// SPDX-License-Identifier: MIT
pragma solidity 0.8.24;
import {Ownable2Step} from "openzeppelin-solidity/contracts/access/Ownable2Step.sol";
import {Pausable} from "openzeppelin-solidity/contracts/security/Pausable.sol";
import {Address} from "openzeppelin-solidity/contracts/utils/Address.sol";
import {IMagpieRouterV3} from "./interfaces/IMagpieRouterV3.sol";
import {LibAsset} from "./libraries/LibAsset.sol";
import {LibRouter, SwapData} from "./libraries/LibRouter.sol";
error ExpiredTransaction();
error InsufficientAmountOut();
error InvalidCall();
error InvalidCommand();
error InvalidTransferFromCall();
error ApprovalFailed();
error TransferFromFailed();
error TransferFailed();
error UniswapV3InvalidAmount();
error InvalidCaller();
error InvalidAmountIn();
error InvalidSignature();
error InvalidOutput();
error InvalidNativeAmount();
enum CommandAction {
    Call, // Represents a generic call to a function within a contract.
    Approval, // Represents an approval operation.
    TransferFrom, // Indicates a transfer-from operation.
    Transfer, // Represents a direct transfer operation.
    Wrap, // This action is used for wrapping native tokens.
    Unwrap, // This action is used for unwrapping native tokens.
    Balance, // Checks the balance of an account or contract for a specific asset.
    Math,
    Comparison,
    EstimateGasStart,
    EstimateGasEnd
}
contract MagpieRouterV3 is IMagpieRouterV3, Ownable2Step, Pausable {
    using LibAsset for address;
    mapping(address => bool) public internalCaller;
    mapping(address => bool) public bridge;
    address public swapFeeAddress;
    /// @dev Restricts swap functions with signatures to only be called by whitelisted internal caller.
    modifier onlyInternalCaller() {
        if (!internalCaller[msg.sender]) {
            revert InvalidCaller();
        }
        _;
    }
    /// @dev Restricts swap functions with signatures to be called only by bridge.
    modifier onlyBridge() {
        if (!bridge[msg.sender]) {
            revert InvalidCaller();
        }
        _;
    }
    /// @dev See {IMagpieRouterV3-updateInternalCaller}
    function updateInternalCaller(address caller, bool value) external onlyOwner {
        internalCaller[caller] = value;
        emit UpdateInternalCaller(msg.sender, caller, value);
    }
    /// @dev See {IMagpieRouterV3-updateBridge}
    function updateBridge(address caller, bool value) external onlyOwner {
        bridge[caller] = value;
        emit UpdateBridge(msg.sender, caller, value);
    }
    /// @dev See {IMagpieRouterV3-updateSwapFeeAddress}
    function updateSwapFeeAddress(address value) external onlyOwner {
        swapFeeAddress = value;
    }
    /// @dev See {IMagpieRouterV3-pause}
    function pause() public onlyOwner whenNotPaused {
        _pause();
    }
    /// @dev See {IMagpieRouterV3-unpause}
    function unpause() public onlyOwner whenPaused {
        _unpause();
    }
    /// @dev See {IMagpieRouterV3-multicall}
    function multicall(bytes[] calldata data) external onlyOwner returns (bytes[] memory results) {
        results = new bytes[](data.length);
        for (uint256 i = 0; i < data.length; i++) {
            results[i] = Address.functionDelegateCall(address(this), data[i]);
        }
        return results;
    }
    /// @dev Handle uniswapV3SwapCallback requests from any protocol that is based on UniswapV3. We dont check for factory since this contract is not supposed to store tokens. We protect the user by handling amountOutMin check at the end of execution by comparing starting and final balance at the destination address.
    fallback() external {
        int256 amount0Delta;
        int256 amount1Delta;
        address assetIn;
        uint256 callDataSize;
        assembly {
            amount0Delta := calldataload(4)
            amount1Delta := calldataload(36)
            assetIn := shr(96, calldataload(132))
            callDataSize := calldatasize()
        }
        if (callDataSize != 164) {
            revert InvalidCall();
        }
        if (amount0Delta <= 0 && amount1Delta <= 0) {
            revert UniswapV3InvalidAmount();
        }
        uint256 amount = amount0Delta > 0 ? uint256(amount0Delta) : uint256(amount1Delta);
        assetIn.transfer(msg.sender, amount);
    }
    /// @dev Retrieves the address to be used for a swap operation.
