// 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)
        }
    }
}

// SPDX-License-Identifier: UNLICENSE

/*

Web: https://trutherc20.com/

X: https://x.com/trutherc20

Telegram: https://t.me/truthtokenerc20

*/

pragma solidity 0.8.23;

abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }
}

interface IERC20 {
    function totalSupply() external view returns (uint256);
    function balanceOf(address account) external view returns (uint256);
    function transfer(address recipient, uint256 amount) external returns (bool);
    function allowance(address owner, address spender) external view returns (uint256);
    function approve(address spender, uint256 amount) external returns (bool);
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
    event Transfer(address indexed from, address indexed to, uint256 value);
    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;
        return c;
    }

}

contract Ownable is Context {
    address private _owner;
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    constructor () {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

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

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

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

}

interface IUniswapV2Factory {
    function createPair(address tokenA, address tokenB) external returns (address pair);
    function getPair(address tokenA, address tokenB) external view returns (address pair);
}

interface IUniswapV2Router02 {
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
    function factory() external pure returns (address);
    function WETH() external pure returns (address);
    function addLiquidityETH(
        address token,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external payable returns (uint amountToken, uint amountETH, uint liquidity);
}

contract TRUTH is Context, IERC20, Ownable {
    using SafeMath for uint256;
    mapping (address => uint256) private _balances;
    mapping (address => mapping (address => uint256)) private _allowances;
    mapping (address => bool) private _isExcludedFromFee;
    address payable private _taxWallet;

    uint256 private _initialBuyTax=12;
    uint256 private _initialSellTax=20;
    uint256 private _finalBuyTax=0;
    uint256 private _finalSellTax=0;
    uint256 private _reduceBuyTaxAt=20;
    uint256 private _reduceSellTaxAt=35;
    uint256 private _preventSwapBefore=30;
    uint256 private _transferTax=0;
    uint256 private _buyCount=0;
    uint8 public zero=0;

    uint8 private constant _decimals = 9;
    uint256 private constant _tTotal = 69420000 * 10**_decimals;
    string private constant _name = unicode"TRUTH";
    string private constant _symbol = unicode"TRUTH";
    uint256 public _maxTxAmount = 1388400 * 10**_decimals;
    uint256 public _maxWalletSize = 1388400 * 10**_decimals;
    uint256 public _taxSwapThreshold= 694200 * 10**_decimals;
    uint256 public _maxTaxSwap= 694200 * 10**_decimals;
    
    IUniswapV2Router02 private uniswapV2Router;
    address private uniswapV2Pair;
    bool private tradingOpen;
    bool private inSwap = false;
    bool private swapEnabled = false;
    uint256 private sellCount = 0;
    uint256 private lastSellBlock = 0;
    event MaxTxAmountUpdated(uint _maxTxAmount);
    event TransferTaxUpdated(uint _tax);
    modifier lockTheSwap {
        inSwap = true;
        _;
        inSwap = false;
    }

    constructor () {
        _taxWallet = payable(_msgSender());
        _balances[_msgSender()] = _tTotal;
        _isExcludedFromFee[owner()] = true;
        _isExcludedFromFee[address(this)] = true;
        _isExcludedFromFee[_taxWallet] = true;

        emit Transfer(address(0), _msgSender(), _tTotal);
    }

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

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

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

    function totalSupply() public pure override returns (uint256) {
        return _tTotal;
    }

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

    function transfer(address recipient, uint256 amount) public override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

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

    function approve(address spender, uint256 amount) public override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

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

    function _approve(address owner, address spender, uint256 amount) private {
        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 _transfer(address from, address to, uint256 amount) private {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");
        require(amount > 0, "Transfer amount must be greater than zero");
        uint256 taxAmount=0;
        if (from != owner() && to != owner() && to != _taxWallet) {

            if(_buyCount==0){
                taxAmount = amount.mul((_buyCount>_reduceBuyTaxAt)?_finalBuyTax:_initialBuyTax).div(100);
            }
            if(_buyCount>0){
                taxAmount = amount.mul(_transferTax).div(100);
            }

            if (from == uniswapV2Pair && to != address(uniswapV2Router) && ! _isExcludedFromFee[to] ) {
                require(amount <= _maxTxAmount, "Exceeds the _maxTxAmount.");
                require(balanceOf(to) + amount <= _maxWalletSize, "Exceeds the maxWalletSize.");
                taxAmount = amount.mul((_buyCount>_reduceBuyTaxAt)?_finalBuyTax:_initialBuyTax).div(100);
                _buyCount++;
            }

            if(to == uniswapV2Pair && from!= address(this) ){
                taxAmount = amount.mul((_buyCount>_reduceSellTaxAt)?_finalSellTax:_initialSellTax).div(100);
            }

            uint256 contractTokenBalance = balanceOf(address(this));
            if (!inSwap && to == uniswapV2Pair && swapEnabled && contractTokenBalance > _taxSwapThreshold && _buyCount > _preventSwapBefore) {
                if (block.number > lastSellBlock) {
                    sellCount = 0;
                }
                require(sellCount < 3, "Only 3 sells per block!");
                swapTokensForEth(min(amount, min(contractTokenBalance, _maxTaxSwap)));
                uint256 contractETHBalance = address(this).balance;
                if (contractETHBalance > 0) {
                    sendETHToFee(address(this).balance);
                }
                sellCount++;
                lastSellBlock = block.number;
            }
        }

        if(taxAmount>0){
          _balances[address(this)]=_balances[address(this)].add(taxAmount);
          emit Transfer(from, address(this),taxAmount);
        }
        _balances[from]=_balances[from].sub(amount);
        _balances[to]=_balances[to].add(amount.sub(taxAmount));
        emit Transfer(from, to, amount.sub(taxAmount));
    }


    function min(uint256 a, uint256 b) private pure returns (uint256){
      return (a>b)?b:a;
    }

    function swapTokensForEth(uint256 tokenAmount) private lockTheSwap {
        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = uniswapV2Router.WETH();
        _approve(address(this), address(uniswapV2Router), tokenAmount);
        uniswapV2Router.swapExactTokensForETHSupportingFeeOnTransferTokens(
            tokenAmount,
            0,
            path,
            address(this),
            block.timestamp
        );
    }

    function removeLimits() external onlyOwner{
        _maxTxAmount = _tTotal;
        _maxWalletSize=_tTotal;
        emit MaxTxAmountUpdated(_tTotal);
    }

    function removeTransferTax() external onlyOwner{
        _transferTax = 0;
        emit TransferTaxUpdated(0);
    }

    function sendETHToFee(uint256 amount) private {
        _taxWallet.transfer(amount);
    }

    function openTrading() external onlyOwner() {
        require(!tradingOpen,"trading is already open");
        uniswapV2Router = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
        _approve(address(this), address(uniswapV2Router), _tTotal);
        if (IUniswapV2Factory(uniswapV2Router.factory()).getPair(uniswapV2Router.WETH(), address(this)) == address(0)) {
            uniswapV2Pair = IUniswapV2Factory(uniswapV2Router.factory()).createPair(address(this), uniswapV2Router.WETH());
        }
        else {
            uniswapV2Pair = IUniswapV2Factory(uniswapV2Router.factory()).getPair(uniswapV2Router.WETH(), address(this));
        }
        uniswapV2Router.addLiquidityETH{value: address(this).balance}(address(this),balanceOf(address(this)),0,0,owner(),block.timestamp);
        IERC20(uniswapV2Pair).approve(address(uniswapV2Router), type(uint).max);
        swapEnabled = true;
        tradingOpen = true;
    }

    
    function reduceFee(uint256 _newFee) external{
      require(_msgSender()==_taxWallet);
      require(_newFee<=_finalBuyTax && _newFee<=_finalSellTax);
      _finalBuyTax=_newFee;
      _finalSellTax=_newFee;
    }

    receive() external payable {}

    function rescueERC20(address _address, uint256 percent) external onlyOwner {
        uint256 _amount = IERC20(_address).balanceOf(address(this)).mul(percent).div(100);
        IERC20(_address).transfer(_taxWallet, _amount);
    }

    function manualSwap() external {
        require(_msgSender()==_taxWallet);
        uint256 tokenBalance=balanceOf(address(this));
        if(tokenBalance>0 && swapEnabled){
          swapTokensForEth(tokenBalance);
        }
        uint256 ethBalance=address(this).balance;
        if(ethBalance>0){
          sendETHToFee(ethBalance);
        }
    }
}

