembly { stor_slot := storageSlot }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
import "@0x/contracts-erc20/contracts/src/v06/LibERC20TokenV06.sol";
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
import "../errors/LibTransformERC20RichErrors.sol";
import "../fixins/FixinCommon.sol";
import "../migrations/LibMigrate.sol";
import "../external/IFlashWallet.sol";
import "../external/FlashWallet.sol";
import "../storage/LibTransformERC20Storage.sol";
import "../transformers/IERC20Transformer.sol";
import "../transformers/LibERC20Transformer.sol";
import "./ITransformERC20.sol";
import "./ITokenSpender.sol";
import "./IFeature.sol";
import "./ISimpleFunctionRegistry.sol";
/// @dev Feature to composably transform between ERC20 tokens.
contract TransformERC20 is
    IFeature,
    ITransformERC20,
    FixinCommon
{
    /// @dev Stack vars for `_transformERC20Private()`.
    struct TransformERC20PrivateState {
        IFlashWallet wallet;
        address transformerDeployer;
        uint256 takerOutputTokenBalanceBefore;
        uint256 takerOutputTokenBalanceAfter;
    }
    // solhint-disable
    /// @dev Name of this feature.
    string public constant override FEATURE_NAME = "TransformERC20";
    /// @dev Version of this feature.
    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 0, 0);
    /// @dev The implementation address of this feature.
    address private immutable _implementation;
    // solhint-enable
    using LibSafeMathV06 for uint256;
    using LibRichErrorsV06 for bytes;
    constructor() public {
        _implementation = address(this);
    }
    /// @dev Initialize and register this feature.
    ///      Should be delegatecalled by `Migrate.migrate()`.
    /// @param transformerDeployer The trusted deployer for transformers.
    /// @return success `LibMigrate.SUCCESS` on success.
    function migrate(address transformerDeployer) external returns (bytes4 success) {
        ISimpleFunctionRegistry(address(this))
            .extend(this.getTransformerDeployer.selector, _implementation);
        ISimpleFunctionRegistry(address(this))
            .extend(this.createTransformWallet.selector, _implementation);
        ISimpleFunctionRegistry(address(this))
            .extend(this.getTransformWallet.selector, _implementation);
        ISimpleFunctionRegistry(address(this))
            .extend(this.setTransformerDeployer.selector, _implementation);
        ISimpleFunctionRegistry(address(this))
            .extend(this.transformERC20.selector, _implementation);
        ISimpleFunctionRegistry(address(this))
            .extend(this._transformERC20.selector, _implementation);
        createTransformWallet();
        LibTransformERC20Storage.getStorage().transformerDeployer = transformerDeployer;
        return LibMigrate.MIGRATE_SUCCESS;
    }
    /// @dev Replace the allowed deployer for transformers.
    ///      Only callable by the owner.
    /// @param transformerDeployer The address of the trusted deployer for transformers.
    function setTransformerDeployer(address transformerDeployer)
        external
        override
        onlyOwner
    {
        LibTransformERC20Storage.getStorage().transformerDeployer = transformerDeployer;
        emit TransformerDeployerUpdated(transformerDeployer);
    }
    /// @dev Return the allowed deployer for transformers.
    /// @return deployer The transform deployer address.
    function getTransformerDeployer()
        public
        override
        view
        returns (address deployer)
    {
        return LibTransformERC20Storage.getStorage().transformerDeployer;
    }
    /// @dev Deploy a new wallet instance and replace the current one with it.
    ///      Useful if we somehow break the current wallet instance.
    ///      Anyone can call this.
    /// @return wallet The new wallet instance.
    function createTransformWallet()
        public
        override
        returns (IFlashWallet wallet)
    {
        wallet = new FlashWallet();
        LibTransformERC20Storage.getStorage().wallet = wallet;
    }
    /// @dev Executes a series of transformations to convert an ERC20 `inputToken`
    ///      to an ERC20 `outputToken`.
    /// @param inputToken The token being provided by the sender.
    ///        If `0xeee...`, ETH is implied and should be provided with the call.`
    /// @param outputToken The token to be acquired by the sender.
    ///        `0xeee...` implies ETH.
    /// @param inputTokenAmount The amount of `inputToken` to take from the sender.
    ///        If set to `uint256(-1)`, the entire spendable balance of the taker
    ///        will be solt.
    /// @param minOutputTokenAmount The minimum amount of `outputToken` the sender
    ///        must receive for the entire transformation to succeed. If set to zero,
    ///        the minimum output token transfer will not be asserted.
    /// @param transformations The transformations to execute on the token balance(s)
    ///        in sequence.
    /// @return outputTokenAmount The amount of `outputToken` received by the sender.
    function transformERC20(
        IERC20TokenV06 inputToken,
        IERC20TokenV06 outputToken,
        uint256 inputTokenAmount,
        uint256 minOutputTokenAmount,
        Transformation[] memory transformations
    )
        public
        override
        payable
        returns (uint256 outputTokenAmount)
    {
        return _transformERC20Private(
            keccak256(msg.data),
            msg.sender,
            inputToken,
            outputToken,
            inputTokenAmount,
            minOutputTokenAmount,
            transformations
        );
    }
    /// @dev Internal version of `transformERC20()`. Only callable from within.
    /// @param callDataHash Hash of the ingress calldata.
    /// @param taker The taker address.
    /// @param inputToken The token being provided by the taker.
    ///        If `0xeee...`, ETH is implied and should be provided with the call.`
    /// @param outputToken The token to be acquired by the taker.
    ///        `0xeee...` implies ETH.
    /// @param inputTokenAmount The amount of `inputToken` to take from the taker.
    ///        If set to `uint256(-1)`, the entire spendable balance of the taker
    ///        will be solt.
    /// @param minOutputTokenAmount The minimum amount of `outputToken` the taker
    ///        must receive for the entire transformation to succeed. If set to zero,
    ///        the minimum output token transfer will not be asserted.
    /// @param transformations The transformations to execute on the token balance(s)
    ///        in sequence.
    /// @return outputTokenAmount The amount of `outputToken` received by the taker.
    function _transformERC20(
        bytes32 callDataHash,
        address payable taker,
        IERC20TokenV06 inputToken,
        IERC20TokenV06 outputToken,
        uint256 inputTokenAmount,
        uint256 minOutputTokenAmount,
        Transformation[] memory transformations
    )
        public
        override
        payable
        onlySelf
        returns (uint256 outputTokenAmount)
    {
        return _transformERC20Private(
            callDataHash,
            taker,
            inputToken,
            outputToken,
            inputTokenAmount,
            minOutputTokenAmount,
            transformations
        );
    }
    /// @dev Private version of `transformERC20()`.
    /// @param callDataHash Hash of the ingress calldata.
    /// @param taker The taker address.
    /// @param inputToken The token being provided by the taker.
    ///        If `0xeee...`, ETH is implied and should be provided with the call.`
    /// @param outputToken The token to be acquired by the taker.
    ///        `0xeee...` implies ETH.
    /// @param inputTokenAmount The amount of `inputToken` to take from the taker.
    ///        If set to `uint256(-1)`, the entire spendable balance of the taker
    ///        will be solt.
    /// @param minOutputTokenAmount The minimum amount of `outputToken` the taker
    ///        must receive for the entire transformation to succeed. If set to zero,
    ///        the minimum output token transfer will not be asserted.
    /// @param transformations The transformations to execute on the token balance(s)
    ///        in sequence.
    /// @return outputTokenAmount The amount of `outputToken` received by the taker.
    function _transformERC20Private(
        bytes32 callDataHash,
        address payable taker,
        IERC20TokenV06 inputToken,
        IERC20TokenV06 outputToken,
        uint256 inputTokenAmount,
        uint256 minOutputTokenAmount,
        Transformation[] memory transformations
    )
        private
        returns (uint256 outputTokenAmount)
    {
        // If the input token amount is -1, transform the taker's entire
        // spendable balance.
        if (inputTokenAmount == uint256(-1)) {
            inputTokenAmount = ITokenSpender(address(this))
                .getSpendableERC20BalanceOf(inputToken, taker);
        }
        TransformERC20PrivateState memory state;
        state.wallet = getTransformWallet();
        state.transformerDeployer = getTransformerDeployer();
        // Remember the initial output token balance of the taker.
        state.takerOutputTokenBalanceBefore =
            LibERC20Transformer.getTokenBalanceOf(outputToken, taker);
        // Pull input tokens from the taker to the wallet and transfer attached ETH.
        _transferInputTokensAndAttachedEth(
            inputToken,
            taker,
            address(state.wallet),
            inputTokenAmount
        );
        // Perform transformations.
        for (uint256 i = 0; i < transformations.length; ++i) {
            _executeTransformation(
                state.wallet,
                transformations[i],
                state.transformerDeployer,
                taker,
                callDataHash
            );
        }
        // Compute how much output token has been transferred to the taker.
        state.takerOutputTokenBalanceAfter =
            LibERC20Transformer.getTokenBalanceOf(outputToken, taker);
        if (state.takerOutputTokenBalanceAfter > state.takerOutputTokenBalanceBefore) {
            outputTokenAmount = state.takerOutputTokenBalanceAfter.safeSub(
                state.takerOutputTokenBalanceBefore
            );
        } else if (state.takerOutputTokenBalanceAfter < state.takerOutputTokenBalanceBefore) {
            LibTransformERC20RichErrors.NegativeTransformERC20OutputError(
                address(outputToken),
                state.takerOutputTokenBalanceBefore - state.takerOutputTokenBalanceAfter
            ).rrevert();
        }
        // Ensure enough output token has been sent to the taker.
        if (outputTokenAmount < minOutputTokenAmount) {
            LibTransformERC20RichErrors.IncompleteTransformERC20Error(
                address(outputToken),
                outputTokenAmount,
                minOutputTokenAmount
            ).rrevert();
        }
        // Emit an event.
        emit TransformedERC20(
            taker,
            address(inputToken),
            address(outputToken),
            inputTokenAmount,
            outputTokenAmount
        );
    }
    /// @dev Return the current wallet instance that will serve as the execution
    ///      context for transformations.
    /// @return wallet The wallet instance.
    function getTransformWallet()
        public
        override
        view
        returns (IFlashWallet wallet)
    {
        return LibTransformERC20Storage.getStorage().wallet;
    }
    /// @dev Transfer input tokens from the taker and any attached ETH to `to`
    /// @param inputToken The token to pull from the taker.
    /// @param from The from (taker) address.
    /// @param to The recipient of tokens and ETH.
    /// @param amount Amount of `inputToken` tokens to transfer.
    function _transferInputTokensAndAttachedEth(
        IERC20TokenV06 inputToken,
        address from,
        address payable to,
        uint256 amount
    )
        private
    {
        // Transfer any attached ETH.
        if (msg.value != 0) {
            to.transfer(msg.value);
        }
        // Transfer input tokens.
        if (!LibERC20Transformer.isTokenETH(inputToken)) {
            // Token is not ETH, so pull ERC20 tokens.
            ITokenSpender(address(this))._spendERC20Tokens(
                inputToken,
                from,
                to,
                amount
            );
        } else if (msg.value < amount) {
             // Token is ETH, so the caller must attach enough ETH to the call.
            LibTransformERC20RichErrors.InsufficientEthAttachedError(
                msg.value,
                amount
            ).rrevert();
        }
    }
    /// @dev Executs a transformer in the context of `wallet`.
    /// @param wallet The wallet instance.
    /// @param transformation The transformation.
    /// @param transformerDeployer The address of the transformer deployer.
    /// @param taker The taker address.
    /// @param callDataHash Hash of the calldata.
    function _executeTransformation(
        IFlashWallet wallet,
        Transformation memory transformation,
        address transformerDeployer,
        address payable taker,
        bytes32 callDataHash
    )
        private
    {
        // Derive the transformer address from the deployment nonce.
        address payable transformer = LibERC20Transformer.getDeployedAddress(
            transformerDeployer,
            transformation.deploymentNonce
        );
        // Call `transformer.transform()` as the wallet.
        bytes memory resultData = wallet.executeDelegateCall(
            // The call target.
            transformer,
            // Call data.
            abi.encodeWithSelector(
                IERC20Transformer.transform.selector,
                callDataHash,
                taker,
                transformation.data
            )
        );
        // Ensure the transformer returned the magic bytes.
        if (resultData.length != 32 ||
            abi.decode(resultData, (bytes4)) != LibERC20Transformer.TRANSFORMER_SUCCESS
        ) {
            LibTransformERC20RichErrors.TransformerFailedError(
                transformer,
                transformation.data,
                resultData
            ).rrevert();
        }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "./LibStorage.sol";
import "../external/IFlashWallet.sol";
/// @dev Storage helpers for the `TokenSpender` feature.
library LibTransformERC20Storage {
    /// @dev Storage bucket for this feature.
    struct Storage {
        // The current wallet instance.
        IFlashWallet wallet;
        // The transformer deployer address.
        address transformerDeployer;
    }
    /// @dev Get the storage bucket for this contract.
    function getStorage() internal pure returns (Storage storage stor) {
        uint256 storageSlot = LibStorage.getStorageSlot(
            LibStorage.StorageId.TransformERC20
        );
        // Dip into assembly to change the slot pointed to by the local
        // variable `stor`.
        // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
        assembly { stor_slot := storageSlot }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
import "@0x/contracts-erc20/contracts/src/v06/LibERC20TokenV06.sol";
library LibERC20Transformer {
    using LibERC20TokenV06 for IERC20TokenV06;
    /// @dev ETH pseudo-token address.
    address constant internal ETH_TOKEN_ADDRESS = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
    /// @dev Return value indicating success in `IERC20Transformer.transform()`.
    ///      This is just `keccak256('TRANSFORMER_SUCCESS')`.
    bytes4 constant internal TRANSFORMER_SUCCESS = 0x13c9929e;
    /// @dev Transfer ERC20 tokens and ETH.
    /// @param token An ERC20 or the ETH pseudo-token address (`ETH_TOKEN_ADDRESS`).
    /// @param to The recipient.
    /// @param amount The transfer amount.
    function transformerTransfer(
        IERC20TokenV06 token,
        address payable to,
        uint256 amount
    )
        internal
    {
        if (isTokenETH(token)) {
            to.transfer(amount);
        } else {
            token.compatTransfer(to, amount);
        }
    }
    /// @dev Check if a token is the ETH pseudo-token.
    /// @param token The token to check.
    /// @return isETH `true` if the token is the ETH pseudo-token.
    function isTokenETH(IERC20TokenV06 token)
        internal
        pure
        returns (bool isETH)
    {
        return address(token) == ETH_TOKEN_ADDRESS;
    }
    /// @dev Check the balance of an ERC20 token or ETH.
    /// @param token An ERC20 or the ETH pseudo-token address (`ETH_TOKEN_ADDRESS`).
    /// @param owner Holder of the tokens.
    /// @return tokenBalance The balance of `owner`.
    function getTokenBalanceOf(IERC20TokenV06 token, address owner)
        internal
        view
        returns (uint256 tokenBalance)
    {
        if (isTokenETH(token)) {
            return owner.balance;
        }
        return token.balanceOf(owner);
    }
    /// @dev RLP-encode a 32-bit or less account nonce.
    /// @param nonce A positive integer in the range 0 <= nonce < 2^32.
    /// @return rlpNonce The RLP encoding.
    function rlpEncodeNonce(uint32 nonce)
        internal
        pure
        returns (bytes memory rlpNonce)
    {
        // See https://github.com/ethereum/wiki/wiki/RLP for RLP encoding rules.
        if (nonce == 0) {
            rlpNonce = new bytes(1);
            rlpNonce[0] = 0x80;
        } else if (nonce < 0x80) {
            rlpNonce = new bytes(1);
            rlpNonce[0] = byte(uint8(nonce));
        } else if (nonce <= 0xFF) {
            rlpNonce = new bytes(2);
            rlpNonce[0] = 0x81;
            rlpNonce[1] = byte(uint8(nonce));
        } else if (nonce <= 0xFFFF) {
            rlpNonce = new bytes(3);
            rlpNonce[0] = 0x82;
            rlpNonce[1] = byte(uint8((nonce & 0xFF00) >> 8));
            rlpNonce[2] = byte(uint8(nonce));
        } else if (nonce <= 0xFFFFFF) {
            rlpNonce = new bytes(4);
            rlpNonce[0] = 0x83;
            rlpNonce[1] = byte(uint8((nonce & 0xFF0000) >> 16));
            rlpNonce[2] = byte(uint8((nonce & 0xFF00) >> 8));
            rlpNonce[3] = byte(uint8(nonce));
        } else {
            rlpNonce = new bytes(5);
            rlpNonce[0] = 0x84;
            rlpNonce[1] = byte(uint8((nonce & 0xFF000000) >> 24));
            rlpNonce[2] = byte(uint8((nonce & 0xFF0000) >> 16));
            rlpNonce[3] = byte(uint8((nonce & 0xFF00) >> 8));
            rlpNonce[4] = byte(uint8(nonce));
        }
    }
    /// @dev Compute the expected deployment address by `deployer` at
    ///      the nonce given by `deploymentNonce`.
    /// @param deployer The address of the deployer.
    /// @param deploymentNonce The nonce that the deployer had when deploying
    ///        a contract.
    /// @return deploymentAddress The deployment address.
    function getDeployedAddress(address deployer, uint32 deploymentNonce)
        internal
        pure
        returns (address payable deploymentAddress)
    {
        // The address of if a deployed contract is the lower 20 bytes of the
        // hash of the RLP-encoded deployer's account address + account nonce.
        // See: https://ethereum.stackexchange.com/questions/760/how-is-the-address-of-an-ethereum-contract-computed
        bytes memory rlpNonce = rlpEncodeNonce(deploymentNonce);
        return address(uint160(uint256(keccak256(abi.encodePacked(
            byte(uint8(0xC0 + 21 + rlpNonce.length)),
            byte(uint8(0x80 + 20)),
            deployer,
            rlpNonce
        )))));
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "../ZeroEx.sol";
import "../features/IOwnable.sol";
import "../features/TokenSpender.sol";
import "../features/TransformERC20.sol";
import "../external/AllowanceTarget.sol";
import "./InitialMigration.sol";
/// @dev A contract for deploying and configuring the full ZeroEx contract.
contract FullMigration {
    // solhint-disable no-empty-blocks,indent
    /// @dev Features to add the the proxy contract.
    struct Features {
        SimpleFunctionRegistry registry;
        Ownable ownable;
        TokenSpender tokenSpender;
        TransformERC20 transformERC20;
    }
    /// @dev Parameters needed to initialize features.
    struct MigrateOpts {
        address transformerDeployer;
    }
    /// @dev The allowed caller of `deploy()`.
    address public immutable deployer;
    /// @dev The initial migration contract.
    InitialMigration private _initialMigration;
    /// @dev Instantiate this contract and set the allowed caller of `deploy()`
    ///      to `deployer`.
    /// @param deployer_ The allowed caller of `deploy()`.
    constructor(address payable deployer_)
        public
    {
        deployer = deployer_;
        // Create an initial migration contract with this contract set to the
        // allowed deployer.
        _initialMigration = new InitialMigration(address(this));
    }
    /// @dev Deploy the `ZeroEx` contract with the full feature set,
    ///      transfer ownership to `owner`, then self-destruct.
    /// @param owner The owner of the contract.
    /// @param features Features to add to the proxy.
    /// @return zeroEx The deployed and configured `ZeroEx` contract.
    /// @param migrateOpts Parameters needed to initialize features.
    function deploy(
        address payable owner,
        Features memory features,
        MigrateOpts memory migrateOpts
    )
        public
        returns (ZeroEx zeroEx)
    {
        require(msg.sender == deployer, "FullMigration/INVALID_SENDER");
        // Perform the initial migration with the owner set to this contract.
        zeroEx = _initialMigration.deploy(
            address(uint160(address(this))),
            InitialMigration.BootstrapFeatures({
                registry: features.registry,
                ownable: features.ownable
            })
        );
        // Add features.
        _addFeatures(zeroEx, owner, features, migrateOpts);
        // Transfer ownership to the real owner.
        IOwnable(address(zeroEx)).transferOwnership(owner);
        // Self-destruct.
        this.die(owner);
    }
    /// @dev Destroy this contract. Only callable from ourselves (from `deploy()`).
    /// @param ethRecipient Receiver of any ETH in this contract.
    function die(address payable ethRecipient)
        external
        virtual
    {
        require(msg.sender == address(this), "FullMigration/INVALID_SENDER");
        // This contract should not hold any funds but we send
        // them to the ethRecipient just in case.
        selfdestruct(ethRecipient);
    }
    /// @dev Deploy and register features to the ZeroEx contract.
    /// @param zeroEx The bootstrapped ZeroEx contract.
    /// @param owner The ultimate owner of the ZeroEx contract.
    /// @param features Features to add to the proxy.
    /// @param migrateOpts Parameters needed to initialize features.
    function _addFeatures(
        ZeroEx zeroEx,
        address owner,
        Features memory features,
        MigrateOpts memory migrateOpts
    )
        private
    {
        IOwnable ownable = IOwnable(address(zeroEx));
        // TokenSpender
        {
            // Create the allowance target.
            AllowanceTarget allowanceTarget = new AllowanceTarget();
            // Let the ZeroEx contract use the allowance target.
            allowanceTarget.addAuthorizedAddress(address(zeroEx));
            // Transfer ownership of the allowance target to the (real) owner.
            allowanceTarget.transferOwnership(owner);
            // Register the feature.
            ownable.migrate(
                address(features.tokenSpender),
                abi.encodeWithSelector(
                    TokenSpender.migrate.selector,
                    allowanceTarget
                ),
                address(this)
            );
        }
        // TransformERC20
        {
            // Register the feature.
            ownable.migrate(
                address(features.transformERC20),
                abi.encodeWithSelector(
                    TransformERC20.migrate.selector,
                    migrateOpts.transformerDeployer
                ),
                address(this)
            );
        }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "../ZeroEx.sol";
import "../features/IBootstrap.sol";
import "../features/SimpleFunctionRegistry.sol";
import "../features/Ownable.sol";
import "./LibBootstrap.sol";
/// @dev A contract for deploying and configuring a minimal ZeroEx contract.
contract InitialMigration {
    /// @dev Features to bootstrap into the the proxy contract.
    struct BootstrapFeatures {
        SimpleFunctionRegistry registry;
        Ownable ownable;
    }
    /// @dev The allowed caller of `deploy()`. In production, this would be
    ///      the governor.
    address public immutable deployer;
    /// @dev The real address of this contract.
    address private immutable _implementation;
    /// @dev Instantiate this contract and set the allowed caller of `deploy()`
    ///      to `deployer_`.
    /// @param deployer_ The allowed caller of `deploy()`.
    constructor(address deployer_) public {
        deployer = deployer_;
        _implementation = address(this);
    }
    /// @dev Deploy the `ZeroEx` contract with the minimum feature set,
    ///      transfers ownership to `owner`, then self-destructs.
    ///      Only callable by `deployer` set in the contstructor.
    /// @param owner The owner of the contract.
    /// @param features Features to bootstrap into the proxy.
    /// @return zeroEx The deployed and configured `ZeroEx` contract.
    function deploy(address payable owner, BootstrapFeatures memory features)
        public
        virtual
        returns (ZeroEx zeroEx)
    {
        // Must be called by the allowed deployer.
        require(msg.sender == deployer, "InitialMigration/INVALID_SENDER");
        // Deploy the ZeroEx contract, setting ourselves as the bootstrapper.
        zeroEx = new ZeroEx();
        // Bootstrap the initial feature set.
        IBootstrap(address(zeroEx)).bootstrap(
            address(this),
            abi.encodeWithSelector(this.bootstrap.selector, owner, features)
        );
        // Self-destruct. This contract should not hold any funds but we send
        // them to the owner just in case.
        this.die(owner);
    }
    /// @dev Sets up the initial state of the `ZeroEx` contract.
    ///      The `ZeroEx` contract will delegatecall into this function.
    /// @param owner The new owner of the ZeroEx contract.
    /// @param features Features to bootstrap into the proxy.
    /// @return success Magic bytes if successful.
    function bootstrap(address owner, BootstrapFeatures memory features)
        public
        virtual
        returns (bytes4 success)
    {
        // Deploy and migrate the initial features.
        // Order matters here.
        // Initialize Registry.
        LibBootstrap.delegatecallBootstrapFunction(
            address(features.registry),
            abi.encodeWithSelector(
                SimpleFunctionRegistry.bootstrap.selector
            )
        );
        // Initialize Ownable.
        LibBootstrap.delegatecallBootstrapFunction(
            address(features.ownable),
            abi.encodeWithSelector(
                Ownable.bootstrap.selector
            )
        );
        // De-register `SimpleFunctionRegistry._extendSelf`.
        SimpleFunctionRegistry(address(this)).rollback(
            SimpleFunctionRegistry._extendSelf.selector,
            address(0)
        );
        // Transfer ownership to the real owner.
        Ownable(address(this)).transferOwnership(owner);
        success = LibBootstrap.BOOTSTRAP_SUCCESS;
    }
    /// @dev Self-destructs this contract. Only callable by this contract.
    /// @param ethRecipient Who to transfer outstanding ETH to.
    function die(address payable ethRecipient) public virtual {
        require(msg.sender == _implementation, "InitialMigration/INVALID_SENDER");
        selfdestruct(ethRecipient);
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
import "@0x/contracts-erc20/contracts/src/v06/LibERC20TokenV06.sol";
import "../errors/LibTransformERC20RichErrors.sol";
import "./Transformer.sol";
import "./LibERC20Transformer.sol";
/// @dev A transformer that transfers tokens to arbitrary addresses.
contract AffiliateFeeTransformer is
    Transformer
{
    // solhint-disable no-empty-blocks
    using LibRichErrorsV06 for bytes;
    using LibSafeMathV06 for uint256;
    using LibERC20Transformer for IERC20TokenV06;
    /// @dev Information for a single fee.
    struct TokenFee {
        // The token to transfer to `recipient`.
        IERC20TokenV06 token;
        // Amount of each `token` to transfer to `recipient`.
        // If `amount == uint256(-1)`, the entire balance of `token` will be
        // transferred.
        uint256 amount;
        // Recipient of `token`.
        address payable recipient;
    }
    uint256 private constant MAX_UINT256 = uint256(-1);
    /// @dev Create this contract.
    constructor()
        public
        Transformer()
    {}
    /// @dev Transfers tokens to recipients.
    /// @param data ABI-encoded `TokenFee[]`, indicating which tokens to transfer.
    /// @return success The success bytes (`LibERC20Transformer.TRANSFORMER_SUCCESS`).
    function transform(
        bytes32, // callDataHash,
        address payable, // taker,
        bytes calldata data
    )
        external
        override
        returns (bytes4 success)
    {
        TokenFee[] memory fees = abi.decode(data, (TokenFee[]));
        // Transfer tokens to recipients.
        for (uint256 i = 0; i < fees.length; ++i) {
            uint256 amount = fees[i].amount;
            if (amount == MAX_UINT256) {
                amount = LibERC20Transformer.getTokenBalanceOf(fees[i].token, address(this));
            }
            if (amount != 0) {
                fees[i].token.transformerTransfer(fees[i].recipient, amount);
            }
        }
        return LibERC20Transformer.TRANSFORMER_SUCCESS;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "../errors/LibTransformERC20RichErrors.sol";
import "./IERC20Transformer.sol";
/// @dev Abstract base class for transformers.
abstract contract Transformer is
    IERC20Transformer
{
    using LibRichErrorsV06 for bytes;
    /// @dev The address of the deployer.
    address public immutable deployer;
    /// @dev The original address of this contract.
    address private immutable _implementation;
    /// @dev Create this contract.
    constructor() public {
        deployer = msg.sender;
        _implementation = address(this);
    }
    /// @dev Destruct this contract. Only callable by the deployer and will not
    ///      succeed in the context of a delegatecall (from another contract).
    /// @param ethRecipient The recipient of ETH held in this contract.
    function die(address payable ethRecipient)
        external
        virtual
    {
        // Only the deployer can call this.
        if (msg.sender != deployer) {
            LibTransformERC20RichErrors
                .OnlyCallableByDeployerError(msg.sender, deployer)
                .rrevert();
        }
        // Must be executing our own context.
        if (address(this) != _implementation) {
            LibTransformERC20RichErrors
                .InvalidExecutionContextError(address(this), _implementation)
                .rrevert();
        }
        selfdestruct(ethRecipient);
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
import "@0x/contracts-utils/contracts/src/v06/LibBytesV06.sol";
import "@0x/contracts-erc20/contracts/src/v06/LibERC20TokenV06.sol";
import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
import "@0x/contracts-utils/contracts/src/v06/LibMathV06.sol";
import "../errors/LibTransformERC20RichErrors.sol";
import "../vendor/v3/IExchange.sol";
import "./Transformer.sol";
import "./LibERC20Transformer.sol";
/// @dev A transformer that fills an ERC20 market sell/buy quote.
contract FillQuoteTransformer is
    Transformer
{
    using LibERC20TokenV06 for IERC20TokenV06;
    using LibERC20Transformer for IERC20TokenV06;
    using LibSafeMathV06 for uint256;
    using LibRichErrorsV06 for bytes;
    /// @dev Whether we are performing a market sell or buy.
    enum Side {
        Sell,
        Buy
    }
    /// @dev Transform data to ABI-encode and pass into `transform()`.
    struct TransformData {
        // Whether we aer performing a market sell or buy.
        Side side;
        // The token being sold.
        // This should be an actual token, not the ETH pseudo-token.
        IERC20TokenV06 sellToken;
        // The token being bought.
        // This should be an actual token, not the ETH pseudo-token.
        IERC20TokenV06 buyToken;
        // The orders to fill.
        IExchange.Order[] orders;
        // Signatures for each respective order in `orders`.
        bytes[] signatures;
        // Maximum fill amount for each order. This may be shorter than the
        // number of orders, where missing entries will be treated as `uint256(-1)`.
        // For sells, this will be the maximum sell amount (taker asset).
        // For buys, this will be the maximum buy amount (maker asset).
        uint256[] maxOrderFillAmounts;
        // Amount of `sellToken` to sell or `buyToken` to buy.
        // For sells, this may be `uint256(-1)` to sell the entire balance of
        // `sellToken`.
        uint256 fillAmount;
    }
    /// @dev Results of a call to `_fillOrder()`.
    struct FillOrderResults {
        // The amount of taker tokens sold, according to balance checks.
        uint256 takerTokenSoldAmount;
        // The amount of maker tokens sold, according to balance checks.
        uint256 makerTokenBoughtAmount;
        // The amount of protocol fee paid.
        uint256 protocolFeePaid;
    }
    /// @dev The Exchange ERC20Proxy ID.
    bytes4 private constant ERC20_ASSET_PROXY_ID = 0xf47261b0;
    /// @dev Maximum uint256 value.
    uint256 private constant MAX_UINT256 = uint256(-1);
    /// @dev The Exchange contract.
    IExchange public immutable exchange;
    /// @dev The ERC20Proxy address.
    address public immutable erc20Proxy;
    /// @dev Create this contract.
    /// @param exchange_ The Exchange V3 instance.
    constructor(IExchange exchange_)
        public
        Transformer()
    {
        exchange = exchange_;
        erc20Proxy = exchange_.getAssetProxy(ERC20_ASSET_PROXY_ID);
    }
    /// @dev Sell this contract's entire balance of of `sellToken` in exchange
    ///      for `buyToken` by filling `orders`. Protocol fees should be attached
    ///      to this call. `buyToken` and excess ETH will be transferred back to the caller.
    /// @param data_ ABI-encoded `TransformData`.
    /// @return success The success bytes (`LibERC20Transformer.TRANSFORMER_SUCCESS`).
    function transform(
        bytes32, // callDataHash,
        address payable, // taker,
        bytes calldata data_
    )
        external
        override
        returns (bytes4 success)
    {
        TransformData memory data = abi.decode(data_, (TransformData));
        // Validate data fields.
        if (data.sellToken.isTokenETH() || data.buyToken.isTokenETH()) {
            LibTransformERC20RichErrors.InvalidTransformDataError(
                LibTransformERC20RichErrors.InvalidTransformDataErrorCode.INVALID_TOKENS,
                data_
            ).rrevert();
        }
        if (data.orders.length != data.signatures.length) {
            LibTransformERC20RichErrors.InvalidTransformDataError(
                LibTransformERC20RichErrors.InvalidTransformDataErrorCode.INVALID_ARRAY_LENGTH,
                data_
            ).rrevert();
        }
        if (data.side == Side.Sell && data.fillAmount == MAX_UINT256) {
            // If `sellAmount == -1 then we are selling
            // the entire balance of `sellToken`. This is useful in cases where
            // the exact sell amount is not exactly known in advance, like when
            // unwrapping Chai/cUSDC/cDAI.
            data.fillAmount = data.sellToken.getTokenBalanceOf(address(this));
        }
        // Approve the ERC20 proxy to spend `sellToken`.
        data.sellToken.approveIfBelow(erc20Proxy, data.fillAmount);
        // Fill the orders.
        uint256 singleProtocolFee = exchange.protocolFeeMultiplier().safeMul(tx.gasprice);
        uint256 ethRemaining = address(this).balance;
        uint256 boughtAmount = 0;
        uint256 soldAmount = 0;
        for (uint256 i = 0; i < data.orders.length; ++i) {
            // Check if we've hit our targets.
            if (data.side == Side.Sell) {
                // Market sell check.
                if (soldAmount >= data.fillAmount) {
                    break;
                }
            } else {
                // Market buy check.
                if (boughtAmount >= data.fillAmount) {
                    break;
                }
            }
            // Ensure we have enough ETH to cover the protocol fee.
            if (ethRemaining < singleProtocolFee) {
                LibTransformERC20RichErrors
                    .InsufficientProtocolFeeError(ethRemaining, singleProtocolFee)
                    .rrevert();
            }
            // Fill the order.
            FillOrderResults memory results;
            if (data.side == Side.Sell) {
                // Market sell.
                results = _sellToOrder(
                    data.buyToken,
                    data.sellToken,
                    data.orders[i],
                    data.signatures[i],
                    data.fillAmount.safeSub(soldAmount).min256(
                        data.maxOrderFillAmounts.length > i
                        ? data.maxOrderFillAmounts[i]
                        : MAX_UINT256
                    ),
                    singleProtocolFee
                );
            } else {
                // Market buy.
                results = _buyFromOrder(
                    data.buyToken,
                    data.sellToken,
                    data.orders[i],
                    data.signatures[i],
                    data.fillAmount.safeSub(boughtAmount).min256(
                        data.maxOrderFillAmounts.length > i
                        ? data.maxOrderFillAmounts[i]
                        : MAX_UINT256
                    ),
                    singleProtocolFee
                );
            }
            // Accumulate totals.
            soldAmount = soldAmount.safeAdd(results.takerTokenSoldAmount);
            boughtAmount = boughtAmount.safeAdd(results.makerTokenBoughtAmount);
            ethRemaining = ethRemaining.safeSub(results.protocolFeePaid);
        }
        // Ensure we hit our targets.
        if (data.side == Side.Sell) {
            // Market sell check.
            if (soldAmount < data.fillAmount) {
                LibTransformERC20RichErrors
                    .IncompleteFillSellQuoteError(
                        address(data.sellToken),
                        soldAmount,
                        data.fillAmount
                    ).rrevert();
            }
        } else {
            // Market buy check.
            if (boughtAmount < data.fillAmount) {
                LibTransformERC20RichErrors
                    .IncompleteFillBuyQuoteError(
                        address(data.buyToken),
                        boughtAmount,
                        data.fillAmount
                    ).rrevert();
            }
        }
        return LibERC20Transformer.TRANSFORMER_SUCCESS;
    }
    /// @dev Try to sell up to `sellAmount` from an order.
    /// @param makerToken The maker/buy token.
    /// @param takerToken The taker/sell token.
    /// @param order The order to fill.
    /// @param signature The signature for `order`.
    /// @param sellAmount Amount of taker token to sell.
    /// @param protocolFee The protocol fee needed to fill `order`.
    function _sellToOrder(
        IERC20TokenV06 makerToken,
        IERC20TokenV06 takerToken,
        IExchange.Order memory order,
        bytes memory signature,
        uint256 sellAmount,
        uint256 protocolFee
    )
        private
        returns (FillOrderResults memory results)
    {
        IERC20TokenV06 takerFeeToken =
            _getTokenFromERC20AssetData(order.takerFeeAssetData);
        uint256 takerTokenFillAmount = sellAmount;
        if (order.takerFee != 0) {
            if (takerFeeToken == makerToken) {
                // Taker fee is payable in the maker token, so we need to
                // approve the proxy to spend the maker token.
                // It isn't worth computing the actual taker fee
                // since `approveIfBelow()` will set the allowance to infinite. We
                // just need a reasonable upper bound to avoid unnecessarily re-approving.
                takerFeeToken.approveIfBelow(erc20Proxy, order.takerFee);
            } else if (takerFeeToken == takerToken){
                // Taker fee is payable in the taker token, so we need to
                // reduce the fill amount to cover the fee.
                // takerTokenFillAmount' =
                //   (takerTokenFillAmount * order.takerAssetAmount) /
                //   (order.takerAssetAmount + order.takerFee)
                takerTokenFillAmount = LibMathV06.getPartialAmountCeil(
                    order.takerAssetAmount,
                    order.takerAssetAmount.safeAdd(order.takerFee),
                    sellAmount
                );
            } else {
                //  Only support taker or maker asset denominated taker fees.
                LibTransformERC20RichErrors.InvalidTakerFeeTokenError(
                    address(takerFeeToken)
                ).rrevert();
            }
        }
        // Clamp fill amount to order size.
        takerTokenFillAmount = LibSafeMathV06.min256(
            takerTokenFillAmount,
            order.takerAssetAmount
        );
        // Perform the fill.
        return _fillOrder(
            order,
            signature,
            takerTokenFillAmount,
            protocolFee,
            makerToken,
            takerFeeToken == takerToken
        );
    }
    /// @dev Try to buy up to `buyAmount` from an order.
    /// @param makerToken The maker/buy token.
    /// @param takerToken The taker/sell token.
    /// @param order The order to fill.
    /// @param signature The signature for `order`.
    /// @param buyAmount Amount of maker token to buy.
    /// @param protocolFee The protocol fee needed to fill `order`.
    function _buyFromOrder(
        IERC20TokenV06 makerToken,
        IERC20TokenV06 takerToken,
        IExchange.Order memory order,
        bytes memory signature,
        uint256 buyAmount,
        uint256 protocolFee
    )
        private
        returns (FillOrderResults memory results)
    {
        IERC20TokenV06 takerFeeToken =
            _getTokenFromERC20AssetData(order.takerFeeAssetData);
        // Compute the default taker token fill amount.
        uint256 takerTokenFillAmount = LibMathV06.getPartialAmountCeil(
            buyAmount,
            order.makerAssetAmount,
            order.takerAssetAmount
        );
        if (order.takerFee != 0) {
            if (takerFeeToken == makerToken) {
                // Taker fee is payable in the maker token.
                // Adjust the taker token fill amount to account for maker
                // tokens being lost to the taker fee.
                // takerTokenFillAmount' =
                //  (order.takerAssetAmount * buyAmount) /
                //  (order.makerAssetAmount - order.takerFee)
                takerTokenFillAmount = LibMathV06.getPartialAmountCeil(
                    buyAmount,
                    order.makerAssetAmount.safeSub(order.takerFee),
                    order.takerAssetAmount
                );
                // Approve the proxy to spend the maker token.
                // It isn't worth computing the actual taker fee
                // since `approveIfBelow()` will set the allowance to infinite. We
                // just need a reasonable upper bound to avoid unnecessarily re-approving.
                takerFeeToken.approveIfBelow(erc20Proxy, order.takerFee);
            } else if (takerFeeToken != takerToken) {
                //  Only support taker or maker asset denominated taker fees.
                LibTransformERC20RichErrors.InvalidTakerFeeTokenError(
                    address(takerFeeToken)
                ).rrevert();
            }
        }
        // Clamp to order size.
        takerTokenFillAmount = LibSafeMathV06.min256(
            order.takerAssetAmount,
            takerTokenFillAmount
        );
        // Perform the fill.
        return _fillOrder(
            order,
            signature,
            takerTokenFillAmount,
            protocolFee,
            makerToken,
            takerFeeToken == takerToken
        );
    }
    /// @dev Attempt to fill an order. If the fill reverts, the revert will be
    ///      swallowed and `results` will be zeroed out.
    /// @param order The order to fill.
    /// @param signature The order signature.
    /// @param takerAssetFillAmount How much taker asset to fill.
    /// @param protocolFee The protocol fee needed to fill this order.
    /// @param makerToken The maker token.
    /// @param isTakerFeeInTakerToken Whether the taker fee token is the same as the
    ///        taker token.
    function _fillOrder(
        IExchange.Order memory order,
        bytes memory signature,
        uint256 takerAssetFillAmount,
        uint256 protocolFee,
        IERC20TokenV06 makerToken,
        bool isTakerFeeInTakerToken
    )
        private
        returns (FillOrderResults memory results)
    {
        // Track changes in the maker token balance.
        uint256 initialMakerTokenBalance = makerToken.balanceOf(address(this));
        try
            exchange.fillOrder
                {value: protocolFee}
                (order, takerAssetFillAmount, signature)
            returns (IExchange.FillResults memory fillResults)
        {
            // Update maker quantity based on changes in token balances.
            results.makerTokenBoughtAmount = makerToken.balanceOf(address(this))
                .safeSub(initialMakerTokenBalance);
            // We can trust the other fill result quantities.
            results.protocolFeePaid = fillResults.protocolFeePaid;
            results.takerTokenSoldAmount = fillResults.takerAssetFilledAmount;
            // If the taker fee is payable in the taker asset, include the
            // taker fee in the total amount sold.
            if (isTakerFeeInTakerToken) {
                results.takerTokenSoldAmount =
                    results.takerTokenSoldAmount.safeAdd(fillResults.takerFeePaid);
            }
        } catch (bytes memory) {
            // Swallow failures, leaving all results as zero.
        }
    }
    /// @dev Extract the token from plain ERC20 asset data.
    ///      If the asset-data is empty, a zero token address will be returned.
    /// @param assetData The order asset data.
    function _getTokenFromERC20AssetData(bytes memory assetData)
        private
        pure
        returns (IERC20TokenV06 token)
    {
        if (assetData.length == 0) {
            return IERC20TokenV06(address(0));
        }
        if (assetData.length != 36 ||
            LibBytesV06.readBytes4(assetData, 0) != ERC20_ASSET_PROXY_ID)
        {
            LibTransformERC20RichErrors
                .InvalidERC20AssetDataError(assetData)
                .rrevert();
        }
        return IERC20TokenV06(LibBytesV06.readAddress(assetData, 16));
    }
}
/*
  Copyright 2019 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
import "./LibSafeMathV06.sol";
import "./errors/LibRichErrorsV06.sol";
import "./errors/LibMathRichErrorsV06.sol";
library LibMathV06 {
    using LibSafeMathV06 for uint256;
    /// @dev Calculates partial value given a numerator and denominator rounded down.
    ///      Reverts if rounding error is >= 0.1%
    /// @param numerator Numerator.
    /// @param denominator Denominator.
    /// @param target Value to calculate partial of.
    /// @return partialAmount Partial value of target rounded down.
    function safeGetPartialAmountFloor(
        uint256 numerator,
        uint256 denominator,
        uint256 target
    )
        internal
        pure
        returns (uint256 partialAmount)
    {
        if (isRoundingErrorFloor(
                numerator,
                denominator,
                target
        )) {
            LibRichErrorsV06.rrevert(LibMathRichErrorsV06.RoundingError(
                numerator,
                denominator,
                target
            ));
        }
        partialAmount = numerator.safeMul(target).safeDiv(denominator);
        return partialAmount;
    }
    /// @dev Calculates partial value given a numerator and denominator rounded down.
    ///      Reverts if rounding error is >= 0.1%
    /// @param numerator Numerator.
    /// @param denominator Denominator.
    /// @param target Value to calculate partial of.
    /// @return partialAmount Partial value of target rounded up.
    function safeGetPartialAmountCeil(
        uint256 numerator,
        uint256 denominator,
        uint256 target
    )
        internal
        pure
        returns (uint256 partialAmount)
    {
        if (isRoundingErrorCeil(
                numerator,
                denominator,
                target
        )) {
            LibRichErrorsV06.rrevert(LibMathRichErrorsV06.RoundingError(
                numerator,
                denominator,
                target
            ));
        }
        // safeDiv computes `floor(a / b)`. We use the identity (a, b integer):
        //       ceil(a / b) = floor((a + b - 1) / b)
        // To implement `ceil(a / b)` using safeDiv.
        partialAmount = numerator.safeMul(target)
            .safeAdd(denominator.safeSub(1))
            .safeDiv(denominator);
        return partialAmount;
    }
    /// @dev Calculates partial value given a numerator and denominator rounded down.
    /// @param numerator Numerator.
    /// @param denominator Denominator.
    /// @param target Value to calculate partial of.
    /// @return partialAmount Partial value of target rounded down.
    function getPartialAmountFloor(
        uint256 numerator,
        uint256 denominator,
        uint256 target
    )
        internal
        pure
        returns (uint256 partialAmount)
    {
        partialAmount = numerator.safeMul(target).safeDiv(denominator);
        return partialAmount;
    }
    /// @dev Calculates partial value given a numerator and denominator rounded down.
    /// @param numerator Numerator.
    /// @param denominator Denominator.
    /// @param target Value to calculate partial of.
    /// @return partialAmount Partial value of target rounded up.
    function getPartialAmountCeil(
        uint256 numerator,
        uint256 denominator,
        uint256 target
    )
        internal
        pure
        returns (uint256 partialAmount)
    {
        // safeDiv computes `floor(a / b)`. We use the identity (a, b integer):
        //       ceil(a / b) = floor((a + b - 1) / b)
        // To implement `ceil(a / b)` using safeDiv.
        partialAmount = numerator.safeMul(target)
            .safeAdd(denominator.safeSub(1))
            .safeDiv(denominator);
        return partialAmount;
    }
    /// @dev Checks if rounding error >= 0.1% when rounding down.
    /// @param numerator Numerator.
    /// @param denominator Denominator.
    /// @param target Value to multiply with numerator/denominator.
    /// @return isError Rounding error is present.
    function isRoundingErrorFloor(
        uint256 numerator,
        uint256 denominator,
        uint256 target
    )
        internal
        pure
        returns (bool isError)
    {
        if (denominator == 0) {
            LibRichErrorsV06.rrevert(LibMathRichErrorsV06.DivisionByZeroError());
        }
        // The absolute rounding error is the difference between the rounded
        // value and the ideal value. The relative rounding error is the
        // absolute rounding error divided by the absolute value of the
        // ideal value. This is undefined when the ideal value is zero.
        //
        // The ideal value is `numerator * target / denominator`.
        // Let's call `numerator * target % denominator` the remainder.
        // The absolute error is `remainder / denominator`.
        //
        // When the ideal value is zero, we require the absolute error to
        // be zero. Fortunately, this is always the case. The ideal value is
        // zero iff `numerator == 0` and/or `target == 0`. In this case the
        // remainder and absolute error are also zero.
        if (target == 0 || numerator == 0) {
            return false;
        }
        // Otherwise, we want the relative rounding error to be strictly
        // less than 0.1%.
        // The relative error is `remainder / (numerator * target)`.
        // We want the relative error less than 1 / 1000:
        //        remainder / (numerator * denominator)  <  1 / 1000
        // or equivalently:
        //        1000 * remainder  <  numerator * target
        // so we have a rounding error iff:
        //        1000 * remainder  >=  numerator * target
        uint256 remainder = mulmod(
            target,
            numerator,
            denominator
        );
        isError = remainder.safeMul(1000) >= numerator.safeMul(target);
        return isError;
    }
    /// @dev Checks if rounding error >= 0.1% when rounding up.
    /// @param numerator Numerator.
    /// @param denominator Denominator.
    /// @param target Value to multiply with numerator/denominator.
    /// @return isError Rounding error is present.
    function isRoundingErrorCeil(
        uint256 numerator,
        uint256 denominator,
        uint256 target
    )
        internal
        pure
        returns (bool isError)
    {
        if (denominator == 0) {
            LibRichErrorsV06.rrevert(LibMathRichErrorsV06.DivisionByZeroError());
        }
        // See the comments in `isRoundingError`.
        if (target == 0 || numerator == 0) {
            // When either is zero, the ideal value and rounded value are zero
            // and there is no rounding error. (Although the relative error
            // is undefined.)
            return false;
        }
        // Compute remainder as before
        uint256 remainder = mulmod(
            target,
            numerator,
            denominator
        );
        remainder = denominator.safeSub(remainder) % denominator;
        isError = remainder.safeMul(1000) >= numerator.safeMul(target);
        return isError;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibMathRichErrorsV06 {
    // bytes4(keccak256("DivisionByZeroError()"))
    bytes internal constant DIVISION_BY_ZERO_ERROR =
        hex"a791837c";
    // bytes4(keccak256("RoundingError(uint256,uint256,uint256)"))
    bytes4 internal constant ROUNDING_ERROR_SELECTOR =
        0x339f3de2;
    // solhint-disable func-name-mixedcase
    function DivisionByZeroError()
        internal
        pure
        returns (bytes memory)
    {
        return DIVISION_BY_ZERO_ERROR;
    }
    function RoundingError(
        uint256 numerator,
        uint256 denominator,
        uint256 target
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            ROUNDING_ERROR_SELECTOR,
            numerator,
            denominator,
            target
        );
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
/// @dev Interface to the V3 Exchange.
interface IExchange {
    /// @dev V3 Order structure.
    struct Order {
        // Address that created the order.
        address makerAddress;
        // Address that is allowed to fill the order.
        // If set to 0, any address is allowed to fill the order.
        address takerAddress;
        // Address that will recieve fees when order is filled.
        address feeRecipientAddress;
        // Address that is allowed to call Exchange contract methods that affect this order.
        // If set to 0, any address is allowed to call these methods.
        address senderAddress;
        // Amount of makerAsset being offered by maker. Must be greater than 0.
        uint256 makerAssetAmount;
        // Amount of takerAsset being bid on by maker. Must be greater than 0.
        uint256 takerAssetAmount;
        // Fee paid to feeRecipient by maker when order is filled.
        uint256 makerFee;
        // Fee paid to feeRecipient by taker when order is filled.
        uint256 takerFee;
        // Timestamp in seconds at which order expires.
        uint256 expirationTimeSeconds;
        // Arbitrary number to facilitate uniqueness of the order's hash.
        uint256 salt;
        // Encoded data that can be decoded by a specified proxy contract when transferring makerAsset.
        // The leading bytes4 references the id of the asset proxy.
        bytes makerAssetData;
        // Encoded data that can be decoded by a specified proxy contract when transferring takerAsset.
        // The leading bytes4 references the id of the asset proxy.
        bytes takerAssetData;
        // Encoded data that can be decoded by a specified proxy contract when transferring makerFeeAsset.
        // The leading bytes4 references the id of the asset proxy.
        bytes makerFeeAssetData;
        // Encoded data that can be decoded by a specified proxy contract when transferring takerFeeAsset.
        // The leading bytes4 references the id of the asset proxy.
        bytes takerFeeAssetData;
    }
    /// @dev V3 `fillOrder()` results.`
    struct FillResults {
        // Total amount of makerAsset(s) filled.
        uint256 makerAssetFilledAmount;
        // Total amount of takerAsset(s) filled.
        uint256 takerAssetFilledAmount;
        // Total amount of fees paid by maker(s) to feeRecipient(s).
        uint256 makerFeePaid;
        // Total amount of fees paid by taker to feeRecipients(s).
        uint256 takerFeePaid;
        // Total amount of fees paid by taker to the staking contract.
        uint256 protocolFeePaid;
    }
    /// @dev Fills the input order.
    /// @param order Order struct containing order specifications.
    /// @param takerAssetFillAmount Desired amount of takerAsset to sell.
    /// @param signature Proof that order has been created by maker.
    /// @return fillResults Amounts filled and fees paid by maker and taker.
    function fillOrder(
        Order calldata order,
        uint256 takerAssetFillAmount,
        bytes calldata signature
    )
        external
        payable
        returns (FillResults memory fillResults);
    /// @dev Returns the protocolFeeMultiplier
    /// @return multiplier The multiplier for protocol fees.
    function protocolFeeMultiplier()
        external
        view
        returns (uint256 multiplier);
    /// @dev Gets an asset proxy.
    /// @param assetProxyId Id of the asset proxy.
    /// @return proxyAddress The asset proxy registered to assetProxyId.
    ///         Returns 0x0 if no proxy is registered.
    function getAssetProxy(bytes4 assetProxyId)
        external
        view
        returns (address proxyAddress);
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
import "@0x/contracts-erc20/contracts/src/v06/LibERC20TokenV06.sol";
import "../errors/LibTransformERC20RichErrors.sol";
import "./Transformer.sol";
import "./LibERC20Transformer.sol";
/// @dev A transformer that transfers tokens to the taker.
contract PayTakerTransformer is
    Transformer
{
    // solhint-disable no-empty-blocks
    using LibRichErrorsV06 for bytes;
    using LibSafeMathV06 for uint256;
    using LibERC20Transformer for IERC20TokenV06;
    /// @dev Transform data to ABI-encode and pass into `transform()`.
    struct TransformData {
        // The tokens to transfer to the taker.
        IERC20TokenV06[] tokens;
        // Amount of each token in `tokens` to transfer to the taker.
        // `uint(-1)` will transfer the entire balance.
        uint256[] amounts;
    }
    /// @dev Maximum uint256 value.
    uint256 private constant MAX_UINT256 = uint256(-1);
    /// @dev Create this contract.
    constructor()
        public
        Transformer()
    {}
    /// @dev Forwards tokens to the taker.
    /// @param taker The taker address (caller of `TransformERC20.transformERC20()`).
    /// @param data_ ABI-encoded `TransformData`, indicating which tokens to transfer.
    /// @return success The success bytes (`LibERC20Transformer.TRANSFORMER_SUCCESS`).
    function transform(
        bytes32, // callDataHash,
        address payable taker,
        bytes calldata data_
    )
        external
        override
        returns (bytes4 success)
    {
        TransformData memory data = abi.decode(data_, (TransformData));
        // Transfer tokens directly to the taker.
        for (uint256 i = 0; i < data.tokens.length; ++i) {
            // The `amounts` array can be shorter than the `tokens` array.
            // Missing elements are treated as `uint256(-1)`.
            uint256 amount = data.amounts.length > i ? data.amounts[i] : uint256(-1);
            if (amount == MAX_UINT256) {
                amount = data.tokens[i].getTokenBalanceOf(address(this));
            }
            if (amount != 0) {
                data.tokens[i].transformerTransfer(taker, amount);
            }
        }
        return LibERC20Transformer.TRANSFORMER_SUCCESS;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
import "@0x/contracts-erc20/contracts/src/v06/IEtherTokenV06.sol";
import "../errors/LibTransformERC20RichErrors.sol";
import "./Transformer.sol";
import "./LibERC20Transformer.sol";
/// @dev A transformer that wraps or unwraps WETH.
contract WethTransformer is
    Transformer
{
    using LibRichErrorsV06 for bytes;
    using LibSafeMathV06 for uint256;
    using LibERC20Transformer for IERC20TokenV06;
    /// @dev Transform data to ABI-encode and pass into `transform()`.
    struct TransformData {
        // The token to wrap/unwrap. Must be either ETH or WETH.
        IERC20TokenV06 token;
        // Amount of `token` to wrap or unwrap.
        // `uint(-1)` will unwrap the entire balance.
        uint256 amount;
    }
    /// @dev The WETH contract address.
    IEtherTokenV06 public immutable weth;
    /// @dev Maximum uint256 value.
    uint256 private constant MAX_UINT256 = uint256(-1);
    /// @dev Construct the transformer and store the WETH address in an immutable.
    /// @param weth_ The weth token.
    constructor(IEtherTokenV06 weth_)
        public
        Transformer()
    {
        weth = weth_;
    }
    /// @dev Wraps and unwraps WETH.
    /// @param data_ ABI-encoded `TransformData`, indicating which token to wrap/umwrap.
    /// @return success The success bytes (`LibERC20Transformer.TRANSFORMER_SUCCESS`).
    function transform(
        bytes32, // callDataHash,
        address payable, // taker,
        bytes calldata data_
    )
        external
        override
        returns (bytes4 success)
    {
        TransformData memory data = abi.decode(data_, (TransformData));
        if (!data.token.isTokenETH() && data.token != weth) {
            LibTransformERC20RichErrors.InvalidTransformDataError(
                LibTransformERC20RichErrors.InvalidTransformDataErrorCode.INVALID_TOKENS,
                data_
            ).rrevert();
        }
        uint256 amount = data.amount;
        if (amount == MAX_UINT256) {
            amount = data.token.getTokenBalanceOf(address(this));
        }
        if (amount != 0) {
            if (data.token.isTokenETH()) {
                // Wrap ETH.
                weth.deposit{value: amount}();
            } else {
                // Unwrap WETH.
                weth.withdraw(amount);
            }
        }
        return LibERC20Transformer.TRANSFORMER_SUCCESS;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
import "./IERC20TokenV06.sol";
interface IEtherTokenV06 is
    IERC20TokenV06
{
    /// @dev Wrap ether.
    function deposit() external payable;
    /// @dev Unwrap ether.
    function withdraw(uint256 amount) external;
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
interface ITestSimpleFunctionRegistryFeature {
    function testFn() external view returns (uint256 id);
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
contract TestCallTarget {
    event CallTargetCalled(
        address context,
        address sender,
        bytes data,
        uint256 value
    );
    bytes4 private constant MAGIC_BYTES = 0x12345678;
    bytes private constant REVERTING_DATA = hex"1337";
    fallback() external payable {
        if (keccak256(msg.data) == keccak256(REVERTING_DATA)) {
            revert("TestCallTarget/REVERT");
        }
        emit CallTargetCalled(
            address(this),
            msg.sender,
            msg.data,
            msg.value
        );
        bytes4 rval = MAGIC_BYTES;
        assembly {
            mstore(0, rval)
            return(0, 32)
        }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
contract TestDelegateCaller {
    function executeDelegateCall(
        address target,
        bytes calldata callData
    )
        external
    {
        (bool success, bytes memory resultData) = target.delegatecall(callData);
        if (!success) {
            assembly { revert(add(resultData, 32), mload(resultData)) }
        }
        assembly { return(add(resultData, 32), mload(resultData)) }
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/LibBytesV06.sol";
import "@0x/contracts-utils/contracts/src/v06/LibMathV06.sol";
import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
import "../src/vendor/v3/IExchange.sol";
import "./TestMintableERC20Token.sol";
contract TestFillQuoteTransformerExchange {
    struct FillBehavior {
        // How much of the order is filled, in taker asset amount.
        uint256 filledTakerAssetAmount;
        // Scaling for maker assets minted, in 1e18.
        uint256 makerAssetMintRatio;
    }
    uint256 private constant PROTOCOL_FEE_MULTIPLIER = 1337;
    using LibSafeMathV06 for uint256;
    function fillOrder(
        IExchange.Order calldata order,
        uint256 takerAssetFillAmount,
        bytes calldata signature
    )
        external
        payable
        returns (IExchange.FillResults memory fillResults)
    {
        require(
            signature.length != 0,
            "TestFillQuoteTransformerExchange/INVALID_SIGNATURE"
        );
        // The signature is the ABI-encoded FillBehavior data.
        FillBehavior memory behavior = abi.decode(signature, (FillBehavior));
        uint256 protocolFee = PROTOCOL_FEE_MULTIPLIER * tx.gasprice;
        require(
            msg.value == protocolFee,
            "TestFillQuoteTransformerExchange/INSUFFICIENT_PROTOCOL_FEE"
        );
        // Return excess protocol fee.
        msg.sender.transfer(msg.value - protocolFee);
        // Take taker tokens.
        TestMintableERC20Token takerToken = _getTokenFromAssetData(order.takerAssetData);
        takerAssetFillAmount = LibSafeMathV06.min256(
            order.takerAssetAmount.safeSub(behavior.filledTakerAssetAmount),
            takerAssetFillAmount
        );
        require(
            takerToken.getSpendableAmount(msg.sender, address(this)) >= takerAssetFillAmount,
            "TestFillQuoteTransformerExchange/INSUFFICIENT_TAKER_FUNDS"
        );
        takerToken.transferFrom(msg.sender, order.makerAddress, takerAssetFillAmount);
        // Mint maker tokens.
        uint256 makerAssetFilledAmount = LibMathV06.getPartialAmountFloor(
            takerAssetFillAmount,
            order.takerAssetAmount,
            order.makerAssetAmount
        );
        TestMintableERC20Token makerToken = _getTokenFromAssetData(order.makerAssetData);
        makerToken.mint(
            msg.sender,
            LibMathV06.getPartialAmountFloor(
                behavior.makerAssetMintRatio,
                1e18,
                makerAssetFilledAmount
            )
        );
        // Take taker fee.
        TestMintableERC20Token takerFeeToken = _getTokenFromAssetData(order.takerFeeAssetData);
        uint256 takerFee = LibMathV06.getPartialAmountFloor(
            takerAssetFillAmount,
            order.takerAssetAmount,
            order.takerFee
        );
        require(
            takerFeeToken.getSpendableAmount(msg.sender, address(this)) >= takerFee,
            "TestFillQuoteTransformerExchange/INSUFFICIENT_TAKER_FEE_FUNDS"
        );
        takerFeeToken.transferFrom(msg.sender, order.feeRecipientAddress, takerFee);
        fillResults.makerAssetFilledAmount = makerAssetFilledAmount;
        fillResults.takerAssetFilledAmount = takerAssetFillAmount;
        fillResults.makerFeePaid = uint256(-1);
        fillResults.takerFeePaid = takerFee;
        fillResults.protocolFeePaid = protocolFee;
    }
    function encodeBehaviorData(FillBehavior calldata behavior)
        external
        pure
        returns (bytes memory encoded)
    {
        return abi.encode(behavior);
    }
    function protocolFeeMultiplier()
        external
        pure
        returns (uint256)
    {
        return PROTOCOL_FEE_MULTIPLIER;
    }
    function getAssetProxy(bytes4)
        external
        view
        returns (address)
    {
        return address(this);
    }
    function _getTokenFromAssetData(bytes memory assetData)
        private
        pure
        returns (TestMintableERC20Token token)
    {
        return TestMintableERC20Token(LibBytesV06.readAddress(assetData, 16));
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
contract TestMintableERC20Token {
    mapping(address => uint256) public balanceOf;
    mapping(address => mapping(address => uint256)) public allowance;
    function transfer(address to, uint256 amount)
        external
        virtual
        returns (bool)
    {
        return transferFrom(msg.sender, to, amount);
    }
    function approve(address spender, uint256 amount)
        external
        virtual
        returns (bool)
    {
        allowance[msg.sender][spender] = amount;
        return true;
    }
    function mint(address owner, uint256 amount)
        external
        virtual
    {
        balanceOf[owner] += amount;
    }
    function burn(address owner, uint256 amount)
        external
        virtual
    {
        require(balanceOf[owner] >= amount, "TestMintableERC20Token/INSUFFICIENT_FUNDS");
        balanceOf[owner] -= amount;
    }
    function transferFrom(address from, address to, uint256 amount)
        public
        virtual
        returns (bool)
    {
        if (from != msg.sender) {
            require(
                allowance[from][msg.sender] >= amount,
                "TestMintableERC20Token/INSUFFICIENT_ALLOWANCE"
            );
            allowance[from][msg.sender] -= amount;
        }
        require(balanceOf[from] >= amount, "TestMintableERC20Token/INSUFFICIENT_FUNDS");
        balanceOf[from] -= amount;
        balanceOf[to] += amount;
        return true;
    }
    function getSpendableAmount(address owner, address spender)
        external
        view
        returns (uint256)
    {
        return balanceOf[owner] < allowance[owner][spender]
            ? balanceOf[owner]
            : allowance[owner][spender];
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "../src/transformers/IERC20Transformer.sol";
import "./TestMintableERC20Token.sol";
import "./TestTransformerHost.sol";
contract TestFillQuoteTransformerHost is
    TestTransformerHost
{
    function executeTransform(
        IERC20Transformer transformer,
        TestMintableERC20Token inputToken,
        uint256 inputTokenAmount,
        bytes calldata data
    )
        external
        payable
    {
        if (inputTokenAmount != 0) {
            inputToken.mint(address(this), inputTokenAmount);
        }
        // Have to make this call externally because transformers aren't payable.
        this.rawExecuteTransform(transformer, bytes32(0), msg.sender, data);
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
import "../src/transformers/IERC20Transformer.sol";
import "../src/transformers/LibERC20Transformer.sol";
contract TestTransformerHost {
    using LibERC20Transformer for IERC20TokenV06;
    using LibRichErrorsV06 for bytes;
    function rawExecuteTransform(
        IERC20Transformer transformer,
        bytes32 callDataHash,
        address taker,
        bytes calldata data
    )
        external
    {
        (bool _success, bytes memory resultData) =
            address(transformer).delegatecall(abi.encodeWithSelector(
                transformer.transform.selector,
                callDataHash,
                taker,
                data
            ));
        if (!_success) {
            resultData.rrevert();
        }
        require(
            abi.decode(resultData, (bytes4)) == LibERC20Transformer.TRANSFORMER_SUCCESS,
            "TestTransformerHost/INVALID_TRANSFORMER_RESULT"
        );
    }
    // solhint-disable
    receive() external payable {}
    // solhint-enable
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "../src/ZeroEx.sol";
import "../src/features/IBootstrap.sol";
import "../src/migrations/FullMigration.sol";
contract TestFullMigration is
    FullMigration
{
    address public dieRecipient;
    // solhint-disable-next-line no-empty-blocks
    constructor(address payable deployer) public FullMigration(deployer) {}
    function die(address payable ethRecipient) external override {
        dieRecipient = ethRecipient;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "../src/ZeroEx.sol";
import "../src/features/IBootstrap.sol";
import "../src/migrations/InitialMigration.sol";
contract TestInitialMigration is
    InitialMigration
{
    address public bootstrapFeature;
    address public dieRecipient;
    // solhint-disable-next-line no-empty-blocks
    constructor(address deployer) public InitialMigration(deployer) {}
    function callBootstrap(ZeroEx zeroEx) external {
        IBootstrap(address(zeroEx)).bootstrap(address(this), new bytes(0));
    }
    function bootstrap(address owner, BootstrapFeatures memory features)
        public
        override
        returns (bytes4 success)
    {
        success = InitialMigration.bootstrap(owner, features);
        // Snoop the bootstrap feature contract.
        bootstrapFeature = ZeroEx(address(uint160(address(this))))
            .getFunctionImplementation(IBootstrap.bootstrap.selector);
    }
    function die(address payable ethRecipient) public override {
        dieRecipient = ethRecipient;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "../src/migrations/LibMigrate.sol";
import "../src/features/IOwnable.sol";
contract TestMigrator {
    event TestMigrateCalled(
        bytes callData,
        address owner
    );
    function succeedingMigrate() external returns (bytes4 success) {
        emit TestMigrateCalled(
            msg.data,
            IOwnable(address(this)).owner()
        );
        return LibMigrate.MIGRATE_SUCCESS;
    }
    function failingMigrate() external returns (bytes4 success) {
        emit TestMigrateCalled(
            msg.data,
            IOwnable(address(this)).owner()
        );
        return 0xdeadbeef;
    }
    function revertingMigrate() external pure {
        revert("OOPSIE");
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
import "../src/transformers/IERC20Transformer.sol";
import "../src/transformers/LibERC20Transformer.sol";
import "./TestMintableERC20Token.sol";
contract TestMintTokenERC20Transformer is
    IERC20Transformer
{
    struct TransformData {
        IERC20TokenV06 inputToken;
        TestMintableERC20Token outputToken;
        uint256 burnAmount;
        uint256 mintAmount;
        uint256 feeAmount;
    }
    event MintTransform(
        address context,
        address caller,
        bytes32 callDataHash,
        address taker,
        bytes data,
        uint256 inputTokenBalance,
        uint256 ethBalance
    );
    function transform(
        bytes32 callDataHash,
        address payable taker,
        bytes calldata data_
    )
        external
        override
        returns (bytes4 success)
    {
        TransformData memory data = abi.decode(data_, (TransformData));
        emit MintTransform(
            address(this),
            msg.sender,
            callDataHash,
            taker,
            data_,
            data.inputToken.balanceOf(address(this)),
            address(this).balance
        );
        // "Burn" input tokens.
        data.inputToken.transfer(address(0), data.burnAmount);
        // Mint output tokens.
        if (LibERC20Transformer.isTokenETH(IERC20TokenV06(address(data.outputToken)))) {
            taker.transfer(data.mintAmount);
        } else {
            data.outputToken.mint(
                taker,
                data.mintAmount
            );
            // Burn fees from output.
            data.outputToken.burn(taker, data.feeAmount);
        }
        return LibERC20Transformer.TRANSFORMER_SUCCESS;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "../src/fixins/FixinCommon.sol";
contract TestSimpleFunctionRegistryFeatureImpl1 is
    FixinCommon
{
    function testFn()
        external
        pure
        returns (uint256 id)
    {
        return 1337;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "../src/fixins/FixinCommon.sol";
contract TestSimpleFunctionRegistryFeatureImpl2 is
    FixinCommon
{
    function testFn()
        external
        pure
        returns (uint256 id)
    {
        return 1338;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "../src/features/TokenSpender.sol";
contract TestTokenSpender is
    TokenSpender
{
    modifier onlySelf() override {
        _;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "./TestMintableERC20Token.sol";
contract TestTokenSpenderERC20Token is
    TestMintableERC20Token
{
    event TransferFromCalled(
        address sender,
        address from,
        address to,
        uint256 amount
    );
    // `transferFrom()` behavior depends on the value of `amount`.
    uint256 constant private EMPTY_RETURN_AMOUNT = 1337;
    uint256 constant private FALSE_RETURN_AMOUNT = 1338;
    uint256 constant private REVERT_RETURN_AMOUNT = 1339;
    function transferFrom(address from, address to, uint256 amount)
        public
        override
        returns (bool)
    {
        emit TransferFromCalled(msg.sender, from, to, amount);
        if (amount == EMPTY_RETURN_AMOUNT) {
            assembly { return(0, 0) }
        }
        if (amount == FALSE_RETURN_AMOUNT) {
            return false;
        }
        if (amount == REVERT_RETURN_AMOUNT) {
            revert("TestTokenSpenderERC20Token/Revert");
        }
        return true;
    }
    function setBalanceAndAllowanceOf(
        address owner,
        uint256 balance,
        address spender,
        uint256 allowance_
    )
        external
    {
        balanceOf[owner] = balance;
        allowance[owner][spender] = allowance_;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "../src/features/TransformERC20.sol";
contract TestTransformERC20 is
    TransformERC20
{
    // solhint-disable no-empty-blocks
    constructor()
        TransformERC20()
        public
    {}
    modifier onlySelf() override {
        _;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "../src/transformers/Transformer.sol";
import "../src/transformers/LibERC20Transformer.sol";
contract TestTransformerBase is
    Transformer
{
    function transform(
        bytes32,
        address payable,
        bytes calldata
    )
        external
        override
        returns (bytes4 success)
    {
        return LibERC20Transformer.TRANSFORMER_SUCCESS;
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "../src/transformers/LibERC20Transformer.sol";
contract TestTransformerDeployerTransformer {
    address payable public immutable deployer;
    constructor() public payable {
        deployer = msg.sender;
    }
    modifier onlyDeployer() {
        require(msg.sender == deployer, "TestTransformerDeployerTransformer/ONLY_DEPLOYER");
        _;
    }
    function die()
        external
        onlyDeployer
    {
        selfdestruct(deployer);
    }
    function isDeployedByDeployer(uint32 nonce)
        external
        view
        returns (bool)
    {
        return LibERC20Transformer.getDeployedAddress(deployer, nonce) == address(this);
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "./TestMintableERC20Token.sol";
contract TestWeth is
    TestMintableERC20Token
{
    function deposit()
        external
        payable
    {
        this.mint(msg.sender, msg.value);
    }
    function withdraw(uint256 amount)
        external
    {
        require(balanceOf[msg.sender] >= amount, "TestWeth/INSUFFICIENT_FUNDS");
        balanceOf[msg.sender] -= amount;
        msg.sender.transfer(amount);
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "../src/transformers/IERC20Transformer.sol";
import "./TestMintableERC20Token.sol";
import "./TestTransformerHost.sol";
import "./TestWeth.sol";
contract TestWethTransformerHost is
    TestTransformerHost
{
    // solhint-disable
    TestWeth private immutable _weth;
    // solhint-enable
    constructor(TestWeth weth) public {
        _weth = weth;
    }
    function executeTransform(
        uint256 wethAmount,
        IERC20Transformer transformer,
        bytes calldata data
    )
        external
        payable
    {
        if (wethAmount != 0) {
            _weth.deposit{value: wethAmount}();
        }
        // Have to make this call externally because transformers aren't payable.
        this.rawExecuteTransform(transformer, bytes32(0), msg.sender, data);
    }
}
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "../src/fixins/FixinCommon.sol";
import "../src/ZeroEx.sol";
contract TestZeroExFeature is
    FixinCommon
{
    event PayableFnCalled(uint256 value);
    event NotPayableFnCalled();
    function payableFn()
        external
        payable
    {
        emit PayableFnCalled(msg.value);
    }
    function notPayableFn()
        external
    {
        emit NotPayableFnCalled();
    }
    // solhint-disable no-empty-blocks
    function unimplmentedFn()
        external
    {}
    function internalFn()
        external
        onlySelf
    {}
}