    /// @param swapData The data structure containing information about the swap.
    /// @param useCaller Boolean indicating whether to use the caller's address.
    /// @param checkSignature Boolean indicating whether to validate the signature.
    /// @return fromAddress The address to be used for the swap operation.
    function getFromAddress(
        SwapData memory swapData,
        bool useCaller,
        bool checkSignature
    ) private view returns (address fromAddress) {
        if (checkSignature) {
            bool hasAffiliate = swapData.hasAffiliate;
            uint256 messagePtr;
            uint256 messageLength = hasAffiliate ? 384 : 320;
            assembly {
                messagePtr := mload(0x40)
                mstore(0x40, add(messagePtr, messageLength))
                switch hasAffiliate
                case 1 {
                    // keccak256("Swap(address router,address sender,address recipient,address fromAsset,address toAsset,uint256 deadline,uint256 amountOutMin,uint256 swapFee,uint256 amountIn,address affiliate,uint256 affiliateFee)")
                    mstore(messagePtr, 0x64d67eff2ff010acba1b1df82fb327ba0dc6d2965ba6b0b472bc14c494c8b4f6)
                }
                default {
                    // keccak256("Swap(address router,address sender,address recipient,address fromAsset,address toAsset,uint256 deadline,uint256 amountOutMin,uint256 swapFee,uint256 amountIn)")
                    mstore(messagePtr, 0x783528850c43ab6adcc3a843186a6558aa806707dd0abb3d2909a2a70b7f22a3)
                }
            }
            fromAddress = LibRouter.verifySignature(
                // keccak256(bytes("Magpie Router")),
                0x86af987965544521ef5b52deabbeb812d3353977e11a2dbe7e0f4905d1e60721,
                // keccak256(bytes("3")),
                0x2a80e1ef1d7842f27f2e6be0972bb708b9a135c38860dbe73c27c3486c34f4de,
                swapData,
                messagePtr,
                messageLength,
                useCaller,
                2
            );
        } else {
            if (useCaller) {
                fromAddress = msg.sender;
            } else {
                revert InvalidCall();
            }
        }
    }
    /// @dev Swaps tokens based on the provided swap data.
    /// @param swapData The data structure containing information about the swap operation.
    /// @param fromAddress The address initiating the swap. This address is responsible for the input assets.
    /// @param fullAmountIn The full amount that was used for the operation. If its 0 then event wont be emited.
    /// @return amountOut The amount of tokens or assets received after the swap.
    /// @return gasUsed The amount of gas consumed by the recorded operation.
    function swap(
        SwapData memory swapData,
        address fromAddress,
        uint256 fullAmountIn
    ) private returns (uint256 amountOut, uint256 gasUsed) {
        address fromAssetAddress = swapData.fromAssetAddress;
        address toAssetAddress = swapData.toAssetAddress;
        address toAddress = swapData.toAddress;
        uint256 amountOutMin = swapData.amountOutMin;
        uint256 amountIn = swapData.amountIn;
        uint256 transferFromAmount;
        amountOut = toAssetAddress.getBalanceOf(toAddress);
        (transferFromAmount, gasUsed) = execute(fromAddress, fromAssetAddress);
        amountOut = toAssetAddress.getBalanceOf(toAddress) - amountOut;
        if (amountOut < amountOutMin) {
            revert InsufficientAmountOut();
        }
        if (!fromAssetAddress.isNative() && amountIn != transferFromAmount) {
            revert InvalidAmountIn();
        }
        if (fullAmountIn > 0) {
            emit Swap(fromAddress, toAddress, fromAssetAddress, toAssetAddress, fullAmountIn, amountOut);
        }
    }
    /// @dev See {IMagpieRouterV3-estimateSwapGas}
    function estimateSwapGas(
        bytes calldata
    ) external payable whenNotPaused returns (uint256 amountOut, uint256 gasUsed) {
        SwapData memory swapData = LibRouter.getData();
        address fromAddress = getFromAddress(swapData, true, true);