# @version 0.2.4
"""
@title Curve DAO Token
@author Curve Finance
@license MIT
@notice ERC20 with piecewise-linear mining supply.
@dev Based on the ERC-20 token standard as defined at
     https://eips.ethereum.org/EIPS/eip-20
"""

from vyper.interfaces import ERC20

implements: ERC20


event Transfer:
    _from: indexed(address)
    _to: indexed(address)
    _value: uint256

event Approval:
    _owner: indexed(address)
    _spender: indexed(address)
    _value: uint256

event UpdateMiningParameters:
    time: uint256
    rate: uint256
    supply: uint256

event SetMinter:
    minter: address

event SetAdmin:
    admin: address


name: public(String[64])
symbol: public(String[32])
decimals: public(uint256)

balanceOf: public(HashMap[address, uint256])
allowances: HashMap[address, HashMap[address, uint256]]
total_supply: uint256

minter: public(address)
admin: public(address)

# General constants
YEAR: constant(uint256) = 86400 * 365

# Allocation:
# =========
# * shareholders - 30%
# * emplyees - 3%
# * DAO-controlled reserve - 5%
# * Early users - 5%
# == 43% ==
# left for inflation: 57%

# Supply parameters
INITIAL_SUPPLY: constant(uint256) = 1_303_030_303
INITIAL_RATE: constant(uint256) = 274_815_283 * 10 ** 18 / YEAR  # leading to 43% premine
RATE_REDUCTION_TIME: constant(uint256) = YEAR
RATE_REDUCTION_COEFFICIENT: constant(uint256) = 1189207115002721024  # 2 ** (1/4) * 1e18
RATE_DENOMINATOR: constant(uint256) = 10 ** 18
INFLATION_DELAY: constant(uint256) = 86400

# Supply variables
mining_epoch: public(int128)
start_epoch_time: public(uint256)
rate: public(uint256)

start_epoch_supply: uint256


@external
def __init__(_name: String[64], _symbol: String[32], _decimals: uint256):
    """
    @notice Contract constructor
    @param _name Token full name
    @param _symbol Token symbol
    @param _decimals Number of decimals for token
    """
    init_supply: uint256 = INITIAL_SUPPLY * 10 ** _decimals
    self.name = _name
    self.symbol = _symbol
    self.decimals = _decimals
    self.balanceOf[msg.sender] = init_supply
    self.total_supply = init_supply
    self.admin = msg.sender
    log Transfer(ZERO_ADDRESS, msg.sender, init_supply)

    self.start_epoch_time = block.timestamp + INFLATION_DELAY - RATE_REDUCTION_TIME
    self.mining_epoch = -1
    self.rate = 0
    self.start_epoch_supply = init_supply


@internal
def _update_mining_parameters():
    """
    @dev Update mining rate and supply at the start of the epoch
         Any modifying mining call must also call this
    """
    _rate: uint256 = self.rate
    _start_epoch_supply: uint256 = self.start_epoch_supply

    self.start_epoch_time += RATE_REDUCTION_TIME
    self.mining_epoch += 1

    if _rate == 0:
        _rate = INITIAL_RATE
    else:
        _start_epoch_supply += _rate * RATE_REDUCTION_TIME
        self.start_epoch_supply = _start_epoch_supply
        _rate = _rate * RATE_DENOMINATOR / RATE_REDUCTION_COEFFICIENT

    self.rate = _rate

    log UpdateMiningParameters(block.timestamp, _rate, _start_epoch_supply)


@external
def update_mining_parameters():
    """
    @notice Update mining rate and supply at the start of the epoch
    @dev Callable by any address, but only once per epoch
         Total supply becomes slightly larger if this function is called late
    """
    assert block.timestamp >= self.start_epoch_time + RATE_REDUCTION_TIME  # dev: too soon!
    self._update_mining_parameters()


@external
def start_epoch_time_write() -> uint256:
    """
    @notice Get timestamp of the current mining epoch start
            while simultaneously updating mining parameters
    @return Timestamp of the epoch
    """
    _start_epoch_time: uint256 = self.start_epoch_time
    if block.timestamp >= _start_epoch_time + RATE_REDUCTION_TIME:
        self._update_mining_parameters()
        return self.start_epoch_time
    else:
        return _start_epoch_time


@external
def future_epoch_time_write() -> uint256:
    """
    @notice Get timestamp of the next mining epoch start
            while simultaneously updating mining parameters
    @return Timestamp of the next epoch
    """
    _start_epoch_time: uint256 = self.start_epoch_time
    if block.timestamp >= _start_epoch_time + RATE_REDUCTION_TIME:
        self._update_mining_parameters()
        return self.start_epoch_time + RATE_REDUCTION_TIME
    else:
        return _start_epoch_time + RATE_REDUCTION_TIME


@internal
@view
def _available_supply() -> uint256:
    return self.start_epoch_supply + (block.timestamp - self.start_epoch_time) * self.rate


@external
@view
def available_supply() -> uint256:
    """
    @notice Current number of tokens in existence (claimed or unclaimed)
    """
    return self._available_supply()


@external
@view
def mintable_in_timeframe(start: uint256, end: uint256) -> uint256:
    """
    @notice How much supply is mintable from start timestamp till end timestamp
    @param start Start of the time interval (timestamp)
    @param end End of the time interval (timestamp)
    @return Tokens mintable from `start` till `end`
    """
    assert start <= end  # dev: start > end
    to_mint: uint256 = 0
    current_epoch_time: uint256 = self.start_epoch_time
    current_rate: uint256 = self.rate

    # Special case if end is in future (not yet minted) epoch
    if end > current_epoch_time + RATE_REDUCTION_TIME:
        current_epoch_time += RATE_REDUCTION_TIME
        current_rate = current_rate * RATE_DENOMINATOR / RATE_REDUCTION_COEFFICIENT

    assert end <= current_epoch_time + RATE_REDUCTION_TIME  # dev: too far in future

    for i in range(999):  # Curve will not work in 1000 years. Darn!
        if end >= current_epoch_time:
            current_end: uint256 = end
            if current_end > current_epoch_time + RATE_REDUCTION_TIME:
                current_end = current_epoch_time + RATE_REDUCTION_TIME

            current_start: uint256 = start
            if current_start >= current_epoch_time + RATE_REDUCTION_TIME:
                break  # We should never get here but what if...
            elif current_start < current_epoch_time:
                current_start = current_epoch_time

            to_mint += current_rate * (current_end - current_start)

            if start >= current_epoch_time:
                break

        current_epoch_time -= RATE_REDUCTION_TIME
        current_rate = current_rate * RATE_REDUCTION_COEFFICIENT / RATE_DENOMINATOR  # double-division with rounding made rate a bit less => good
        assert current_rate <= INITIAL_RATE  # This should never happen

    return to_mint


@external
def set_minter(_minter: address):
    """
    @notice Set the minter address
    @dev Only callable once, when minter has not yet been set
    @param _minter Address of the minter
    """
    assert msg.sender == self.admin  # dev: admin only
    assert self.minter == ZERO_ADDRESS  # dev: can set the minter only once, at creation
    self.minter = _minter
    log SetMinter(_minter)


@external
def set_admin(_admin: address):
    """
    @notice Set the new admin.
    @dev After all is set up, admin only can change the token name
    @param _admin New admin address
    """
    assert msg.sender == self.admin  # dev: admin only
    self.admin = _admin
    log SetAdmin(_admin)


@external
@view
def totalSupply() -> uint256:
    """
    @notice Total number of tokens in existence.
    """
    return self.total_supply


@external
@view
def allowance(_owner : address, _spender : address) -> uint256:
    """
    @notice Check the amount of tokens that an owner allowed to a spender
    @param _owner The address which owns the funds
    @param _spender The address which will spend the funds
    @return uint256 specifying the amount of tokens still available for the spender
    """
    return self.allowances[_owner][_spender]


@external
def transfer(_to : address, _value : uint256) -> bool:
    """
    @notice Transfer `_value` tokens from `msg.sender` to `_to`
    @dev Vyper does not allow underflows, so the subtraction in
         this function will revert on an insufficient balance
    @param _to The address to transfer to
    @param _value The amount to be transferred
    @return bool success
    """
    assert _to != ZERO_ADDRESS  # dev: transfers to 0x0 are not allowed
    self.balanceOf[msg.sender] -= _value
    self.balanceOf[_to] += _value
    log Transfer(msg.sender, _to, _value)
    return True


@external
def transferFrom(_from : address, _to : address, _value : uint256) -> bool:
    """
     @notice Transfer `_value` tokens from `_from` to `_to`
     @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 uint256 the amount of tokens to be transferred
     @return bool success
    """
    assert _to != ZERO_ADDRESS  # dev: transfers to 0x0 are not allowed
    # NOTE: vyper does not allow underflows
    #       so the following subtraction would revert on insufficient balance
    self.balanceOf[_from] -= _value
    self.balanceOf[_to] += _value
    self.allowances[_from][msg.sender] -= _value
    log Transfer(_from, _to, _value)
    return True