// Copyright (C) 2015, 2016, 2017 Dapphub

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity ^0.4.18;

contract WETH9 {
    string public name     = "Wrapped Ether";
    string public symbol   = "WETH";
    uint8  public decimals = 18;

    event  Approval(address indexed src, address indexed guy, uint wad);
    event  Transfer(address indexed src, address indexed dst, uint wad);
    event  Deposit(address indexed dst, uint wad);
    event  Withdrawal(address indexed src, uint wad);

    mapping (address => uint)                       public  balanceOf;
    mapping (address => mapping (address => uint))  public  allowance;

    function() public payable {
        deposit();
    }
    function deposit() public payable {
        balanceOf[msg.sender] += msg.value;
        Deposit(msg.sender, msg.value);
    }
    function withdraw(uint wad) public {
        require(balanceOf[msg.sender] >= wad);
        balanceOf[msg.sender] -= wad;
        msg.sender.transfer(wad);
        Withdrawal(msg.sender, wad);
    }

    function totalSupply() public view returns (uint) {
        return this.balance;
    }

    function approve(address guy, uint wad) public returns (bool) {
        allowance[msg.sender][guy] = wad;
        Approval(msg.sender, guy, wad);
        return true;
    }

    function transfer(address dst, uint wad) public returns (bool) {
        return transferFrom(msg.sender, dst, wad);
    }

    function transferFrom(address src, address dst, uint wad)
        public
        returns (bool)
    {
        require(balanceOf[src] >= wad);

        if (src != msg.sender && allowance[src][msg.sender] != uint(-1)) {
            require(allowance[src][msg.sender] >= wad);
            allowance[src][msg.sender] -= wad;
        }

        balanceOf[src] -= wad;
        balanceOf[dst] += wad;

        Transfer(src, dst, wad);

        return true;
    }
}


/*
                    GNU GENERAL PUBLIC LICENSE
                       Version 3, 29 June 2007

 Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
 Everyone is permitted to copy and distribute verbatim copies
 of this license document, but changing it is not allowed.