        if (swapData.hasPermit) {
            LibRouter.permit(swapData, fromAddress);
        }
        LibRouter.transferFees(swapData, fromAddress, swapData.swapFee == 0 ? address(0) : swapFeeAddress);
        (amountOut, gasUsed) = swap(
            swapData,
            fromAddress,
            swapData.amountIn + swapData.swapFee + swapData.affiliateFee
        );
    }
    /// @dev See {IMagpieRouterV3-swapWithMagpieSignature}
    function swapWithMagpieSignature(bytes calldata) external payable whenNotPaused returns (uint256 amountOut) {
        SwapData memory swapData = LibRouter.getData();
        address fromAddress = getFromAddress(swapData, true, true);
        if (swapData.hasPermit) {
            LibRouter.permit(swapData, fromAddress);
        }
        LibRouter.transferFees(swapData, fromAddress, swapData.swapFee == 0 ? address(0) : swapFeeAddress);
        (amountOut, ) = swap(swapData, fromAddress, swapData.amountIn + swapData.swapFee + swapData.affiliateFee);
    }
    /// @dev See {IMagpieRouterV3-swapWithUserSignature}
    function swapWithUserSignature(bytes calldata) external payable onlyInternalCaller returns (uint256 amountOut) {
        SwapData memory swapData = LibRouter.getData();
        if (msg.value > 0) {
            revert InvalidNativeAmount();
        }
        address fromAddress = getFromAddress(swapData, false, true);
        if (swapData.hasPermit) {
            LibRouter.permit(swapData, fromAddress);
        }
        LibRouter.transferFees(swapData, fromAddress, swapData.swapFee == 0 ? address(0) : swapFeeAddress);
        (amountOut, ) = swap(swapData, fromAddress, swapData.amountIn + swapData.swapFee + swapData.affiliateFee);
    }
    /// @dev See {IMagpieRouterV3-swapWithoutSignature}
    function swapWithoutSignature(bytes calldata) external payable onlyBridge returns (uint256 amountOut) {
        SwapData memory swapData = LibRouter.getData();
        address fromAddress = getFromAddress(swapData, true, false);
        (amountOut, ) = swap(swapData, fromAddress, 0);
    }
    /// @dev Prepares CommandData for command iteration.
    function getCommandData()
        private
        pure
        returns (uint16 commandsOffset, uint16 commandsOffsetEnd, uint16 outputsLength)
    {
        assembly {
            commandsOffset := add(70, shr(240, calldataload(68))) // dataOffset + dataLength
            commandsOffsetEnd := add(68, calldataload(36)) // commandsOffsetEnd / swapArgsOffset + swapArgsLength (swapArgsOffset - 32)
            outputsLength := shr(240, calldataload(70)) // dataOffset + 32
        }
    }
    /// @dev Handles the execution of a sequence of commands for the swap operation.
    /// @param fromAddress The address from which the assets will be swapped.
    /// @param fromAssetAddress The address of the asset to be swapped.
    /// @return transferFromAmount The amount transferred from the specified address.
    /// @return gasUsed The amount of gas used during the execution of the swap.
    function execute(
        address fromAddress,
        address fromAssetAddress
    ) private returns (uint256 transferFromAmount, uint256 gasUsed) {
        (uint16 commandsOffset, uint16 commandsOffsetEnd, uint16 outputsLength) = getCommandData();
        uint256 outputPtr;
        assembly {
            outputPtr := mload(0x40)
            mstore(0x40, add(outputPtr, outputsLength))
        }
        uint256 outputOffsetPtr = outputPtr;
        unchecked {
            for (uint256 i = commandsOffset; i < commandsOffsetEnd; ) {
                (transferFromAmount, gasUsed, outputOffsetPtr) = executeCommand(
                    i,
                    fromAddress,
                    fromAssetAddress,
                    outputPtr,
                    outputOffsetPtr,
                    transferFromAmount,
                    gasUsed
                );
                i += 9;
            }
        }
        if (outputOffsetPtr > outputPtr + outputsLength) {
            revert InvalidOutput();
        }
    }
    /// @dev Builds the input for a specific command.