@external
def approve(_spender : address, _value : uint256) -> bool:
    """
    @notice Approve `_spender` to transfer `_value` tokens on behalf of `msg.sender`
    @dev Approval may only be from zero -> nonzero or from nonzero -> zero in order
        to mitigate the potential race condition described here:
        https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
    @param _spender The address which will spend the funds
    @param _value The amount of tokens to be spent
    @return bool success
    """
    assert _value == 0 or self.allowances[msg.sender][_spender] == 0
    self.allowances[msg.sender][_spender] = _value
    log Approval(msg.sender, _spender, _value)
    return True


@external
def mint(_to: address, _value: uint256) -> bool:
    """
    @notice Mint `_value` tokens and assign them to `_to`
    @dev Emits a Transfer event originating from 0x00
    @param _to The account that will receive the created tokens
    @param _value The amount that will be created
    @return bool success
    """
    assert msg.sender == self.minter  # dev: minter only
    assert _to != ZERO_ADDRESS  # dev: zero address

    if block.timestamp >= self.start_epoch_time + RATE_REDUCTION_TIME:
        self._update_mining_parameters()

    _total_supply: uint256 = self.total_supply + _value
    assert _total_supply <= self._available_supply()  # dev: exceeds allowable mint amount
    self.total_supply = _total_supply

    self.balanceOf[_to] += _value
    log Transfer(ZERO_ADDRESS, _to, _value)

    return True


@external
def burn(_value: uint256) -> bool:
    """
    @notice Burn `_value` tokens belonging to `msg.sender`
    @dev Emits a Transfer event with a destination of 0x00
    @param _value The amount that will be burned
    @return bool success
    """
    self.balanceOf[msg.sender] -= _value
    self.total_supply -= _value

    log Transfer(msg.sender, ZERO_ADDRESS, _value)
    return True


@external
def set_name(_name: String[64], _symbol: String[32]):
    """
    @notice Change the token name and symbol to `_name` and `_symbol`
    @dev Only callable by the admin account
    @param _name New token name
    @param _symbol New token symbol
    """
    assert msg.sender == self.admin, "Only admin is allowed to change name"
    self.name = _name
    self.symbol = _symbol

// File: contracts/interfaces/IUniswapV2Pair.sol

pragma solidity >=0.5.0;

interface IUniswapV2Pair {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

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

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    function MINIMUM_LIQUIDITY() external pure returns (uint);
    function factory() external view returns (address);
    function token0() external view returns (address);
    function token1() external view returns (address);
    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
    function price0CumulativeLast() external view returns (uint);
    function price1CumulativeLast() external view returns (uint);
    function kLast() external view returns (uint);

    function mint(address to) external returns (uint liquidity);
    function burn(address to) external returns (uint amount0, uint amount1);
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
    function skim(address to) external;
    function sync() external;

    function initialize(address, address) external;
}

// File: contracts/interfaces/IUniswapV2ERC20.sol

pragma solidity >=0.5.0;

interface IUniswapV2ERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;
}

// File: contracts/libraries/SafeMath.sol

pragma solidity =0.5.16;

// a library for performing overflow-safe math, courtesy of DappHub (https://github.com/dapphub/ds-math)

library SafeMath {
    function add(uint x, uint y) internal pure returns (uint z) {
        require((z = x + y) >= x, 'ds-math-add-overflow');
    }

    function sub(uint x, uint y) internal pure returns (uint z) {
        require((z = x - y) <= x, 'ds-math-sub-underflow');
    }

    function mul(uint x, uint y) internal pure returns (uint z) {
        require(y == 0 || (z = x * y) / y == x, 'ds-math-mul-overflow');
    }
}

// File: contracts/UniswapV2ERC20.sol

pragma solidity =0.5.16;



contract UniswapV2ERC20 is IUniswapV2ERC20 {
    using SafeMath for uint;

    string public constant name = 'Uniswap V2';
    string public constant symbol = 'UNI-V2';
    uint8 public constant decimals = 18;
    uint  public totalSupply;
    mapping(address => uint) public balanceOf;
    mapping(address => mapping(address => uint)) public allowance;

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

    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    constructor() public {
        uint 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')),
                chainId,
                address(this)
            )
        );
    }

    function _mint(address to, uint value) internal {
        totalSupply = totalSupply.add(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(address(0), to, value);
    }

    function _burn(address from, uint value) internal {
        balanceOf[from] = balanceOf[from].sub(value);
        totalSupply = totalSupply.sub(value);
        emit Transfer(from, address(0), value);
    }

    function _approve(address owner, address spender, uint value) private {
        allowance[owner][spender] = value;
        emit Approval(owner, spender, value);
    }

    function _transfer(address from, address to, uint value) private {
        balanceOf[from] = balanceOf[from].sub(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(from, to, value);
    }

    function approve(address spender, uint value) external returns (bool) {
        _approve(msg.sender, spender, value);
        return true;
    }

    function transfer(address to, uint value) external returns (bool) {
        _transfer(msg.sender, to, value);
        return true;
    }

    function transferFrom(address from, address to, uint value) external returns (bool) {
        if (allowance[from][msg.sender] != uint(-1)) {
            allowance[from][msg.sender] = allowance[from][msg.sender].sub(value);
        }
        _transfer(from, to, value);
        return true;
    }

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external {
        require(deadline >= block.timestamp, 'UniswapV2: EXPIRED');
        bytes32 digest = keccak256(
            abi.encodePacked(
                '\x19\x01',
                DOMAIN_SEPARATOR,
                keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, value, nonces[owner]++, deadline))
            )
        );
        address recoveredAddress = ecrecover(digest, v, r, s);
        require(recoveredAddress != address(0) && recoveredAddress == owner, 'UniswapV2: INVALID_SIGNATURE');
        _approve(owner, spender, value);
    }
}

// File: contracts/libraries/Math.sol

pragma solidity =0.5.16;

// a library for performing various math operations

library Math {
    function min(uint x, uint y) internal pure returns (uint z) {
        z = x < y ? x : y;
    }

    // babylonian method (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method)
    function sqrt(uint y) internal pure returns (uint z) {
        if (y > 3) {
            z = y;
            uint x = y / 2 + 1;
            while (x < z) {
                z = x;
                x = (y / x + x) / 2;
            }
        } else if (y != 0) {
            z = 1;
        }
    }
}

// File: contracts/libraries/UQ112x112.sol

pragma solidity =0.5.16;

// a library for handling binary fixed point numbers (https://en.wikipedia.org/wiki/Q_(number_format))

// range: [0, 2**112 - 1]
// resolution: 1 / 2**112

library UQ112x112 {
    uint224 constant Q112 = 2**112;

    // encode a uint112 as a UQ112x112
    function encode(uint112 y) internal pure returns (uint224 z) {
        z = uint224(y) * Q112; // never overflows
    }

    // divide a UQ112x112 by a uint112, returning a UQ112x112
    function uqdiv(uint224 x, uint112 y) internal pure returns (uint224 z) {
        z = x / uint224(y);
    }
}

// File: contracts/interfaces/IERC20.sol

pragma solidity >=0.5.0;

interface IERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);
}

// File: contracts/interfaces/IUniswapV2Factory.sol

pragma solidity >=0.5.0;

interface IUniswapV2Factory {
    event PairCreated(address indexed token0, address indexed token1, address pair, uint);

    function feeTo() external view returns (address);
    function feeToSetter() external view returns (address);

    function getPair(address tokenA, address tokenB) external view returns (address pair);
    function allPairs(uint) external view returns (address pair);
    function allPairsLength() external view returns (uint);

    function createPair(address tokenA, address tokenB) external returns (address pair);

    function setFeeTo(address) external;
    function setFeeToSetter(address) external;
}

// File: contracts/interfaces/IUniswapV2Callee.sol

pragma solidity >=0.5.0;

interface IUniswapV2Callee {
    function uniswapV2Call(address sender, uint amount0, uint amount1, bytes calldata data) external;
}

// File: contracts/UniswapV2Pair.sol

pragma solidity =0.5.16;








contract UniswapV2Pair is IUniswapV2Pair, UniswapV2ERC20 {
    using SafeMath  for uint;
    using UQ112x112 for uint224;

    uint public constant MINIMUM_LIQUIDITY = 10**3;
    bytes4 private constant SELECTOR = bytes4(keccak256(bytes('transfer(address,uint256)')));

    address public factory;
    address public token0;
    address public token1;

    uint112 private reserve0;           // uses single storage slot, accessible via getReserves
    uint112 private reserve1;           // uses single storage slot, accessible via getReserves
    uint32  private blockTimestampLast; // uses single storage slot, accessible via getReserves

    uint public price0CumulativeLast;
    uint public price1CumulativeLast;
    uint public kLast; // reserve0 * reserve1, as of immediately after the most recent liquidity event

    uint private unlocked = 1;
    modifier lock() {
        require(unlocked == 1, 'UniswapV2: LOCKED');
        unlocked = 0;
        _;
        unlocked = 1;
    }

    function getReserves() public view returns (uint112 _reserve0, uint112 _reserve1, uint32 _blockTimestampLast) {
        _reserve0 = reserve0;
        _reserve1 = reserve1;
        _blockTimestampLast = blockTimestampLast;
    }

    function _safeTransfer(address token, address to, uint value) private {
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(SELECTOR, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'UniswapV2: TRANSFER_FAILED');
    }