                            Preamble

  The GNU General Public License is a free, copyleft license for
software and other kinds of works.

  The licenses for most software and other practical works are designed
to take away your freedom to share and change the works.  By contrast,
the GNU General Public License is intended to guarantee your freedom to
share and change all versions of a program--to make sure it remains free
software for all its users.  We, the Free Software Foundation, use the
GNU General Public License for most of our software; it applies also to
any other work released this way by its authors.  You can apply it to
your programs, too.

  When we speak of free software, we are referring to freedom, not
price.  Our General Public Licenses are designed to make sure that you
have the freedom to distribute copies of free software (and charge for
them if you wish), that you receive source code or can get it if you
want it, that you can change the software or use pieces of it in new
free programs, and that you know you can do these things.

  To protect your rights, we need to prevent others from denying you
these rights or asking you to surrender the rights.  Therefore, you have
certain responsibilities if you distribute copies of the software, or if
you modify it: responsibilities to respect the freedom of others.

  For example, if you distribute copies of such a program, whether
gratis or for a fee, you must pass on to the recipients the same
freedoms that you received.  You must make sure that they, too, receive
or can get the source code.  And you must show them these terms so they
know their rights.

  Developers that use the GNU GPL protect your rights with two steps:
(1) assert copyright on the software, and (2) offer you this License
giving you legal permission to copy, distribute and/or modify it.

  For the developers' and authors' protection, the GPL clearly explains
that there is no warranty for this free software.  For both users' and
authors' sake, the GPL requires that modified versions be marked as
changed, so that their problems will not be attributed erroneously to
authors of previous versions.

  Some devices are designed to deny users access to install or run
modified versions of the software inside them, although the manufacturer
can do so.  This is fundamentally incompatible with the aim of
protecting users' freedom to change the software.  The systematic
pattern of such abuse occurs in the area of products for individuals to
use, which is precisely where it is most unacceptable.  Therefore, we
have designed this version of the GPL to prohibit the practice for those
products.  If such problems arise substantially in other domains, we
stand ready to extend this provision to those domains in future versions
of the GPL, as needed to protect the freedom of users.

  Finally, every program is threatened constantly by software patents.
States should not allow patents to restrict development and use of
software on general-purpose computers, but in those that do, we wish to
avoid the special danger that patents applied to a free program could
make it effectively proprietary.  To prevent this, the GPL assures that
patents cannot be used to render the program non-free.

  The precise terms and conditions for copying, distribution and
modification follow.

                       TERMS AND CONDITIONS

  0. Definitions.

  "This License" refers to version 3 of the GNU General Public License.

  "Copyright" also means copyright-like laws that apply to other kinds of
works, such as semiconductor masks.

  "The Program" refers to any copyrightable work licensed under this
License.  Each licensee is addressed as "you".  "Licensees" and
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  To "modify" a work means to copy from or adapt all or part of the work
in a fashion requiring copyright permission, other than the making of an
exact copy.  The resulting work is called a "modified version" of the
earlier work or a work "based on" the earlier work.

  A "covered work" means either the unmodified Program or a work based
on the Program.

  To "propagate" a work means to do anything with it that, without
permission, would make you directly or secondarily liable for
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  To "convey" a work means any kind of propagation that enables other
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  An interactive user interface displays "Appropriate Legal Notices"
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feature that (1) displays an appropriate copyright notice, and (2)
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  All rights granted under this License are granted for the term of
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  You may make, run and propagate covered works that you do not
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  You may convey verbatim copies of the Program's source code as you
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and you may offer support or warranty protection for a fee.

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  You may convey a work based on the Program, or the modifications to
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    a) The work must carry prominent notices stating that you modified
    it, and giving a relevant date.

    b) The work must carry prominent notices stating that it is
    released under this License and any conditions added under section
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    License to anyone who comes into possession of a copy.  This
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  You may convey a covered work in object code form under the terms
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  If the disclaimer of warranty and limitation of liability provided
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                     END OF TERMS AND CONDITIONS

            How to Apply These Terms to Your New Programs

  If you develop a new program, and you want it to be of the greatest
possible use to the public, the best way to achieve this is to make it
free software which everyone can redistribute and change under these terms.

  To do so, attach the following notices to the program.  It is safest
to attach them to the start of each source file to most effectively
state the exclusion of warranty; and each file should have at least
the "copyright" line and a pointer to where the full notice is found.

    <one line to give the program's name and a brief idea of what it does.>
    Copyright (C) <year>  <name of author>

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.

Also add information on how to contact you by electronic and paper mail.

  If the program does terminal interaction, make it output a short
notice like this when it starts in an interactive mode:

    <program>  Copyright (C) <year>  <name of author>
    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
    This is free software, and you are welcome to redistribute it
    under certain conditions; type `show c' for details.

The hypothetical commands `show w' and `show c' should show the appropriate
parts of the General Public License.  Of course, your program's commands
might be different; for a GUI interface, you would use an "about box".

  You should also get your employer (if you work as a programmer) or school,
if any, to sign a "copyright disclaimer" for the program, if necessary.
For more information on this, and how to apply and follow the GNU GPL, see
<http://www.gnu.org/licenses/>.

  The GNU General Public License does not permit incorporating your program
into proprietary programs.  If your program is a subroutine library, you
may consider it more useful to permit linking proprietary applications with
the library.  If this is what you want to do, use the GNU Lesser General
Public License instead of this License.  But first, please read
<http://www.gnu.org/philosophy/why-not-lgpl.html>.

*/

// File: contracts/BTRFLY.sol


pragma solidity 0.7.5;

library EnumerableSet {

  // To implement this library for multiple types with as little code
  // repetition as possible, we write it in terms of a generic Set type with
  // bytes32 values.
  // The Set implementation uses private functions, and user-facing
  // implementations (such as AddressSet) are just wrappers around the
  // underlying Set.
  // This means that we can only create new EnumerableSets for types that fit
  // in bytes32.
  struct Set {
    // Storage of set values
    bytes32[] _values;

    // Position of the value in the `values` array, plus 1 because index 0
    // means a value is not in the set.
    mapping (bytes32 => uint256) _indexes;
  }

  /**
   * @dev Add a value to a set. O(1).
   *
   * Returns true if the value was added to the set, that is if it was not
   * already present.
   */
  function _add(Set storage set, bytes32 value) private returns (bool) {
    if (!_contains(set, value)) {
      set._values.push(value);
      // The value is stored at length-1, but we add 1 to all indexes
      // and use 0 as a sentinel value
      set._indexes[value] = set._values.length;
      return true;
    } else {
      return false;
    }
  }

  /**
   * @dev Removes a value from a set. O(1).
   *
   * Returns true if the value was removed from the set, that is if it was
   * present.
   */
  function _remove(Set storage set, bytes32 value) private returns (bool) {
    // We read and store the value's index to prevent multiple reads from the same storage slot
    uint256 valueIndex = set._indexes[value];

    if (valueIndex != 0) { // Equivalent to contains(set, value)
      // To delete an element from the _values array in O(1), we swap the element to delete with the last one in
      // the array, and then remove the last element (sometimes called as 'swap and pop').
      // This modifies the order of the array, as noted in {at}.

      uint256 toDeleteIndex = valueIndex - 1;
      uint256 lastIndex = set._values.length - 1;

      // When the value to delete is the last one, the swap operation is unnecessary. However, since this occurs
      // so rarely, we still do the swap anyway to avoid the gas cost of adding an 'if' statement.

      bytes32 lastvalue = set._values[lastIndex];

      // Move the last value to the index where the value to delete is
      set._values[toDeleteIndex] = lastvalue;
      // Update the index for the moved value
      set._indexes[lastvalue] = toDeleteIndex + 1; // All indexes are 1-based

      // Delete the slot where the moved value was stored
      set._values.pop();

      // Delete the index for the deleted slot
      delete set._indexes[value];

      return true;
    } else {
      return false;
    }
  }

  /**
   * @dev Returns true if the value is in the set. O(1).
   */
  function _contains(Set storage set, bytes32 value) private view returns (bool) {
    return set._indexes[value] != 0;
  }

  /**
   * @dev Returns the number of values on the set. O(1).
   */
  function _length(Set storage set) private view returns (uint256) {
    return set._values.length;
  }

   /**
    * @dev Returns the value stored at position `index` in the set. O(1).
    *
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
  function _at(Set storage set, uint256 index) private view returns (bytes32) {
    require(set._values.length > index, "EnumerableSet: index out of bounds");
    return set._values[index];
  }

  function _getValues( Set storage set_ ) private view returns ( bytes32[] storage ) {
    return set_._values;
  }

  // TODO needs insert function that maintains order.
  // TODO needs NatSpec documentation comment.
  /**
   * Inserts new value by moving existing value at provided index to end of array and setting provided value at provided index
   */
  function _insert(Set storage set_, uint256 index_, bytes32 valueToInsert_ ) private returns ( bool ) {
    require(  set_._values.length > index_ );
    require( !_contains( set_, valueToInsert_ ), "Remove value you wish to insert if you wish to reorder array." );
    bytes32 existingValue_ = _at( set_, index_ );
    set_._values[index_] = valueToInsert_;
    return _add( set_, existingValue_);
  } 

  struct Bytes4Set {
    Set _inner;
  }

  /**
   * @dev Add a value to a set. O(1).
   *
   * Returns true if the value was added to the set, that is if it was not
   * already present.
   */
  function add(Bytes4Set storage set, bytes4 value) internal returns (bool) {
    return _add(set._inner, value);
  }

  /**
   * @dev Removes a value from a set. O(1).
   *
   * Returns true if the value was removed from the set, that is if it was
   * present.
   */
  function remove(Bytes4Set storage set, bytes4 value) internal returns (bool) {
    return _remove(set._inner, value);
  }

  /**
   * @dev Returns true if the value is in the set. O(1).
   */
  function contains(Bytes4Set storage set, bytes4 value) internal view returns (bool) {
    return _contains(set._inner, value);
  }

  /**
   * @dev Returns the number of values on the set. O(1).
   */
  function length(Bytes4Set storage set) internal view returns (uint256) {
    return _length(set._inner);
  }

  /**
   * @dev Returns the value stored at position `index` in the set. O(1).
   *
   * Note that there are no guarantees on the ordering of values inside the
   * array, and it may change when more values are added or removed.
   *
   * Requirements:
   *
   * - `index` must be strictly less than {length}.
   */
  function at(Bytes4Set storage set, uint256 index) internal view returns ( bytes4 ) {
    return bytes4( _at( set._inner, index ) );
  }

  function getValues( Bytes4Set storage set_ ) internal view returns ( bytes4[] memory ) {
    bytes4[] memory bytes4Array_;
    for( uint256 iteration_ = 0; _length( set_._inner ) > iteration_; iteration_++ ) {
      bytes4Array_[iteration_] = bytes4( _at( set_._inner, iteration_ ) );
    }
    return bytes4Array_;
  }

  function insert( Bytes4Set storage set_, uint256 index_, bytes4 valueToInsert_ ) internal returns ( bool ) {
    return _insert( set_._inner, index_, valueToInsert_ );
  }

    struct Bytes32Set {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _add(set._inner, value);
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _remove(set._inner, value);
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
        return _contains(set._inner, value);
    }

    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function length(Bytes32Set storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(Bytes32Set storage set, uint256 index) internal view returns ( bytes32 ) {
        return _at(set._inner, index);
    }

  function getValues( Bytes32Set storage set_ ) internal view returns ( bytes4[] memory ) {
    bytes4[] memory bytes4Array_;

      for( uint256 iteration_ = 0; _length( set_._inner ) >= iteration_; iteration_++ ){
        bytes4Array_[iteration_] = bytes4( at( set_, iteration_ ) );
      }

      return bytes4Array_;
  }

  function insert( Bytes32Set storage set_, uint256 index_, bytes32 valueToInsert_ ) internal returns ( bool ) {
    return _insert( set_._inner, index_, valueToInsert_ );
  }

  // AddressSet
  struct AddressSet {
    Set _inner;
  }

  /**
   * @dev Add a value to a set. O(1).
   *
   * Returns true if the value was added to the set, that is if it was not
   * already present.
   */
  function add(AddressSet storage set, address value) internal returns (bool) {
    return _add(set._inner, bytes32(uint256(value)));
  }

  /**
   * @dev Removes a value from a set. O(1).
   *
   * Returns true if the value was removed from the set, that is if it was
   * present.
   */
  function remove(AddressSet storage set, address value) internal returns (bool) {
    return _remove(set._inner, bytes32(uint256(value)));
  }

  /**
   * @dev Returns true if the value is in the set. O(1).
   */
  function contains(AddressSet storage set, address value) internal view returns (bool) {
    return _contains(set._inner, bytes32(uint256(value)));
  }

  /**
   * @dev Returns the number of values in the set. O(1).
   */
  function length(AddressSet storage set) internal view returns (uint256) {
    return _length(set._inner);
  }

  /**
   * @dev Returns the value stored at position `index` in the set. O(1).
   *
   * Note that there are no guarantees on the ordering of values inside the
   * array, and it may change when more values are added or removed.
   *
   * Requirements:
   *
   * - `index` must be strictly less than {length}.
   */
  function at(AddressSet storage set, uint256 index) internal view returns (address) {
    return address(uint256(_at(set._inner, index)));
  }

  /**
   * TODO Might require explicit conversion of bytes32[] to address[].
   *  Might require iteration.
   */
  function getValues( AddressSet storage set_ ) internal view returns ( address[] memory ) {

    address[] memory addressArray;

    for( uint256 iteration_ = 0; _length(set_._inner) >= iteration_; iteration_++ ){
      addressArray[iteration_] = at( set_, iteration_ );
    }

    return addressArray;
  }

  function insert(AddressSet storage set_, uint256 index_, address valueToInsert_ ) internal returns ( bool ) {
    return _insert( set_._inner, index_, bytes32(uint256(valueToInsert_)) );
  }


    // UintSet

    struct UintSet {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(UintSet storage set, uint256 value) internal returns (bool) {
        return _add(set._inner, bytes32(value));
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(UintSet storage set, uint256 value) internal returns (bool) {
        return _remove(set._inner, bytes32(value));
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(UintSet storage set, uint256 value) internal view returns (bool) {
        return _contains(set._inner, bytes32(value));
    }

    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function length(UintSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

   /**
    * @dev Returns the value stored at position `index` in the set. O(1).
    *
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function at(UintSet storage set, uint256 index) internal view returns (uint256) {
        return uint256(_at(set._inner, index));
    }

    struct UInt256Set {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(UInt256Set storage set, uint256 value) internal returns (bool) {
        return _add(set._inner, bytes32(value));
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(UInt256Set storage set, uint256 value) internal returns (bool) {
        return _remove(set._inner, bytes32(value));
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(UInt256Set storage set, uint256 value) internal view returns (bool) {
        return _contains(set._inner, bytes32(value));
    }

    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function length(UInt256Set storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(UInt256Set storage set, uint256 index) internal view returns (uint256) {
        return uint256(_at(set._inner, index));
    }
}

interface IERC20 {
  /**
   * @dev Returns the amount of tokens in existence.
   */
  function totalSupply() external view returns (uint256);

  /**
   * @dev Returns the amount of tokens owned by `account`.
   */
  function balanceOf(address account) external view returns (uint256);

  /**
   * @dev Moves `amount` tokens from the caller's account to `recipient`.
   *
   * Returns a boolean value indicating whether the operation succeeded.
   *
   * Emits a {Transfer} event.
   */
  function transfer(address recipient, uint256 amount) external returns (bool);

  /**
   * @dev Returns the remaining number of tokens that `spender` will be
   * allowed to spend on behalf of `owner` through {transferFrom}. This is
   * zero by default.
   *
   * This value changes when {approve} or {transferFrom} are called.
   */
  function allowance(address owner, address spender) external view returns (uint256);

  /**
   * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
   *
   * Returns a boolean value indicating whether the operation succeeded.
   *
   * IMPORTANT: Beware that changing an allowance with this method brings the risk
   * that someone may use both the old and the new allowance by unfortunate
   * transaction ordering. One possible solution to mitigate this race
   * condition is to first reduce the spender's allowance to 0 and set the
   * desired value afterwards:
   * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
   *
   * Emits an {Approval} event.
   */
  function approve(address spender, uint256 amount) external returns (bool);

  /**
   * @dev Moves `amount` tokens from `sender` to `recipient` using the
   * allowance mechanism. `amount` is then deducted from the caller's
   * allowance.
   *
   * Returns a boolean value indicating whether the operation succeeded.
   *
   * Emits a {Transfer} event.
   */
  function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);

  /**
   * @dev Emitted when `value` tokens are moved from one account (`from`) to
   * another (`to`).
   *
   * Note that `value` may be zero.
   */
  event Transfer(address indexed from, address indexed to, uint256 value);

  /**
   * @dev Emitted when the allowance of a `spender` for an `owner` is set by
   * a call to {approve}. `value` is the new allowance.
   */
  event Approval(address indexed owner, address indexed spender, uint256 value);
}

library SafeMath {

    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }

    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }

    function mul(uint256 a, uint256 b) internal pure returns (uint256) {

        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
    }

    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }

    function sqrrt(uint256 a) internal pure returns (uint c) {
        if (a > 3) {
            c = a;
            uint b = add( div( a, 2), 1 );
            while (b < c) {
                c = b;
                b = div( add( div( a, b ), b), 2 );
            }
        } else if (a != 0) {
            c = 1;
        }
    }

    function percentageAmount( uint256 total_, uint8 percentage_ ) internal pure returns ( uint256 percentAmount_ ) {
        return div( mul( total_, percentage_ ), 1000 );
    }

    function substractPercentage( uint256 total_, uint8 percentageToSub_ ) internal pure returns ( uint256 result_ ) {
        return sub( total_, div( mul( total_, percentageToSub_ ), 1000 ) );
    }

    function percentageOfTotal( uint256 part_, uint256 total_ ) internal pure returns ( uint256 percent_ ) {
        return div( mul(part_, 100) , total_ );
    }

    function average(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b) / 2 can overflow, so we distribute
        return (a / 2) + (b / 2) + ((a % 2 + b % 2) / 2);
    }

    function quadraticPricing( uint256 payment_, uint256 multiplier_ ) internal pure returns (uint256) {
        return sqrrt( mul( multiplier_, payment_ ) );
    }

  function bondingCurve( uint256 supply_, uint256 multiplier_ ) internal pure returns (uint256) {
      return mul( multiplier_, supply_ );
  }
}

abstract contract ERC20 is IERC20 {

  using SafeMath for uint256;

  // TODO comment actual hash value.
  bytes32 constant private ERC20TOKEN_ERC1820_INTERFACE_ID = keccak256( "ERC20Token" );
    
  // Present in ERC777
  mapping (address => uint256) internal _balances;

  // Present in ERC777
  mapping (address => mapping (address => uint256)) internal _allowances;

  // Present in ERC777
  uint256 internal _totalSupply;

  // Present in ERC777
  string internal _name;
    
  // Present in ERC777
  string internal _symbol;
    
  // Present in ERC777
  uint8 internal _decimals;

  constructor (string memory name_, string memory symbol_, uint8 decimals_) {
    _name = name_;
    _symbol = symbol_;
    _decimals = decimals_;
  }

  function name() public view returns (string memory) {
    return _name;
  }

  function symbol() public view returns (string memory) {
    return _symbol;
  }

  function decimals() public view returns (uint8) {
    return _decimals;
  }

  function totalSupply() public view override returns (uint256) {
    return _totalSupply;
  }

  function balanceOf(address account) public view virtual override returns (uint256) {
    return _balances[account];
  }

  function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
    _transfer(msg.sender, recipient, amount);
    return true;
  }

    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        _approve(msg.sender, spender, amount);
        return true;
    }

    function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(sender, recipient, amount);
        _approve(sender, msg.sender, _allowances[sender][msg.sender].sub(amount, "ERC20: transfer amount exceeds allowance"));
        return true;
    }

    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        _approve(msg.sender, spender, _allowances[msg.sender][spender].add(addedValue));
        return true;
    }

    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        _approve(msg.sender, spender, _allowances[msg.sender][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
        return true;
    }

    function _transfer(address sender, address recipient, uint256 amount) internal virtual {
      require(sender != address(0), "ERC20: transfer from the zero address");
      require(recipient != address(0), "ERC20: transfer to the zero address");

      _beforeTokenTransfer(sender, recipient, amount);

      _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
      _balances[recipient] = _balances[recipient].add(amount);
      emit Transfer(sender, recipient, amount);
    }

    function _mint(address account_, uint256 amount_) internal virtual {
        require(account_ != address(0), "ERC20: mint to the zero address");
        _beforeTokenTransfer(address( this ), account_, amount_);
        _totalSupply = _totalSupply.add(amount_);
        _balances[account_] = _balances[account_].add(amount_);
        emit Transfer(address( this ), account_, amount_);
    }

    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        _balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
        _totalSupply = _totalSupply.sub(amount);
        emit Transfer(account, address(0), amount);
    }

    function _approve(address owner, address spender, uint256 amount) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

  function _beforeTokenTransfer( address from_, address to_, uint256 amount_ ) internal virtual { }
}

library Counters {
    using SafeMath for uint256;

    struct Counter {
        uint256 _value; // default: 0
    }

    function current(Counter storage counter) internal view returns (uint256) {
        return counter._value;
    }

    function increment(Counter storage counter) internal {
        counter._value += 1;
    }

    function decrement(Counter storage counter) internal {
        counter._value = counter._value.sub(1);
    }
}

interface IERC2612Permit {

    function permit(
        address owner,
        address spender,
        uint256 amount,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;

    function nonces(address owner) external view returns (uint256);
}

abstract contract ERC20Permit is ERC20, IERC2612Permit {
    using Counters for Counters.Counter;

    mapping(address => Counters.Counter) private _nonces;

    // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
    bytes32 public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;

    bytes32 public DOMAIN_SEPARATOR;

    constructor() {
        uint256 chainID;
        assembly {
            chainID := chainid()
        }

        DOMAIN_SEPARATOR = keccak256(
            abi.encode(
                keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"),
                keccak256(bytes(name())),
                keccak256(bytes("1")), // Version
                chainID,
                address(this)
            )
        );
    }

    function permit(
        address owner,
        address spender,
        uint256 amount,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) public virtual override {
        require(block.timestamp <= deadline, "Permit: expired deadline");

        bytes32 hashStruct =
            keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, amount, _nonces[owner].current(), deadline));

        bytes32 _hash = keccak256(abi.encodePacked(uint16(0x1901), DOMAIN_SEPARATOR, hashStruct));

        address signer = ecrecover(_hash, v, r, s);
        require(signer != address(0) && signer == owner, "ZeroSwapPermit: Invalid signature");

        _nonces[owner].increment();
        _approve(owner, spender, amount);
    }

    function nonces(address owner) public view override returns (uint256) {
        return _nonces[owner].current();
    }
}

interface IOwnable {
  function owner() external view returns (address);

  function renounceOwnership() external;
  
  function transferOwnership( address newOwner_ ) external;
}

contract Ownable is IOwnable {
    
  address internal _owner;

  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

  constructor () {
    _owner = msg.sender;
    emit OwnershipTransferred( address(0), _owner );
  }

  function owner() public view override returns (address) {
    return _owner;
  }

  modifier onlyOwner() {
    require( _owner == msg.sender, "Ownable: caller is not the owner" );
    _;
  }

  function renounceOwnership() public virtual override onlyOwner() {
    emit OwnershipTransferred( _owner, address(0) );
    _owner = address(0);
  }

  function transferOwnership( address newOwner_ ) public virtual override onlyOwner() {
    require( newOwner_ != address(0), "Ownable: new owner is the zero address");
    emit OwnershipTransferred( _owner, newOwner_ );
    _owner = newOwner_;
  }
}

contract VaultOwned is Ownable {
    
  address internal _vault;

  function setVault( address vault_ ) public onlyOwner() returns ( bool ) {
    _vault = vault_;

    return true;
  }

  function vault() public view returns (address) {
    return _vault;
  }

  modifier onlyVault() {
    require( _vault == msg.sender, "VaultOwned: caller is not the Vault" );
    _;
  }

}


abstract contract FrozenToken is ERC20Permit, Ownable {

  using SafeMath for uint256;

  bool public isTokenFrozen = true;
  mapping (address => bool ) public isAuthorisedOperators;


  modifier onlyAuthorisedOperators () {
    require(!isTokenFrozen || isAuthorisedOperators[msg.sender], 'Frozen: token frozen or msg.sender not authorised');
    _;
  }


  function unFreezeToken () external onlyOwner () {
    isTokenFrozen = false;
  }

  function changeAuthorisation (address operator, bool status) public onlyOwner {
    require(operator != address(0), "Frozen: new operator cant be zero address");
    isAuthorisedOperators[operator] = status; 
  }


  function addBatchAuthorisedOperators(address[] memory authorisedOperatorsArray) external onlyOwner {
    for (uint i = 0; i < authorisedOperatorsArray.length; i++) {
    changeAuthorisation(authorisedOperatorsArray[i],true);
    }
  }


  function transfer(address recipient, uint256 amount) public virtual override onlyAuthorisedOperators returns (bool){
  _transfer(msg.sender, recipient, amount);
    return true;
  }

  function transferFrom(address sender, address recipient, uint256 amount) public virtual override onlyAuthorisedOperators returns (bool) {
    _transfer(sender, recipient, amount);
    _approve(sender, msg.sender, _allowances[sender][msg.sender].sub(amount, "ERC20: transfer amount exceeds allowance"));
    return true;
  }

}

contract BTRFLY is VaultOwned, FrozenToken {
  using SafeMath for uint256;

  constructor() ERC20("BTRFLY", "BTRFLY", 9) ERC20Permit() {
    setVault(msg.sender);
  }

  function mint(address account_, uint256 amount_) external onlyVault() {
  _mint(account_, amount_);
  }

  function burn(uint256 amount) public virtual {
    _burn(msg.sender, amount);
  }
  
  function burnFrom(address account_, uint256 amount_) public virtual {
    _burnFrom(account_, amount_);
  }

  function _burnFrom(address account_, uint256 amount_) public virtual {
    uint256 decreasedAllowance_ =
        allowance(account_, msg.sender).sub(
            amount_,
            "ERC20: burn amount exceeds allowance"
        );

    _approve(account_, msg.sender, decreasedAllowance_);
    _burn(account_, amount_);
  }
  
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "./Proxy.sol";
interface ERC165 {
    function supportsInterface(bytes4 id) external view returns (bool);
}
///@notice Proxy implementing EIP173 for ownership management
contract EIP173Proxy is Proxy {
    // ////////////////////////// EVENTS ///////////////////////////////////////////////////////////////////////
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    // /////////////////////// CONSTRUCTOR //////////////////////////////////////////////////////////////////////
    constructor(
        address implementationAddress,
        address ownerAddress,
        bytes memory data
    ) payable {
        _setImplementation(implementationAddress, data);
        _setOwner(ownerAddress);
    }
    // ///////////////////// EXTERNAL ///////////////////////////////////////////////////////////////////////////
    function owner() external view returns (address) {
        return _owner();
    }
    function supportsInterface(bytes4 id) external view returns (bool) {
        if (id == 0x01ffc9a7 || id == 0x7f5828d0) {
            return true;
        }
        if (id == 0xFFFFFFFF) {
            return false;
        }
        ERC165 implementation;
        // solhint-disable-next-line security/no-inline-assembly
        assembly {
            implementation := sload(0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc)
        }
        // Technically this is not standard compliant as ERC-165 require 30,000 gas which that call cannot ensure
        // because it is itself inside `supportsInterface` that might only get 30,000 gas.
        // In practise this is unlikely to be an issue.
        try implementation.supportsInterface(id) returns (bool support) {
            return support;
        } catch {
            return false;
        }
    }
    function transferOwnership(address newOwner) external onlyOwner {
        _setOwner(newOwner);
    }
    function upgradeTo(address newImplementation) external onlyOwner {
        _setImplementation(newImplementation, "");
    }
    function upgradeToAndCall(address newImplementation, bytes calldata data) external payable onlyOwner {
        _setImplementation(newImplementation, data);
    }
    // /////////////////////// MODIFIERS ////////////////////////////////////////////////////////////////////////
    modifier onlyOwner() {
        require(msg.sender == _owner(), "NOT_AUTHORIZED");
        _;
    }
    // ///////////////////////// INTERNAL //////////////////////////////////////////////////////////////////////
    function _owner() internal view returns (address adminAddress) {
        // solhint-disable-next-line security/no-inline-assembly
        assembly {
            adminAddress := sload(0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103)
        }
    }
    function _setOwner(address newOwner) internal {
        address previousOwner = _owner();
        // solhint-disable-next-line security/no-inline-assembly
        assembly {
            sstore(0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103, newOwner)
        }
        emit OwnershipTransferred(previousOwner, newOwner);
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
// EIP-1967
abstract contract Proxy {
    // /////////////////////// EVENTS ///////////////////////////////////////////////////////////////////////////
    event ProxyImplementationUpdated(address indexed previousImplementation, address indexed newImplementation);
    // ///////////////////// EXTERNAL ///////////////////////////////////////////////////////////////////////////
    receive() external payable virtual {
        revert("ETHER_REJECTED"); // explicit reject by default
    }
    fallback() external payable {
        _fallback();
    }
    // ///////////////////////// INTERNAL //////////////////////////////////////////////////////////////////////
    function _fallback() internal {
        // solhint-disable-next-line security/no-inline-assembly
        assembly {
            let implementationAddress := sload(0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc)
            calldatacopy(0x0, 0x0, calldatasize())
            let success := delegatecall(gas(), implementationAddress, 0x0, calldatasize(), 0, 0)
            let retSz := returndatasize()
            returndatacopy(0, 0, retSz)
            switch success
                case 0 {
                    revert(0, retSz)
                }
                default {
                    return(0, retSz)
                }
        }
    }
    function _setImplementation(address newImplementation, bytes memory data) internal {
        address previousImplementation;
        // solhint-disable-next-line security/no-inline-assembly
        assembly {
            previousImplementation := sload(0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc)
        }
        // solhint-disable-next-line security/no-inline-assembly
        assembly {
            sstore(0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc, newImplementation)
        }
        emit ProxyImplementationUpdated(previousImplementation, newImplementation);
        if (data.length > 0) {
            (bool success, ) = newImplementation.delegatecall(data);
            if (!success) {
                assembly {
                    // This assembly ensure the revert contains the exact string data
                    let returnDataSize := returndatasize()
                    returndatacopy(0, 0, returnDataSize)
                    revert(0, returnDataSize)
                }
            }
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "./EIP173Proxy.sol";
///@notice Proxy implementing EIP173 for ownership management that accept ETH via receive
contract EIP173ProxyWithReceive is EIP173Proxy {
    constructor(
        address implementationAddress,
        address ownerAddress,
        bytes memory data
    ) payable EIP173Proxy(implementationAddress, ownerAddress, data) {}
    receive() external payable override {}
}

// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
import "./interfaces/GPv2Authentication.sol";
import "./libraries/GPv2EIP1967.sol";
import "./mixins/Initializable.sol";
import "./mixins/StorageAccessible.sol";
/// @title Gnosis Protocol v2 Access Control Contract
/// @author Gnosis Developers
contract GPv2AllowListAuthentication is
    GPv2Authentication,
    Initializable,
    StorageAccessible
{
    /// @dev The address of the manager that has permissions to add and remove
    /// solvers.
    address public manager;
    /// @dev The set of allowed solvers. Allowed solvers have a value of `true`
    /// in this mapping.
    mapping(address => bool) private solvers;
    /// @dev Event emitted when the manager changes.
    event ManagerChanged(address newManager, address oldManager);
    /// @dev Event emitted when a solver gets added.
    event SolverAdded(address solver);
    /// @dev Event emitted when a solver gets removed.
    event SolverRemoved(address solver);
    /// @dev Initialize the manager to a value.
    ///
    /// This method is a contract initializer that is called exactly once after
    /// creation. An initializer is used instead of a constructor so that this
    /// contract can be used behind a proxy.
    ///
    /// This initializer is idempotent.
    ///
    /// @param manager_ The manager to initialize the contract with.
    function initializeManager(address manager_) external initializer {
        manager = manager_;
        emit ManagerChanged(manager_, address(0));
    }
    /// @dev Modifier that ensures a method can only be called by the contract
    /// manager. Reverts if called by other addresses.
    modifier onlyManager() {
        require(manager == msg.sender, "GPv2: caller not manager");
        _;
    }
    /// @dev Modifier that ensures method can be either called by the contract
    /// manager or the proxy owner.
    ///
    /// This modifier assumes that the proxy uses an EIP-1967 compliant storage
    /// slot for the admin.
    modifier onlyManagerOrOwner() {
        require(
            manager == msg.sender || GPv2EIP1967.getAdmin() == msg.sender,
            "GPv2: not authorized"
        );
        _;
    }
    /// @dev Set the manager for this contract.
    ///
    /// This method can be called by the current manager (if they want to to
    /// reliquish the role and give it to another address) or the contract
    /// owner (i.e. the proxy admin).
    ///
    /// @param manager_ The new contract manager address.
    function setManager(address manager_) external onlyManagerOrOwner {
        address oldManager = manager;
        manager = manager_;
        emit ManagerChanged(manager_, oldManager);
    }
    /// @dev Add an address to the set of allowed solvers. This method can only
    /// be called by the contract manager.
    ///
    /// This function is idempotent.
    ///
    /// @param solver The solver address to add.
    function addSolver(address solver) external onlyManager {
        solvers[solver] = true;
        emit SolverAdded(solver);
    }
    /// @dev Removes an address to the set of allowed solvers. This method can
    /// only be called by the contract manager.
    ///
    /// This function is idempotent.
    ///
    /// @param solver The solver address to remove.
    function removeSolver(address solver) external onlyManager {
        solvers[solver] = false;
        emit SolverRemoved(solver);
    }
    /// @inheritdoc GPv2Authentication
    function isSolver(address prospectiveSolver)
        external
        view
        override
        returns (bool)
    {
        return solvers[prospectiveSolver];
    }
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
/// @title Gnosis Protocol v2 Authentication Interface
/// @author Gnosis Developers
interface GPv2Authentication {
    /// @dev determines whether the provided address is an authenticated solver.
    /// @param prospectiveSolver the address of prospective solver.
    /// @return true when prospectiveSolver is an authenticated solver, otherwise false.
    function isSolver(address prospectiveSolver) external view returns (bool);
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
library GPv2EIP1967 {
    /// @dev The storage slot where the proxy administrator is stored, defined
    /// as `keccak256('eip1967.proxy.admin') - 1`.
    bytes32 internal constant ADMIN_SLOT =
        hex"b53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103";
    /// @dev Returns the address stored in the EIP-1967 administrator storage
    /// slot for the current contract. If this method is not called from an
    /// contract behind an EIP-1967 proxy, then it will most likely return
    /// `address(0)`, as the implementation slot is likely to be unset.
    ///
    /// @return admin The administrator address.
    function getAdmin() internal view returns (address admin) {
        // solhint-disable-next-line no-inline-assembly
        assembly {
            admin := sload(ADMIN_SLOT)
        }
    }
    /// @dev Sets the storage at the EIP-1967 administrator slot to be the
    /// specified address.
    ///
    /// @param admin The administrator address to set.
    function setAdmin(address admin) internal {
        // solhint-disable-next-line no-inline-assembly
        assembly {
            sstore(ADMIN_SLOT, admin)
        }
    }
}
// SPDX-License-Identifier: MIT
// Vendored from OpenZeppelin contracts with minor modifications:
// - Modified Solidity version
// - Formatted code
// - Shortned revert messages
// - Inlined `Address.isContract` implementation
// <https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v3.4.0/contracts/proxy/Initializable.sol>
pragma solidity ^0.7.6;
/**
 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
 * behind a proxy. Since a proxied contract can't have a constructor, it's common to move constructor logic to an
 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
 *
 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
 * possible by providing the encoded function call as the `_data` argument to {UpgradeableProxy-constructor}.
 *
 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
 */
abstract contract Initializable {
    /**
     * @dev Indicates that the contract has been initialized.
     */
    bool private _initialized;
    /**
     * @dev Indicates that the contract is in the process of being initialized.
     */
    bool private _initializing;
    /**
     * @dev Modifier to protect an initializer function from being invoked twice.
     */
    modifier initializer() {
        require(
            _initializing || _isConstructor() || !_initialized,
            "Initializable: initialized"
        );
        bool isTopLevelCall = !_initializing;
        if (isTopLevelCall) {
            _initializing = true;
            _initialized = true;
        }
        _;
        if (isTopLevelCall) {
            _initializing = false;
        }
    }
    /// @dev Returns true if and only if the function is running in the constructor
    function _isConstructor() private view returns (bool) {
        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly {
            size := extcodesize(address())
        }
        return size == 0;
    }
}
// SPDX-License-Identifier: LGPL-3.0-only
// Vendored from Gnosis utility contracts with minor modifications:
// - Modified Solidity version
// - Formatted code
// - Added linter directives to ignore low level call and assembly warnings
// <https://github.com/gnosis/util-contracts/blob/v3.1.0-solc-7/contracts/StorageAccessible.sol>
pragma solidity ^0.7.6;
/// @title ViewStorageAccessible - Interface on top of StorageAccessible base class to allow simulations from view functions
interface ViewStorageAccessible {
    /**
     * @dev Same as `simulateDelegatecall` on StorageAccessible. Marked as view so that it can be called from external contracts
     * that want to run simulations from within view functions. Will revert if the invoked simulation attempts to change state.
     */
    function simulateDelegatecall(
        address targetContract,
        bytes memory calldataPayload
    ) external view returns (bytes memory);
    /**
     * @dev Same as `getStorageAt` on StorageAccessible. This method allows reading aribtrary ranges of storage.
     */
    function getStorageAt(uint256 offset, uint256 length)
        external
        view
        returns (bytes memory);
}
/// @title StorageAccessible - generic base contract that allows callers to access all internal storage.
contract StorageAccessible {
    /**
     * @dev Reads `length` bytes of storage in the currents contract
     * @param offset - the offset in the current contract's storage in words to start reading from
     * @param length - the number of words (32 bytes) of data to read
     * @return the bytes that were read.
     */
    function getStorageAt(uint256 offset, uint256 length)
        external
        view
        returns (bytes memory)
    {
        bytes memory result = new bytes(length * 32);
        for (uint256 index = 0; index < length; index++) {
            // solhint-disable-next-line no-inline-assembly
            assembly {
                let word := sload(add(offset, index))
                mstore(add(add(result, 0x20), mul(index, 0x20)), word)
            }
        }
        return result;
    }
    /**
     * @dev Performs a delegetecall on a targetContract in the context of self.
     * Internally reverts execution to avoid side effects (making it static). Catches revert and returns encoded result as bytes.
     * @param targetContract Address of the contract containing the code to execute.
     * @param calldataPayload Calldata that should be sent to the target contract (encoded method name and arguments).
     */
    function simulateDelegatecall(
        address targetContract,
        bytes memory calldataPayload
    ) public returns (bytes memory response) {
        bytes memory innerCall =
            abi.encodeWithSelector(
                this.simulateDelegatecallInternal.selector,
                targetContract,
                calldataPayload
            );
        // solhint-disable-next-line avoid-low-level-calls
        (, response) = address(this).call(innerCall);
        bool innerSuccess = response[response.length - 1] == 0x01;
        setLength(response, response.length - 1);
        if (innerSuccess) {
            return response;
        } else {
            revertWith(response);
        }
    }
    /**
     * @dev Performs a delegetecall on a targetContract in the context of self.
     * Internally reverts execution to avoid side effects (making it static). Returns encoded result as revert message
     * concatenated with the success flag of the inner call as a last byte.
     * @param targetContract Address of the contract containing the code to execute.
     * @param calldataPayload Calldata that should be sent to the target contract (encoded method name and arguments).
     */
    function simulateDelegatecallInternal(
        address targetContract,
        bytes memory calldataPayload
    ) external returns (bytes memory response) {
        bool success;
        // solhint-disable-next-line avoid-low-level-calls
        (success, response) = targetContract.delegatecall(calldataPayload);
        revertWith(abi.encodePacked(response, success));
    }
    function revertWith(bytes memory response) internal pure {
        // solhint-disable-next-line no-inline-assembly
        assembly {
            revert(add(response, 0x20), mload(response))
        }
    }
    function setLength(bytes memory buffer, uint256 length) internal pure {
        // solhint-disable-next-line no-inline-assembly
        assembly {
            mstore(buffer, length)
        }
    }
}

// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
import "./interfaces/GPv2Authentication.sol";
import "./libraries/GPv2EIP1967.sol";
import "./mixins/Initializable.sol";
import "./mixins/StorageAccessible.sol";
/// @title Gnosis Protocol v2 Access Control Contract
/// @author Gnosis Developers
contract GPv2AllowListAuthentication is
    GPv2Authentication,
    Initializable,
    StorageAccessible
{
    /// @dev The address of the manager that has permissions to add and remove
    /// solvers.
    address public manager;
    /// @dev The set of allowed solvers. Allowed solvers have a value of `true`
    /// in this mapping.
    mapping(address => bool) private solvers;
    /// @dev Event emitted when the manager changes.
    event ManagerChanged(address newManager, address oldManager);
    /// @dev Event emitted when a solver gets added.
    event SolverAdded(address solver);
    /// @dev Event emitted when a solver gets removed.
    event SolverRemoved(address solver);
    /// @dev Initialize the manager to a value.
    ///
    /// This method is a contract initializer that is called exactly once after
    /// creation. An initializer is used instead of a constructor so that this
    /// contract can be used behind a proxy.
    ///
    /// This initializer is idempotent.
    ///
    /// @param manager_ The manager to initialize the contract with.
    function initializeManager(address manager_) external initializer {
        manager = manager_;
        emit ManagerChanged(manager_, address(0));
    }
    /// @dev Modifier that ensures a method can only be called by the contract
    /// manager. Reverts if called by other addresses.
    modifier onlyManager() {
        require(manager == msg.sender, "GPv2: caller not manager");
        _;
    }
    /// @dev Modifier that ensures method can be either called by the contract
    /// manager or the proxy owner.
    ///
    /// This modifier assumes that the proxy uses an EIP-1967 compliant storage
    /// slot for the admin.
    modifier onlyManagerOrOwner() {
        require(
            manager == msg.sender || GPv2EIP1967.getAdmin() == msg.sender,
            "GPv2: not authorized"
        );
        _;
    }
    /// @dev Set the manager for this contract.
    ///
    /// This method can be called by the current manager (if they want to to
    /// reliquish the role and give it to another address) or the contract
    /// owner (i.e. the proxy admin).
    ///
    /// @param manager_ The new contract manager address.
    function setManager(address manager_) external onlyManagerOrOwner {
        address oldManager = manager;
        manager = manager_;
        emit ManagerChanged(manager_, oldManager);
    }
    /// @dev Add an address to the set of allowed solvers. This method can only
    /// be called by the contract manager.
    ///
    /// This function is idempotent.
    ///
    /// @param solver The solver address to add.
    function addSolver(address solver) external onlyManager {
        solvers[solver] = true;
        emit SolverAdded(solver);
    }
    /// @dev Removes an address to the set of allowed solvers. This method can
    /// only be called by the contract manager.
    ///
    /// This function is idempotent.
    ///
    /// @param solver The solver address to remove.
    function removeSolver(address solver) external onlyManager {
        solvers[solver] = false;
        emit SolverRemoved(solver);
    }
    /// @inheritdoc GPv2Authentication
    function isSolver(address prospectiveSolver)
        external
        view
        override
        returns (bool)
    {
        return solvers[prospectiveSolver];
    }
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
/// @title Gnosis Protocol v2 Authentication Interface
/// @author Gnosis Developers
interface GPv2Authentication {
    /// @dev determines whether the provided address is an authenticated solver.
    /// @param prospectiveSolver the address of prospective solver.
    /// @return true when prospectiveSolver is an authenticated solver, otherwise false.
    function isSolver(address prospectiveSolver) external view returns (bool);
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
library GPv2EIP1967 {
    /// @dev The storage slot where the proxy administrator is stored, defined
    /// as `keccak256('eip1967.proxy.admin') - 1`.
    bytes32 internal constant ADMIN_SLOT =
        hex"b53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103";
    /// @dev Returns the address stored in the EIP-1967 administrator storage
    /// slot for the current contract. If this method is not called from an
    /// contract behind an EIP-1967 proxy, then it will most likely return
    /// `address(0)`, as the implementation slot is likely to be unset.
    ///
    /// @return admin The administrator address.
    function getAdmin() internal view returns (address admin) {
        // solhint-disable-next-line no-inline-assembly
        assembly {
            admin := sload(ADMIN_SLOT)
        }
    }
    /// @dev Sets the storage at the EIP-1967 administrator slot to be the
    /// specified address.
    ///
    /// @param admin The administrator address to set.
    function setAdmin(address admin) internal {
        // solhint-disable-next-line no-inline-assembly
        assembly {
            sstore(ADMIN_SLOT, admin)
        }
    }
}
// SPDX-License-Identifier: MIT
// Vendored from OpenZeppelin contracts with minor modifications:
// - Modified Solidity version
// - Formatted code
// - Shortned revert messages
// - Inlined `Address.isContract` implementation
// <https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v3.4.0/contracts/proxy/Initializable.sol>
pragma solidity ^0.7.6;
/**
 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
 * behind a proxy. Since a proxied contract can't have a constructor, it's common to move constructor logic to an
 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
 *
 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
 * possible by providing the encoded function call as the `_data` argument to {UpgradeableProxy-constructor}.
 *
 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
 */
abstract contract Initializable {
    /**
     * @dev Indicates that the contract has been initialized.
     */
    bool private _initialized;
    /**
     * @dev Indicates that the contract is in the process of being initialized.
     */
    bool private _initializing;
    /**
     * @dev Modifier to protect an initializer function from being invoked twice.
     */
    modifier initializer() {
        require(
            _initializing || _isConstructor() || !_initialized,
            "Initializable: initialized"
        );
        bool isTopLevelCall = !_initializing;
        if (isTopLevelCall) {
            _initializing = true;
            _initialized = true;
        }
        _;
        if (isTopLevelCall) {
            _initializing = false;
        }
    }
    /// @dev Returns true if and only if the function is running in the constructor
    function _isConstructor() private view returns (bool) {
        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly {
            size := extcodesize(address())
        }
        return size == 0;
    }
}
// SPDX-License-Identifier: LGPL-3.0-only
// Vendored from Gnosis utility contracts with minor modifications:
// - Modified Solidity version
// - Formatted code
// - Added linter directives to ignore low level call and assembly warnings
// <https://github.com/gnosis/util-contracts/blob/v3.1.0-solc-7/contracts/StorageAccessible.sol>
pragma solidity ^0.7.6;
/// @title ViewStorageAccessible - Interface on top of StorageAccessible base class to allow simulations from view functions
interface ViewStorageAccessible {
    /**
     * @dev Same as `simulateDelegatecall` on StorageAccessible. Marked as view so that it can be called from external contracts
     * that want to run simulations from within view functions. Will revert if the invoked simulation attempts to change state.
     */
    function simulateDelegatecall(
        address targetContract,
        bytes memory calldataPayload
    ) external view returns (bytes memory);
    /**
     * @dev Same as `getStorageAt` on StorageAccessible. This method allows reading aribtrary ranges of storage.
     */
    function getStorageAt(uint256 offset, uint256 length)
        external
        view
        returns (bytes memory);
}
/// @title StorageAccessible - generic base contract that allows callers to access all internal storage.
contract StorageAccessible {
    /**
     * @dev Reads `length` bytes of storage in the currents contract
     * @param offset - the offset in the current contract's storage in words to start reading from
     * @param length - the number of words (32 bytes) of data to read
     * @return the bytes that were read.
     */
    function getStorageAt(uint256 offset, uint256 length)
        external
        view
        returns (bytes memory)
    {
        bytes memory result = new bytes(length * 32);
        for (uint256 index = 0; index < length; index++) {
            // solhint-disable-next-line no-inline-assembly
            assembly {
                let word := sload(add(offset, index))
                mstore(add(add(result, 0x20), mul(index, 0x20)), word)
            }
        }
        return result;
    }
    /**
     * @dev Performs a delegetecall on a targetContract in the context of self.
     * Internally reverts execution to avoid side effects (making it static). Catches revert and returns encoded result as bytes.
     * @param targetContract Address of the contract containing the code to execute.
     * @param calldataPayload Calldata that should be sent to the target contract (encoded method name and arguments).
     */
    function simulateDelegatecall(
        address targetContract,
        bytes memory calldataPayload
    ) public returns (bytes memory response) {
        bytes memory innerCall =
            abi.encodeWithSelector(
                this.simulateDelegatecallInternal.selector,
                targetContract,
                calldataPayload
            );
        // solhint-disable-next-line avoid-low-level-calls
        (, response) = address(this).call(innerCall);
        bool innerSuccess = response[response.length - 1] == 0x01;
        setLength(response, response.length - 1);
        if (innerSuccess) {
            return response;
        } else {
            revertWith(response);
        }
    }
    /**
     * @dev Performs a delegetecall on a targetContract in the context of self.
     * Internally reverts execution to avoid side effects (making it static). Returns encoded result as revert message
     * concatenated with the success flag of the inner call as a last byte.
     * @param targetContract Address of the contract containing the code to execute.
     * @param calldataPayload Calldata that should be sent to the target contract (encoded method name and arguments).
     */
    function simulateDelegatecallInternal(
        address targetContract,
        bytes memory calldataPayload
    ) external returns (bytes memory response) {
        bool success;
        // solhint-disable-next-line avoid-low-level-calls
        (success, response) = targetContract.delegatecall(calldataPayload);
        revertWith(abi.encodePacked(response, success));
    }
    function revertWith(bytes memory response) internal pure {
        // solhint-disable-next-line no-inline-assembly
        assembly {
            revert(add(response, 0x20), mload(response))
        }
    }
    function setLength(bytes memory buffer, uint256 length) internal pure {
        // solhint-disable-next-line no-inline-assembly
        assembly {
            mstore(buffer, length)
        }
    }
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
import "../GPv2AllowListAuthentication.sol";
contract GPv2AllowListAuthenticationV2 is GPv2AllowListAuthentication {
    function newMethod() external pure returns (uint256) {
        return 1337;
    }
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
import "../GPv2AllowListAuthentication.sol";
import "../libraries/GPv2EIP1967.sol";
contract GPv2AllowListAuthenticationTestInterface is
    GPv2AllowListAuthentication
{
    constructor(address owner) {
        GPv2EIP1967.setAdmin(owner);
    }
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
pragma abicoder v2;
import "./GPv2VaultRelayer.sol";
import "./interfaces/GPv2Authentication.sol";
import "./interfaces/IERC20.sol";
import "./interfaces/IVault.sol";
import "./libraries/GPv2Interaction.sol";
import "./libraries/GPv2Order.sol";
import "./libraries/GPv2Trade.sol";
import "./libraries/GPv2Transfer.sol";
import "./libraries/SafeCast.sol";
import "./libraries/SafeMath.sol";
import "./mixins/GPv2Signing.sol";
import "./mixins/ReentrancyGuard.sol";
import "./mixins/StorageAccessible.sol";
/// @title Gnosis Protocol v2 Settlement Contract
/// @author Gnosis Developers
contract GPv2Settlement is GPv2Signing, ReentrancyGuard, StorageAccessible {
    using GPv2Order for bytes;
    using GPv2Transfer for IVault;
    using SafeCast for int256;
    using SafeCast for uint256;
    using SafeMath for uint256;
    /// @dev The authenticator is used to determine who can call the settle function.
    /// That is, only authorised solvers have the ability to invoke settlements.
    /// Any valid authenticator implements an isSolver method called by the onlySolver
    /// modifier below.
    GPv2Authentication public immutable authenticator;
    /// @dev The Balancer Vault the protocol uses for managing user funds.
    IVault public immutable vault;
    /// @dev The Balancer Vault relayer which can interact on behalf of users.
    /// This contract is created during deployment
    GPv2VaultRelayer public immutable vaultRelayer;
    /// @dev Map each user order by UID to the amount that has been filled so
    /// far. If this amount is larger than or equal to the amount traded in the
    /// order (amount sold for sell orders, amount bought for buy orders) then
    /// the order cannot be traded anymore. If the order is fill or kill, then
    /// this value is only used to determine whether the order has already been
    /// executed.
    mapping(bytes => uint256) public filledAmount;
    /// @dev Event emitted for each executed trade.
    event Trade(
        address indexed owner,
        IERC20 sellToken,
        IERC20 buyToken,
        uint256 sellAmount,
        uint256 buyAmount,
        uint256 feeAmount,
        bytes orderUid
    );
    /// @dev Event emitted for each executed interaction.
    ///
    /// For gas effeciency, only the interaction calldata selector (first 4
    /// bytes) is included in the event. For interactions without calldata or
    /// whose calldata is shorter than 4 bytes, the selector will be `0`.
    event Interaction(address indexed target, uint256 value, bytes4 selector);
    /// @dev Event emitted when a settlement complets
    event Settlement(address indexed solver);
    /// @dev Event emitted when an order is invalidated.
    event OrderInvalidated(address indexed owner, bytes orderUid);
    constructor(GPv2Authentication authenticator_, IVault vault_) {
        authenticator = authenticator_;
        vault = vault_;
        vaultRelayer = new GPv2VaultRelayer(vault_);
    }
    // solhint-disable-next-line no-empty-blocks
    receive() external payable {
        // NOTE: Include an empty receive function so that the settlement
        // contract can receive Ether from contract interactions.
    }
    /// @dev This modifier is called by settle function to block any non-listed
    /// senders from settling batches.
    modifier onlySolver {
        require(authenticator.isSolver(msg.sender), "GPv2: not a solver");
        _;
    }
    /// @dev Modifier to ensure that an external function is only callable as a
    /// settlement interaction.
    modifier onlyInteraction {
        require(address(this) == msg.sender, "GPv2: not an interaction");
        _;
    }
    /// @dev Settle the specified orders at a clearing price. Note that it is
    /// the responsibility of the caller to ensure that all GPv2 invariants are
    /// upheld for the input settlement, otherwise this call will revert.
    /// Namely:
    /// - All orders are valid and signed
    /// - Accounts have sufficient balance and approval.
    /// - Settlement contract has sufficient balance to execute trades. Note
    ///   this implies that the accumulated fees held in the contract can also
    ///   be used for settlement. This is OK since:
    ///   - Solvers need to be authorized
    ///   - Misbehaving solvers will be slashed for abusing accumulated fees for
    ///     settlement
    ///   - Critically, user orders are entirely protected
    ///
    /// @param tokens An array of ERC20 tokens to be traded in the settlement.
    /// Trades encode tokens as indices into this array.
    /// @param clearingPrices An array of clearing prices where the `i`-th price
    /// is for the `i`-th token in the [`tokens`] array.
    /// @param trades Trades for signed orders.
    /// @param interactions Smart contract interactions split into three
    /// separate lists to be run before the settlement, during the settlement
    /// and after the settlement respectively.
    function settle(
        IERC20[] calldata tokens,
        uint256[] calldata clearingPrices,
        GPv2Trade.Data[] calldata trades,
        GPv2Interaction.Data[][3] calldata interactions
    ) external nonReentrant onlySolver {
        executeInteractions(interactions[0]);
        (
            GPv2Transfer.Data[] memory inTransfers,
            GPv2Transfer.Data[] memory outTransfers
        ) = computeTradeExecutions(tokens, clearingPrices, trades);
        vaultRelayer.transferFromAccounts(inTransfers);
        executeInteractions(interactions[1]);
        vault.transferToAccounts(outTransfers);
        executeInteractions(interactions[2]);
        emit Settlement(msg.sender);
    }
    /// @dev Settle an order directly against Balancer V2 pools.
    ///
    /// @param swaps The Balancer V2 swap steps to use for trading.
    /// @param tokens An array of ERC20 tokens to be traded in the settlement.
    /// Swaps and the trade encode tokens as indices into this array.
    /// @param trade The trade to match directly against Balancer liquidity. The
    /// order will always be fully executed, so the trade's `executedAmount`
    /// field is used to represent a swap limit amount.
    function swap(
        IVault.BatchSwapStep[] calldata swaps,
        IERC20[] calldata tokens,
        GPv2Trade.Data calldata trade
    ) external nonReentrant onlySolver {
        RecoveredOrder memory recoveredOrder = allocateRecoveredOrder();
        GPv2Order.Data memory order = recoveredOrder.data;
        recoverOrderFromTrade(recoveredOrder, tokens, trade);
        IVault.SwapKind kind =
            order.kind == GPv2Order.KIND_SELL
                ? IVault.SwapKind.GIVEN_IN
                : IVault.SwapKind.GIVEN_OUT;
        IVault.FundManagement memory funds;
        funds.sender = recoveredOrder.owner;
        funds.fromInternalBalance =
            order.sellTokenBalance == GPv2Order.BALANCE_INTERNAL;
        funds.recipient = payable(recoveredOrder.receiver);
        funds.toInternalBalance =
            order.buyTokenBalance == GPv2Order.BALANCE_INTERNAL;
        int256[] memory limits = new int256[](tokens.length);
        uint256 limitAmount = trade.executedAmount;
        // NOTE: Array allocation initializes elements to 0, so we only need to
        // set the limits we care about. This ensures that the swap will respect
        // the order's limit price.
        if (order.kind == GPv2Order.KIND_SELL) {
            require(limitAmount >= order.buyAmount, "GPv2: limit too low");
            limits[trade.sellTokenIndex] = order.sellAmount.toInt256();
            limits[trade.buyTokenIndex] = -limitAmount.toInt256();
        } else {
            require(limitAmount <= order.sellAmount, "GPv2: limit too high");
            limits[trade.sellTokenIndex] = limitAmount.toInt256();
            limits[trade.buyTokenIndex] = -order.buyAmount.toInt256();
        }
        GPv2Transfer.Data memory feeTransfer;
        feeTransfer.account = recoveredOrder.owner;
        feeTransfer.token = order.sellToken;
        feeTransfer.amount = order.feeAmount;
        feeTransfer.balance = order.sellTokenBalance;
        int256[] memory tokenDeltas =
            vaultRelayer.batchSwapWithFee(
                kind,
                swaps,
                tokens,
                funds,
                limits,
                // NOTE: Specify a deadline to ensure that an expire order
                // cannot be used to trade.
                order.validTo,
                feeTransfer
            );
        bytes memory orderUid = recoveredOrder.uid;
        uint256 executedSellAmount =
            tokenDeltas[trade.sellTokenIndex].toUint256();
        uint256 executedBuyAmount =
            (-tokenDeltas[trade.buyTokenIndex]).toUint256();
        // NOTE: Check that the orders were completely filled and update their
        // filled amounts to avoid replaying them. The limit price and order
        // validity have already been verified when executing the swap through
        // the `limit` and `deadline` parameters.
        require(filledAmount[orderUid] == 0, "GPv2: order filled");
        if (order.kind == GPv2Order.KIND_SELL) {
            require(
                executedSellAmount == order.sellAmount,
                "GPv2: sell amount not respected"
            );
            filledAmount[orderUid] = order.sellAmount;
        } else {
            require(
                executedBuyAmount == order.buyAmount,
                "GPv2: buy amount not respected"
            );
            filledAmount[orderUid] = order.buyAmount;
        }
        emit Trade(
            recoveredOrder.owner,
            order.sellToken,
            order.buyToken,
            executedSellAmount,
            executedBuyAmount,
            order.feeAmount,
            orderUid
        );
        emit Settlement(msg.sender);
    }
    /// @dev Invalidate onchain an order that has been signed offline.
    ///
    /// @param orderUid The unique identifier of the order that is to be made
    /// invalid after calling this function. The user that created the order
    /// must be the the sender of this message. See [`extractOrderUidParams`]
    /// for details on orderUid.
    function invalidateOrder(bytes calldata orderUid) external {
        (, address owner, ) = orderUid.extractOrderUidParams();
        require(owner == msg.sender, "GPv2: caller does not own order");
        filledAmount[orderUid] = uint256(-1);
        emit OrderInvalidated(owner, orderUid);
    }
    /// @dev Free storage from the filled amounts of **expired** orders to claim
    /// a gas refund. This method can only be called as an interaction.
    ///
    /// @param orderUids The unique identifiers of the expired order to free
    /// storage for.
    function freeFilledAmountStorage(bytes[] calldata orderUids)
        external
        onlyInteraction
    {
        freeOrderStorage(filledAmount, orderUids);
    }
    /// @dev Free storage from the pre signatures of **expired** orders to claim
    /// a gas refund. This method can only be called as an interaction.
    ///
    /// @param orderUids The unique identifiers of the expired order to free
    /// storage for.
    function freePreSignatureStorage(bytes[] calldata orderUids)
        external
        onlyInteraction
    {
        freeOrderStorage(preSignature, orderUids);
    }
    /// @dev Process all trades one at a time returning the computed net in and
    /// out transfers for the trades.
    ///
    /// This method reverts if processing of any single trade fails. See
    /// [`computeTradeExecution`] for more details.
    ///
    /// @param tokens An array of ERC20 tokens to be traded in the settlement.
    /// @param clearingPrices An array of token clearing prices.
    /// @param trades Trades for signed orders.
    /// @return inTransfers Array of in transfers of executed sell amounts.
    /// @return outTransfers Array of out transfers of executed buy amounts.
    function computeTradeExecutions(
        IERC20[] calldata tokens,
        uint256[] calldata clearingPrices,
        GPv2Trade.Data[] calldata trades
    )
        internal
        returns (
            GPv2Transfer.Data[] memory inTransfers,
            GPv2Transfer.Data[] memory outTransfers
        )
    {
        RecoveredOrder memory recoveredOrder = allocateRecoveredOrder();
        inTransfers = new GPv2Transfer.Data[](trades.length);
        outTransfers = new GPv2Transfer.Data[](trades.length);
        for (uint256 i = 0; i < trades.length; i++) {
            GPv2Trade.Data calldata trade = trades[i];
            recoverOrderFromTrade(recoveredOrder, tokens, trade);
            computeTradeExecution(
                recoveredOrder,
                clearingPrices[trade.sellTokenIndex],
                clearingPrices[trade.buyTokenIndex],
                trade.executedAmount,
                inTransfers[i],
                outTransfers[i]
            );
        }
    }
    /// @dev Compute the in and out transfer amounts for a single trade.
    /// This function reverts if:
    /// - The order has expired
    /// - The order's limit price is not respected
    /// - The order gets over-filled
    /// - The fee discount is larger than the executed fee
    ///
    /// @param recoveredOrder The recovered order to process.
    /// @param sellPrice The price of the order's sell token.
    /// @param buyPrice The price of the order's buy token.
    /// @param executedAmount The portion of the order to execute. This will be
    /// ignored for fill-or-kill orders.
    /// @param inTransfer Memory location for computed executed sell amount
    /// transfer.
    /// @param outTransfer Memory location for computed executed buy amount
    /// transfer.
    function computeTradeExecution(
        RecoveredOrder memory recoveredOrder,
        uint256 sellPrice,
        uint256 buyPrice,
        uint256 executedAmount,
        GPv2Transfer.Data memory inTransfer,
        GPv2Transfer.Data memory outTransfer
    ) internal {
        GPv2Order.Data memory order = recoveredOrder.data;
        bytes memory orderUid = recoveredOrder.uid;
        // solhint-disable-next-line not-rely-on-time
        require(order.validTo >= block.timestamp, "GPv2: order expired");
        // NOTE: The following computation is derived from the equation:
        // ```
        // amount_x * price_x = amount_y * price_y
        // ```
        // Intuitively, if a chocolate bar is 0,50€ and a beer is 4€, 1 beer
        // is roughly worth 8 chocolate bars (`1 * 4 = 8 * 0.5`). From this
        // equation, we can derive:
        // - The limit price for selling `x` and buying `y` is respected iff
        // ```
        // limit_x * price_x >= limit_y * price_y
        // ```
        // - The executed amount of token `y` given some amount of `x` and
        //   clearing prices is:
        // ```
        // amount_y = amount_x * price_x / price_y
        // ```
        require(
            order.sellAmount.mul(sellPrice) >= order.buyAmount.mul(buyPrice),
            "GPv2: limit price not respected"
        );
        uint256 executedSellAmount;
        uint256 executedBuyAmount;
        uint256 executedFeeAmount;
        uint256 currentFilledAmount;
        if (order.kind == GPv2Order.KIND_SELL) {
            if (order.partiallyFillable) {
                executedSellAmount = executedAmount;
                executedFeeAmount = order.feeAmount.mul(executedSellAmount).div(
                    order.sellAmount
                );
            } else {
                executedSellAmount = order.sellAmount;
                executedFeeAmount = order.feeAmount;
            }
            executedBuyAmount = executedSellAmount.mul(sellPrice).ceilDiv(
                buyPrice
            );
            currentFilledAmount = filledAmount[orderUid].add(
                executedSellAmount
            );
            require(
                currentFilledAmount <= order.sellAmount,
                "GPv2: order filled"
            );
        } else {
            if (order.partiallyFillable) {
                executedBuyAmount = executedAmount;
                executedFeeAmount = order.feeAmount.mul(executedBuyAmount).div(
                    order.buyAmount
                );
            } else {
                executedBuyAmount = order.buyAmount;
                executedFeeAmount = order.feeAmount;
            }
            executedSellAmount = executedBuyAmount.mul(buyPrice).div(sellPrice);
            currentFilledAmount = filledAmount[orderUid].add(executedBuyAmount);
            require(
                currentFilledAmount <= order.buyAmount,
                "GPv2: order filled"
            );
        }
        executedSellAmount = executedSellAmount.add(executedFeeAmount);
        filledAmount[orderUid] = currentFilledAmount;
        emit Trade(
            recoveredOrder.owner,
            order.sellToken,
            order.buyToken,
            executedSellAmount,
            executedBuyAmount,
            executedFeeAmount,
            orderUid
        );
        inTransfer.account = recoveredOrder.owner;
        inTransfer.token = order.sellToken;
        inTransfer.amount = executedSellAmount;
        inTransfer.balance = order.sellTokenBalance;
        outTransfer.account = recoveredOrder.receiver;
        outTransfer.token = order.buyToken;
        outTransfer.amount = executedBuyAmount;
        outTransfer.balance = order.buyTokenBalance;
    }
    /// @dev Execute a list of arbitrary contract calls from this contract.
    /// @param interactions The list of interactions to execute.
    function executeInteractions(GPv2Interaction.Data[] calldata interactions)
        internal
    {
        for (uint256 i; i < interactions.length; i++) {
            GPv2Interaction.Data calldata interaction = interactions[i];
            // To prevent possible attack on user funds, we explicitly disable
            // any interactions with the vault relayer contract.
            require(
                interaction.target != address(vaultRelayer),
                "GPv2: forbidden interaction"
            );
            GPv2Interaction.execute(interaction);
            emit Interaction(
                interaction.target,
                interaction.value,
                GPv2Interaction.selector(interaction)
            );
        }
    }
    /// @dev Claims refund for the specified storage and order UIDs.
    ///
    /// This method reverts if any of the orders are still valid.
    ///
    /// @param orderUids Order refund data for freeing storage.
    /// @param orderStorage Order storage mapped on a UID.
    function freeOrderStorage(
        mapping(bytes => uint256) storage orderStorage,
        bytes[] calldata orderUids
    ) internal {
        for (uint256 i = 0; i < orderUids.length; i++) {
            bytes calldata orderUid = orderUids[i];
            (, , uint32 validTo) = orderUid.extractOrderUidParams();
            // solhint-disable-next-line not-rely-on-time
            require(validTo < block.timestamp, "GPv2: order still valid");
            orderStorage[orderUid] = 0;
        }
    }
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
pragma abicoder v2;
import "./interfaces/IERC20.sol";
import "./interfaces/IVault.sol";
import "./libraries/GPv2Transfer.sol";
/// @title Gnosis Protocol v2 Vault Relayer Contract
/// @author Gnosis Developers
contract GPv2VaultRelayer {
    using GPv2Transfer for IVault;
    /// @dev The creator of the contract which has special permissions. This
    /// value is set at creation time and cannot change.
    address private immutable creator;
    /// @dev The vault this relayer is for.
    IVault private immutable vault;
    constructor(IVault vault_) {
        creator = msg.sender;
        vault = vault_;
    }
    /// @dev Modifier that ensures that a function can only be called by the
    /// creator of this contract.
    modifier onlyCreator {
        require(msg.sender == creator, "GPv2: not creator");
        _;
    }
    /// @dev Transfers all sell amounts for the executed trades from their
    /// owners to the caller.
    ///
    /// This function reverts if:
    /// - The caller is not the creator of the vault relayer
    /// - Any ERC20 transfer fails
    ///
    /// @param transfers The transfers to execute.
    function transferFromAccounts(GPv2Transfer.Data[] calldata transfers)
        external
        onlyCreator
    {
        vault.transferFromAccounts(transfers, msg.sender);
    }
    /// @dev Performs a Balancer batched swap on behalf of a user and sends a
    /// fee to the caller.
    ///
    /// This function reverts if:
    /// - The caller is not the creator of the vault relayer
    /// - The swap fails
    /// - The fee transfer fails
    ///
    /// @param kind The Balancer swap kind, this can either be `GIVEN_IN` for
    /// sell orders or `GIVEN_OUT` for buy orders.
    /// @param swaps The swaps to perform.
    /// @param tokens The tokens for the swaps. Swaps encode to and from tokens
    /// as indices into this array.
    /// @param funds The fund management settings, specifying the user the swap
    /// is being performed for as well as the recipient of the proceeds.
    /// @param limits Swap limits for encoding limit prices.
    /// @param deadline The deadline for the swap.
    /// @param feeTransfer The transfer data for the caller fee.
    /// @return tokenDeltas The executed swap amounts.
    function batchSwapWithFee(
        IVault.SwapKind kind,
        IVault.BatchSwapStep[] calldata swaps,
        IERC20[] memory tokens,
        IVault.FundManagement memory funds,
        int256[] memory limits,
        uint256 deadline,
        GPv2Transfer.Data calldata feeTransfer
    ) external onlyCreator returns (int256[] memory tokenDeltas) {
        tokenDeltas = vault.batchSwap(
            kind,
            swaps,
            tokens,
            funds,
            limits,
            deadline
        );
        vault.fastTransferFromAccount(feeTransfer, msg.sender);
    }
}
// SPDX-License-Identifier: MIT
// Vendored from OpenZeppelin contracts with minor modifications:
// - Modified Solidity version
// - Formatted code
// - Added `name`, `symbol` and `decimals` function declarations
// <https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v3.4.0/contracts/token/ERC20/IERC20.sol>
pragma solidity ^0.7.6;
/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);
    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);
    /**
     * @dev Returns the number of decimals the token uses.
     */
    function decimals() external view returns (uint8);
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);
    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);
    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount)
        external
        returns (bool);
    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender)
        external
        view
        returns (uint256);
    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);
    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external returns (bool);
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);
    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(
        address indexed owner,
        address indexed spender,
        uint256 value
    );
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.6;
pragma abicoder v2;
import "./IERC20.sol";
/**
 * @dev Minimal interface for the Vault core contract only containing methods
 * used by Gnosis Protocol V2. Original source:
 * <https://github.com/balancer-labs/balancer-core-v2/blob/v1.0.0/contracts/vault/interfaces/IVault.sol>
 */
interface IVault {
    // Internal Balance
    //
    // Users can deposit tokens into the Vault, where they are allocated to their Internal Balance, and later
    // transferred or withdrawn. It can also be used as a source of tokens when joining Pools, as a destination
    // when exiting them, and as either when performing swaps. This usage of Internal Balance results in greatly reduced
    // gas costs when compared to relying on plain ERC20 transfers, leading to large savings for frequent users.
    //
    // Internal Balance management features batching, which means a single contract call can be used to perform multiple
    // operations of different kinds, with different senders and recipients, at once.
    /**
     * @dev Performs a set of user balance operations, which involve Internal Balance (deposit, withdraw or transfer)
     * and plain ERC20 transfers using the Vault's allowance. This last feature is particularly useful for relayers, as
     * it lets integrators reuse a user's Vault allowance.
     *
     * For each operation, if the caller is not `sender`, it must be an authorized relayer for them.
     */
    function manageUserBalance(UserBalanceOp[] memory ops) external payable;
    /**
     * @dev Data for `manageUserBalance` operations, which include the possibility for ETH to be sent and received
     without manual WETH wrapping or unwrapping.
     */
    struct UserBalanceOp {
        UserBalanceOpKind kind;
        IERC20 asset;
        uint256 amount;
        address sender;
        address payable recipient;
    }
    // There are four possible operations in `manageUserBalance`:
    //
    // - DEPOSIT_INTERNAL
    // Increases the Internal Balance of the `recipient` account by transferring tokens from the corresponding
    // `sender`. The sender must have allowed the Vault to use their tokens via `IERC20.approve()`.
    //
    // ETH can be used by passing the ETH sentinel value as the asset and forwarding ETH in the call: it will be wrapped
    // and deposited as WETH. Any ETH amount remaining will be sent back to the caller (not the sender, which is
    // relevant for relayers).
    //
    // Emits an `InternalBalanceChanged` event.
    //
    //
    // - WITHDRAW_INTERNAL
    // Decreases the Internal Balance of the `sender` account by transferring tokens to the `recipient`.
    //
    // ETH can be used by passing the ETH sentinel value as the asset. This will deduct WETH instead, unwrap it and send
    // it to the recipient as ETH.
    //
    // Emits an `InternalBalanceChanged` event.
    //
    //
    // - TRANSFER_INTERNAL
    // Transfers tokens from the Internal Balance of the `sender` account to the Internal Balance of `recipient`.
    //
    // Reverts if the ETH sentinel value is passed.
    //
    // Emits an `InternalBalanceChanged` event.
    //
    //
    // - TRANSFER_EXTERNAL
    // Transfers tokens from `sender` to `recipient`, using the Vault's ERC20 allowance. This is typically used by
    // relayers, as it lets them reuse a user's Vault allowance.
    //
    // Reverts if the ETH sentinel value is passed.
    //
    // Emits an `ExternalBalanceTransfer` event.
    enum UserBalanceOpKind {
        DEPOSIT_INTERNAL,
        WITHDRAW_INTERNAL,
        TRANSFER_INTERNAL,
        TRANSFER_EXTERNAL
    }
    // Swaps
    //
    // Users can swap tokens with Pools by calling the `swap` and `batchSwap` functions. To do this,
    // they need not trust Pool contracts in any way: all security checks are made by the Vault. They must however be
    // aware of the Pools' pricing algorithms in order to estimate the prices Pools will quote.
    //
    // The `swap` function executes a single swap, while `batchSwap` can perform multiple swaps in sequence.
    // In each individual swap, tokens of one kind are sent from the sender to the Pool (this is the 'token in'),
    // and tokens of another kind are sent from the Pool to the recipient in exchange (this is the 'token out').
    // More complex swaps, such as one token in to multiple tokens out can be achieved by batching together
    // individual swaps.
    //
    // There are two swap kinds:
    //  - 'given in' swaps, where the amount of tokens in (sent to the Pool) is known, and the Pool determines (via the
    // `onSwap` hook) the amount of tokens out (to send to the recipient).
    //  - 'given out' swaps, where the amount of tokens out (received from the Pool) is known, and the Pool determines
    // (via the `onSwap` hook) the amount of tokens in (to receive from the sender).
    //
    // Additionally, it is possible to chain swaps using a placeholder input amount, which the Vault replaces with
    // the calculated output of the previous swap. If the previous swap was 'given in', this will be the calculated
    // tokenOut amount. If the previous swap was 'given out', it will use the calculated tokenIn amount. These extended
    // swaps are known as 'multihop' swaps, since they 'hop' through a number of intermediate tokens before arriving at
    // the final intended token.
    //
    // In all cases, tokens are only transferred in and out of the Vault (or withdrawn from and deposited into Internal
    // Balance) after all individual swaps have been completed, and the net token balance change computed. This makes
    // certain swap patterns, such as multihops, or swaps that interact with the same token pair in multiple Pools, cost
    // much less gas than they would otherwise.
    //
    // It also means that under certain conditions it is possible to perform arbitrage by swapping with multiple
    // Pools in a way that results in net token movement out of the Vault (profit), with no tokens being sent in (only
    // updating the Pool's internal accounting).
    //
    // To protect users from front-running or the market changing rapidly, they supply a list of 'limits' for each token
    // involved in the swap, where either the maximum number of tokens to send (by passing a positive value) or the
    // minimum amount of tokens to receive (by passing a negative value) is specified.
    //
    // Additionally, a 'deadline' timestamp can also be provided, forcing the swap to fail if it occurs after
    // this point in time (e.g. if the transaction failed to be included in a block promptly).
    //
    // If interacting with Pools that hold WETH, it is possible to both send and receive ETH directly: the Vault will do
    // the wrapping and unwrapping. To enable this mechanism, the IAsset sentinel value (the zero address) must be
    // passed in the `assets` array instead of the WETH address. Note that it is possible to combine ETH and WETH in the
    // same swap. Any excess ETH will be sent back to the caller (not the sender, which is relevant for relayers).
    //
    // Finally, Internal Balance can be used when either sending or receiving tokens.
    enum SwapKind {GIVEN_IN, GIVEN_OUT}
    /**
     * @dev Performs a swap with a single Pool.
     *
     * If the swap is 'given in' (the number of tokens to send to the Pool is known), it returns the amount of tokens
     * taken from the Pool, which must be greater than or equal to `limit`.
     *
     * If the swap is 'given out' (the number of tokens to take from the Pool is known), it returns the amount of tokens
     * sent to the Pool, which must be less than or equal to `limit`.
     *
     * Internal Balance usage and the recipient are determined by the `funds` struct.
     *
     * Emits a `Swap` event.
     */
    function swap(
        SingleSwap memory singleSwap,
        FundManagement memory funds,
        uint256 limit,
        uint256 deadline
    ) external payable returns (uint256);
    /**
     * @dev Data for a single swap executed by `swap`. `amount` is either `amountIn` or `amountOut` depending on
     * the `kind` value.
     *
     * `assetIn` and `assetOut` are either token addresses, or the IAsset sentinel value for ETH (the zero address).
     * Note that Pools never interact with ETH directly: it will be wrapped to or unwrapped from WETH by the Vault.
     *
     * The `userData` field is ignored by the Vault, but forwarded to the Pool in the `onSwap` hook, and may be
     * used to extend swap behavior.
     */
    struct SingleSwap {
        bytes32 poolId;
        SwapKind kind;
        IERC20 assetIn;
        IERC20 assetOut;
        uint256 amount;
        bytes userData;
    }
    /**
     * @dev Performs a series of swaps with one or multiple Pools. In each individual swap, the caller determines either
     * the amount of tokens sent to or received from the Pool, depending on the `kind` value.
     *
     * Returns an array with the net Vault asset balance deltas. Positive amounts represent tokens (or ETH) sent to the
     * Vault, and negative amounts represent tokens (or ETH) sent by the Vault. Each delta corresponds to the asset at
     * the same index in the `assets` array.
     *
     * Swaps are executed sequentially, in the order specified by the `swaps` array. Each array element describes a
     * Pool, the token to be sent to this Pool, the token to receive from it, and an amount that is either `amountIn` or
     * `amountOut` depending on the swap kind.
     *
     * Multihop swaps can be executed by passing an `amount` value of zero for a swap. This will cause the amount in/out
     * of the previous swap to be used as the amount in for the current one. In a 'given in' swap, 'tokenIn' must equal
     * the previous swap's `tokenOut`. For a 'given out' swap, `tokenOut` must equal the previous swap's `tokenIn`.
     *
     * The `assets` array contains the addresses of all assets involved in the swaps. These are either token addresses,
     * or the IAsset sentinel value for ETH (the zero address). Each entry in the `swaps` array specifies tokens in and
     * out by referencing an index in `assets`. Note that Pools never interact with ETH directly: it will be wrapped to
     * or unwrapped from WETH by the Vault.
     *
     * Internal Balance usage, sender, and recipient are determined by the `funds` struct. The `limits` array specifies
     * the minimum or maximum amount of each token the vault is allowed to transfer.
     *
     * `batchSwap` can be used to make a single swap, like `swap` does, but doing so requires more gas than the
     * equivalent `swap` call.
     *
     * Emits `Swap` events.
     */
    function batchSwap(
        SwapKind kind,
        BatchSwapStep[] memory swaps,
        IERC20[] memory assets,
        FundManagement memory funds,
        int256[] memory limits,
        uint256 deadline
    ) external payable returns (int256[] memory);
    /**
     * @dev Data for each individual swap executed by `batchSwap`. The asset in and out fields are indexes into the
     * `assets` array passed to that function, and ETH assets are converted to WETH.
     *
     * If `amount` is zero, the multihop mechanism is used to determine the actual amount based on the amount in/out
     * from the previous swap, depending on the swap kind.
     *
     * The `userData` field is ignored by the Vault, but forwarded to the Pool in the `onSwap` hook, and may be
     * used to extend swap behavior.
     */
    struct BatchSwapStep {
        bytes32 poolId;
        uint256 assetInIndex;
        uint256 assetOutIndex;
        uint256 amount;
        bytes userData;
    }
    /**
     * @dev All tokens in a swap are either sent from the `sender` account to the Vault, or from the Vault to the
     * `recipient` account.
     *
     * If the caller is not `sender`, it must be an authorized relayer for them.
     *
     * If `fromInternalBalance` is true, the `sender`'s Internal Balance will be preferred, performing an ERC20
     * transfer for the difference between the requested amount and the User's Internal Balance (if any). The `sender`
     * must have allowed the Vault to use their tokens via `IERC20.approve()`. This matches the behavior of
     * `joinPool`.
     *
     * If `toInternalBalance` is true, tokens will be deposited to `recipient`'s internal balance instead of
     * transferred. This matches the behavior of `exitPool`.
     *
     * Note that ETH cannot be deposited to or withdrawn from Internal Balance: attempting to do so will trigger a
     * revert.
     */
    struct FundManagement {
        address sender;
        bool fromInternalBalance;
        address payable recipient;
        bool toInternalBalance;
    }
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
/// @title Gnosis Protocol v2 Interaction Library
/// @author Gnosis Developers
library GPv2Interaction {
    /// @dev Interaction data for performing arbitrary contract interactions.
    /// Submitted to [`GPv2Settlement.settle`] for code execution.
    struct Data {
        address target;
        uint256 value;
        bytes callData;
    }
    /// @dev Execute an arbitrary contract interaction.
    ///
    /// @param interaction Interaction data.
    function execute(Data calldata interaction) internal {
        address target = interaction.target;
        uint256 value = interaction.value;
        bytes calldata callData = interaction.callData;
        // NOTE: Use assembly to call the interaction instead of a low level
        // call for two reasons:
        // - We don't want to copy the return data, since we discard it for
        // interactions.
        // - Solidity will under certain conditions generate code to copy input
        // calldata twice to memory (the second being a "memcopy loop").
        // <https://github.com/gnosis/gp-v2-contracts/pull/417#issuecomment-775091258>
        // solhint-disable-next-line no-inline-assembly
        assembly {
            let freeMemoryPointer := mload(0x40)
            calldatacopy(freeMemoryPointer, callData.offset, callData.length)
            if iszero(
                call(
                    gas(),
                    target,
                    value,
                    freeMemoryPointer,
                    callData.length,
                    0,
                    0
                )
            ) {
                returndatacopy(0, 0, returndatasize())
                revert(0, returndatasize())
            }
        }
    }
    /// @dev Extracts the Solidity ABI selector for the specified interaction.
    ///
    /// @param interaction Interaction data.
    /// @return result The 4 byte function selector of the call encoded in
    /// this interaction.
    function selector(Data calldata interaction)
        internal
        pure
        returns (bytes4 result)
    {
        bytes calldata callData = interaction.callData;
        if (callData.length >= 4) {
            // NOTE: Read the first word of the interaction's calldata. The
            // value does not need to be shifted since `bytesN` values are left
            // aligned, and the value does not need to be masked since masking
            // occurs when the value is accessed and not stored:
            // <https://docs.soliditylang.org/en/v0.7.6/abi-spec.html#encoding-of-indexed-event-parameters>
            // <https://docs.soliditylang.org/en/v0.7.6/assembly.html#access-to-external-variables-functions-and-libraries>
            // solhint-disable-next-line no-inline-assembly
            assembly {
                result := calldataload(callData.offset)
            }
        }
    }
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
import "../interfaces/IERC20.sol";
/// @title Gnosis Protocol v2 Order Library
/// @author Gnosis Developers
library GPv2Order {
    /// @dev The complete data for a Gnosis Protocol order. This struct contains
    /// all order parameters that are signed for submitting to GP.
    struct Data {
        IERC20 sellToken;
        IERC20 buyToken;
        address receiver;
        uint256 sellAmount;
        uint256 buyAmount;
        uint32 validTo;
        bytes32 appData;
        uint256 feeAmount;
        bytes32 kind;
        bool partiallyFillable;
        bytes32 sellTokenBalance;
        bytes32 buyTokenBalance;
    }
    /// @dev The order EIP-712 type hash for the [`GPv2Order.Data`] struct.
    ///
    /// This value is pre-computed from the following expression:
    /// ```
    /// keccak256(
    ///     "Order(" +
    ///         "address sellToken," +
    ///         "address buyToken," +
    ///         "address receiver," +
    ///         "uint256 sellAmount," +
    ///         "uint256 buyAmount," +
    ///         "uint32 validTo," +
    ///         "bytes32 appData," +
    ///         "uint256 feeAmount," +
    ///         "string kind," +
    ///         "bool partiallyFillable" +
    ///         "string sellTokenBalance" +
    ///         "string buyTokenBalance" +
    ///     ")"
    /// )
    /// ```
    bytes32 internal constant TYPE_HASH =
        hex"d5a25ba2e97094ad7d83dc28a6572da797d6b3e7fc6663bd93efb789fc17e489";
    /// @dev The marker value for a sell order for computing the order struct
    /// hash. This allows the EIP-712 compatible wallets to display a
    /// descriptive string for the order kind (instead of 0 or 1).
    ///
    /// This value is pre-computed from the following expression:
    /// ```
    /// keccak256("sell")
    /// ```
    bytes32 internal constant KIND_SELL =
        hex"f3b277728b3fee749481eb3e0b3b48980dbbab78658fc419025cb16eee346775";
    /// @dev The OrderKind marker value for a buy order for computing the order
    /// struct hash.
    ///
    /// This value is pre-computed from the following expression:
    /// ```
    /// keccak256("buy")
    /// ```
    bytes32 internal constant KIND_BUY =
        hex"6ed88e868af0a1983e3886d5f3e95a2fafbd6c3450bc229e27342283dc429ccc";
    /// @dev The TokenBalance marker value for using direct ERC20 balances for
    /// computing the order struct hash.
    ///
    /// This value is pre-computed from the following expression:
    /// ```
    /// keccak256("erc20")
    /// ```
    bytes32 internal constant BALANCE_ERC20 =
        hex"5a28e9363bb942b639270062aa6bb295f434bcdfc42c97267bf003f272060dc9";
    /// @dev The TokenBalance marker value for using Balancer Vault external
    /// balances (in order to re-use Vault ERC20 approvals) for computing the
    /// order struct hash.
    ///
    /// This value is pre-computed from the following expression:
    /// ```
    /// keccak256("external")
    /// ```
    bytes32 internal constant BALANCE_EXTERNAL =
        hex"abee3b73373acd583a130924aad6dc38cfdc44ba0555ba94ce2ff63980ea0632";
    /// @dev The TokenBalance marker value for using Balancer Vault internal
    /// balances for computing the order struct hash.
    ///
    /// This value is pre-computed from the following expression:
    /// ```
    /// keccak256("internal")
    /// ```
    bytes32 internal constant BALANCE_INTERNAL =
        hex"4ac99ace14ee0a5ef932dc609df0943ab7ac16b7583634612f8dc35a4289a6ce";
    /// @dev Marker address used to indicate that the receiver of the trade
    /// proceeds should the owner of the order.
    ///
    /// This is chosen to be `address(0)` for gas efficiency as it is expected
    /// to be the most common case.
    address internal constant RECEIVER_SAME_AS_OWNER = address(0);
    /// @dev The byte length of an order unique identifier.
    uint256 internal constant UID_LENGTH = 56;
    /// @dev Returns the actual receiver for an order. This function checks
    /// whether or not the [`receiver`] field uses the marker value to indicate
    /// it is the same as the order owner.
    ///
    /// @return receiver The actual receiver of trade proceeds.
    function actualReceiver(Data memory order, address owner)
        internal
        pure
        returns (address receiver)
    {
        if (order.receiver == RECEIVER_SAME_AS_OWNER) {
            receiver = owner;
        } else {
            receiver = order.receiver;
        }
    }
    /// @dev Return the EIP-712 signing hash for the specified order.
    ///
    /// @param order The order to compute the EIP-712 signing hash for.
    /// @param domainSeparator The EIP-712 domain separator to use.
    /// @return orderDigest The 32 byte EIP-712 struct hash.
    function hash(Data memory order, bytes32 domainSeparator)
        internal
        pure
        returns (bytes32 orderDigest)
    {
        bytes32 structHash;
        // NOTE: Compute the EIP-712 order struct hash in place. As suggested
        // in the EIP proposal, noting that the order struct has 10 fields, and
        // including the type hash `(12 + 1) * 32 = 416` bytes to hash.
        // <https://github.com/ethereum/EIPs/blob/master/EIPS/eip-712.md#rationale-for-encodedata>
        // solhint-disable-next-line no-inline-assembly
        assembly {
            let dataStart := sub(order, 32)
            let temp := mload(dataStart)
            mstore(dataStart, TYPE_HASH)
            structHash := keccak256(dataStart, 416)
            mstore(dataStart, temp)
        }
        // NOTE: Now that we have the struct hash, compute the EIP-712 signing
        // hash using scratch memory past the free memory pointer. The signing
        // hash is computed from `"\\x19\\x01" || domainSeparator || structHash`.
        // <https://docs.soliditylang.org/en/v0.7.6/internals/layout_in_memory.html#layout-in-memory>
        // <https://github.com/ethereum/EIPs/blob/master/EIPS/eip-712.md#specification>
        // solhint-disable-next-line no-inline-assembly
        assembly {
            let freeMemoryPointer := mload(0x40)
            mstore(freeMemoryPointer, "\\x19\\x01")
            mstore(add(freeMemoryPointer, 2), domainSeparator)
            mstore(add(freeMemoryPointer, 34), structHash)
            orderDigest := keccak256(freeMemoryPointer, 66)
        }
    }
    /// @dev Packs order UID parameters into the specified memory location. The
    /// result is equivalent to `abi.encodePacked(...)` with the difference that
    /// it allows re-using the memory for packing the order UID.
    ///
    /// This function reverts if the order UID buffer is not the correct size.
    ///
    /// @param orderUid The buffer pack the order UID parameters into.
    /// @param orderDigest The EIP-712 struct digest derived from the order
    /// parameters.
    /// @param owner The address of the user who owns this order.
    /// @param validTo The epoch time at which the order will stop being valid.
    function packOrderUidParams(
        bytes memory orderUid,
        bytes32 orderDigest,
        address owner,
        uint32 validTo
    ) internal pure {
        require(orderUid.length == UID_LENGTH, "GPv2: uid buffer overflow");
        // NOTE: Write the order UID to the allocated memory buffer. The order
        // parameters are written to memory in **reverse order** as memory
        // operations write 32-bytes at a time and we want to use a packed
        // encoding. This means, for example, that after writing the value of
        // `owner` to bytes `20:52`, writing the `orderDigest` to bytes `0:32`
        // will **overwrite** bytes `20:32`. This is desirable as addresses are
        // only 20 bytes and `20:32` should be `0`s:
        //
        //        |           1111111111222222222233333333334444444444555555
        //   byte | 01234567890123456789012345678901234567890123456789012345
        // -------+---------------------------------------------------------
        //  field | [.........orderDigest..........][......owner.......][vT]
        // -------+---------------------------------------------------------
        // mstore |                         [000000000000000000000000000.vT]
        //        |                     [00000000000.......owner.......]
        //        | [.........orderDigest..........]
        //
        // Additionally, since Solidity `bytes memory` are length prefixed,
        // 32 needs to be added to all the offsets.
        //
        // solhint-disable-next-line no-inline-assembly
        assembly {
            mstore(add(orderUid, 56), validTo)
            mstore(add(orderUid, 52), owner)
            mstore(add(orderUid, 32), orderDigest)
        }
    }
    /// @dev Extracts specific order information from the standardized unique
    /// order id of the protocol.
    ///
    /// @param orderUid The unique identifier used to represent an order in
    /// the protocol. This uid is the packed concatenation of the order digest,
    /// the validTo order parameter and the address of the user who created the
    /// order. It is used by the user to interface with the contract directly,
    /// and not by calls that are triggered by the solvers.
    /// @return orderDigest The EIP-712 signing digest derived from the order
    /// parameters.
    /// @return owner The address of the user who owns this order.
    /// @return validTo The epoch time at which the order will stop being valid.
    function extractOrderUidParams(bytes calldata orderUid)
        internal
        pure
        returns (
            bytes32 orderDigest,
            address owner,
            uint32 validTo
        )
    {
        require(orderUid.length == UID_LENGTH, "GPv2: invalid uid");
        // Use assembly to efficiently decode packed calldata.
        // solhint-disable-next-line no-inline-assembly
        assembly {
            orderDigest := calldataload(orderUid.offset)
            owner := shr(96, calldataload(add(orderUid.offset, 32)))
            validTo := shr(224, calldataload(add(orderUid.offset, 52)))
        }
    }
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
import "../interfaces/IERC20.sol";
import "../mixins/GPv2Signing.sol";
import "./GPv2Order.sol";
/// @title Gnosis Protocol v2 Trade Library.
/// @author Gnosis Developers
library GPv2Trade {
    using GPv2Order for GPv2Order.Data;
    using GPv2Order for bytes;
    /// @dev A struct representing a trade to be executed as part a batch
    /// settlement.
    struct Data {
        uint256 sellTokenIndex;
        uint256 buyTokenIndex;
        address receiver;
        uint256 sellAmount;
        uint256 buyAmount;
        uint32 validTo;
        bytes32 appData;
        uint256 feeAmount;
        uint256 flags;
        uint256 executedAmount;
        bytes signature;
    }
    /// @dev Extracts the order data and signing scheme for the specified trade.
    ///
    /// @param trade The trade.
    /// @param tokens The list of tokens included in the settlement. The token
    /// indices in the trade parameters map to tokens in this array.
    /// @param order The memory location to extract the order data to.
    function extractOrder(
        Data calldata trade,
        IERC20[] calldata tokens,
        GPv2Order.Data memory order
    ) internal pure returns (GPv2Signing.Scheme signingScheme) {
        order.sellToken = tokens[trade.sellTokenIndex];
        order.buyToken = tokens[trade.buyTokenIndex];
        order.receiver = trade.receiver;
        order.sellAmount = trade.sellAmount;
        order.buyAmount = trade.buyAmount;
        order.validTo = trade.validTo;
        order.appData = trade.appData;
        order.feeAmount = trade.feeAmount;
        (
            order.kind,
            order.partiallyFillable,
            order.sellTokenBalance,
            order.buyTokenBalance,
            signingScheme
        ) = extractFlags(trade.flags);
    }
    /// @dev Decodes trade flags.
    ///
    /// Trade flags are used to tightly encode information on how to decode
    /// an order. Examples that directly affect the structure of an order are
    /// the kind of order (either a sell or a buy order) as well as whether the
    /// order is partially fillable or if it is a "fill-or-kill" order. It also
    /// encodes the signature scheme used to validate the order. As the most
    /// likely values are fill-or-kill sell orders by an externally owned
    /// account, the flags are chosen such that `0x00` represents this kind of
    /// order. The flags byte uses the following format:
    ///
    /// ```
    /// bit | 31 ...   | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
    /// ----+----------+---+---+-------+---+---+
    ///     | reserved | *   * | * | *   * | * | * |
    ///                  |   |   |   |   |   |   |
    ///                  |   |   |   |   |   |   +---- order kind bit, 0 for a sell order
    ///                  |   |   |   |   |   |         and 1 for a buy order
    ///                  |   |   |   |   |   |
    ///                  |   |   |   |   |   +-------- order fill bit, 0 for fill-or-kill
    ///                  |   |   |   |   |             and 1 for a partially fillable order
    ///                  |   |   |   |   |
    ///                  |   |   |   +---+------------ use internal sell token balance bit:
    ///                  |   |   |                     0x: ERC20 token balance
    ///                  |   |   |                     10: external Balancer Vault balance
    ///                  |   |   |                     11: internal Balancer Vault balance
    ///                  |   |   |
    ///                  |   |   +-------------------- use buy token balance bit
    ///                  |   |                         0: ERC20 token balance
    ///                  |   |                         1: internal Balancer Vault balance
    ///                  |   |
    ///                  +---+------------------------ signature scheme bits:
    ///                                                00: EIP-712
    ///                                                01: eth_sign
    ///                                                10: EIP-1271
    ///                                                11: pre_sign
    /// ```
    function extractFlags(uint256 flags)
        internal
        pure
        returns (
            bytes32 kind,
            bool partiallyFillable,
            bytes32 sellTokenBalance,
            bytes32 buyTokenBalance,
            GPv2Signing.Scheme signingScheme
        )
    {
        if (flags & 0x01 == 0) {
            kind = GPv2Order.KIND_SELL;
        } else {
            kind = GPv2Order.KIND_BUY;
        }
        partiallyFillable = flags & 0x02 != 0;
        if (flags & 0x08 == 0) {
            sellTokenBalance = GPv2Order.BALANCE_ERC20;
        } else if (flags & 0x04 == 0) {
            sellTokenBalance = GPv2Order.BALANCE_EXTERNAL;
        } else {
            sellTokenBalance = GPv2Order.BALANCE_INTERNAL;
        }
        if (flags & 0x10 == 0) {
            buyTokenBalance = GPv2Order.BALANCE_ERC20;
        } else {
            buyTokenBalance = GPv2Order.BALANCE_INTERNAL;
        }
        // NOTE: Take advantage of the fact that Solidity will revert if the
        // following expression does not produce a valid enum value. This means
        // we check here that the leading reserved bits must be 0.
        signingScheme = GPv2Signing.Scheme(flags >> 5);
    }
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
pragma abicoder v2;
import "../interfaces/IERC20.sol";
import "../interfaces/IVault.sol";
import "./GPv2Order.sol";
import "./GPv2SafeERC20.sol";
/// @title Gnosis Protocol v2 Transfers
/// @author Gnosis Developers
library GPv2Transfer {
    using GPv2SafeERC20 for IERC20;
    /// @dev Transfer data.
    struct Data {
        address account;
        IERC20 token;
        uint256 amount;
        bytes32 balance;
    }
    /// @dev Ether marker address used to indicate an Ether transfer.
    address internal constant BUY_ETH_ADDRESS =
        0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
    /// @dev Execute the specified transfer from the specified account to a
    /// recipient. The recipient will either receive internal Vault balances or
    /// ERC20 token balances depending on whether the account is using internal
    /// balances or not.
    ///
    /// This method is used for transferring fees to the settlement contract
    /// when settling a single order directly with Balancer.
    ///
    /// Note that this method is subtly different from `transferFromAccounts`
    /// with a single transfer with respect to how it deals with internal
    /// balances. Specifically, this method will perform an **internal balance
    /// transfer to the settlement contract instead of a withdrawal to the
    /// external balance of the settlement contract** for trades that specify
    /// trading with internal balances. This is done as a gas optimization in
    /// the single order "fast-path".
    ///
    /// @param vault The Balancer vault to use.
    /// @param transfer The transfer to perform specifying the sender account.
    /// @param recipient The recipient for the transfer.
    function fastTransferFromAccount(
        IVault vault,
        Data calldata transfer,
        address recipient
    ) internal {
        require(
            address(transfer.token) != BUY_ETH_ADDRESS,
            "GPv2: cannot transfer native ETH"
        );
        if (transfer.balance == GPv2Order.BALANCE_ERC20) {
            transfer.token.safeTransferFrom(
                transfer.account,
                recipient,
                transfer.amount
            );
        } else {
            IVault.UserBalanceOp[] memory balanceOps =
                new IVault.UserBalanceOp[](1);
            IVault.UserBalanceOp memory balanceOp = balanceOps[0];
            balanceOp.kind = transfer.balance == GPv2Order.BALANCE_EXTERNAL
                ? IVault.UserBalanceOpKind.TRANSFER_EXTERNAL
                : IVault.UserBalanceOpKind.TRANSFER_INTERNAL;
            balanceOp.asset = transfer.token;
            balanceOp.amount = transfer.amount;
            balanceOp.sender = transfer.account;
            balanceOp.recipient = payable(recipient);
            vault.manageUserBalance(balanceOps);
        }
    }
    /// @dev Execute the specified transfers from the specified accounts to a
    /// single recipient. The recipient will receive all transfers as ERC20
    /// token balances, regardless of whether or not the accounts are using
    /// internal Vault balances.
    ///
    /// This method is used for accumulating user balances into the settlement
    /// contract.
    ///
    /// @param vault The Balancer vault to use.
    /// @param transfers The batched transfers to perform specifying the
    /// sender accounts.
    /// @param recipient The single recipient for all the transfers.
    function transferFromAccounts(
        IVault vault,
        Data[] calldata transfers,
        address recipient
    ) internal {
        // NOTE: Allocate buffer of Vault balance operations large enough to
        // hold all GP transfers. This is done to avoid re-allocations (which
        // are gas inefficient) while still allowing all transfers to be batched
        // into a single Vault call.
        IVault.UserBalanceOp[] memory balanceOps =
            new IVault.UserBalanceOp[](transfers.length);
        uint256 balanceOpCount = 0;
        for (uint256 i = 0; i < transfers.length; i++) {
            Data calldata transfer = transfers[i];
            require(
                address(transfer.token) != BUY_ETH_ADDRESS,
                "GPv2: cannot transfer native ETH"
            );
            if (transfer.balance == GPv2Order.BALANCE_ERC20) {
                transfer.token.safeTransferFrom(
                    transfer.account,
                    recipient,
                    transfer.amount
                );
            } else {
                IVault.UserBalanceOp memory balanceOp =
                    balanceOps[balanceOpCount++];
                balanceOp.kind = transfer.balance == GPv2Order.BALANCE_EXTERNAL
                    ? IVault.UserBalanceOpKind.TRANSFER_EXTERNAL
                    : IVault.UserBalanceOpKind.WITHDRAW_INTERNAL;
                balanceOp.asset = transfer.token;
                balanceOp.amount = transfer.amount;
                balanceOp.sender = transfer.account;
                balanceOp.recipient = payable(recipient);
            }
        }
        if (balanceOpCount > 0) {
            truncateBalanceOpsArray(balanceOps, balanceOpCount);
            vault.manageUserBalance(balanceOps);
        }
    }
    /// @dev Execute the specified transfers to their respective accounts.
    ///
    /// This method is used for paying out trade proceeds from the settlement
    /// contract.
    ///
    /// @param vault The Balancer vault to use.
    /// @param transfers The batched transfers to perform.
    function transferToAccounts(IVault vault, Data[] memory transfers)
        internal
    {
        IVault.UserBalanceOp[] memory balanceOps =
            new IVault.UserBalanceOp[](transfers.length);
        uint256 balanceOpCount = 0;
        for (uint256 i = 0; i < transfers.length; i++) {
            Data memory transfer = transfers[i];
            if (address(transfer.token) == BUY_ETH_ADDRESS) {
                require(
                    transfer.balance != GPv2Order.BALANCE_INTERNAL,
                    "GPv2: unsupported internal ETH"
                );
                payable(transfer.account).transfer(transfer.amount);
            } else if (transfer.balance == GPv2Order.BALANCE_ERC20) {
                transfer.token.safeTransfer(transfer.account, transfer.amount);
            } else {
                IVault.UserBalanceOp memory balanceOp =
                    balanceOps[balanceOpCount++];
                balanceOp.kind = IVault.UserBalanceOpKind.DEPOSIT_INTERNAL;
                balanceOp.asset = transfer.token;
                balanceOp.amount = transfer.amount;
                balanceOp.sender = address(this);
                balanceOp.recipient = payable(transfer.account);
            }
        }
        if (balanceOpCount > 0) {
            truncateBalanceOpsArray(balanceOps, balanceOpCount);
            vault.manageUserBalance(balanceOps);
        }
    }
    /// @dev Truncate a Vault balance operation array to its actual size.
    ///
    /// This method **does not** check whether or not the new length is valid,
    /// and specifying a size that is larger than the array's actual length is
    /// undefined behaviour.
    ///
    /// @param balanceOps The memory array of balance operations to truncate.
    /// @param newLength The new length to set.
    function truncateBalanceOpsArray(
        IVault.UserBalanceOp[] memory balanceOps,
        uint256 newLength
    ) private pure {
        // NOTE: Truncate the vault transfers array to the specified length.
        // This is done by setting the array's length which occupies the first
        // word in memory pointed to by the `balanceOps` memory variable.
        // <https://docs.soliditylang.org/en/v0.7.6/internals/layout_in_memory.html>
        // solhint-disable-next-line no-inline-assembly
        assembly {
            mstore(balanceOps, newLength)
        }
    }
}
// SPDX-License-Identifier: MIT
// Vendored from OpenZeppelin contracts with minor modifications:
// - Modified Solidity version
// - Formatted code
// - Shortened revert messages
// - Removed unused methods
// - Convert to `type(*).*` notation
// <https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v3.4.0/contracts/utils/SafeCast.sol>
pragma solidity ^0.7.6;
/**
 * @dev Wrappers over Solidity's uintXX/intXX casting operators with added overflow
 * checks.
 *
 * Downcasting from uint256/int256 in Solidity does not revert on overflow. This can
 * easily result in undesired exploitation or bugs, since developers usually
 * assume that overflows raise errors. `SafeCast` restores this intuition by
 * reverting the transaction when such an operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 *
 * Can be combined with {SafeMath} and {SignedSafeMath} to extend it to smaller types, by performing
 * all math on `uint256` and `int256` and then downcasting.
 */
library SafeCast {
    /**
     * @dev Converts a signed int256 into an unsigned uint256.
     *
     * Requirements:
     *
     * - input must be greater than or equal to 0.
     */
    function toUint256(int256 value) internal pure returns (uint256) {
        require(value >= 0, "SafeCast: not positive");
        return uint256(value);
    }
    /**
     * @dev Converts an unsigned uint256 into a signed int256.
     *
     * Requirements:
     *
     * - input must be less than or equal to maxInt256.
     */
    function toInt256(uint256 value) internal pure returns (int256) {
        require(
            value <= uint256(type(int256).max),
            "SafeCast: int256 overflow"
        );
        return int256(value);
    }
}
// SPDX-License-Identifier: MIT
// Vendored from OpenZeppelin contracts with minor modifications:
// - Modified Solidity version
// - Formatted code
// - Shortened some revert messages
// - Removed unused methods
// - Added `ceilDiv` method
// <https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v3.4.0/contracts/math/SafeMath.sol>
pragma solidity ^0.7.6;
/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");
        return c;
    }
    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SafeMath: subtraction overflow");
        return a - b;
    }
    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) return 0;
        uint256 c = a * b;
        require(c / a == b, "SafeMath: mul overflow");
        return c;
    }
    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: division by 0");
        return a / b;
    }
    /**
     * @dev Returns the ceiling integer division of two unsigned integers,
     * reverting on division by zero. The result is rounded towards up the
     * nearest integer, instead of truncating the fractional part.
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     * - The sum of the dividend and divisor cannot overflow.
     */
    function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: ceiling division by 0");
        return a / b + (a % b == 0 ? 0 : 1);
    }
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
import "../interfaces/GPv2EIP1271.sol";
import "../libraries/GPv2Order.sol";
import "../libraries/GPv2Trade.sol";
/// @title Gnosis Protocol v2 Signing Library.
/// @author Gnosis Developers
abstract contract GPv2Signing {
    using GPv2Order for GPv2Order.Data;
    using GPv2Order for bytes;
    /// @dev Recovered trade data containing the extracted order and the
    /// recovered owner address.
    struct RecoveredOrder {
        GPv2Order.Data data;
        bytes uid;
        address owner;
        address receiver;
    }
    /// @dev Signing scheme used for recovery.
    enum Scheme {Eip712, EthSign, Eip1271, PreSign}
    /// @dev The EIP-712 domain type hash used for computing the domain
    /// separator.
    bytes32 private constant DOMAIN_TYPE_HASH =
        keccak256(
            "EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"
        );
    /// @dev The EIP-712 domain name used for computing the domain separator.
    bytes32 private constant DOMAIN_NAME = keccak256("Gnosis Protocol");
    /// @dev The EIP-712 domain version used for computing the domain separator.
    bytes32 private constant DOMAIN_VERSION = keccak256("v2");
    /// @dev Marker value indicating an order is pre-signed.
    uint256 private constant PRE_SIGNED =
        uint256(keccak256("GPv2Signing.Scheme.PreSign"));
    /// @dev The domain separator used for signing orders that gets mixed in
    /// making signatures for different domains incompatible. This domain
    /// separator is computed following the EIP-712 standard and has replay
    /// protection mixed in so that signed orders are only valid for specific
    /// GPv2 contracts.
    bytes32 public immutable domainSeparator;
    /// @dev Storage indicating whether or not an order has been signed by a
    /// particular address.
    mapping(bytes => uint256) public preSignature;
    /// @dev Event that is emitted when an account either pre-signs an order or
    /// revokes an existing pre-signature.
    event PreSignature(address indexed owner, bytes orderUid, bool signed);
    constructor() {
        // NOTE: Currently, the only way to get the chain ID in solidity is
        // using assembly.
        uint256 chainId;
        // solhint-disable-next-line no-inline-assembly
        assembly {
            chainId := chainid()
        }
        domainSeparator = keccak256(
            abi.encode(
                DOMAIN_TYPE_HASH,
                DOMAIN_NAME,
                DOMAIN_VERSION,
                chainId,
                address(this)
            )
        );
    }
    /// @dev Sets a presignature for the specified order UID.
    ///
    /// @param orderUid The unique identifier of the order to pre-sign.
    function setPreSignature(bytes calldata orderUid, bool signed) external {
        (, address owner, ) = orderUid.extractOrderUidParams();
        require(owner == msg.sender, "GPv2: cannot presign order");
        if (signed) {
            preSignature[orderUid] = PRE_SIGNED;
        } else {
            preSignature[orderUid] = 0;
        }
        emit PreSignature(owner, orderUid, signed);
    }
    /// @dev Returns an empty recovered order with a pre-allocated buffer for
    /// packing the unique identifier.
    ///
    /// @return recoveredOrder The empty recovered order data.
    function allocateRecoveredOrder()
        internal
        pure
        returns (RecoveredOrder memory recoveredOrder)
    {
        recoveredOrder.uid = new bytes(GPv2Order.UID_LENGTH);
    }
    /// @dev Extracts order data and recovers the signer from the specified
    /// trade.
    ///
    /// @param recoveredOrder Memory location used for writing the recovered order data.
    /// @param tokens The list of tokens included in the settlement. The token
    /// indices in the trade parameters map to tokens in this array.
    /// @param trade The trade data to recover the order data from.
    function recoverOrderFromTrade(
        RecoveredOrder memory recoveredOrder,
        IERC20[] calldata tokens,
        GPv2Trade.Data calldata trade
    ) internal view {
        GPv2Order.Data memory order = recoveredOrder.data;
        Scheme signingScheme = GPv2Trade.extractOrder(trade, tokens, order);
        (bytes32 orderDigest, address owner) =
            recoverOrderSigner(order, signingScheme, trade.signature);
        recoveredOrder.uid.packOrderUidParams(
            orderDigest,
            owner,
            order.validTo
        );
        recoveredOrder.owner = owner;
        recoveredOrder.receiver = order.actualReceiver(owner);
    }
    /// @dev The length of any signature from an externally owned account.
    uint256 private constant ECDSA_SIGNATURE_LENGTH = 65;
    /// @dev Recovers an order's signer from the specified order and signature.
    ///
    /// @param order The order to recover a signature for.
    /// @param signingScheme The signing scheme.
    /// @param signature The signature bytes.
    /// @return orderDigest The computed order hash.
    /// @return owner The recovered address from the specified signature.
    function recoverOrderSigner(
        GPv2Order.Data memory order,
        Scheme signingScheme,
        bytes calldata signature
    ) internal view returns (bytes32 orderDigest, address owner) {
        orderDigest = order.hash(domainSeparator);
        if (signingScheme == Scheme.Eip712) {
            owner = recoverEip712Signer(orderDigest, signature);
        } else if (signingScheme == Scheme.EthSign) {
            owner = recoverEthsignSigner(orderDigest, signature);
        } else if (signingScheme == Scheme.Eip1271) {
            owner = recoverEip1271Signer(orderDigest, signature);
        } else {
            // signingScheme == Scheme.PreSign
            owner = recoverPreSigner(orderDigest, signature, order.validTo);
        }
    }
    /// @dev Perform an ECDSA recover for the specified message and calldata
    /// signature.
    ///
    /// The signature is encoded by tighyly packing the following struct:
    /// ```
    /// struct EncodedSignature {
    ///     bytes32 r;
    ///     bytes32 s;
    ///     uint8 v;
    /// }
    /// ```
    ///
    /// @param message The signed message.
    /// @param encodedSignature The encoded signature.
    function ecdsaRecover(bytes32 message, bytes calldata encodedSignature)
        internal
        pure
        returns (address signer)
    {
        require(
            encodedSignature.length == ECDSA_SIGNATURE_LENGTH,
            "GPv2: malformed ecdsa signature"
        );
        bytes32 r;
        bytes32 s;
        uint8 v;
        // NOTE: Use assembly to efficiently decode signature data.
        // solhint-disable-next-line no-inline-assembly
        assembly {
            // r = uint256(encodedSignature[0:32])
            r := calldataload(encodedSignature.offset)
            // s = uint256(encodedSignature[32:64])
            s := calldataload(add(encodedSignature.offset, 32))
            // v = uint8(encodedSignature[64])
            v := shr(248, calldataload(add(encodedSignature.offset, 64)))
        }
        signer = ecrecover(message, v, r, s);
        require(signer != address(0), "GPv2: invalid ecdsa signature");
    }
    /// @dev Decodes signature bytes originating from an EIP-712-encoded
    /// signature.
    ///
    /// EIP-712 signs typed data. The specifications are described in the
    /// related EIP (<https://eips.ethereum.org/EIPS/eip-712>).
    ///
    /// EIP-712 signatures are encoded as standard ECDSA signatures as described
    /// in the corresponding decoding function [`ecdsaRecover`].
    ///
    /// @param orderDigest The EIP-712 signing digest derived from the order
    /// parameters.
    /// @param encodedSignature Calldata pointing to tightly packed signature
    /// bytes.
    /// @return owner The address of the signer.
    function recoverEip712Signer(
        bytes32 orderDigest,
        bytes calldata encodedSignature
    ) internal pure returns (address owner) {
        owner = ecdsaRecover(orderDigest, encodedSignature);
    }
    /// @dev Decodes signature bytes originating from the output of the eth_sign
    /// RPC call.
    ///
    /// The specifications are described in the Ethereum documentation
    /// (<https://eth.wiki/json-rpc/API#eth_sign>).
    ///
    /// eth_sign signatures are encoded as standard ECDSA signatures as
    /// described in the corresponding decoding function
    /// [`ecdsaRecover`].
    ///
    /// @param orderDigest The EIP-712 signing digest derived from the order
    /// parameters.
    /// @param encodedSignature Calldata pointing to tightly packed signature
    /// bytes.
    /// @return owner The address of the signer.
    function recoverEthsignSigner(
        bytes32 orderDigest,
        bytes calldata encodedSignature
    ) internal pure returns (address owner) {
        // The signed message is encoded as:
        // `"\\x19Ethereum Signed Message:\
" || length || data`, where
        // the length is a constant (32 bytes) and the data is defined as:
        // `orderDigest`.
        bytes32 ethsignDigest =
            keccak256(
                abi.encodePacked(
                    "\\x19Ethereum Signed Message:\
32",
                    orderDigest
                )
            );
        owner = ecdsaRecover(ethsignDigest, encodedSignature);
    }
    /// @dev Verifies the input calldata as an EIP-1271 contract signature and
    /// returns the address of the signer.
    ///
    /// The encoded signature tightly packs the following struct:
    ///
    /// ```
    /// struct EncodedEip1271Signature {
    ///     address owner;
    ///     bytes signature;
    /// }
    /// ```
    ///
    /// This function enforces that the encoded data stores enough bytes to
    /// cover the full length of the decoded signature.
    ///
    /// @param encodedSignature The encoded EIP-1271 signature.
    /// @param orderDigest The EIP-712 signing digest derived from the order
    /// parameters.
    /// @return owner The address of the signer.
    function recoverEip1271Signer(
        bytes32 orderDigest,
        bytes calldata encodedSignature
    ) internal view returns (address owner) {
        // NOTE: Use assembly to read the verifier address from the encoded
        // signature bytes.
        // solhint-disable-next-line no-inline-assembly
        assembly {
            // owner = address(encodedSignature[0:20])
            owner := shr(96, calldataload(encodedSignature.offset))
        }
        // NOTE: Configure prettier to ignore the following line as it causes
        // a panic in the Solidity plugin.
        // prettier-ignore
        bytes calldata signature = encodedSignature[20:];
        require(
            EIP1271Verifier(owner).isValidSignature(orderDigest, signature) ==
                GPv2EIP1271.MAGICVALUE,
            "GPv2: invalid eip1271 signature"
        );
    }
    /// @dev Verifies the order has been pre-signed. The signature is the
    /// address of the signer of the order.
    ///
    /// @param orderDigest The EIP-712 signing digest derived from the order
    /// parameters.
    /// @param encodedSignature The pre-sign signature reprenting the order UID.
    /// @param validTo The order expiry timestamp.
    /// @return owner The address of the signer.
    function recoverPreSigner(
        bytes32 orderDigest,
        bytes calldata encodedSignature,
        uint32 validTo
    ) internal view returns (address owner) {
        require(encodedSignature.length == 20, "GPv2: malformed presignature");
        // NOTE: Use assembly to read the owner address from the encoded
        // signature bytes.
        // solhint-disable-next-line no-inline-assembly
        assembly {
            // owner = address(encodedSignature[0:20])
            owner := shr(96, calldataload(encodedSignature.offset))
        }
        bytes memory orderUid = new bytes(GPv2Order.UID_LENGTH);
        orderUid.packOrderUidParams(orderDigest, owner, validTo);
        require(
            preSignature[orderUid] == PRE_SIGNED,
            "GPv2: order not presigned"
        );
    }
}
// SPDX-License-Identifier: MIT
// Vendored from OpenZeppelin contracts with minor modifications:
// - Modified Solidity version
// - Formatted code
// <https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v3.4.0/contracts/utils/ReentrancyGuard.sol>
pragma solidity ^0.7.6;
/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuard {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.
    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;
    uint256 private _status;
    constructor() {
        _status = _NOT_ENTERED;
    }
    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and make it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;
        _;
        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
import "../interfaces/IERC20.sol";
/// @title Gnosis Protocol v2 Safe ERC20 Transfer Library
/// @author Gnosis Developers
/// @dev Gas-efficient version of Openzeppelin's SafeERC20 contract that notably
/// does not revert when calling a non-contract.
library GPv2SafeERC20 {
    /// @dev Wrapper around a call to the ERC20 function `transfer` that reverts
    /// also when the token returns `false`.
    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        bytes4 selector_ = token.transfer.selector;
        // solhint-disable-next-line no-inline-assembly
        assembly {
            let freeMemoryPointer := mload(0x40)
            mstore(freeMemoryPointer, selector_)
            mstore(
                add(freeMemoryPointer, 4),
                and(to, 0xffffffffffffffffffffffffffffffffffffffff)
            )
            mstore(add(freeMemoryPointer, 36), value)
            if iszero(call(gas(), token, 0, freeMemoryPointer, 68, 0, 0)) {
                returndatacopy(0, 0, returndatasize())
                revert(0, returndatasize())
            }
        }
        require(getLastTansferResult(token), "GPv2: failed transfer");
    }
    /// @dev Wrapper around a call to the ERC20 function `transferFrom` that
    /// reverts also when the token returns `false`.
    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        bytes4 selector_ = token.transferFrom.selector;
        // solhint-disable-next-line no-inline-assembly
        assembly {
            let freeMemoryPointer := mload(0x40)
            mstore(freeMemoryPointer, selector_)
            mstore(
                add(freeMemoryPointer, 4),
                and(from, 0xffffffffffffffffffffffffffffffffffffffff)
            )
            mstore(
                add(freeMemoryPointer, 36),
                and(to, 0xffffffffffffffffffffffffffffffffffffffff)
            )
            mstore(add(freeMemoryPointer, 68), value)
            if iszero(call(gas(), token, 0, freeMemoryPointer, 100, 0, 0)) {
                returndatacopy(0, 0, returndatasize())
                revert(0, returndatasize())
            }
        }
        require(getLastTansferResult(token), "GPv2: failed transferFrom");
    }
    /// @dev Verifies that the last return was a successful `transfer*` call.
    /// This is done by checking that the return data is either empty, or
    /// is a valid ABI encoded boolean.
    function getLastTansferResult(IERC20 token)
        private
        view
        returns (bool success)
    {
        // NOTE: Inspecting previous return data requires assembly. Note that
        // we write the return data to memory 0 in the case where the return
        // data size is 32, this is OK since the first 64 bytes of memory are
        // reserved by Solidy as a scratch space that can be used within
        // assembly blocks.
        // <https://docs.soliditylang.org/en/v0.7.6/internals/layout_in_memory.html>
        // solhint-disable-next-line no-inline-assembly
        assembly {
            /// @dev Revert with an ABI encoded Solidity error with a message
            /// that fits into 32-bytes.
            ///
            /// An ABI encoded Solidity error has the following memory layout:
            ///
            /// ------------+----------------------------------
            ///  byte range | value
            /// ------------+----------------------------------
            ///  0x00..0x04 |        selector("Error(string)")
            ///  0x04..0x24 |      string offset (always 0x20)
            ///  0x24..0x44 |                    string length
            ///  0x44..0x64 | string value, padded to 32-bytes
            function revertWithMessage(length, message) {
                mstore(0x00, "\\x08\\xc3\\x79\\xa0")
                mstore(0x04, 0x20)
                mstore(0x24, length)
                mstore(0x44, message)
                revert(0x00, 0x64)
            }
            switch returndatasize()
                // Non-standard ERC20 transfer without return.
                case 0 {
                    // NOTE: When the return data size is 0, verify that there
                    // is code at the address. This is done in order to maintain
                    // compatibility with Solidity calling conventions.
                    // <https://docs.soliditylang.org/en/v0.7.6/control-structures.html#external-function-calls>
                    if iszero(extcodesize(token)) {
                        revertWithMessage(20, "GPv2: not a contract")
                    }
                    success := 1
                }
                // Standard ERC20 transfer returning boolean success value.
                case 32 {
                    returndatacopy(0, 0, returndatasize())
                    // NOTE: For ABI encoding v1, any non-zero value is accepted
                    // as `true` for a boolean. In order to stay compatible with
                    // OpenZeppelin's `SafeERC20` library which is known to work
                    // with the existing ERC20 implementation we care about,
                    // make sure we return success for any non-zero return value
                    // from the `transfer*` call.
                    success := iszero(iszero(mload(0)))
                }
                default {
                    revertWithMessage(31, "GPv2: malformed transfer result")
                }
        }
    }
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
library GPv2EIP1271 {
    /// @dev Value returned by a call to `isValidSignature` if the signature
    /// was verified successfully. The value is defined in EIP-1271 as:
    /// bytes4(keccak256("isValidSignature(bytes32,bytes)"))
    bytes4 internal constant MAGICVALUE = 0x1626ba7e;
}
/// @title EIP1271 Interface
/// @dev Standardized interface for an implementation of smart contract
/// signatures as described in EIP-1271. The code that follows is identical to
/// the code in the standard with the exception of formatting and syntax
/// changes to adapt the code to our Solidity version.
interface EIP1271Verifier {
    /// @dev Should return whether the signature provided is valid for the
    /// provided data
    /// @param _hash      Hash of the data to be signed
    /// @param _signature Signature byte array associated with _data
    ///
    /// MUST return the bytes4 magic value 0x1626ba7e when function passes.
    /// MUST NOT modify state (using STATICCALL for solc < 0.5, view modifier for
    /// solc > 0.5)
    /// MUST allow external calls
    ///
    function isValidSignature(bytes32 _hash, bytes memory _signature)
        external
        view
        returns (bytes4 magicValue);
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
pragma abicoder v2;
import "../interfaces/GPv2EIP1271.sol";
import "../interfaces/IERC20.sol";
import "../libraries/GPv2Order.sol";
import "../libraries/GPv2SafeERC20.sol";
import "../libraries/SafeMath.sol";
import "../GPv2Settlement.sol";
/// @title Proof of Concept Smart Order
/// @author Gnosis Developers
contract SmartSellOrder is EIP1271Verifier {
    using GPv2Order for GPv2Order.Data;
    using GPv2SafeERC20 for IERC20;
    using SafeMath for uint256;
    bytes32 public constant APPDATA = keccak256("SmartSellOrder");
    address public immutable owner;
    bytes32 public immutable domainSeparator;
    IERC20 public immutable sellToken;
    IERC20 public immutable buyToken;
    uint256 public immutable totalSellAmount;
    uint256 public immutable totalFeeAmount;
    uint32 public immutable validTo;
    constructor(
        GPv2Settlement settlement,
        IERC20 sellToken_,
        IERC20 buyToken_,
        uint32 validTo_,
        uint256 totalSellAmount_,
        uint256 totalFeeAmount_
    ) {
        owner = msg.sender;
        domainSeparator = settlement.domainSeparator();
        sellToken = sellToken_;
        buyToken = buyToken_;
        validTo = validTo_;
        totalSellAmount = totalSellAmount_;
        totalFeeAmount = totalFeeAmount_;
        sellToken_.approve(
            address(settlement.vaultRelayer()),
            type(uint256).max
        );
    }
    modifier onlyOwner {
        require(msg.sender == owner, "not owner");
        _;
    }
    function withdraw(uint256 amount) external onlyOwner {
        sellToken.safeTransfer(owner, amount);
    }
    function close() external onlyOwner {
        uint256 balance = sellToken.balanceOf(address(this));
        if (balance != 0) {
            sellToken.safeTransfer(owner, balance);
        }
        selfdestruct(payable(owner));
    }
    function isValidSignature(bytes32 hash, bytes memory signature)
        external
        view
        override
        returns (bytes4 magicValue)
    {
        uint256 sellAmount = abi.decode(signature, (uint256));
        GPv2Order.Data memory order = orderForSellAmount(sellAmount);
        if (order.hash(domainSeparator) == hash) {
            magicValue = GPv2EIP1271.MAGICVALUE;
        }
    }
    function orderForSellAmount(uint256 sellAmount)
        public
        view
        returns (GPv2Order.Data memory order)
    {
        order.sellToken = sellToken;
        order.buyToken = buyToken;
        order.receiver = owner;
        order.sellAmount = sellAmount;
        order.buyAmount = buyAmountForSellAmount(sellAmount);
        order.validTo = validTo;
        order.appData = APPDATA;
        order.feeAmount = totalFeeAmount.mul(sellAmount).div(totalSellAmount);
        order.kind = GPv2Order.KIND_SELL;
        // NOTE: We counter-intuitively set `partiallyFillable` to `false`, even
        // if the smart order as a whole acts like a partially fillable order.
        // This is done since, once a settlement commits to a specific sell
        // amount, then it is expected to use it completely and not partially.
        order.partiallyFillable = false;
        order.sellTokenBalance = GPv2Order.BALANCE_ERC20;
        order.buyTokenBalance = GPv2Order.BALANCE_ERC20;
    }
    function buyAmountForSellAmount(uint256 sellAmount)
        private
        view
        returns (uint256 buyAmount)
    {
        uint256 feeAdjustedBalance =
            sellToken.balanceOf(address(this)).mul(totalSellAmount).div(
                totalSellAmount.add(totalFeeAmount)
            );
        uint256 soldAmount =
            totalSellAmount > feeAdjustedBalance
                ? totalSellAmount - feeAdjustedBalance
                : 0;
        // NOTE: This is currently a silly price strategy where the xrate
        // increases linearly from 1:1 to 1:2 as the smart order gets filled.
        // This can be extended to more complex "price curves".
        buyAmount = sellAmount
            .mul(totalSellAmount.add(sellAmount).add(soldAmount))
            .div(totalSellAmount);
    }
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
import "../libraries/SafeMath.sol";
abstract contract NonStandardERC20 {
    using SafeMath for uint256;
    mapping(address => uint256) public balanceOf;
    mapping(address => mapping(address => uint256)) public allowance;
    function mint(address to, uint256 amount) external {
        balanceOf[to] = balanceOf[to].add(amount);
    }
    function approve(address spender, uint256 amount) external {
        allowance[msg.sender][spender] = amount;
    }
    function transfer_(address to, uint256 amount) internal {
        balanceOf[msg.sender] = balanceOf[msg.sender].sub(amount);
        balanceOf[to] = balanceOf[to].add(amount);
    }
    function transferFrom_(
        address from,
        address to,
        uint256 amount
    ) internal {
        allowance[from][msg.sender] = allowance[from][msg.sender].sub(amount);
        balanceOf[from] = balanceOf[from].sub(amount);
        balanceOf[to] = balanceOf[to].add(amount);
    }
}
contract ERC20NoReturn is NonStandardERC20 {
    function transfer(address to, uint256 amount) external {
        transfer_(to, amount);
    }
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) external {
        transferFrom_(from, to, amount);
    }
}
contract ERC20ReturningUint is NonStandardERC20 {
    // Largest 256-bit prime :)
    uint256 private constant OK =
        115792089237316195423570985008687907853269984665640564039457584007913129639747;
    function transfer(address to, uint256 amount) external returns (uint256) {
        transfer_(to, amount);
        return OK;
    }
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) external returns (uint256) {
        transferFrom_(from, to, amount);
        return OK;
    }
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
pragma abicoder v2;
import "../interfaces/IERC20.sol";
import "../libraries/GPv2SafeERC20.sol";
contract GPv2SafeERC20TestInterface {
    using GPv2SafeERC20 for IERC20;
    function transfer(
        IERC20 token,
        address to,
        uint256 value
    ) public {
        token.safeTransfer(to, value);
    }
    function transferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) public {
        token.safeTransferFrom(from, to, value);
    }
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
pragma abicoder v2;
import "../libraries/GPv2Order.sol";
import "../libraries/GPv2Trade.sol";
contract GPv2TradeTestInterface {
    function extractOrderTest(
        IERC20[] calldata tokens,
        GPv2Trade.Data calldata trade
    ) external pure returns (GPv2Order.Data memory order) {
        GPv2Trade.extractOrder(trade, tokens, order);
    }
    function extractFlagsTest(uint256 flags)
        external
        pure
        returns (
            bytes32 kind,
            bool partiallyFillable,
            bytes32 sellTokenBalance,
            bytes32 buyTokenBalance,
            GPv2Signing.Scheme signingScheme
        )
    {
        return GPv2Trade.extractFlags(flags);
    }
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
pragma abicoder v2;
import "../libraries/GPv2Order.sol";
import "../libraries/GPv2Trade.sol";
import "../mixins/GPv2Signing.sol";
contract GPv2SigningTestInterface is GPv2Signing {
    function recoverOrderFromTradeTest(
        IERC20[] calldata tokens,
        GPv2Trade.Data calldata trade
    ) external view returns (RecoveredOrder memory recoveredOrder) {
        recoveredOrder = allocateRecoveredOrder();
        recoverOrderFromTrade(recoveredOrder, tokens, trade);
    }
    function recoverOrderSignerTest(
        GPv2Order.Data memory order,
        GPv2Signing.Scheme signingScheme,
        bytes calldata signature
    ) external view returns (address owner) {
        (, owner) = recoverOrderSigner(order, signingScheme, signature);
    }
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
import "../interfaces/GPv2EIP1271.sol";
/// @dev This contract implements the standard described in EIP-1271 with the
/// minor change that the verification function changes the state. This is
/// forbidden by the standard specifications.
contract StateChangingEIP1271 {
    uint256 public state = 0;
    // solhint-disable-next-line no-unused-vars
    function isValidSignature(bytes32 _hash, bytes memory _signature)
        public
        returns (bytes4 magicValue)
    {
        state += 1;
        magicValue = GPv2EIP1271.MAGICVALUE;
        // The following lines are here to suppress no-unused-var compiler-time
        // warnings when compiling the contracts. The warning is forwarded by
        // Hardhat from Solc. It is currently not possible to selectively
        // ignore Solc warinings:
        // <https://github.com/ethereum/solidity/issues/269>
        _hash;
        _signature;
    }
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
pragma abicoder v2;
import "../libraries/GPv2Order.sol";
contract GPv2OrderTestInterface {
    using GPv2Order for GPv2Order.Data;
    using GPv2Order for bytes;
    function typeHashTest() external pure returns (bytes32) {
        return GPv2Order.TYPE_HASH;
    }
    function hashTest(GPv2Order.Data memory order, bytes32 domainSeparator)
        external
        pure
        returns (bytes32 orderDigest)
    {
        orderDigest = order.hash(domainSeparator);
    }
    function packOrderUidParamsTest(
        uint256 bufferLength,
        bytes32 orderDigest,
        address owner,
        uint32 validTo
    ) external pure returns (bytes memory orderUid) {
        orderUid = new bytes(bufferLength);
        orderUid.packOrderUidParams(orderDigest, owner, validTo);
    }
    function extractOrderUidParamsTest(bytes calldata orderUid)
        external
        pure
        returns (
            bytes32 orderDigest,
            address owner,
            uint32 validTo
        )
    {
        return orderUid.extractOrderUidParams();
    }
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
pragma abicoder v2;
import "../libraries/GPv2Transfer.sol";
contract GPv2TransferTestInterface {
    function fastTransferFromAccountTest(
        IVault vault,
        GPv2Transfer.Data calldata transfer,
        address recipient
    ) external {
        GPv2Transfer.fastTransferFromAccount(vault, transfer, recipient);
    }
    function transferFromAccountsTest(
        IVault vault,
        GPv2Transfer.Data[] calldata transfers,
        address recipient
    ) external {
        GPv2Transfer.transferFromAccounts(vault, transfers, recipient);
    }
    function transferToAccountsTest(
        IVault vault,
        GPv2Transfer.Data[] memory transfers
    ) external {
        GPv2Transfer.transferToAccounts(vault, transfers);
    }
    // solhint-disable-next-line no-empty-blocks
    receive() external payable {}
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
pragma abicoder v2;
import "../GPv2Settlement.sol";
import "../libraries/GPv2Interaction.sol";
import "../libraries/GPv2Trade.sol";
import "../libraries/GPv2Transfer.sol";
contract GPv2SettlementTestInterface is GPv2Settlement {
    constructor(GPv2Authentication authenticator_, IVault vault)
        GPv2Settlement(authenticator_, vault)
    // solhint-disable-next-line no-empty-blocks
    {
    }
    function setFilledAmount(bytes calldata orderUid, uint256 amount) external {
        filledAmount[orderUid] = amount;
    }
    function computeTradeExecutionsTest(
        IERC20[] calldata tokens,
        uint256[] calldata clearingPrices,
        GPv2Trade.Data[] calldata trades
    )
        external
        returns (
            GPv2Transfer.Data[] memory inTransfers,
            GPv2Transfer.Data[] memory outTransfers
        )
    {
        (inTransfers, outTransfers) = computeTradeExecutions(
            tokens,
            clearingPrices,
            trades
        );
    }
    function computeTradeExecutionMemoryTest() external returns (uint256 mem) {
        RecoveredOrder memory recoveredOrder;
        GPv2Transfer.Data memory inTransfer;
        GPv2Transfer.Data memory outTransfer;
        // NOTE: Solidity stores the free memory pointer at address 0x40. Read
        // it before and after calling `processOrder` to ensure that there are
        // no memory allocations.
        // solhint-disable-next-line no-inline-assembly
        assembly {
            mem := mload(0x40)
        }
        // solhint-disable-next-line not-rely-on-time
        recoveredOrder.data.validTo = uint32(block.timestamp);
        computeTradeExecution(recoveredOrder, 1, 1, 0, inTransfer, outTransfer);
        // solhint-disable-next-line no-inline-assembly
        assembly {
            mem := sub(mload(0x40), mem)
        }
    }
    function executeInteractionsTest(
        GPv2Interaction.Data[] calldata interactions
    ) external {
        executeInteractions(interactions);
    }
    function freeFilledAmountStorageTest(bytes[] calldata orderUids) external {
        this.freeFilledAmountStorage(orderUids);
    }
    function freePreSignatureStorageTest(bytes[] calldata orderUids) external {
        this.freePreSignatureStorage(orderUids);
    }
}
// SPDX-License-Identifier: LGPL-3.0-or-later
pragma solidity ^0.7.6;
pragma abicoder v2;
import "../libraries/GPv2Interaction.sol";
contract GPv2InteractionTestInterface {
    // solhint-disable-next-line no-empty-blocks
    receive() external payable {}
    function executeTest(GPv2Interaction.Data calldata interaction) external {
        GPv2Interaction.execute(interaction);
    }
    function selectorTest(GPv2Interaction.Data calldata interaction)
        external
        pure
        returns (bytes4)
    {
        return GPv2Interaction.selector(interaction);
    }
}