    /// @param i Command data position.
    /// @param outputPtr Memory pointer of the currently available output.
    /// @return input Calculated input data.
    /// @return nativeAmount Native token amount.
    function getInput(uint256 i, uint256 outputPtr) private view returns (bytes memory input, uint256 nativeAmount) {
        assembly {
            let sequencesPositionEnd := shr(240, calldataload(add(i, 5)))
            input := mload(0x40)
            nativeAmount := 0
            let j := shr(240, calldataload(add(i, 3))) // sequencesPosition
            let inputOffsetPtr := add(input, 32)
            for {
            } lt(j, sequencesPositionEnd) {
            } {
                let sequenceType := shr(248, calldataload(j))
                switch sequenceType
                // NativeAmount
                case 0 {
                    switch shr(240, calldataload(add(j, 3)))
                    case 1 {
                        nativeAmount := mload(add(outputPtr, shr(240, calldataload(add(j, 1)))))
                    }
                    default {
                        let p := shr(240, calldataload(add(j, 1)))
                        nativeAmount := shr(shr(248, calldataload(p)), calldataload(add(p, 1)))
                    }
                    j := add(j, 5)
                }
                // Selector
                case 1 {
                    mstore(inputOffsetPtr, calldataload(shr(240, calldataload(add(j, 1)))))
                    inputOffsetPtr := add(inputOffsetPtr, 4)
                    j := add(j, 3)
                }
                // Address
                case 2 {
                    mstore(inputOffsetPtr, shr(96, calldataload(shr(240, calldataload(add(j, 1))))))
                    inputOffsetPtr := add(inputOffsetPtr, 32)
                    j := add(j, 3)
                }
                // Amount
                case 3 {
                    let p := shr(240, calldataload(add(j, 1)))
                    mstore(inputOffsetPtr, shr(shr(248, calldataload(p)), calldataload(add(p, 1))))
                    inputOffsetPtr := add(inputOffsetPtr, 32)
                    j := add(j, 3)
                }
                // Data
                case 4 {
                    let l := shr(240, calldataload(add(j, 3)))
                    calldatacopy(inputOffsetPtr, shr(240, calldataload(add(j, 1))), l)
                    inputOffsetPtr := add(inputOffsetPtr, l)
                    j := add(j, 5)
                }
                // CommandOutput
                case 5 {
                    mstore(inputOffsetPtr, mload(add(outputPtr, shr(240, calldataload(add(j, 1))))))
                    inputOffsetPtr := add(inputOffsetPtr, 32)
                    j := add(j, 3)
                }
                // RouterAddress
                case 6 {
                    mstore(inputOffsetPtr, address())
                    inputOffsetPtr := add(inputOffsetPtr, 32)
                    j := add(j, 1)
                }
                // SenderAddress
                case 7 {
                    mstore(inputOffsetPtr, caller())
                    inputOffsetPtr := add(inputOffsetPtr, 32)
                    j := add(j, 1)
                }
                default {
                    // InvalidSequenceType
                    mstore(0, 0xa90b6fde00000000000000000000000000000000000000000000000000000000)
                    revert(0, 4)
                }
            }
            mstore(input, sub(inputOffsetPtr, add(input, 32)))
            mstore(0x40, inputOffsetPtr)
        }
    }
    /// @dev Executes a command call with the given parameters.
    /// @param i The command data position.
    /// @param outputPtr The pointer to the output location in memory.
    /// @param outputOffsetPtr The pointer to the offset of the output in memory.