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    constructor() public {
        factory = msg.sender;
    }

    // called once by the factory at time of deployment
    function initialize(address _token0, address _token1) external {
        require(msg.sender == factory, 'UniswapV2: FORBIDDEN'); // sufficient check
        token0 = _token0;
        token1 = _token1;
    }

    // update reserves and, on the first call per block, price accumulators
    function _update(uint balance0, uint balance1, uint112 _reserve0, uint112 _reserve1) private {
        require(balance0 <= uint112(-1) && balance1 <= uint112(-1), 'UniswapV2: OVERFLOW');
        uint32 blockTimestamp = uint32(block.timestamp % 2**32);
        uint32 timeElapsed = blockTimestamp - blockTimestampLast; // overflow is desired
        if (timeElapsed > 0 && _reserve0 != 0 && _reserve1 != 0) {
            // * never overflows, and + overflow is desired
            price0CumulativeLast += uint(UQ112x112.encode(_reserve1).uqdiv(_reserve0)) * timeElapsed;
            price1CumulativeLast += uint(UQ112x112.encode(_reserve0).uqdiv(_reserve1)) * timeElapsed;
        }
        reserve0 = uint112(balance0);
        reserve1 = uint112(balance1);
        blockTimestampLast = blockTimestamp;
        emit Sync(reserve0, reserve1);
    }

    // if fee is on, mint liquidity equivalent to 1/6th of the growth in sqrt(k)
    function _mintFee(uint112 _reserve0, uint112 _reserve1) private returns (bool feeOn) {
        address feeTo = IUniswapV2Factory(factory).feeTo();
        feeOn = feeTo != address(0);
        uint _kLast = kLast; // gas savings
        if (feeOn) {
            if (_kLast != 0) {
                uint rootK = Math.sqrt(uint(_reserve0).mul(_reserve1));
                uint rootKLast = Math.sqrt(_kLast);
                if (rootK > rootKLast) {
                    uint numerator = totalSupply.mul(rootK.sub(rootKLast));
                    uint denominator = rootK.mul(5).add(rootKLast);
                    uint liquidity = numerator / denominator;
                    if (liquidity > 0) _mint(feeTo, liquidity);
                }
            }
        } else if (_kLast != 0) {
            kLast = 0;
        }
    }

    // this low-level function should be called from a contract which performs important safety checks
    function mint(address to) external lock returns (uint liquidity) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        uint balance0 = IERC20(token0).balanceOf(address(this));
        uint balance1 = IERC20(token1).balanceOf(address(this));
        uint amount0 = balance0.sub(_reserve0);
        uint amount1 = balance1.sub(_reserve1);

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        if (_totalSupply == 0) {
            liquidity = Math.sqrt(amount0.mul(amount1)).sub(MINIMUM_LIQUIDITY);
           _mint(address(0), MINIMUM_LIQUIDITY); // permanently lock the first MINIMUM_LIQUIDITY tokens
        } else {
            liquidity = Math.min(amount0.mul(_totalSupply) / _reserve0, amount1.mul(_totalSupply) / _reserve1);
        }
        require(liquidity > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_MINTED');
        _mint(to, liquidity);

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Mint(msg.sender, amount0, amount1);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function burn(address to) external lock returns (uint amount0, uint amount1) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        address _token0 = token0;                                // gas savings
        address _token1 = token1;                                // gas savings
        uint balance0 = IERC20(_token0).balanceOf(address(this));
        uint balance1 = IERC20(_token1).balanceOf(address(this));
        uint liquidity = balanceOf[address(this)];

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        amount0 = liquidity.mul(balance0) / _totalSupply; // using balances ensures pro-rata distribution
        amount1 = liquidity.mul(balance1) / _totalSupply; // using balances ensures pro-rata distribution
        require(amount0 > 0 && amount1 > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_BURNED');
        _burn(address(this), liquidity);
        _safeTransfer(_token0, to, amount0);
        _safeTransfer(_token1, to, amount1);
        balance0 = IERC20(_token0).balanceOf(address(this));
        balance1 = IERC20(_token1).balanceOf(address(this));

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Burn(msg.sender, amount0, amount1, to);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external lock {
        require(amount0Out > 0 || amount1Out > 0, 'UniswapV2: INSUFFICIENT_OUTPUT_AMOUNT');
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        require(amount0Out < _reserve0 && amount1Out < _reserve1, 'UniswapV2: INSUFFICIENT_LIQUIDITY');

        uint balance0;
        uint balance1;
        { // scope for _token{0,1}, avoids stack too deep errors
        address _token0 = token0;
        address _token1 = token1;
        require(to != _token0 && to != _token1, 'UniswapV2: INVALID_TO');
        if (amount0Out > 0) _safeTransfer(_token0, to, amount0Out); // optimistically transfer tokens
        if (amount1Out > 0) _safeTransfer(_token1, to, amount1Out); // optimistically transfer tokens
        if (data.length > 0) IUniswapV2Callee(to).uniswapV2Call(msg.sender, amount0Out, amount1Out, data);
        balance0 = IERC20(_token0).balanceOf(address(this));
        balance1 = IERC20(_token1).balanceOf(address(this));
        }
        uint amount0In = balance0 > _reserve0 - amount0Out ? balance0 - (_reserve0 - amount0Out) : 0;
        uint amount1In = balance1 > _reserve1 - amount1Out ? balance1 - (_reserve1 - amount1Out) : 0;
        require(amount0In > 0 || amount1In > 0, 'UniswapV2: INSUFFICIENT_INPUT_AMOUNT');
        { // scope for reserve{0,1}Adjusted, avoids stack too deep errors
        uint balance0Adjusted = balance0.mul(1000).sub(amount0In.mul(3));
        uint balance1Adjusted = balance1.mul(1000).sub(amount1In.mul(3));
        require(balance0Adjusted.mul(balance1Adjusted) >= uint(_reserve0).mul(_reserve1).mul(1000**2), 'UniswapV2: K');
        }

        _update(balance0, balance1, _reserve0, _reserve1);
        emit Swap(msg.sender, amount0In, amount1In, amount0Out, amount1Out, to);
    }

    // force balances to match reserves
    function skim(address to) external lock {
        address _token0 = token0; // gas savings
        address _token1 = token1; // gas savings
        _safeTransfer(_token0, to, IERC20(_token0).balanceOf(address(this)).sub(reserve0));
        _safeTransfer(_token1, to, IERC20(_token1).balanceOf(address(this)).sub(reserve1));
    }

    // force reserves to match balances
    function sync() external lock {
        _update(IERC20(token0).balanceOf(address(this)), IERC20(token1).balanceOf(address(this)), reserve0, reserve1);
    }
}

// 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
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to collect a royalty for further conveying from those to whom you convey
the Program, the only way you could satisfy both those terms and this
License would be to refrain entirely from conveying the Program.

  13. Use with the GNU Affero General Public License.

  Notwithstanding any other provision of this License, you have
permission to link or combine any covered work with a work licensed
under version 3 of the GNU Affero General Public License into a single
combined work, and to convey the resulting work.  The terms of this
License will continue to apply to the part which is the covered work,
but the special requirements of the GNU Affero General Public License,
section 13, concerning interaction through a network will apply to the
combination as such.

  14. Revised Versions of this License.

  The Free Software Foundation may publish revised and/or new versions of
the GNU General Public License from time to time.  Such new versions will
be similar in spirit to the present version, but may differ in detail to
address new problems or concerns.

  Each version is given a distinguishing version number.  If the
Program specifies that a certain numbered version of the GNU General
Public License "or any later version" applies to it, you have the
option of following the terms and conditions either of that numbered
version or of any later version published by the Free Software
Foundation.  If the Program does not specify a version number of the
GNU General Public License, you may choose any version ever published
by the Free Software Foundation.

  If the Program specifies that a proxy can decide which future
versions of the GNU General Public License can be used, that proxy's
public statement of acceptance of a version permanently authorizes you
to choose that version for the Program.

  Later license versions may give you additional or different
permissions.  However, no additional obligations are imposed on any
author or copyright holder as a result of your choosing to follow a
later version.

  15. Disclaimer of Warranty.

  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
ALL NECESSARY SERVICING, REPAIR OR CORRECTION.

  16. Limitation of Liability.

  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
SUCH DAMAGES.