// File: @openzeppelin/contracts/math/SafeMath.sol

// SPDX-License-Identifier: MIT

pragma solidity ^0.6.0;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts with custom message when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol

pragma solidity ^0.6.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount)
        external
        returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender)
        external
        view
        returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(
        address indexed owner,
        address indexed spender,
        uint256 value
    );
}

// File: contracts/v1/AbstractFiatTokenV1.sol

/**
 * Copyright (c) 2018-2020 CENTRE SECZ
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

pragma solidity 0.6.12;

abstract contract AbstractFiatTokenV1 is IERC20 {
    function _approve(
        address owner,
        address spender,
        uint256 value
    ) internal virtual;

    function _transfer(
        address from,
        address to,
        uint256 value
    ) internal virtual;
}

// File: contracts/v1/Ownable.sol

/**
 * Copyright (c) 2018 zOS Global Limited.
 * Copyright (c) 2018-2020 CENTRE SECZ
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
pragma solidity 0.6.12;

/**
 * @notice The Ownable contract has an owner address, and provides basic
 * authorization control functions
 * @dev Forked from https://github.com/OpenZeppelin/openzeppelin-labs/blob/3887ab77b8adafba4a26ace002f3a684c1a3388b/upgradeability_ownership/contracts/ownership/Ownable.sol
 * Modifications:
 * 1. Consolidate OwnableStorage into this contract (7/13/18)
 * 2. Reformat, conform to Solidity 0.6 syntax, and add error messages (5/13/20)
 * 3. Make public functions external (5/27/20)
 */
contract Ownable {
    // Owner of the contract
    address private _owner;

    /**
     * @dev Event to show ownership has been transferred
     * @param previousOwner representing the address of the previous owner
     * @param newOwner representing the address of the new owner
     */
    event OwnershipTransferred(address previousOwner, address newOwner);

    /**
     * @dev The constructor sets the original owner of the contract to the sender account.
     */
    constructor() public {
        setOwner(msg.sender);
    }

    /**
     * @dev Tells the address of the owner
     * @return the address of the owner
     */
    function owner() external view returns (address) {
        return _owner;
    }

    /**
     * @dev Sets a new owner address
     */
    function setOwner(address newOwner) internal {
        _owner = newOwner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(msg.sender == _owner, "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Allows the current owner to transfer control of the contract to a newOwner.
     * @param newOwner The address to transfer ownership to.
     */
    function transferOwnership(address newOwner) external onlyOwner {
        require(
            newOwner != address(0),
            "Ownable: new owner is the zero address"
        );
        emit OwnershipTransferred(_owner, newOwner);
        setOwner(newOwner);
    }
}

// File: contracts/v1/Pausable.sol

/**
 * Copyright (c) 2016 Smart Contract Solutions, Inc.
 * Copyright (c) 2018-2020 CENTRE SECZ0
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

pragma solidity 0.6.12;

/**
 * @notice Base contract which allows children to implement an emergency stop
 * mechanism
 * @dev Forked from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/feb665136c0dae9912e08397c1a21c4af3651ef3/contracts/lifecycle/Pausable.sol
 * Modifications:
 * 1. Added pauser role, switched pause/unpause to be onlyPauser (6/14/2018)
 * 2. Removed whenNotPause/whenPaused from pause/unpause (6/14/2018)
 * 3. Removed whenPaused (6/14/2018)
 * 4. Switches ownable library to use ZeppelinOS (7/12/18)
 * 5. Remove constructor (7/13/18)
 * 6. Reformat, conform to Solidity 0.6 syntax and add error messages (5/13/20)
 * 7. Make public functions external (5/27/20)
 */
contract Pausable is Ownable {
    event Pause();
    event Unpause();
    event PauserChanged(address indexed newAddress);

    address public pauser;
    bool public paused = false;