    /// @return New outputOffsetPtr position.
    function executeCommandCall(uint256 i, uint256 outputPtr, uint256 outputOffsetPtr) private returns (uint256) {
        bytes memory input;
        uint256 nativeAmount;
        (input, nativeAmount) = getInput(i, outputPtr);
        uint256 outputLength;
        assembly {
            outputLength := shr(240, calldataload(add(i, 1)))
            switch shr(224, mload(add(input, 32))) // selector
            case 0 {
                // InvalidSelector
                mstore(0, 0x7352d91c00000000000000000000000000000000000000000000000000000000)
                revert(0, 4)
            }
            case 0x23b872dd {
                // Blacklist transferFrom in custom calls
                // InvalidTransferFromCall
                mstore(0, 0x1751a8e400000000000000000000000000000000000000000000000000000000)
                revert(0, 4)
            }
            default {
                let targetAddress := shr(96, calldataload(shr(240, calldataload(add(i, 7))))) // targetPosition
                if eq(targetAddress, address()) {
                    // InvalidCall
                    mstore(0, 0xae962d4e00000000000000000000000000000000000000000000000000000000)
                    revert(0, 4)
                }
                if iszero(
                    call(
                        gas(),
                        targetAddress,
                        nativeAmount,
                        add(input, 32),
                        mload(input),
                        outputOffsetPtr,
                        outputLength
                    )
                ) {
                    returndatacopy(0, 0, returndatasize())
                    revert(0, returndatasize())
                }
            }
        }
        outputOffsetPtr += outputLength;
        return outputOffsetPtr;
    }
    /// @dev Executes a command approval with the given parameters.
    /// @param i The command data position.
    /// @param outputPtr The pointer to the output location in memory.
    function executeCommandApproval(uint256 i, uint256 outputPtr) private {
        (bytes memory input, ) = getInput(i, outputPtr);
        address self;
        address spender;
        uint256 amount;
        assembly {
            self := mload(add(input, 32))
            spender := mload(add(input, 64))
            amount := mload(add(input, 96))
        }
        self.approve(spender, amount);
    }
    /// @dev Executes a transfer command from a specific address and asset.
    /// @param i The command position.
    /// @param outputPtr The pointer to the output location in memory.
    /// @param fromAssetAddress The address of the asset to transfer from.
    /// @param fromAddress The address to transfer the asset from.
    /// @param transferFromAmount The accumulated amount of the asset to transfer.
    /// @return Accumulated transfer amount.
    function executeCommandTransferFrom(
        uint256 i,
        uint256 outputPtr,
        address fromAssetAddress,
        address fromAddress,
        uint256 transferFromAmount
    ) private returns (uint256) {
        (bytes memory input, ) = getInput(i, outputPtr);
        uint256 amount;
        assembly {
            amount := mload(add(input, 64))
        }
        if (amount > 0) {
            address to;
            assembly {
                to := mload(add(input, 32))
            }
            fromAssetAddress.transferFrom(fromAddress, to, amount);
            transferFromAmount += amount;
        }
        return transferFromAmount;
    }
    /// @dev Executes a transfer command with the given parameters.
    /// @param i The command data position.
    /// @param outputPtr The pointer to the output location in memory.
    function executeCommandTransfer(uint256 i, uint256 outputPtr) private {
        (bytes memory input, ) = getInput(i, outputPtr);
        uint256 amount;
        assembly {
            amount := mload(add(input, 96))
        }
        if (amount > 0) {
            address self;
            address recipient;
            assembly {
                self := mload(add(input, 32))
                recipient := mload(add(input, 64))
            }
            self.transfer(recipient, amount);
        }
    }
    /// @dev Executes a wrap command with the given parameters.
    /// @param i The command data position.
    /// @param outputPtr The pointer to the output location in memory.
    function executeCommandWrap(uint256 i, uint256 outputPtr) private {
        (bytes memory input, ) = getInput(i, outputPtr);
        address self;
        uint256 amount;
        assembly {
            self := mload(add(input, 32))
            amount := mload(add(input, 64))
        }
        self.wrap(amount);
    }
    /// @dev Executes an unwrap command with the given parameters.
    /// @param i The command data position.
    /// @param outputPtr The pointer to the output location in memory.
    function executeCommandUnwrap(uint256 i, uint256 outputPtr) private {
        (bytes memory input, ) = getInput(i, outputPtr);
        address self;
        uint256 amount;
        assembly {
            self := mload(add(input, 32))
            amount := mload(add(input, 64))
        }
        self.unwrap(amount);
    }
    /// @dev Executes a balance command and returns the resulting balance.
    /// @param i The command data position.