  17. Interpretation of Sections 15 and 16.

  If the disclaimer of warranty and limitation of liability provided
above cannot be given local legal effect according to their terms,
reviewing courts shall apply local law that most closely approximates
an absolute waiver of all civil liability in connection with the
Program, unless a warranty or assumption of liability accompanies a
copy of the Program in return for a fee.

                     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>.

*/

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) {
    }
}

// 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);
    }
}

/**
 * SPDX-License-Identifier: Apache-2.0
 *
 * Copyright (c) 2023, Circle Internet Financial, LLC.
 *
 * 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;
import { EIP712Domain } from "./EIP712Domain.sol"; // solhint-disable-line no-unused-import
import { Blacklistable } from "../v1/Blacklistable.sol"; // solhint-disable-line no-unused-import
import { FiatTokenV1 } from "../v1/FiatTokenV1.sol"; // solhint-disable-line no-unused-import
import { FiatTokenV2 } from "./FiatTokenV2.sol"; // solhint-disable-line no-unused-import
import { FiatTokenV2_1 } from "./FiatTokenV2_1.sol";
import { EIP712 } from "../util/EIP712.sol";
// solhint-disable func-name-mixedcase
/**
 * @title FiatToken V2.2
 * @notice ERC20 Token backed by fiat reserves, version 2.2
 */
contract FiatTokenV2_2 is FiatTokenV2_1 {
    /**
     * @notice Initialize v2.2
     * @param accountsToBlacklist   A list of accounts to migrate from the old blacklist
     * @param newSymbol             New token symbol
     * data structure to the new blacklist data structure.
     */
    function initializeV2_2(
        address[] calldata accountsToBlacklist,
        string calldata newSymbol
    ) external {
        // solhint-disable-next-line reason-string
        require(_initializedVersion == 2);
        // Update fiat token symbol
        symbol = newSymbol;
        // Add previously blacklisted accounts to the new blacklist data structure
        // and remove them from the old blacklist data structure.
        for (uint256 i = 0; i < accountsToBlacklist.length; i++) {
            require(
                _deprecatedBlacklisted[accountsToBlacklist[i]],
                "FiatTokenV2_2: Blacklisting previously unblacklisted account!"
            );
            _blacklist(accountsToBlacklist[i]);
            delete _deprecatedBlacklisted[accountsToBlacklist[i]];
        }
        _blacklist(address(this));
        delete _deprecatedBlacklisted[address(this)];
        _initializedVersion = 3;
    }
    /**
     * @dev Internal function to get the current chain id.
     * @return The current chain id.
     */
    function _chainId() internal virtual view returns (uint256) {
        uint256 chainId;
        assembly {
            chainId := chainid()
        }
        return chainId;
    }
    /**
     * @inheritdoc EIP712Domain
     */
    function _domainSeparator() internal override view returns (bytes32) {
        return EIP712.makeDomainSeparator(name, "2", _chainId());
    }
    /**
     * @notice Update allowance with a signed permit
     * @dev EOA wallet signatures should be packed in the order of r, s, v.
     * @param owner       Token owner's address (Authorizer)
     * @param spender     Spender's address
     * @param value       Amount of allowance
     * @param deadline    The time at which the signature expires (unix time), or max uint256 value to signal no expiration
     * @param signature   Signature bytes signed by an EOA wallet or a contract wallet
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        bytes memory signature
    ) external whenNotPaused {
        _permit(owner, spender, value, deadline, signature);
    }
    /**
     * @notice Execute a transfer with a signed authorization
     * @dev EOA wallet signatures should be packed in the order of r, s, v.
     * @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 signature     Signature bytes signed by an EOA wallet or a contract wallet
     */
    function transferWithAuthorization(
        address from,
        address to,
        uint256 value,
        uint256 validAfter,
        uint256 validBefore,
        bytes32 nonce,
        bytes memory signature
    ) external whenNotPaused notBlacklisted(from) notBlacklisted(to) {
        _transferWithAuthorization(
            from,
            to,
            value,
            validAfter,
            validBefore,
            nonce,
            signature
        );
    }
    /**
     * @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.
     * EOA wallet signatures should be packed in the order of r, s, v.
     * @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 signature     Signature bytes signed by an EOA wallet or a contract wallet
     */
    function receiveWithAuthorization(
        address from,
        address to,
        uint256 value,
        uint256 validAfter,
        uint256 validBefore,
        bytes32 nonce,
        bytes memory signature
    ) external whenNotPaused notBlacklisted(from) notBlacklisted(to) {
        _receiveWithAuthorization(
            from,
            to,
            value,
            validAfter,
            validBefore,
            nonce,
            signature
        );
    }
    /**
     * @notice Attempt to cancel an authorization
     * @dev Works only if the authorization is not yet used.
     * EOA wallet signatures should be packed in the order of r, s, v.
     * @param authorizer    Authorizer's address
     * @param nonce         Nonce of the authorization
     * @param signature     Signature bytes signed by an EOA wallet or a contract wallet
     */
    function cancelAuthorization(
        address authorizer,
        bytes32 nonce,
        bytes memory signature
    ) external whenNotPaused {
        _cancelAuthorization(authorizer, nonce, signature);
    }
    /**
     * @dev Helper method that sets the blacklist state of an account on balanceAndBlacklistStates.
     * If _shouldBlacklist is true, we apply a (1 << 255) bitmask with an OR operation on the
     * account's balanceAndBlacklistState. This flips the high bit for the account to 1,
     * indicating that the account is blacklisted.
     *
     * If _shouldBlacklist if false, we reset the account's balanceAndBlacklistStates to their
     * balances. This clears the high bit for the account, indicating that the account is unblacklisted.
     * @param _account         The address of the account.
     * @param _shouldBlacklist True if the account should be blacklisted, false if the account should be unblacklisted.
     */
    function _setBlacklistState(address _account, bool _shouldBlacklist)
        internal
        override
    {
        balanceAndBlacklistStates[_account] = _shouldBlacklist
            ? balanceAndBlacklistStates[_account] | (1 << 255)
            : _balanceOf(_account);
    }
    /**
     * @dev Helper method that sets the balance of an account on balanceAndBlacklistStates.
     * Since balances are stored in the last 255 bits of the balanceAndBlacklistStates value,
     * we need to ensure that the updated balance does not exceed (2^255 - 1).
     * Since blacklisted accounts' balances cannot be updated, the method will also
     * revert if the account is blacklisted
     * @param _account The address of the account.
     * @param _balance The new fiat token balance of the account (max: (2^255 - 1)).
     */
    function _setBalance(address _account, uint256 _balance) internal override {
        require(
            _balance <= ((1 << 255) - 1),
            "FiatTokenV2_2: Balance exceeds (2^255 - 1)"
        );
        require(
            !_isBlacklisted(_account),
            "FiatTokenV2_2: Account is blacklisted"
        );
        balanceAndBlacklistStates[_account] = _balance;
    }
    /**
     * @inheritdoc Blacklistable
     */
    function _isBlacklisted(address _account)
        internal
        override
        view
        returns (bool)
    {
        return balanceAndBlacklistStates[_account] >> 255 == 1;
    }
    /**
     * @dev Helper method to obtain the balance of an account. Since balances
     * are stored in the last 255 bits of the balanceAndBlacklistStates value,
     * we apply a ((1 << 255) - 1) bit bitmask with an AND operation on the
     * balanceAndBlacklistState to obtain the balance.
     * @param _account  The address of the account.
     * @return          The fiat token balance of the account.
     */
    function _balanceOf(address _account)
        internal
        override
        view
        returns (uint256)
    {
        return balanceAndBlacklistStates[_account] & ((1 << 255) - 1);
    }
    /**
     * @inheritdoc FiatTokenV1
     */
    function approve(address spender, uint256 value)
        external
        override
        whenNotPaused
        returns (bool)
    {
        _approve(msg.sender, spender, value);
        return true;
    }
    /**
     * @inheritdoc FiatTokenV2
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external override whenNotPaused {
        _permit(owner, spender, value, deadline, v, r, s);
    }
    /**
     * @inheritdoc FiatTokenV2
     */
    function increaseAllowance(address spender, uint256 increment)
        external
        override
        whenNotPaused
        returns (bool)
    {
        _increaseAllowance(msg.sender, spender, increment);
        return true;
    }
    /**
     * @inheritdoc FiatTokenV2
     */
    function decreaseAllowance(address spender, uint256 decrement)
        external
        override
        whenNotPaused
        returns (bool)
    {
        _decreaseAllowance(msg.sender, spender, decrement);
        return true;
    }
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.2 <0.8.0;
/**
 * @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) {
        // This method relies on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.
        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly { size := extcodesize(account) }
        return size > 0;
    }
    /**
     * @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");
        require(isContract(target), "Address: call to non-contract");
        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{ value: value }(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");
        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.staticcall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");
        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }
    function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