    /**
     * @dev Modifier to make a function callable only when the contract is not paused.
     */
    modifier whenNotPaused() {
        require(!paused, "Pausable: paused");
        _;
    }

    /**
     * @dev throws if called by any account other than the pauser
     */
    modifier onlyPauser() {
        require(msg.sender == pauser, "Pausable: caller is not the pauser");
        _;
    }

    /**
     * @dev called by the owner to pause, triggers stopped state
     */
    function pause() external onlyPauser {
        paused = true;
        emit Pause();
    }

    /**
     * @dev called by the owner to unpause, returns to normal state
     */
    function unpause() external onlyPauser {
        paused = false;
        emit Unpause();
    }

    /**
     * @dev update the pauser role
     */
    function updatePauser(address _newPauser) external onlyOwner {
        require(
            _newPauser != address(0),
            "Pausable: new pauser is the zero address"
        );
        pauser = _newPauser;
        emit PauserChanged(pauser);
    }
}

// File: contracts/v1/Blacklistable.sol

/**
 * Copyright (c) 2018-2020 CENTRE SECZ
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

pragma solidity 0.6.12;

/**
 * @title Blacklistable Token
 * @dev Allows accounts to be blacklisted by a "blacklister" role
 */
contract Blacklistable is Ownable {
    address public blacklister;
    mapping(address => bool) internal blacklisted;

    event Blacklisted(address indexed _account);
    event UnBlacklisted(address indexed _account);
    event BlacklisterChanged(address indexed newBlacklister);

    /**
     * @dev Throws if called by any account other than the blacklister
     */
    modifier onlyBlacklister() {
        require(
            msg.sender == blacklister,
            "Blacklistable: caller is not the blacklister"
        );
        _;
    }

    /**
     * @dev Throws if argument account is blacklisted
     * @param _account The address to check
     */
    modifier notBlacklisted(address _account) {
        require(
            !blacklisted[_account],
            "Blacklistable: account is blacklisted"
        );
        _;
    }

    /**
     * @dev Checks if account is blacklisted
     * @param _account The address to check
     */
    function isBlacklisted(address _account) external view returns (bool) {
        return blacklisted[_account];
    }

    /**
     * @dev Adds account to blacklist
     * @param _account The address to blacklist
     */
    function blacklist(address _account) external onlyBlacklister {
        blacklisted[_account] = true;
        emit Blacklisted(_account);
    }

    /**
     * @dev Removes account from blacklist
     * @param _account The address to remove from the blacklist
     */
    function unBlacklist(address _account) external onlyBlacklister {
        blacklisted[_account] = false;
        emit UnBlacklisted(_account);
    }

    function updateBlacklister(address _newBlacklister) external onlyOwner {
        require(
            _newBlacklister != address(0),
            "Blacklistable: new blacklister is the zero address"
        );
        blacklister = _newBlacklister;
        emit BlacklisterChanged(blacklister);
    }
}

// File: contracts/v1/FiatTokenV1.sol

/**
 *
 * Copyright (c) 2018-2020 CENTRE SECZ
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

pragma solidity 0.6.12;

/**
 * @title FiatToken
 * @dev ERC20 Token backed by fiat reserves
 */
contract FiatTokenV1 is AbstractFiatTokenV1, Ownable, Pausable, Blacklistable {
    using SafeMath for uint256;

    string public name;
    string public symbol;
    uint8 public decimals;
    string public currency;
    address public masterMinter;
    bool internal initialized;

    mapping(address => uint256) internal balances;
    mapping(address => mapping(address => uint256)) internal allowed;
    uint256 internal totalSupply_ = 0;
    mapping(address => bool) internal minters;
    mapping(address => uint256) internal minterAllowed;

    event Mint(address indexed minter, address indexed to, uint256 amount);
    event Burn(address indexed burner, uint256 amount);
    event MinterConfigured(address indexed minter, uint256 minterAllowedAmount);
    event MinterRemoved(address indexed oldMinter);
    event MasterMinterChanged(address indexed newMasterMinter);

    function initialize(
        string memory tokenName,
        string memory tokenSymbol,
        string memory tokenCurrency,
        uint8 tokenDecimals,
        address newMasterMinter,
        address newPauser,
        address newBlacklister,
        address newOwner
    ) public {
        require(!initialized, "FiatToken: contract is already initialized");
        require(
            newMasterMinter != address(0),
            "FiatToken: new masterMinter is the zero address"
        );
        require(
            newPauser != address(0),
            "FiatToken: new pauser is the zero address"
        );
        require(
            newBlacklister != address(0),
            "FiatToken: new blacklister is the zero address"
        );
        require(
            newOwner != address(0),
            "FiatToken: new owner is the zero address"
        );

        name = tokenName;
        symbol = tokenSymbol;
        currency = tokenCurrency;
        decimals = tokenDecimals;
        masterMinter = newMasterMinter;
        pauser = newPauser;
        blacklister = newBlacklister;
        setOwner(newOwner);
        initialized = true;
    }

    /**
     * @dev Throws if called by any account other than a minter
     */
    modifier onlyMinters() {
        require(minters[msg.sender], "FiatToken: caller is not a minter");
        _;
    }

    /**
     * @dev Function to mint tokens
     * @param _to The address that will receive the minted tokens.
     * @param _amount The amount of tokens to mint. Must be less than or equal
     * to the minterAllowance of the caller.
     * @return A boolean that indicates if the operation was successful.
     */
    function mint(address _to, uint256 _amount)
        external
        whenNotPaused
        onlyMinters
        notBlacklisted(msg.sender)
        notBlacklisted(_to)
        returns (bool)
    {
        require(_to != address(0), "FiatToken: mint to the zero address");
        require(_amount > 0, "FiatToken: mint amount not greater than 0");

        uint256 mintingAllowedAmount = minterAllowed[msg.sender];
        require(
            _amount <= mintingAllowedAmount,
            "FiatToken: mint amount exceeds minterAllowance"
        );

        totalSupply_ = totalSupply_.add(_amount);
        balances[_to] = balances[_to].add(_amount);
        minterAllowed[msg.sender] = mintingAllowedAmount.sub(_amount);
        emit Mint(msg.sender, _to, _amount);
        emit Transfer(address(0), _to, _amount);
        return true;
    }

    /**
     * @dev Throws if called by any account other than the masterMinter
     */
    modifier onlyMasterMinter() {
        require(
            msg.sender == masterMinter,
            "FiatToken: caller is not the masterMinter"
        );
        _;
    }

    /**
     * @dev Get minter allowance for an account
     * @param minter The address of the minter
     */
    function minterAllowance(address minter) external view returns (uint256) {
        return minterAllowed[minter];
    }

    /**
     * @dev Checks if account is a minter
     * @param account The address to check
     */
    function isMinter(address account) external view returns (bool) {
        return minters[account];
    }

    /**
     * @notice Amount of remaining tokens spender is allowed to transfer on
     * behalf of the token owner
     * @param owner     Token owner's address
     * @param spender   Spender's address
     * @return Allowance amount
     */
    function allowance(address owner, address spender)
        external
        override
        view
        returns (uint256)
    {
        return allowed[owner][spender];
    }

    /**
     * @dev Get totalSupply of token
     */
    function totalSupply() external override view returns (uint256) {
        return totalSupply_;
    }

    /**
     * @dev Get token balance of an account
     * @param account address The account
     */
    function balanceOf(address account)
        external
        override
        view
        returns (uint256)
    {
        return balances[account];
    }

    /**
     * @notice Set spender's allowance over the caller's tokens to be a given
     * value.
     * @param spender   Spender's address
     * @param value     Allowance amount
     * @return True if successful
     */
    function approve(address spender, uint256 value)
        external
        override
        whenNotPaused
        notBlacklisted(msg.sender)
        notBlacklisted(spender)
        returns (bool)
    {
        _approve(msg.sender, spender, value);
        return true;
    }

    /**
     * @dev Internal function to set allowance
     * @param owner     Token owner's address
     * @param spender   Spender's address
     * @param value     Allowance amount
     */
    function _approve(
        address owner,
        address spender,
        uint256 value
    ) internal override {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");
        allowed[owner][spender] = value;
        emit Approval(owner, spender, value);
    }

    /**
     * @notice Transfer tokens by spending allowance
     * @param from  Payer's address
     * @param to    Payee's address
     * @param value Transfer amount
     * @return True if successful
     */
    function transferFrom(
        address from,
        address to,
        uint256 value
    )
        external
        override
        whenNotPaused
        notBlacklisted(msg.sender)
        notBlacklisted(from)
        notBlacklisted(to)
        returns (bool)
    {
        require(
            value <= allowed[from][msg.sender],
            "ERC20: transfer amount exceeds allowance"
        );
        _transfer(from, to, value);
        allowed[from][msg.sender] = allowed[from][msg.sender].sub(value);
        return true;
    }

    /**
     * @notice Transfer tokens from the caller
     * @param to    Payee's address
     * @param value Transfer amount
     * @return True if successful
     */
    function transfer(address to, uint256 value)
        external
        override
        whenNotPaused
        notBlacklisted(msg.sender)
        notBlacklisted(to)
        returns (bool)
    {
        _transfer(msg.sender, to, value);
        return true;
    }

    /**
     * @notice Internal function to process transfers
     * @param from  Payer's address
     * @param to    Payee's address
     * @param value Transfer amount
     */
    function _transfer(
        address from,
        address to,
        uint256 value
    ) internal override {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");
        require(
            value <= balances[from],
            "ERC20: transfer amount exceeds balance"
        );

        balances[from] = balances[from].sub(value);
        balances[to] = balances[to].add(value);
        emit Transfer(from, to, value);
    }

    /**
     * @dev Function to add/update a new minter
     * @param minter The address of the minter
     * @param minterAllowedAmount The minting amount allowed for the minter
     * @return True if the operation was successful.
     */
    function configureMinter(address minter, uint256 minterAllowedAmount)
        external
        whenNotPaused
        onlyMasterMinter
        returns (bool)
    {
        minters[minter] = true;
        minterAllowed[minter] = minterAllowedAmount;
        emit MinterConfigured(minter, minterAllowedAmount);
        return true;
    }

    /**
     * @dev Function to remove a minter
     * @param minter The address of the minter to remove
     * @return True if the operation was successful.
     */
    function removeMinter(address minter)
        external
        onlyMasterMinter
        returns (bool)
    {
        minters[minter] = false;
        minterAllowed[minter] = 0;
        emit MinterRemoved(minter);
        return true;
    }

    /**
     * @dev allows a minter to burn some of its own tokens
     * Validates that caller is a minter and that sender is not blacklisted
     * amount is less than or equal to the minter's account balance
     * @param _amount uint256 the amount of tokens to be burned
     */
    function burn(uint256 _amount)
        external
        whenNotPaused
        onlyMinters
        notBlacklisted(msg.sender)
    {
        uint256 balance = balances[msg.sender];
        require(_amount > 0, "FiatToken: burn amount not greater than 0");
        require(balance >= _amount, "FiatToken: burn amount exceeds balance");

        totalSupply_ = totalSupply_.sub(_amount);
        balances[msg.sender] = balance.sub(_amount);
        emit Burn(msg.sender, _amount);
        emit Transfer(msg.sender, address(0), _amount);
    }

    function updateMasterMinter(address _newMasterMinter) external onlyOwner {
        require(
            _newMasterMinter != address(0),
            "FiatToken: new masterMinter is the zero address"
        );
        masterMinter = _newMasterMinter;
        emit MasterMinterChanged(masterMinter);
    }
}

// File: @openzeppelin/contracts/utils/Address.sol

pragma solidity ^0.6.2;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // According to EIP-1052, 0x0 is the value returned for not-yet created accounts
        // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
        // for accounts without code, i.e. `keccak256('')`
        bytes32 codehash;

            bytes32 accountHash
         = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
        // solhint-disable-next-line no-inline-assembly
        assembly {
            codehash := extcodehash(account)
        }
        return (codehash != accountHash && codehash != 0x0);
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(
            address(this).balance >= amount,
            "Address: insufficient balance"
        );

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (bool success, ) = recipient.call{ value: amount }("");
        require(
            success,
            "Address: unable to send value, recipient may have reverted"
        );
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain`call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data)
        internal
        returns (bytes memory)
    {
        return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return _functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return
            functionCallWithValue(
                target,
                data,
                value,
                "Address: low-level call with value failed"
            );
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(
            address(this).balance >= value,
            "Address: insufficient balance for call"
        );
        return _functionCallWithValue(target, data, value, errorMessage);
    }

    function _functionCallWithValue(
        address target,
        bytes memory data,
        uint256 weiValue,
        string memory errorMessage
    ) private returns (bytes memory) {
        require(isContract(target), "Address: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{
            value: weiValue
        }(data);
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// File: @openzeppelin/contracts/token/ERC20/SafeERC20.sol

pragma solidity ^0.6.0;

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using SafeMath for uint256;
    using Address for address;

    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(token.transfer.selector, to, value)
        );
    }

    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(token.transferFrom.selector, from, to, value)
        );
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        // solhint-disable-next-line max-line-length
        require(
            (value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(token.approve.selector, spender, value)
        );
    }

    function safeIncreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender).add(
            value
        );
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(
                token.approve.selector,
                spender,
                newAllowance
            )
        );
    }

    function safeDecreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender).sub(
            value,
            "SafeERC20: decreased allowance below zero"
        );
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(
                token.approve.selector,
                spender,
                newAllowance
            )
        );
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(
            data,
            "SafeERC20: low-level call failed"
        );
        if (returndata.length > 0) {
            // Return data is optional
            // solhint-disable-next-line max-line-length
            require(
                abi.decode(returndata, (bool)),
                "SafeERC20: ERC20 operation did not succeed"
            );
        }
    }
}

// File: contracts/v1.1/Rescuable.sol

/**
 * Copyright (c) 2018-2020 CENTRE SECZ
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

pragma solidity 0.6.12;

contract Rescuable is Ownable {
    using SafeERC20 for IERC20;

    address private _rescuer;

    event RescuerChanged(address indexed newRescuer);

    /**
     * @notice Returns current rescuer
     * @return Rescuer's address
     */
    function rescuer() external view returns (address) {
        return _rescuer;
    }

    /**
     * @notice Revert if called by any account other than the rescuer.
     */
    modifier onlyRescuer() {
        require(msg.sender == _rescuer, "Rescuable: caller is not the rescuer");
        _;
    }

    /**
     * @notice Rescue ERC20 tokens locked up in this contract.
     * @param tokenContract ERC20 token contract address
     * @param to        Recipient address
     * @param amount    Amount to withdraw
     */
    function rescueERC20(
        IERC20 tokenContract,
        address to,
        uint256 amount
    ) external onlyRescuer {
        tokenContract.safeTransfer(to, amount);
    }

    /**
     * @notice Assign the rescuer role to a given address.
     * @param newRescuer New rescuer's address
     */
    function updateRescuer(address newRescuer) external onlyOwner {
        require(
            newRescuer != address(0),
            "Rescuable: new rescuer is the zero address"
        );
        _rescuer = newRescuer;
        emit RescuerChanged(newRescuer);
    }
}

// File: contracts/v1.1/FiatTokenV1_1.sol

/**
 * Copyright (c) 2018-2020 CENTRE SECZ
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

pragma solidity 0.6.12;

/**
 * @title FiatTokenV1_1
 * @dev ERC20 Token backed by fiat reserves
 */
contract FiatTokenV1_1 is FiatTokenV1, Rescuable {

}

// File: contracts/v2/AbstractFiatTokenV2.sol

/**
 * Copyright (c) 2018-2020 CENTRE SECZ
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

pragma solidity 0.6.12;

abstract contract AbstractFiatTokenV2 is AbstractFiatTokenV1 {
    function _increaseAllowance(
        address owner,
        address spender,
        uint256 increment
    ) internal virtual;

    function _decreaseAllowance(
        address owner,
        address spender,
        uint256 decrement
    ) internal virtual;
}

// File: contracts/util/ECRecover.sol

/**
 * Copyright (c) 2016-2019 zOS Global Limited
 * Copyright (c) 2018-2020 CENTRE SECZ
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

pragma solidity 0.6.12;

/**
 * @title ECRecover
 * @notice A library that provides a safe ECDSA recovery function
 */
library ECRecover {
    /**
     * @notice Recover signer's address from a signed message
     * @dev Adapted from: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/65e4ffde586ec89af3b7e9140bdc9235d1254853/contracts/cryptography/ECDSA.sol
     * Modifications: Accept v, r, and s as separate arguments
     * @param digest    Keccak-256 hash digest of the signed message
     * @param v         v of the signature
     * @param r         r of the signature
     * @param s         s of the signature
     * @return Signer address
     */
    function recover(
        bytes32 digest,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal pure returns (address) {
        // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
        // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
        // the valid range for s in (281): 0 < s < secp256k1n ÷ 2 + 1, and for v in (282): v ∈ {27, 28}. Most
        // signatures from current libraries generate a unique signature with an s-value in the lower half order.
        //
        // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
        // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
        // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
        // these malleable signatures as well.
        if (
            uint256(s) >
            0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0
        ) {
            revert("ECRecover: invalid signature 's' value");
        }

        if (v != 27 && v != 28) {
            revert("ECRecover: invalid signature 'v' value");
        }

        // If the signature is valid (and not malleable), return the signer address
        address signer = ecrecover(digest, v, r, s);
        require(signer != address(0), "ECRecover: invalid signature");

        return signer;
    }
}

// File: contracts/util/EIP712.sol

/**
 * Copyright (c) 2018-2020 CENTRE SECZ
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

pragma solidity 0.6.12;

/**
 * @title EIP712
 * @notice A library that provides EIP712 helper functions
 */
library EIP712 {
    /**
     * @notice Make EIP712 domain separator
     * @param name      Contract name
     * @param version   Contract version
     * @return Domain separator
     */
    function makeDomainSeparator(string memory name, string memory version)
        internal
        view
        returns (bytes32)
    {
        uint256 chainId;
        assembly {
            chainId := chainid()
        }
        return
            keccak256(
                abi.encode(
                    // keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)")
                    0x8b73c3c69bb8fe3d512ecc4cf759cc79239f7b179b0ffacaa9a75d522b39400f,
                    keccak256(bytes(name)),
                    keccak256(bytes(version)),
                    chainId,
                    address(this)
                )
            );
    }

    /**
     * @notice Recover signer's address from a EIP712 signature
     * @param domainSeparator   Domain separator
     * @param v                 v of the signature
     * @param r                 r of the signature
     * @param s                 s of the signature
     * @param typeHashAndData   Type hash concatenated with data
     * @return Signer's address
     */
    function recover(
        bytes32 domainSeparator,
        uint8 v,
        bytes32 r,
        bytes32 s,
        bytes memory typeHashAndData
    ) internal pure returns (address) {
        bytes32 digest = keccak256(
            abi.encodePacked(
                "\x19\x01",
                domainSeparator,
                keccak256(typeHashAndData)
            )
        );
        return ECRecover.recover(digest, v, r, s);
    }
}

// File: contracts/v2/EIP712Domain.sol

/**
 * Copyright (c) 2018-2020 CENTRE SECZ
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

pragma solidity 0.6.12;

/**
 * @title EIP712 Domain
 */
contract EIP712Domain {
    /**
     * @dev EIP712 Domain Separator
     */
    bytes32 public DOMAIN_SEPARATOR;
}

// File: contracts/v2/EIP3009.sol

/**
 * Copyright (c) 2018-2020 CENTRE SECZ
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

pragma solidity 0.6.12;

/**
 * @title EIP-3009
 * @notice Provide internal implementation for gas-abstracted transfers
 * @dev Contracts that inherit from this must wrap these with publicly
 * accessible functions, optionally adding modifiers where necessary
 */
abstract contract EIP3009 is AbstractFiatTokenV2, EIP712Domain {
    // keccak256("TransferWithAuthorization(address from,address to,uint256 value,uint256 validAfter,uint256 validBefore,bytes32 nonce)")
    bytes32
        public constant TRANSFER_WITH_AUTHORIZATION_TYPEHASH = 0x7c7c6cdb67a18743f49ec6fa9b35f50d52ed05cbed4cc592e13b44501c1a2267;

    // keccak256("ReceiveWithAuthorization(address from,address to,uint256 value,uint256 validAfter,uint256 validBefore,bytes32 nonce)")
    bytes32
        public constant RECEIVE_WITH_AUTHORIZATION_TYPEHASH = 0xd099cc98ef71107a616c4f0f941f04c322d8e254fe26b3c6668db87aae413de8;

    // keccak256("CancelAuthorization(address authorizer,bytes32 nonce)")
    bytes32
        public constant CANCEL_AUTHORIZATION_TYPEHASH = 0x158b0a9edf7a828aad02f63cd515c68ef2f50ba807396f6d12842833a1597429;

    /**
     * @dev authorizer address => nonce => bool (true if nonce is used)
     */
    mapping(address => mapping(bytes32 => bool)) private _authorizationStates;

    event AuthorizationUsed(address indexed authorizer, bytes32 indexed nonce);
    event AuthorizationCanceled(
        address indexed authorizer,
        bytes32 indexed nonce
    );

    /**
     * @notice Returns the state of an authorization
     * @dev Nonces are randomly generated 32-byte data unique to the
     * authorizer's address
     * @param authorizer    Authorizer's address
     * @param nonce         Nonce of the authorization
     * @return True if the nonce is used
     */
    function authorizationState(address authorizer, bytes32 nonce)
        external
        view
        returns (bool)
    {
        return _authorizationStates[authorizer][nonce];
    }

    /**
     * @notice Execute a transfer with a signed authorization
     * @param from          Payer's address (Authorizer)
     * @param to            Payee's address
     * @param value         Amount to be transferred
     * @param validAfter    The time after which this is valid (unix time)
     * @param validBefore   The time before which this is valid (unix time)
     * @param nonce         Unique nonce
     * @param v             v of the signature
     * @param r             r of the signature
     * @param s             s of the signature
     */
    function _transferWithAuthorization(
        address from,
        address to,
        uint256 value,
        uint256 validAfter,
        uint256 validBefore,
        bytes32 nonce,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal {
        _requireValidAuthorization(from, nonce, validAfter, validBefore);

        bytes memory data = abi.encode(
            TRANSFER_WITH_AUTHORIZATION_TYPEHASH,
            from,
            to,
            value,
            validAfter,
            validBefore,
            nonce
        );
        require(
            EIP712.recover(DOMAIN_SEPARATOR, v, r, s, data) == from,
            "FiatTokenV2: invalid signature"
        );

        _markAuthorizationAsUsed(from, nonce);
        _transfer(from, to, value);
    }

    /**
     * @notice Receive a transfer with a signed authorization from the payer
     * @dev This has an additional check to ensure that the payee's address
     * matches the caller of this function to prevent front-running attacks.
     * @param from          Payer's address (Authorizer)
     * @param to            Payee's address
     * @param value         Amount to be transferred
     * @param validAfter    The time after which this is valid (unix time)
     * @param validBefore   The time before which this is valid (unix time)
     * @param nonce         Unique nonce
     * @param v             v of the signature
     * @param r             r of the signature
     * @param s             s of the signature
     */
    function _receiveWithAuthorization(
        address from,
        address to,
        uint256 value,
        uint256 validAfter,
        uint256 validBefore,
        bytes32 nonce,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal {
        require(to == msg.sender, "FiatTokenV2: caller must be the payee");
        _requireValidAuthorization(from, nonce, validAfter, validBefore);

        bytes memory data = abi.encode(
            RECEIVE_WITH_AUTHORIZATION_TYPEHASH,
            from,
            to,
            value,
            validAfter,
            validBefore,
            nonce
        );
        require(
            EIP712.recover(DOMAIN_SEPARATOR, v, r, s, data) == from,
            "FiatTokenV2: invalid signature"
        );

        _markAuthorizationAsUsed(from, nonce);
        _transfer(from, to, value);
    }

    /**
     * @notice Attempt to cancel an authorization
     * @param authorizer    Authorizer's address
     * @param nonce         Nonce of the authorization
     * @param v             v of the signature
     * @param r             r of the signature
     * @param s             s of the signature
     */
    function _cancelAuthorization(
        address authorizer,
        bytes32 nonce,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal {
        _requireUnusedAuthorization(authorizer, nonce);

        bytes memory data = abi.encode(
            CANCEL_AUTHORIZATION_TYPEHASH,
            authorizer,
            nonce
        );
        require(
            EIP712.recover(DOMAIN_SEPARATOR, v, r, s, data) == authorizer,
            "FiatTokenV2: invalid signature"
        );

        _authorizationStates[authorizer][nonce] = true;
        emit AuthorizationCanceled(authorizer, nonce);
    }

    /**
     * @notice Check that an authorization is unused
     * @param authorizer    Authorizer's address
     * @param nonce         Nonce of the authorization
     */
    function _requireUnusedAuthorization(address authorizer, bytes32 nonce)
        private
        view
    {
        require(
            !_authorizationStates[authorizer][nonce],
            "FiatTokenV2: authorization is used or canceled"
        );
    }

    /**
     * @notice Check that authorization is valid
     * @param authorizer    Authorizer's address
     * @param nonce         Nonce of the authorization
     * @param validAfter    The time after which this is valid (unix time)
     * @param validBefore   The time before which this is valid (unix time)
     */
    function _requireValidAuthorization(
        address authorizer,
        bytes32 nonce,
        uint256 validAfter,
        uint256 validBefore
    ) private view {
        require(
            now > validAfter,
            "FiatTokenV2: authorization is not yet valid"
        );
        require(now < validBefore, "FiatTokenV2: authorization is expired");
        _requireUnusedAuthorization(authorizer, nonce);
    }

    /**
     * @notice Mark an authorization as used
     * @param authorizer    Authorizer's address
     * @param nonce         Nonce of the authorization
     */
    function _markAuthorizationAsUsed(address authorizer, bytes32 nonce)
        private
    {
        _authorizationStates[authorizer][nonce] = true;
        emit AuthorizationUsed(authorizer, nonce);
    }
}

// File: contracts/v2/EIP2612.sol

/**
 * Copyright (c) 2018-2020 CENTRE SECZ
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

pragma solidity 0.6.12;

/**
 * @title EIP-2612
 * @notice Provide internal implementation for gas-abstracted approvals
 */
abstract contract EIP2612 is AbstractFiatTokenV2, EIP712Domain {
    // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)")
    bytes32
        public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;

    mapping(address => uint256) private _permitNonces;

    /**
     * @notice Nonces for permit
     * @param owner Token owner's address (Authorizer)
     * @return Next nonce
     */
    function nonces(address owner) external view returns (uint256) {
        return _permitNonces[owner];
    }

    /**
     * @notice Verify a signed approval permit and execute if valid
     * @param owner     Token owner's address (Authorizer)
     * @param spender   Spender's address
     * @param value     Amount of allowance
     * @param deadline  The time at which this expires (unix time)
     * @param v         v of the signature
     * @param r         r of the signature
     * @param s         s of the signature
     */
    function _permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal {
        require(deadline >= now, "FiatTokenV2: permit is expired");

        bytes memory data = abi.encode(
            PERMIT_TYPEHASH,
            owner,
            spender,
            value,
            _permitNonces[owner]++,
            deadline
        );
        require(
            EIP712.recover(DOMAIN_SEPARATOR, v, r, s, data) == owner,
            "EIP2612: invalid signature"
        );

        _approve(owner, spender, value);
    }
}

// File: contracts/v2/FiatTokenV2.sol

/**
 * Copyright (c) 2018-2020 CENTRE SECZ
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

pragma solidity 0.6.12;

/**
 * @title FiatToken V2
 * @notice ERC20 Token backed by fiat reserves, version 2
 */
contract FiatTokenV2 is FiatTokenV1_1, EIP3009, EIP2612 {
    uint8 internal _initializedVersion;

    /**
     * @notice Initialize v2
     * @param newName   New token name
     */
    function initializeV2(string calldata newName) external {
        // solhint-disable-next-line reason-string
        require(initialized && _initializedVersion == 0);
        name = newName;
        DOMAIN_SEPARATOR = EIP712.makeDomainSeparator(newName, "2");
        _initializedVersion = 1;
    }

    /**
     * @notice Increase the allowance by a given increment
     * @param spender   Spender's address
     * @param increment Amount of increase in allowance
     * @return True if successful
     */
    function increaseAllowance(address spender, uint256 increment)
        external
        whenNotPaused
        notBlacklisted(msg.sender)
        notBlacklisted(spender)
        returns (bool)
    {
        _increaseAllowance(msg.sender, spender, increment);
        return true;
    }

    /**
     * @notice Decrease the allowance by a given decrement
     * @param spender   Spender's address
     * @param decrement Amount of decrease in allowance
     * @return True if successful
     */
    function decreaseAllowance(address spender, uint256 decrement)
        external
        whenNotPaused
        notBlacklisted(msg.sender)
        notBlacklisted(spender)
        returns (bool)
    {
        _decreaseAllowance(msg.sender, spender, decrement);
        return true;
    }

    /**
     * @notice Execute a transfer with a signed authorization
     * @param from          Payer's address (Authorizer)
     * @param to            Payee's address
     * @param value         Amount to be transferred
     * @param validAfter    The time after which this is valid (unix time)
     * @param validBefore   The time before which this is valid (unix time)
     * @param nonce         Unique nonce
     * @param v             v of the signature
     * @param r             r of the signature
     * @param s             s of the signature
     */
    function transferWithAuthorization(
        address from,
        address to,
        uint256 value,
        uint256 validAfter,
        uint256 validBefore,
        bytes32 nonce,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external whenNotPaused notBlacklisted(from) notBlacklisted(to) {
        _transferWithAuthorization(
            from,
            to,
            value,
            validAfter,
            validBefore,
            nonce,
            v,
            r,
            s
        );
    }

    /**
     * @notice Receive a transfer with a signed authorization from the payer
     * @dev This has an additional check to ensure that the payee's address
     * matches the caller of this function to prevent front-running attacks.
     * @param from          Payer's address (Authorizer)
     * @param to            Payee's address
     * @param value         Amount to be transferred
     * @param validAfter    The time after which this is valid (unix time)
     * @param validBefore   The time before which this is valid (unix time)
     * @param nonce         Unique nonce
     * @param v             v of the signature
     * @param r             r of the signature
     * @param s             s of the signature
     */
    function receiveWithAuthorization(
        address from,
        address to,
        uint256 value,
        uint256 validAfter,
        uint256 validBefore,
        bytes32 nonce,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external whenNotPaused notBlacklisted(from) notBlacklisted(to) {
        _receiveWithAuthorization(
            from,
            to,
            value,
            validAfter,
            validBefore,
            nonce,
            v,
            r,
            s
        );
    }

    /**
     * @notice Attempt to cancel an authorization
     * @dev Works only if the authorization is not yet used.
     * @param authorizer    Authorizer's address
     * @param nonce         Nonce of the authorization
     * @param v             v of the signature
     * @param r             r of the signature
     * @param s             s of the signature
     */
    function cancelAuthorization(
        address authorizer,
        bytes32 nonce,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external whenNotPaused {
        _cancelAuthorization(authorizer, nonce, v, r, s);
    }

    /**
     * @notice Update allowance with a signed permit
     * @param owner       Token owner's address (Authorizer)
     * @param spender     Spender's address
     * @param value       Amount of allowance
     * @param deadline    Expiration time, seconds since the epoch
     * @param v           v of the signature
     * @param r           r of the signature
     * @param s           s of the signature
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external whenNotPaused notBlacklisted(owner) notBlacklisted(spender) {
        _permit(owner, spender, value, deadline, v, r, s);
    }

    /**
     * @notice Internal function to increase the allowance by a given increment
     * @param owner     Token owner's address
     * @param spender   Spender's address
     * @param increment Amount of increase
     */
    function _increaseAllowance(
        address owner,
        address spender,
        uint256 increment
    ) internal override {
        _approve(owner, spender, allowed[owner][spender].add(increment));
    }

    /**
     * @notice Internal function to decrease the allowance by a given decrement
     * @param owner     Token owner's address
     * @param spender   Spender's address
     * @param decrement Amount of decrease
     */
    function _decreaseAllowance(
        address owner,
        address spender,
        uint256 decrement
    ) internal override {
        _approve(
            owner,
            spender,
            allowed[owner][spender].sub(
                decrement,
                "ERC20: decreased allowance below zero"
            )
        );
    }
}

// File: contracts/v2/FiatTokenV2_1.sol

/**
 * Copyright (c) 2018-2020 CENTRE SECZ
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

pragma solidity 0.6.12;

// solhint-disable func-name-mixedcase

/**
 * @title FiatToken V2.1
 * @notice ERC20 Token backed by fiat reserves, version 2.1
 */
contract FiatTokenV2_1 is FiatTokenV2 {
    /**
     * @notice Initialize v2.1
     * @param lostAndFound  The address to which the locked funds are sent
     */
    function initializeV2_1(address lostAndFound) external {
        // solhint-disable-next-line reason-string
        require(_initializedVersion == 1);

        uint256 lockedAmount = balances[address(this)];
        if (lockedAmount > 0) {
            _transfer(address(this), lostAndFound, lockedAmount);
        }
        blacklisted[address(this)] = true;

        _initializedVersion = 2;
    }

    /**
     * @notice Version string for the EIP712 domain separator
     * @return Version string
     */
    function version() external view returns (string memory) {
        return "2";
    }
}

// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2021 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
import "@0x/contracts-erc20/contracts/src/v06/IEtherTokenV06.sol";
import "../vendor/IUniswapV3Pool.sol";
import "../migrations/LibMigrate.sol";
import "../fixins/FixinCommon.sol";
import "../fixins/FixinTokenSpender.sol";
import "./interfaces/IFeature.sol";
import "./interfaces/IUniswapV3Feature.sol";
/// @dev VIP uniswap fill functions.
contract UniswapV3Feature is
    IFeature,
    IUniswapV3Feature,
    FixinCommon,
    FixinTokenSpender
{
    /// @dev Name of this feature.
    string public constant override FEATURE_NAME = "UniswapV3Feature";
    /// @dev Version of this feature.
    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 1, 0);
    /// @dev WETH contract.
    IEtherTokenV06 private immutable WETH;
    /// @dev UniswapV3 Factory contract address prepended with '0xff' and left-aligned.
    bytes32 private immutable UNI_FF_FACTORY_ADDRESS;
    /// @dev UniswapV3 pool init code hash.
    bytes32 private immutable UNI_POOL_INIT_CODE_HASH;
    /// @dev Minimum size of an encoded swap path:
    ///      sizeof(address(inputToken) | uint24(fee) | address(outputToken))
    uint256 private constant SINGLE_HOP_PATH_SIZE = 20 + 3 + 20;
    /// @dev How many bytes to skip ahead in an encoded path to start at the next hop:
    ///      sizeof(address(inputToken) | uint24(fee))
    uint256 private constant PATH_SKIP_HOP_SIZE = 20 + 3;
    /// @dev The size of the swap callback data.
    uint256 private constant SWAP_CALLBACK_DATA_SIZE = 128;
    /// @dev Minimum tick price sqrt ratio.
    uint160 internal constant MIN_PRICE_SQRT_RATIO = 4295128739;
    /// @dev Minimum tick price sqrt ratio.
    uint160 internal constant MAX_PRICE_SQRT_RATIO = 1461446703485210103287273052203988822378723970342;
    /// @dev Mask of lower 20 bytes.
    uint256 private constant ADDRESS_MASK = 0x00ffffffffffffffffffffffffffffffffffffffff;
    /// @dev Mask of lower 3 bytes.
    uint256 private constant UINT24_MASK = 0xffffff;
    /// @dev Construct this contract.
    /// @param weth The WETH contract.
    /// @param uniFactory The UniswapV3 factory contract.
    /// @param poolInitCodeHash The UniswapV3 pool init code hash.
    constructor(
        IEtherTokenV06 weth,
        address uniFactory,
        bytes32 poolInitCodeHash
    ) public {
        WETH = weth;
        UNI_FF_FACTORY_ADDRESS = bytes32((uint256(0xff) << 248) | (uint256(uniFactory) << 88));
        UNI_POOL_INIT_CODE_HASH = poolInitCodeHash;
    }
    /// @dev Initialize and register this feature.
    ///      Should be delegatecalled by `Migrate.migrate()`.
    /// @return success `LibMigrate.SUCCESS` on success.
    function migrate()
        external
        returns (bytes4 success)
    {
        _registerFeatureFunction(this.sellEthForTokenToUniswapV3.selector);
        _registerFeatureFunction(this.sellTokenForEthToUniswapV3.selector);
        _registerFeatureFunction(this.sellTokenForTokenToUniswapV3.selector);
        _registerFeatureFunction(this._sellHeldTokenForTokenToUniswapV3.selector);
        _registerFeatureFunction(this.uniswapV3SwapCallback.selector);
        return LibMigrate.MIGRATE_SUCCESS;
    }
    /// @dev Sell attached ETH directly against uniswap v3.
    /// @param encodedPath Uniswap-encoded path, where the first token is WETH.
    /// @param recipient The recipient of the bought tokens. Can be zero for sender.
    /// @param minBuyAmount Minimum amount of the last token in the path to buy.
    /// @return buyAmount Amount of the last token in the path bought.
    function sellEthForTokenToUniswapV3(
        bytes memory encodedPath,
        uint256 minBuyAmount,
        address recipient
    )
        public
        payable
        override
        returns (uint256 buyAmount)
    {
        // Wrap ETH.
        WETH.deposit{ value: msg.value }();
        return _swap(
            encodedPath,
            msg.value,
            minBuyAmount,
            address(this), // we are payer because we hold the WETH
            _normalizeRecipient(recipient)
        );
    }
    /// @dev Sell a token for ETH directly against uniswap v3.
    /// @param encodedPath Uniswap-encoded path, where the last token is WETH.
    /// @param sellAmount amount of the first token in the path to sell.
    /// @param minBuyAmount Minimum amount of ETH to buy.
    /// @param recipient The recipient of the bought tokens. Can be zero for sender.
    /// @return buyAmount Amount of ETH bought.
    function sellTokenForEthToUniswapV3(
        bytes memory encodedPath,
        uint256 sellAmount,
        uint256 minBuyAmount,
        address payable recipient
    )
        public
        override
        returns (uint256 buyAmount)
    {
        buyAmount = _swap(
            encodedPath,
            sellAmount,
            minBuyAmount,
            msg.sender,
            address(this) // we are recipient because we need to unwrap WETH
        );
        WETH.withdraw(buyAmount);
        // Transfer ETH to recipient.
        (bool success, bytes memory revertData) =
            _normalizeRecipient(recipient).call{ value: buyAmount }("");
        if (!success) {
            revertData.rrevert();
        }
    }
    /// @dev Sell a token for another token directly against uniswap v3.
    /// @param encodedPath Uniswap-encoded path.
    /// @param sellAmount amount of the first token in the path to sell.
    /// @param minBuyAmount Minimum amount of the last token in the path to buy.
    /// @param recipient The recipient of the bought tokens. Can be zero for sender.
    /// @return buyAmount Amount of the last token in the path bought.
    function sellTokenForTokenToUniswapV3(
        bytes memory encodedPath,
        uint256 sellAmount,
        uint256 minBuyAmount,
        address recipient
    )
        public
        override
        returns (uint256 buyAmount)
    {
        buyAmount = _swap(
            encodedPath,
            sellAmount,
            minBuyAmount,
            msg.sender,
            _normalizeRecipient(recipient)
        );
    }
    /// @dev Sell a token for another token directly against uniswap v3.
    ///      Private variant, uses tokens held by `address(this)`.
    /// @param encodedPath Uniswap-encoded path.
    /// @param sellAmount amount of the first token in the path to sell.
    /// @param minBuyAmount Minimum amount of the last token in the path to buy.
    /// @param recipient The recipient of the bought tokens. Can be zero for sender.
    /// @return buyAmount Amount of the last token in the path bought.
    function _sellHeldTokenForTokenToUniswapV3(
        bytes memory encodedPath,
        uint256 sellAmount,
        uint256 minBuyAmount,
        address recipient
    )
        public
        override
        onlySelf
        returns (uint256 buyAmount)
    {
        buyAmount = _swap(
            encodedPath,
            sellAmount,
            minBuyAmount,
            address(this),
            _normalizeRecipient(recipient)
        );
    }
    /// @dev The UniswapV3 pool swap callback which pays the funds requested
    ///      by the caller/pool to the pool. Can only be called by a valid
    ///      UniswapV3 pool.
    /// @param amount0Delta Token0 amount owed.
    /// @param amount1Delta Token1 amount owed.
    /// @param data Arbitrary data forwarded from swap() caller. An ABI-encoded
    ///        struct of: inputToken, outputToken, fee, payer
    function uniswapV3SwapCallback(
        int256 amount0Delta,
        int256 amount1Delta,
        bytes calldata data
    )
        external
        override
    {
        IERC20TokenV06 token0;
        IERC20TokenV06 token1;
        address payer;
        {
            uint24 fee;
            // Decode the data.
            require(data.length == SWAP_CALLBACK_DATA_SIZE, "UniswapFeature/INVALID_SWAP_CALLBACK_DATA");
            assembly {
                let p := add(36, calldataload(68))
                token0 := calldataload(p)
                token1 := calldataload(add(p, 32))
                fee := calldataload(add(p, 64))
                payer := calldataload(add(p, 96))
            }
            (token0, token1) = token0 < token1
                ? (token0, token1)
                : (token1, token0);
            // Only a valid pool contract can call this function.
            require(
                msg.sender == address(_toPool(token0, fee, token1)),
                "UniswapV3Feature/INVALID_SWAP_CALLBACK_CALLER"
            );
        }
        // Pay the amount owed to the pool.
        if (amount0Delta > 0) {
            _pay(token0, payer, msg.sender, uint256(amount0Delta));
        } else if (amount1Delta > 0) {
            _pay(token1, payer, msg.sender, uint256(amount1Delta));
        } else {
            revert("UniswapV3Feature/INVALID_SWAP_AMOUNTS");
        }
    }
    // Executes successive swaps along an encoded uniswap path.
    function _swap(
        bytes memory encodedPath,
        uint256 sellAmount,
        uint256 minBuyAmount,
        address payer,
        address recipient
    )
        private
        returns (uint256 buyAmount)
    {
        if (sellAmount != 0) {
            require(sellAmount <= uint256(type(int256).max), "UniswapV3Feature/SELL_AMOUNT_OVERFLOW");
            // Perform a swap for each hop in the path.
            bytes memory swapCallbackData = new bytes(SWAP_CALLBACK_DATA_SIZE);
            while (true) {
                bool isPathMultiHop = _isPathMultiHop(encodedPath);
                bool zeroForOne;
                IUniswapV3Pool pool;
                {
                    (
                        IERC20TokenV06 inputToken,
                        uint24 fee,
                        IERC20TokenV06 outputToken
                    ) = _decodeFirstPoolInfoFromPath(encodedPath);
                    pool = _toPool(inputToken, fee, outputToken);
                    zeroForOne = inputToken < outputToken;
                    _updateSwapCallbackData(
                        swapCallbackData,
                        inputToken,
                        outputToken,
                        fee,
                        payer
                    );
                }
                (int256 amount0, int256 amount1) = pool.swap(
                    // Intermediate tokens go to this contract.
                    isPathMultiHop ? address(this) : recipient,
                    zeroForOne,
                    int256(sellAmount),
                    zeroForOne
                        ? MIN_PRICE_SQRT_RATIO + 1
                        : MAX_PRICE_SQRT_RATIO - 1,
                    swapCallbackData
                );
                {
                    int256 _buyAmount = -(zeroForOne ? amount1 : amount0);
                    require(_buyAmount >= 0, "UniswapV3Feature/INVALID_BUY_AMOUNT");
                    buyAmount = uint256(_buyAmount);
                }
                if (!isPathMultiHop) {
                    // Done.
                    break;
                }
                // Continue with next hop.
                payer = address(this); // Subsequent hops are paid for by us.
                sellAmount = buyAmount;
                // Skip to next hop along path.
                encodedPath = _shiftHopFromPathInPlace(encodedPath);
            }
        }
        require(minBuyAmount <= buyAmount, "UniswapV3Feature/UNDERBOUGHT");
    }
    // Pay tokens from `payer` to `to`, using `transferFrom()` if
    // `payer` != this contract.
    function _pay(
        IERC20TokenV06 token,
        address payer,
        address to,
        uint256 amount
    )
        private
    {
        if (payer != address(this)) {
            _transferERC20TokensFrom(token, payer, to, amount);
        } else {
            _transferERC20Tokens(token, to, amount);
        }
    }
    // Update `swapCallbackData` in place with new values.
    function _updateSwapCallbackData(
        bytes memory swapCallbackData,
        IERC20TokenV06 inputToken,
        IERC20TokenV06 outputToken,
        uint24 fee,
        address payer
    )
        private
        pure
    {
        assembly {
            let p := add(swapCallbackData, 32)
            mstore(p, inputToken)
            mstore(add(p, 32), outputToken)
            mstore(add(p, 64), and(UINT24_MASK, fee))
            mstore(add(p, 96), and(ADDRESS_MASK, payer))
        }
    }
    // Compute the pool address given two tokens and a fee.
    function _toPool(
        IERC20TokenV06 inputToken,
        uint24 fee,
        IERC20TokenV06 outputToken
    )
        private
        view
        returns (IUniswapV3Pool pool)
    {
        // address(keccak256(abi.encodePacked(
        //     hex"ff",
        //     UNI_FACTORY_ADDRESS,
        //     keccak256(abi.encode(inputToken, outputToken, fee)),
        //     UNI_POOL_INIT_CODE_HASH
        // )))
        bytes32 ffFactoryAddress = UNI_FF_FACTORY_ADDRESS;
        bytes32 poolInitCodeHash = UNI_POOL_INIT_CODE_HASH;
        (IERC20TokenV06 token0, IERC20TokenV06 token1) = inputToken < outputToken
            ? (inputToken, outputToken)
            : (outputToken, inputToken);
        assembly {
            let s := mload(0x40)
            let p := s
            mstore(p, ffFactoryAddress)
            p := add(p, 21)
            // Compute the inner hash in-place
                mstore(p, token0)
                mstore(add(p, 32), token1)
                mstore(add(p, 64), and(UINT24_MASK, fee))
                mstore(p, keccak256(p, 96))
            p := add(p, 32)
            mstore(p, poolInitCodeHash)
            pool := and(ADDRESS_MASK, keccak256(s, 85))
        }
    }
    // Return whether or not an encoded uniswap path contains more than one hop.
    function _isPathMultiHop(bytes memory encodedPath)
        private
        pure
        returns (bool isMultiHop)
    {
        return encodedPath.length > SINGLE_HOP_PATH_SIZE;
    }
    // Return the first input token, output token, and fee of an encoded uniswap path.
    function _decodeFirstPoolInfoFromPath(bytes memory encodedPath)
        private
        pure
        returns (
            IERC20TokenV06 inputToken,
            uint24 fee,
            IERC20TokenV06 outputToken
        )
    {
        require(encodedPath.length >= SINGLE_HOP_PATH_SIZE, "UniswapV3Feature/BAD_PATH_ENCODING");
        assembly {
            let p := add(encodedPath, 32)
            inputToken := shr(96, mload(p))
            p := add(p, 20)
            fee := shr(232, mload(p))
            p := add(p, 3)
            outputToken := shr(96, mload(p))
        }
    }
    // Skip past the first hop of an encoded uniswap path in-place.
    function _shiftHopFromPathInPlace(bytes memory encodedPath)
        private
        pure
        returns (bytes memory shiftedEncodedPath)
    {
        require(encodedPath.length >= PATH_SKIP_HOP_SIZE, "UniswapV3Feature/BAD_PATH_ENCODING");
        uint256 shiftSize = PATH_SKIP_HOP_SIZE;
        uint256 newSize = encodedPath.length - shiftSize;
        assembly {
            shiftedEncodedPath := add(encodedPath, shiftSize)
            mstore(shiftedEncodedPath, newSize)
        }
    }
    // Convert null address values to msg.sender.
    function _normalizeRecipient(address recipient)
        private
        view
        returns (address payable normalizedRecipient)
    {
        return recipient == address(0) ? msg.sender : payable(recipient);
    }
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
interface IERC20TokenV06 {
    // solhint-disable no-simple-event-func-name
    event Transfer(
        address indexed from,
        address indexed to,
        uint256 value
    );
    event Approval(
        address indexed owner,
        address indexed spender,
        uint256 value
    );
    /// @dev send `value` token to `to` from `msg.sender`
    /// @param to The address of the recipient
    /// @param value The amount of token to be transferred
    /// @return True if transfer was successful
    function transfer(address to, uint256 value)
        external
        returns (bool);
    /// @dev send `value` token to `to` from `from` on the condition it is approved by `from`
    /// @param from The address of the sender
    /// @param to The address of the recipient
    /// @param value The amount of token to be transferred
    /// @return True if transfer was successful
    function transferFrom(
        address from,
        address to,
        uint256 value
    )
        external
        returns (bool);
    /// @dev `msg.sender` approves `spender` to spend `value` tokens
    /// @param spender The address of the account able to transfer the tokens
    /// @param value The amount of wei to be approved for transfer
    /// @return Always true if the call has enough gas to complete execution
    function approve(address spender, uint256 value)
        external
        returns (bool);
    /// @dev Query total supply of token
    /// @return Total supply of token
    function totalSupply()
        external
        view
        returns (uint256);
    /// @dev Get the balance of `owner`.
    /// @param owner The address from which the balance will be retrieved
    /// @return Balance of owner
    function balanceOf(address owner)
        external
        view
        returns (uint256);
    /// @dev Get the allowance for `spender` to spend from `owner`.
    /// @param owner The address of the account owning tokens
    /// @param spender The address of the account able to transfer the tokens
    /// @return Amount of remaining tokens allowed to spent
    function allowance(address owner, address spender)
        external
        view
        returns (uint256);
    /// @dev Get the number of decimals this token has.
    function decimals()
        external
        view
        returns (uint8);
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
import "./IERC20TokenV06.sol";
interface IEtherTokenV06 is
    IERC20TokenV06
{
    /// @dev Wrap ether.
    function deposit() external payable;
    /// @dev Unwrap ether.
    function withdraw(uint256 amount) external;
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2021 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.12;
interface IUniswapV3Pool {
    /// @notice Swap token0 for token1, or token1 for token0
    /// @dev The caller of this method receives a callback in the form of IUniswapV3SwapCallback#uniswapV3SwapCallback
    /// @param recipient The address to receive the output of the swap
    /// @param zeroForOne The direction of the swap, true for token0 to token1, false for token1 to token0
    /// @param amountSpecified The amount of the swap, which implicitly configures the swap as exact input (positive), or exact output (negative)
    /// @param sqrtPriceLimitX96 The Q64.96 sqrt price limit. If zero for one, the price cannot be less than this
    /// value after the swap. If one for zero, the price cannot be greater than this value after the swap
    /// @param data Any data to be passed through to the callback
    /// @return amount0 The delta of the balance of token0 of the pool, exact when negative, minimum when positive
    /// @return amount1 The delta of the balance of token1 of the pool, exact when negative, minimum when positive
    function swap(
        address recipient,
        bool zeroForOne,
        int256 amountSpecified,
        uint160 sqrtPriceLimitX96,
        bytes calldata data
    )
        external
        returns (int256 amount0, int256 amount1);
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "../errors/LibOwnableRichErrors.sol";
library LibMigrate {
    /// @dev Magic bytes returned by a migrator to indicate success.
    ///      This is `keccack('MIGRATE_SUCCESS')`.
    bytes4 internal constant MIGRATE_SUCCESS = 0x2c64c5ef;
    using LibRichErrorsV06 for bytes;
    /// @dev Perform a delegatecall and ensure it returns the magic bytes.
    /// @param target The call target.
    /// @param data The call data.
    function delegatecallMigrateFunction(
        address target,
        bytes memory data
    )
        internal
    {
        (bool success, bytes memory resultData) = target.delegatecall(data);
        if (!success ||
            resultData.length != 32 ||
            abi.decode(resultData, (bytes4)) != MIGRATE_SUCCESS)
        {
            LibOwnableRichErrors.MigrateCallFailedError(target, resultData).rrevert();
        }
    }
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibRichErrorsV06 {
    // bytes4(keccak256("Error(string)"))
    bytes4 internal constant STANDARD_ERROR_SELECTOR = 0x08c379a0;
    // solhint-disable func-name-mixedcase
    /// @dev ABI encode a standard, string revert error payload.
    ///      This is the same payload that would be included by a `revert(string)`
    ///      solidity statement. It has the function signature `Error(string)`.
    /// @param message The error string.
    /// @return The ABI encoded error.
    function StandardError(string memory message)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            STANDARD_ERROR_SELECTOR,
            bytes(message)
        );
    }
    // solhint-enable func-name-mixedcase
    /// @dev Reverts an encoded rich revert reason `errorData`.
    /// @param errorData ABI encoded error data.
    function rrevert(bytes memory errorData)
        internal
        pure
    {
        assembly {
            revert(add(errorData, 0x20), mload(errorData))
        }
    }
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibOwnableRichErrors {
    // solhint-disable func-name-mixedcase
    function OnlyOwnerError(
        address sender,
        address owner
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("OnlyOwnerError(address,address)")),
            sender,
            owner
        );
    }
    function TransferOwnerToZeroError()
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("TransferOwnerToZeroError()"))
        );
    }
    function MigrateCallFailedError(address target, bytes memory resultData)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("MigrateCallFailedError(address,bytes)")),
            target,
            resultData
        );
    }
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
import "../errors/LibCommonRichErrors.sol";
import "../errors/LibOwnableRichErrors.sol";
import "../features/interfaces/IOwnableFeature.sol";
import "../features/interfaces/ISimpleFunctionRegistryFeature.sol";
/// @dev Common feature utilities.
abstract contract FixinCommon {
    using LibRichErrorsV06 for bytes;
    /// @dev The implementation address of this feature.
    address internal immutable _implementation;
    /// @dev The caller must be this contract.
    modifier onlySelf() virtual {
        if (msg.sender != address(this)) {
            LibCommonRichErrors.OnlyCallableBySelfError(msg.sender).rrevert();
        }
        _;
    }
    /// @dev The caller of this function must be the owner.
    modifier onlyOwner() virtual {
        {
            address owner = IOwnableFeature(address(this)).owner();
            if (msg.sender != owner) {
                LibOwnableRichErrors.OnlyOwnerError(
                    msg.sender,
                    owner
                ).rrevert();
            }
        }
        _;
    }
    constructor() internal {
        // Remember this feature's original address.
        _implementation = address(this);
    }
    /// @dev Registers a function implemented by this feature at `_implementation`.
    ///      Can and should only be called within a `migrate()`.
    /// @param selector The selector of the function whose implementation
    ///        is at `_implementation`.
    function _registerFeatureFunction(bytes4 selector)
        internal
    {
        ISimpleFunctionRegistryFeature(address(this)).extend(selector, _implementation);
    }
    /// @dev Encode a feature version as a `uint256`.
    /// @param major The major version number of the feature.
    /// @param minor The minor version number of the feature.
    /// @param revision The revision number of the feature.
    /// @return encodedVersion The encoded version number.
    function _encodeVersion(uint32 major, uint32 minor, uint32 revision)
        internal
        pure
        returns (uint256 encodedVersion)
    {
        return (uint256(major) << 64) | (uint256(minor) << 32) | uint256(revision);
    }
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibCommonRichErrors {
    // solhint-disable func-name-mixedcase
    function OnlyCallableBySelfError(address sender)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("OnlyCallableBySelfError(address)")),
            sender
        );
    }
    function IllegalReentrancyError(bytes4 selector, uint256 reentrancyFlags)
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            bytes4(keccak256("IllegalReentrancyError(bytes4,uint256)")),
            selector,
            reentrancyFlags
        );
    }
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-utils/contracts/src/v06/interfaces/IOwnableV06.sol";
// solhint-disable no-empty-blocks
/// @dev Owner management and migration features.
interface IOwnableFeature is
    IOwnableV06
{
    /// @dev Emitted when `migrate()` is called.
    /// @param caller The caller of `migrate()`.
    /// @param migrator The migration contract.
    /// @param newOwner The address of the new owner.
    event Migrated(address caller, address migrator, address newOwner);
    /// @dev Execute a migration function in the context of the ZeroEx contract.
    ///      The result of the function being called should be the magic bytes
    ///      0x2c64c5ef (`keccack('MIGRATE_SUCCESS')`). Only callable by the owner.
    ///      The owner will be temporarily set to `address(this)` inside the call.
    ///      Before returning, the owner will be set to `newOwner`.
    /// @param target The migrator contract address.
    /// @param newOwner The address of the new owner.
    /// @param data The call data.
    function migrate(address target, bytes calldata data, address newOwner) external;
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
interface IOwnableV06 {
    /// @dev Emitted by Ownable when ownership is transferred.
    /// @param previousOwner The previous owner of the contract.
    /// @param newOwner The new owner of the contract.
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    /// @dev Transfers ownership of the contract to a new address.
    /// @param newOwner The address that will become the owner.
    function transferOwnership(address newOwner) external;
    /// @dev The owner of this contract.
    /// @return ownerAddress The owner address.
    function owner() external view returns (address ownerAddress);
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
/// @dev Basic registry management features.
interface ISimpleFunctionRegistryFeature {
    /// @dev A function implementation was updated via `extend()` or `rollback()`.
    /// @param selector The function selector.
    /// @param oldImpl The implementation contract address being replaced.
    /// @param newImpl The replacement implementation contract address.
    event ProxyFunctionUpdated(bytes4 indexed selector, address oldImpl, address newImpl);
    /// @dev Roll back to a prior implementation of a function.
    /// @param selector The function selector.
    /// @param targetImpl The address of an older implementation of the function.
    function rollback(bytes4 selector, address targetImpl) external;
    /// @dev Register or replace a function.
    /// @param selector The function selector.
    /// @param impl The implementation contract for the function.
    function extend(bytes4 selector, address impl) external;
    /// @dev Retrieve the length of the rollback history for a function.
    /// @param selector The function selector.
    /// @return rollbackLength The number of items in the rollback history for
    ///         the function.
    function getRollbackLength(bytes4 selector)
        external
        view
        returns (uint256 rollbackLength);
    /// @dev Retrieve an entry in the rollback history for a function.
    /// @param selector The function selector.
    /// @param idx The index in the rollback history.
    /// @return impl An implementation address for the function at
    ///         index `idx`.
    function getRollbackEntryAtIndex(bytes4 selector, uint256 idx)
        external
        view
        returns (address impl);
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-erc20/contracts/src/v06/IEtherTokenV06.sol";
import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
/// @dev Helpers for moving tokens around.
abstract contract FixinTokenSpender {
    // Mask of the lower 20 bytes of a bytes32.
    uint256 constant private ADDRESS_MASK = 0x000000000000000000000000ffffffffffffffffffffffffffffffffffffffff;
    /// @dev Transfers ERC20 tokens from `owner` to `to`.
    /// @param token The token to spend.
    /// @param owner The owner of the tokens.
    /// @param to The recipient of the tokens.
    /// @param amount The amount of `token` to transfer.
    function _transferERC20TokensFrom(
        IERC20TokenV06 token,
        address owner,
        address to,
        uint256 amount
    )
        internal
    {
        require(address(token) != address(this), "FixinTokenSpender/CANNOT_INVOKE_SELF");
        assembly {
            let ptr := mload(0x40) // free memory pointer
            // selector for transferFrom(address,address,uint256)
            mstore(ptr, 0x23b872dd00000000000000000000000000000000000000000000000000000000)
            mstore(add(ptr, 0x04), and(owner, ADDRESS_MASK))
            mstore(add(ptr, 0x24), and(to, ADDRESS_MASK))
            mstore(add(ptr, 0x44), amount)
            let success := call(
                gas(),
                and(token, ADDRESS_MASK),
                0,
                ptr,
                0x64,
                ptr,
                32
            )
            let rdsize := returndatasize()
            // Check for ERC20 success. ERC20 tokens should return a boolean,
            // but some don't. We accept 0-length return data as success, or at
            // least 32 bytes that starts with a 32-byte boolean true.
            success := and(
                success,                             // call itself succeeded
                or(
                    iszero(rdsize),                  // no return data, or
                    and(
                        iszero(lt(rdsize, 32)),      // at least 32 bytes
                        eq(mload(ptr), 1)            // starts with uint256(1)
                    )
                )
            )
            if iszero(success) {
                returndatacopy(ptr, 0, rdsize)
                revert(ptr, rdsize)
            }
        }
    }
    /// @dev Transfers ERC20 tokens from ourselves to `to`.
    /// @param token The token to spend.
    /// @param to The recipient of the tokens.
    /// @param amount The amount of `token` to transfer.
    function _transferERC20Tokens(
        IERC20TokenV06 token,
        address to,
        uint256 amount
    )
        internal
    {
        require(address(token) != address(this), "FixinTokenSpender/CANNOT_INVOKE_SELF");
        assembly {
            let ptr := mload(0x40) // free memory pointer
            // selector for transfer(address,uint256)
            mstore(ptr, 0xa9059cbb00000000000000000000000000000000000000000000000000000000)
            mstore(add(ptr, 0x04), and(to, ADDRESS_MASK))
            mstore(add(ptr, 0x24), amount)
            let success := call(
                gas(),
                and(token, ADDRESS_MASK),
                0,
                ptr,
                0x44,
                ptr,
                32
            )
            let rdsize := returndatasize()
            // Check for ERC20 success. ERC20 tokens should return a boolean,
            // but some don't. We accept 0-length return data as success, or at
            // least 32 bytes that starts with a 32-byte boolean true.
            success := and(
                success,                             // call itself succeeded
                or(
                    iszero(rdsize),                  // no return data, or
                    and(
                        iszero(lt(rdsize, 32)),      // at least 32 bytes
                        eq(mload(ptr), 1)            // starts with uint256(1)
                    )
                )
            )
            if iszero(success) {
                returndatacopy(ptr, 0, rdsize)
                revert(ptr, rdsize)
            }
        }
    }
    /// @dev Gets the maximum amount of an ERC20 token `token` that can be
    ///      pulled from `owner` by this address.
    /// @param token The token to spend.
    /// @param owner The owner of the tokens.
    /// @return amount The amount of tokens that can be pulled.
    function _getSpendableERC20BalanceOf(
        IERC20TokenV06 token,
        address owner
    )
        internal
        view
        returns (uint256)
    {
        return LibSafeMathV06.min256(
            token.allowance(owner, address(this)),
            token.balanceOf(owner)
        );
    }
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
import "./errors/LibRichErrorsV06.sol";
import "./errors/LibSafeMathRichErrorsV06.sol";
library LibSafeMathV06 {
    function safeMul(uint256 a, uint256 b)
        internal
        pure
        returns (uint256)
    {
        if (a == 0) {
            return 0;
        }
        uint256 c = a * b;
        if (c / a != b) {
            LibRichErrorsV06.rrevert(LibSafeMathRichErrorsV06.Uint256BinOpError(
                LibSafeMathRichErrorsV06.BinOpErrorCodes.MULTIPLICATION_OVERFLOW,
                a,
                b
            ));
        }
        return c;
    }
    function safeDiv(uint256 a, uint256 b)
        internal
        pure
        returns (uint256)
    {
        if (b == 0) {
            LibRichErrorsV06.rrevert(LibSafeMathRichErrorsV06.Uint256BinOpError(
                LibSafeMathRichErrorsV06.BinOpErrorCodes.DIVISION_BY_ZERO,
                a,
                b
            ));
        }
        uint256 c = a / b;
        return c;
    }
    function safeSub(uint256 a, uint256 b)
        internal
        pure
        returns (uint256)
    {
        if (b > a) {
            LibRichErrorsV06.rrevert(LibSafeMathRichErrorsV06.Uint256BinOpError(
                LibSafeMathRichErrorsV06.BinOpErrorCodes.SUBTRACTION_UNDERFLOW,
                a,
                b
            ));
        }
        return a - b;
    }
    function safeAdd(uint256 a, uint256 b)
        internal
        pure
        returns (uint256)
    {
        uint256 c = a + b;
        if (c < a) {
            LibRichErrorsV06.rrevert(LibSafeMathRichErrorsV06.Uint256BinOpError(
                LibSafeMathRichErrorsV06.BinOpErrorCodes.ADDITION_OVERFLOW,
                a,
                b
            ));
        }
        return c;
    }
    function max256(uint256 a, uint256 b)
        internal
        pure
        returns (uint256)
    {
        return a >= b ? a : b;
    }
    function min256(uint256 a, uint256 b)
        internal
        pure
        returns (uint256)
    {
        return a < b ? a : b;
    }
    function safeMul128(uint128 a, uint128 b)
        internal
        pure
        returns (uint128)
    {
        if (a == 0) {
            return 0;
        }
        uint128 c = a * b;
        if (c / a != b) {
            LibRichErrorsV06.rrevert(LibSafeMathRichErrorsV06.Uint256BinOpError(
                LibSafeMathRichErrorsV06.BinOpErrorCodes.MULTIPLICATION_OVERFLOW,
                a,
                b
            ));
        }
        return c;
    }
    function safeDiv128(uint128 a, uint128 b)
        internal
        pure
        returns (uint128)
    {
        if (b == 0) {
            LibRichErrorsV06.rrevert(LibSafeMathRichErrorsV06.Uint256BinOpError(
                LibSafeMathRichErrorsV06.BinOpErrorCodes.DIVISION_BY_ZERO,
                a,
                b
            ));
        }
        uint128 c = a / b;
        return c;
    }
    function safeSub128(uint128 a, uint128 b)
        internal
        pure
        returns (uint128)
    {
        if (b > a) {
            LibRichErrorsV06.rrevert(LibSafeMathRichErrorsV06.Uint256BinOpError(
                LibSafeMathRichErrorsV06.BinOpErrorCodes.SUBTRACTION_UNDERFLOW,
                a,
                b
            ));
        }
        return a - b;
    }
    function safeAdd128(uint128 a, uint128 b)
        internal
        pure
        returns (uint128)
    {
        uint128 c = a + b;
        if (c < a) {
            LibRichErrorsV06.rrevert(LibSafeMathRichErrorsV06.Uint256BinOpError(
                LibSafeMathRichErrorsV06.BinOpErrorCodes.ADDITION_OVERFLOW,
                a,
                b
            ));
        }
        return c;
    }
    function max128(uint128 a, uint128 b)
        internal
        pure
        returns (uint128)
    {
        return a >= b ? a : b;
    }
    function min128(uint128 a, uint128 b)
        internal
        pure
        returns (uint128)
    {
        return a < b ? a : b;
    }
    function safeDowncastToUint128(uint256 a)
        internal
        pure
        returns (uint128)
    {
        if (a > type(uint128).max) {
            LibRichErrorsV06.rrevert(LibSafeMathRichErrorsV06.Uint256DowncastError(
                LibSafeMathRichErrorsV06.DowncastErrorCodes.VALUE_TOO_LARGE_TO_DOWNCAST_TO_UINT128,
                a
            ));
        }
        return uint128(a);
    }
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
library LibSafeMathRichErrorsV06 {
    // bytes4(keccak256("Uint256BinOpError(uint8,uint256,uint256)"))
    bytes4 internal constant UINT256_BINOP_ERROR_SELECTOR =
        0xe946c1bb;
    // bytes4(keccak256("Uint256DowncastError(uint8,uint256)"))
    bytes4 internal constant UINT256_DOWNCAST_ERROR_SELECTOR =
        0xc996af7b;
    enum BinOpErrorCodes {
        ADDITION_OVERFLOW,
        MULTIPLICATION_OVERFLOW,
        SUBTRACTION_UNDERFLOW,
        DIVISION_BY_ZERO
    }
    enum DowncastErrorCodes {
        VALUE_TOO_LARGE_TO_DOWNCAST_TO_UINT32,
        VALUE_TOO_LARGE_TO_DOWNCAST_TO_UINT64,
        VALUE_TOO_LARGE_TO_DOWNCAST_TO_UINT96,
        VALUE_TOO_LARGE_TO_DOWNCAST_TO_UINT128
    }
    // solhint-disable func-name-mixedcase
    function Uint256BinOpError(
        BinOpErrorCodes errorCode,
        uint256 a,
        uint256 b
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            UINT256_BINOP_ERROR_SELECTOR,
            errorCode,
            a,
            b
        );
    }
    function Uint256DowncastError(
        DowncastErrorCodes errorCode,
        uint256 a
    )
        internal
        pure
        returns (bytes memory)
    {
        return abi.encodeWithSelector(
            UINT256_DOWNCAST_ERROR_SELECTOR,
            errorCode,
            a
        );
    }
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
/// @dev Basic interface for a feature contract.
interface IFeature {
    // solhint-disable func-name-mixedcase
    /// @dev The name of this feature set.
    function FEATURE_NAME() external view returns (string memory name);
    /// @dev The version of this feature set.
    function FEATURE_VERSION() external view returns (uint256 version);
}
// SPDX-License-Identifier: Apache-2.0
/*
  Copyright 2020 ZeroEx Intl.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/
pragma solidity ^0.6.5;
pragma experimental ABIEncoderV2;
import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
/// @dev VIP uniswap v3 fill functions.
interface IUniswapV3Feature {
    /// @dev Sell attached ETH directly against uniswap v3.
    /// @param encodedPath Uniswap-encoded path, where the first token is WETH.
    /// @param minBuyAmount Minimum amount of the last token in the path to buy.
    /// @param recipient The recipient of the bought tokens. Can be zero for sender.
    /// @return buyAmount Amount of the last token in the path bought.
    function sellEthForTokenToUniswapV3(
        bytes memory encodedPath,
        uint256 minBuyAmount,
        address recipient
    )
        external
        payable
        returns (uint256 buyAmount);
    /// @dev Sell a token for ETH directly against uniswap v3.
    /// @param encodedPath Uniswap-encoded path, where the last token is WETH.
    /// @param sellAmount amount of the first token in the path to sell.
    /// @param minBuyAmount Minimum amount of ETH to buy.
    /// @param recipient The recipient of the bought tokens. Can be zero for sender.
    /// @return buyAmount Amount of ETH bought.
    function sellTokenForEthToUniswapV3(
        bytes memory encodedPath,
        uint256 sellAmount,
        uint256 minBuyAmount,
        address payable recipient
    )
        external
        returns (uint256 buyAmount);
    /// @dev Sell a token for another token directly against uniswap v3.
    /// @param encodedPath Uniswap-encoded path.
    /// @param sellAmount amount of the first token in the path to sell.
    /// @param minBuyAmount Minimum amount of the last token in the path to buy.
    /// @param recipient The recipient of the bought tokens. Can be zero for sender.
    /// @return buyAmount Amount of the last token in the path bought.
    function sellTokenForTokenToUniswapV3(
        bytes memory encodedPath,
        uint256 sellAmount,
        uint256 minBuyAmount,
        address recipient
    )
        external
        returns (uint256 buyAmount);
    /// @dev Sell a token for another token directly against uniswap v3.
    ///      Private variant, uses tokens held by `address(this)`.
    /// @param encodedPath Uniswap-encoded path.
    /// @param sellAmount amount of the first token in the path to sell.
    /// @param minBuyAmount Minimum amount of the last token in the path to buy.
    /// @param recipient The recipient of the bought tokens. Can be zero for sender.
    /// @return buyAmount Amount of the last token in the path bought.
    function _sellHeldTokenForTokenToUniswapV3(
        bytes memory encodedPath,
        uint256 sellAmount,
        uint256 minBuyAmount,
        address recipient
    )
        external
        returns (uint256 buyAmount);
    /// @dev The UniswapV3 pool swap callback which pays the funds requested
    ///      by the caller/pool to the pool. Can only be called by a valid
    ///      UniswapV3 pool.
    /// @param amount0Delta Token0 amount owed.
    /// @param amount1Delta Token1 amount owed.
    /// @param data Arbitrary data forwarded from swap() caller. An ABI-encoded
    ///        struct of: inputToken, outputToken, fee, payer
    function uniswapV3SwapCallback(
        int256 amount0Delta,
        int256 amount1Delta,
        bytes calldata data
    )
        external;
}