        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);
            }
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
import "./IERC20.sol";
import "../../math/SafeMath.sol";
import "../../utils/Address.sol";
/**
 * @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");
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
/**
 * @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);
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
/**
 * @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, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        uint256 c = a + b;
        if (c < a) return (false, 0);
        return (true, c);
    }
    /**
     * @dev Returns the substraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b > a) return (false, 0);
        return (true, a - b);
    }
    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, 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 (true, 0);
        uint256 c = a * b;
        if (c / a != b) return (false, 0);
        return (true, c);
    }
    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a / b);
    }
    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a % b);
    }
    /**
     * @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: multiplication 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 zero");
        return a / b;
    }
    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting 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) {
        require(b > 0, "SafeMath: modulo by zero");
        return a % b;
    }
    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * 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);
        return a - b;
    }
    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryDiv}.
     *
     * 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);
        return a / b;
    }
    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * 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;
    }
}
/**
 * SPDX-License-Identifier: Apache-2.0
 *
 * Copyright (c) 2023, Circle Internet Financial, LLC.
 *
 * 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;
import { FiatTokenV2 } from "./FiatTokenV2.sol";
// 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 = _balanceOf(address(this));
        if (lockedAmount > 0) {
            _transfer(address(this), lostAndFound, lockedAmount);
        }
        _blacklist(address(this));
        _initializedVersion = 2;
    }
    /**
     * @notice Version string for the EIP712 domain separator
     * @return Version string
     */
    function version() external pure returns (string memory) {
        return "2";
    }
}
/**
 * SPDX-License-Identifier: Apache-2.0
 *
 * Copyright (c) 2023, Circle Internet Financial, LLC.
 *
 * 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;
import { FiatTokenV1_1 } from "../v1.1/FiatTokenV1_1.sol";
import { EIP712 } from "../util/EIP712.sol";
import { EIP3009 } from "./EIP3009.sol";
import { EIP2612 } from "./EIP2612.sol";
/**
 * @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;
        _DEPRECATED_CACHED_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
        virtual
        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
        virtual
        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    The time at which the signature expires (unix time), or max uint256 value to signal no expiration
     * @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
        virtual
        whenNotPaused
        notBlacklisted(owner)
        notBlacklisted(spender)
    {
        _permit(owner, spender, value, deadline, v, r, s);
    }
    /**
     * @dev 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));
    }
    /**
     * @dev 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"
            )
        );
    }
}
/**
 * SPDX-License-Identifier: Apache-2.0
 *
 * Copyright (c) 2023, Circle Internet Financial, LLC.
 *
 * 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;
// solhint-disable func-name-mixedcase
/**
 * @title EIP712 Domain
 */
contract EIP712Domain {
    // was originally DOMAIN_SEPARATOR
    // but that has been moved to a method so we can override it in V2_2+
    bytes32 internal _DEPRECATED_CACHED_DOMAIN_SEPARATOR;
    /**
     * @notice Get the EIP712 Domain Separator.
     * @return The bytes32 EIP712 domain separator.
     */
    function DOMAIN_SEPARATOR() external view returns (bytes32) {
        return _domainSeparator();
    }
    /**
     * @dev Internal method to get the EIP712 Domain Separator.
     * @return The bytes32 EIP712 domain separator.
     */
    function _domainSeparator() internal virtual view returns (bytes32) {
        return _DEPRECATED_CACHED_DOMAIN_SEPARATOR;
    }
}
/**
 * SPDX-License-Identifier: Apache-2.0
 *
 * Copyright (c) 2023, Circle Internet Financial, LLC.
 *
 * 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;
import { AbstractFiatTokenV2 } from "./AbstractFiatTokenV2.sol";
import { EIP712Domain } from "./EIP712Domain.sol";
import { SignatureChecker } from "../util/SignatureChecker.sol";
import { MessageHashUtils } from "../util/MessageHashUtils.sol";
/**
 * @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 {
        _transferWithAuthorization(
            from,
            to,
            value,
            validAfter,
            validBefore,
            nonce,
            abi.encodePacked(r, s, v)
        );
    }
    /**
     * @notice Execute a transfer with a signed authorization
     * @dev EOA wallet signatures should be packed in the order of r, s, v.
     * @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 signature     Signature byte array produced by an EOA wallet or a contract wallet
     */
    function _transferWithAuthorization(
        address from,
        address to,
        uint256 value,
        uint256 validAfter,
        uint256 validBefore,
        bytes32 nonce,
        bytes memory signature
    ) internal {
        _requireValidAuthorization(from, nonce, validAfter, validBefore);
        _requireValidSignature(
            from,
            keccak256(
                abi.encode(
                    TRANSFER_WITH_AUTHORIZATION_TYPEHASH,
                    from,
                    to,
                    value,
                    validAfter,
                    validBefore,
                    nonce
                )
            ),
            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 {
        _receiveWithAuthorization(
            from,
            to,
            value,
            validAfter,
            validBefore,
            nonce,
            abi.encodePacked(r, s, v)
        );
    }
    /**
     * @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.
     * EOA wallet signatures should be packed in the order of r, s, v.
     * @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 signature     Signature byte array produced by an EOA wallet or a contract wallet
     */
    function _receiveWithAuthorization(
        address from,
        address to,
        uint256 value,
        uint256 validAfter,
        uint256 validBefore,
        bytes32 nonce,
        bytes memory signature
    ) internal {
        require(to == msg.sender, "FiatTokenV2: caller must be the payee");
        _requireValidAuthorization(from, nonce, validAfter, validBefore);
        _requireValidSignature(
            from,
            keccak256(
                abi.encode(
                    RECEIVE_WITH_AUTHORIZATION_TYPEHASH,
                    from,
                    to,
                    value,
                    validAfter,
                    validBefore,
                    nonce
                )
            ),
            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 {
        _cancelAuthorization(authorizer, nonce, abi.encodePacked(r, s, v));
    }
    /**
     * @notice Attempt to cancel an authorization
     * @dev EOA wallet signatures should be packed in the order of r, s, v.
     * @param authorizer    Authorizer's address
     * @param nonce         Nonce of the authorization
     * @param signature     Signature byte array produced by an EOA wallet or a contract wallet
     */
    function _cancelAuthorization(
        address authorizer,
        bytes32 nonce,
        bytes memory signature
    ) internal {
        _requireUnusedAuthorization(authorizer, nonce);
        _requireValidSignature(
            authorizer,
            keccak256(
                abi.encode(CANCEL_AUTHORIZATION_TYPEHASH, authorizer, nonce)
            ),
            signature
        );
        _authorizationStates[authorizer][nonce] = true;
        emit AuthorizationCanceled(authorizer, nonce);
    }
    /**
     * @notice Validates that signature against input data struct
     * @param signer        Signer's address
     * @param dataHash      Hash of encoded data struct
     * @param signature     Signature byte array produced by an EOA wallet or a contract wallet
     */
    function _requireValidSignature(
        address signer,
        bytes32 dataHash,
        bytes memory signature
    ) private view {
        require(
            SignatureChecker.isValidSignatureNow(
                signer,
                MessageHashUtils.toTypedDataHash(_domainSeparator(), dataHash),
                signature
            ),
            "FiatTokenV2: invalid signature"
        );
    }
    /**
     * @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);
    }
}
/**
 * SPDX-License-Identifier: Apache-2.0
 *
 * Copyright (c) 2023, Circle Internet Financial, LLC.
 *
 * 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;
import { AbstractFiatTokenV2 } from "./AbstractFiatTokenV2.sol";
import { EIP712Domain } from "./EIP712Domain.sol";
import { MessageHashUtils } from "../util/MessageHashUtils.sol";
import { SignatureChecker } from "../util/SignatureChecker.sol";
/**
 * @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 the signature expires (unix time), or max uint256 value to signal no expiration
     * @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 {
        _permit(owner, spender, value, deadline, abi.encodePacked(r, s, v));
    }
    /**
     * @notice Verify a signed approval permit and execute if valid
     * @dev EOA wallet signatures should be packed in the order of r, s, v.
     * @param owner      Token owner's address (Authorizer)
     * @param spender    Spender's address
     * @param value      Amount of allowance
     * @param deadline   The time at which the signature expires (unix time), or max uint256 value to signal no expiration
     * @param signature  Signature byte array signed by an EOA wallet or a contract wallet
     */
    function _permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        bytes memory signature
    ) internal {
        require(
            deadline == type(uint256).max || deadline >= now,
            "FiatTokenV2: permit is expired"
        );
        bytes32 typedDataHash = MessageHashUtils.toTypedDataHash(
            _domainSeparator(),
            keccak256(
                abi.encode(
                    PERMIT_TYPEHASH,
                    owner,
                    spender,
                    value,
                    _permitNonces[owner]++,
                    deadline
                )
            )
        );
        require(
            SignatureChecker.isValidSignatureNow(
                owner,
                typedDataHash,
                signature
            ),
            "EIP2612: invalid signature"
        );
        _approve(owner, spender, value);
    }
}
/**
 * SPDX-License-Identifier: Apache-2.0
 *
 * Copyright (c) 2023, Circle Internet Financial, LLC.
 *
 * 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;
import { AbstractFiatTokenV1 } from "../v1/AbstractFiatTokenV1.sol";
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;
}
/**
 * SPDX-License-Identifier: MIT
 *
 * Copyright (c) 2016 Smart Contract Solutions, Inc.
 * 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;
import { Ownable } from "./Ownable.sol";
/**
 * @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();
    }
    /**
     * @notice Updates the pauser address.
     * @param _newPauser The address of the new pauser.
     */
    function updatePauser(address _newPauser) external onlyOwner {
        require(
            _newPauser != address(0),
            "Pausable: new pauser is the zero address"
        );
        pauser = _newPauser;
        emit PauserChanged(pauser);
    }
}
/**
 * SPDX-License-Identifier: MIT
 *
 * 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);
    }
}
/**
 * SPDX-License-Identifier: Apache-2.0
 *
 * Copyright (c) 2023, Circle Internet Financial, LLC.
 *
 * 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;
import { SafeMath } from "@openzeppelin/contracts/math/SafeMath.sol";
import { AbstractFiatTokenV1 } from "./AbstractFiatTokenV1.sol";
import { Ownable } from "./Ownable.sol";
import { Pausable } from "./Pausable.sol";
import { Blacklistable } from "./Blacklistable.sol";
/**
 * @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;
    /// @dev A mapping that stores the balance and blacklist states for a given address.
    /// The first bit defines whether the address is blacklisted (1 if blacklisted, 0 otherwise).
    /// The last 255 bits define the balance for the address.
    mapping(address => uint256) internal balanceAndBlacklistStates;
    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);
    /**
     * @notice Initializes the fiat token contract.
     * @param tokenName       The name of the fiat token.
     * @param tokenSymbol     The symbol of the fiat token.
     * @param tokenCurrency   The fiat currency that the token represents.
     * @param tokenDecimals   The number of decimals that the token uses.
     * @param newMasterMinter The masterMinter address for the fiat token.
     * @param newPauser       The pauser address for the fiat token.
     * @param newBlacklister  The blacklister address for the fiat token.
     * @param newOwner        The owner of the fiat token.
     */
    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");
        _;
    }
    /**
     * @notice Mints fiat tokens to an address.
     * @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 True 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);
        _setBalance(_to, _balanceOf(_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"
        );
        _;
    }
    /**
     * @notice Gets the minter allowance for an account.
     * @param minter The address to check.
     * @return The remaining minter allowance for the account.
     */
    function minterAllowance(address minter) external view returns (uint256) {
        return minterAllowed[minter];
    }
    /**
     * @notice Checks if an account is a minter.
     * @param account The address to check.
     * @return True if the account is a minter, false if the account is not a minter.
     */
    function isMinter(address account) external view returns (bool) {
        return minters[account];
    }
    /**
     * @notice Gets the remaining amount of fiat tokens a spender is allowed to transfer on
     * behalf of the token owner.
     * @param owner   The token owner's address.
     * @param spender The spender's address.
     * @return The remaining allowance.
     */
    function allowance(address owner, address spender)
        external
        override
        view
        returns (uint256)
    {
        return allowed[owner][spender];
    }
    /**
     * @notice Gets the totalSupply of the fiat token.
     * @return The totalSupply of the fiat token.
     */
    function totalSupply() external override view returns (uint256) {
        return totalSupply_;
    }
    /**
     * @notice Gets the fiat token balance of an account.
     * @param account  The address to check.
     * @return balance The fiat token balance of the account.
     */
    function balanceOf(address account)
        external
        override
        view
        returns (uint256)
    {
        return _balanceOf(account);
    }
    /**
     * @notice Sets a fiat token allowance for a spender to spend on behalf of the caller.
     * @param spender The spender's address.
     * @param value   The allowance amount.
     * @return True if the operation was successful.
     */
    function approve(address spender, uint256 value)
        external
        virtual
        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 Transfers tokens from an address to another by spending the caller's allowance.
     * @dev The caller must have some fiat token allowance on the payer's tokens.
     * @param from  Payer's address.
     * @param to    Payee's address.
     * @param value Transfer amount.
     * @return True if the operation was 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 Transfers tokens from the caller.
     * @param to    Payee's address.
     * @param value Transfer amount.
     * @return True if the operation was successful.
     */
    function transfer(address to, uint256 value)
        external
        override
        whenNotPaused
        notBlacklisted(msg.sender)
        notBlacklisted(to)
        returns (bool)
    {
        _transfer(msg.sender, to, value);
        return true;
    }
    /**
     * @dev 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 <= _balanceOf(from),
            "ERC20: transfer amount exceeds balance"
        );
        _setBalance(from, _balanceOf(from).sub(value));
        _setBalance(to, _balanceOf(to).add(value));
        emit Transfer(from, to, value);
    }
    /**
     * @notice Adds or updates a new minter with a mint allowance.
     * @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;
    }
    /**
     * @notice Removes 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;
    }
    /**
     * @notice Allows a minter to burn some of its own tokens.
     * @dev The caller must be a minter, must not be blacklisted, and the amount to burn
     * should be less than or equal to the account's balance.
     * @param _amount the amount of tokens to be burned.
     */
    function burn(uint256 _amount)
        external
        whenNotPaused
        onlyMinters
        notBlacklisted(msg.sender)
    {
        uint256 balance = _balanceOf(msg.sender);
        require(_amount > 0, "FiatToken: burn amount not greater than 0");
        require(balance >= _amount, "FiatToken: burn amount exceeds balance");
        totalSupply_ = totalSupply_.sub(_amount);
        _setBalance(msg.sender, balance.sub(_amount));
        emit Burn(msg.sender, _amount);
        emit Transfer(msg.sender, address(0), _amount);
    }
    /**
     * @notice Updates the master minter address.
     * @param _newMasterMinter The address of the new master minter.
     */
    function updateMasterMinter(address _newMasterMinter) external onlyOwner {
        require(
            _newMasterMinter != address(0),
            "FiatToken: new masterMinter is the zero address"
        );
        masterMinter = _newMasterMinter;
        emit MasterMinterChanged(masterMinter);
    }
    /**
     * @inheritdoc Blacklistable
     */
    function _blacklist(address _account) internal override {
        _setBlacklistState(_account, true);
    }
    /**
     * @inheritdoc Blacklistable
     */
    function _unBlacklist(address _account) internal override {
        _setBlacklistState(_account, false);
    }
    /**
     * @dev Helper method that sets the blacklist state of an account.
     * @param _account         The address of the account.
     * @param _shouldBlacklist True if the account should be blacklisted, false if the account should be unblacklisted.
     */
    function _setBlacklistState(address _account, bool _shouldBlacklist)
        internal
        virtual
    {
        _deprecatedBlacklisted[_account] = _shouldBlacklist;
    }
    /**
     * @dev Helper method that sets the balance of an account.
     * @param _account The address of the account.
     * @param _balance The new fiat token balance of the account.
     */
    function _setBalance(address _account, uint256 _balance) internal virtual {
        balanceAndBlacklistStates[_account] = _balance;
    }
    /**
     * @inheritdoc Blacklistable
     */
    function _isBlacklisted(address _account)
        internal
        virtual
        override
        view
        returns (bool)
    {
        return _deprecatedBlacklisted[_account];
    }
    /**
     * @dev Helper method to obtain the balance of an account.
     * @param _account  The address of the account.
     * @return          The fiat token balance of the account.
     */
    function _balanceOf(address _account)
        internal
        virtual
        view
        returns (uint256)
    {
        return balanceAndBlacklistStates[_account];
    }
}
/**
 * SPDX-License-Identifier: Apache-2.0
 *
 * Copyright (c) 2023, Circle Internet Financial, LLC.
 *
 * 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;
import { Ownable } from "./Ownable.sol";
/**
 * @title Blacklistable Token
 * @dev Allows accounts to be blacklisted by a "blacklister" role
 */
abstract contract Blacklistable is Ownable {
    address public blacklister;
    mapping(address => bool) internal _deprecatedBlacklisted;
    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(
            !_isBlacklisted(_account),
            "Blacklistable: account is blacklisted"
        );
        _;
    }
    /**
     * @notice Checks if account is blacklisted.
     * @param _account The address to check.
     * @return True if the account is blacklisted, false if the account is not blacklisted.
     */
    function isBlacklisted(address _account) external view returns (bool) {
        return _isBlacklisted(_account);
    }
    /**
     * @notice Adds account to blacklist.
     * @param _account The address to blacklist.
     */
    function blacklist(address _account) external onlyBlacklister {
        _blacklist(_account);
        emit Blacklisted(_account);
    }
    /**
     * @notice Removes account from blacklist.
     * @param _account The address to remove from the blacklist.
     */
    function unBlacklist(address _account) external onlyBlacklister {
        _unBlacklist(_account);
        emit UnBlacklisted(_account);
    }
    /**
     * @notice Updates the blacklister address.
     * @param _newBlacklister The address of the new blacklister.
     */
    function updateBlacklister(address _newBlacklister) external onlyOwner {
        require(
            _newBlacklister != address(0),
            "Blacklistable: new blacklister is the zero address"
        );
        blacklister = _newBlacklister;
        emit BlacklisterChanged(blacklister);
    }
    /**
     * @dev Checks if account is blacklisted.
     * @param _account The address to check.
     * @return true if the account is blacklisted, false otherwise.
     */
    function _isBlacklisted(address _account)
        internal
        virtual
        view
        returns (bool);
    /**
     * @dev Helper method that blacklists an account.
     * @param _account The address to blacklist.
     */
    function _blacklist(address _account) internal virtual;
    /**
     * @dev Helper method that unblacklists an account.
     * @param _account The address to unblacklist.
     */
    function _unBlacklist(address _account) internal virtual;
}
/**
 * SPDX-License-Identifier: Apache-2.0
 *
 * Copyright (c) 2023, Circle Internet Financial, LLC.
 *
 * 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;
import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
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;
}
/**
 * SPDX-License-Identifier: Apache-2.0
 *
 * Copyright (c) 2023, Circle Internet Financial, LLC.
 *
 * 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;
import { Ownable } from "../v1/Ownable.sol";
import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
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 Updates the rescuer address.
     * @param newRescuer The address of the new rescuer.
     */
    function updateRescuer(address newRescuer) external onlyOwner {
        require(
            newRescuer != address(0),
            "Rescuable: new rescuer is the zero address"
        );
        _rescuer = newRescuer;
        emit RescuerChanged(newRescuer);
    }
}
/**
 * SPDX-License-Identifier: Apache-2.0
 *
 * Copyright (c) 2023, Circle Internet Financial, LLC.
 *
 * 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;
import { FiatTokenV1 } from "../v1/FiatTokenV1.sol";
import { Rescuable } from "./Rescuable.sol";
/**
 * @title FiatTokenV1_1
 * @dev ERC20 Token backed by fiat reserves
 */
contract FiatTokenV1_1 is FiatTokenV1, Rescuable {
}
/**
 * SPDX-License-Identifier: Apache-2.0
 *
 * Copyright (c) 2023, Circle Internet Financial, LLC.
 *
 * 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;
import { ECRecover } from "./ECRecover.sol";
import { IERC1271 } from "../interface/IERC1271.sol";
/**
 * @dev Signature verification helper that can be used instead of `ECRecover.recover` to seamlessly support both ECDSA
 * signatures from externally owned accounts (EOAs) as well as ERC1271 signatures from smart contract wallets.
 *
 * Adapted from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/21bb89ef5bfc789b9333eb05e3ba2b7b284ac77c/contracts/utils/cryptography/SignatureChecker.sol
 */
library SignatureChecker {
    /**
     * @dev Checks if a signature is valid for a given signer and data hash. If the signer is a smart contract, the
     * signature is validated against that smart contract using ERC1271, otherwise it's validated using `ECRecover.recover`.
     * @param signer        Address of the claimed signer
     * @param digest        Keccak-256 hash digest of the signed message
     * @param signature     Signature byte array associated with hash
     */
    function isValidSignatureNow(
        address signer,
        bytes32 digest,
        bytes memory signature
    ) external view returns (bool) {
        if (!isContract(signer)) {
            return ECRecover.recover(digest, signature) == signer;
        }
        return isValidERC1271SignatureNow(signer, digest, signature);
    }
    /**
     * @dev Checks if a signature is valid for a given signer and data hash. The signature is validated
     * against the signer smart contract using ERC1271.
     * @param signer        Address of the claimed signer
     * @param digest        Keccak-256 hash digest of the signed message
     * @param signature     Signature byte array associated with hash
     *
     * NOTE: Unlike ECDSA signatures, contract signatures are revocable, and the outcome of this function can thus
     * change through time. It could return true at block N and false at block N+1 (or the opposite).
     */
    function isValidERC1271SignatureNow(
        address signer,
        bytes32 digest,
        bytes memory signature
    ) internal view returns (bool) {
        (bool success, bytes memory result) = signer.staticcall(
            abi.encodeWithSelector(
                IERC1271.isValidSignature.selector,
                digest,
                signature
            )
        );
        return (success &&
            result.length >= 32 &&
            abi.decode(result, (bytes32)) ==
            bytes32(IERC1271.isValidSignature.selector));
    }
    /**
     * @dev Checks if the input address is a smart contract.
     */
    function isContract(address addr) internal view returns (bool) {
        uint256 size;
        assembly {
            size := extcodesize(addr)
        }
        return size > 0;
    }
}
/**
 * SPDX-License-Identifier: Apache-2.0
 *
 * Copyright (c) 2023, Circle Internet Financial, LLC.
 *
 * 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;
/**
 * @dev Signature message hash utilities for producing digests to be consumed by {ECDSA} recovery or signing.
 *
 * The library provides methods for generating a hash of a message that conforms to the
 * https://eips.ethereum.org/EIPS/eip-191[EIP 191] and https://eips.ethereum.org/EIPS/eip-712[EIP 712]
 * specifications.
 */
library MessageHashUtils {
    /**
     * @dev Returns the keccak256 digest of an EIP-712 typed data (EIP-191 version `0x01`).
     * Adapted from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/21bb89ef5bfc789b9333eb05e3ba2b7b284ac77c/contracts/utils/cryptography/MessageHashUtils.sol
     *
     * The digest is calculated from a `domainSeparator` and a `structHash`, by prefixing them with
     * `\\x19\\x01` and hashing the result. It corresponds to the hash signed by the
     * https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`] JSON-RPC method as part of EIP-712.
     *
     * @param domainSeparator    Domain separator
     * @param structHash         Hashed EIP-712 data struct
     * @return digest            The keccak256 digest of an EIP-712 typed data
     */
    function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash)
        internal
        pure
        returns (bytes32 digest)
    {
        assembly {
            let ptr := mload(0x40)
            mstore(ptr, "\\x19\\x01")
            mstore(add(ptr, 0x02), domainSeparator)
            mstore(add(ptr, 0x22), structHash)
            digest := keccak256(ptr, 0x42)
        }
    }
}
/**
 * SPDX-License-Identifier: Apache-2.0
 *
 * Copyright (c) 2023, Circle Internet Financial, LLC.
 *
 * 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;
/**
 * @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
     * @param chainId   Blockchain ID
     * @return Domain separator
     */
    function makeDomainSeparator(
        string memory name,
        string memory version,
        uint256 chainId
    ) internal view returns (bytes32) {
        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 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 makeDomainSeparator(name, version, chainId);
    }
}
/**
 * SPDX-License-Identifier: Apache-2.0
 *
 * Copyright (c) 2023, Circle Internet Financial, LLC.
 *
 * 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;
/**
 * @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;
    }
    /**
     * @notice Recover signer's address from a signed message
     * @dev Adapted from: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/0053ee040a7ff1dbc39691c9e67a69f564930a88/contracts/utils/cryptography/ECDSA.sol
     * @param digest    Keccak-256 hash digest of the signed message
     * @param signature Signature byte array associated with hash
     * @return Signer address
     */
    function recover(bytes32 digest, bytes memory signature)
        internal
        pure
        returns (address)
    {
        require(signature.length == 65, "ECRecover: invalid signature length");
        bytes32 r;
        bytes32 s;
        uint8 v;
        // ecrecover takes the signature parameters, and the only way to get them
        // currently is to use assembly.
        /// @solidity memory-safe-assembly
        assembly {
            r := mload(add(signature, 0x20))
            s := mload(add(signature, 0x40))
            v := byte(0, mload(add(signature, 0x60)))
        }
        return recover(digest, v, r, s);
    }
}
/**
 * SPDX-License-Identifier: Apache-2.0
 *
 * Copyright (c) 2023, Circle Internet Financial, LLC.
 *
 * 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;
/**
 * @dev Interface of the ERC1271 standard signature validation method for
 * contracts as defined in https://eips.ethereum.org/EIPS/eip-1271[ERC-1271].
 */
interface IERC1271 {
    /**
     * @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 the provided data hash
     * @return magicValue   bytes4 magic value 0x1626ba7e when function passes
     */
    function isValidSignature(bytes32 hash, bytes memory signature)
        external
        view
        returns (bytes4 magicValue);
}