    /// @param outputPtr The pointer to the output location in memory.
    /// @param outputOffsetPtr The pointer to the offset of the output in memory.
    /// @return New outputOffsetPtr position.
    function executeCommandBalance(
        uint256 i,
        uint256 outputPtr,
        uint256 outputOffsetPtr
    ) private view returns (uint256) {
        (bytes memory input, ) = getInput(i, outputPtr);
        address self;
        uint256 amount;
        assembly {
            self := mload(add(input, 32))
        }
        amount = self.getBalance();
        assembly {
            mstore(outputOffsetPtr, amount)
        }
        outputOffsetPtr += 32;
        return outputOffsetPtr;
    }
    /// @dev Executes a mathematical command.
    /// @param i The command data position.
    /// @param outputPtr The pointer to the output location in memory.
    /// @param outputOffsetPtr The pointer to the offset of the output in memory.
    /// @return New outputOffsetPtr position.
    function executeCommandMath(uint256 i, uint256 outputPtr, uint256 outputOffsetPtr) private view returns (uint256) {
        (bytes memory input, ) = getInput(i, outputPtr);
        assembly {
            function math(currentInputPtr) -> amount {
                let currentOutputPtr := mload(0x40)
                let j := 0
                let amount0 := 0
                let amount1 := 0
                let operator := 0
                for {
                } lt(j, 10) {
                } {
                    let pos := add(currentInputPtr, mul(j, 3))
                    let amount0Index := shr(248, mload(add(pos, 1)))
                    switch lt(amount0Index, 10)
                    case 1 {
                        amount0 := mload(add(currentOutputPtr, mul(amount0Index, 32)))
                    }
                    default {
                        amount0Index := sub(amount0Index, 10)
                        amount0 := mload(add(add(currentInputPtr, 32), mul(amount0Index, 32)))
                    }
                    let amount1Index := shr(248, mload(add(pos, 2)))
                    switch lt(amount1Index, 10)
                    case 1 {
                        amount1 := mload(add(currentOutputPtr, mul(amount1Index, 32)))
                    }
                    default {
                        amount1Index := sub(amount1Index, 10)
                        amount1 := mload(add(add(currentInputPtr, 32), mul(amount1Index, 32)))
                    }
                    operator := shr(248, mload(pos))
                    switch operator
                    // None
                    case 0 {
                        let finalPtr := add(currentOutputPtr, mul(sub(j, 1), 32))
                        amount := mload(finalPtr)
                        mstore(0x40, add(finalPtr, 32))
                        leave
                    }
                    // Add
                    case 1 {
                        mstore(add(currentOutputPtr, mul(j, 32)), add(amount0, amount1))
                    }
                    // Sub
                    case 2 {
                        mstore(add(currentOutputPtr, mul(j, 32)), sub(amount0, amount1))
                    }
                    // Mul
                    case 3 {
                        mstore(add(currentOutputPtr, mul(j, 32)), mul(amount0, amount1))
                    }
                    // Div
                    case 4 {
                        mstore(add(currentOutputPtr, mul(j, 32)), div(amount0, amount1))
                    }
                    // Pow
                    case 5 {
                        mstore(add(currentOutputPtr, mul(j, 32)), exp(amount0, amount1))
                    }
                    // Abs128
                    case 6 {
                        if gt(amount0, 170141183460469231731687303715884105727) {
                            let mask := sar(127, amount0)
                            amount0 := xor(amount0, mask)
                            amount0 := sub(amount0, mask)
                        }
                        mstore(add(currentOutputPtr, mul(j, 32)), amount0)
                    }
                    // Abs256
                    case 7 {
                        if gt(amount0, 57896044618658097711785492504343953926634992332820282019728792003956564819967) {
                            let mask := sar(255, amount0)
                            amount0 := xor(amount0, mask)
                            amount0 := sub(amount0, mask)
                        }
                        mstore(add(currentOutputPtr, mul(j, 32)), amount0)
                    }
                    // Shr
                    case 8 {
                        mstore(add(currentOutputPtr, mul(j, 32)), shr(amount0, amount1))
                    }
                    // Shl
                    case 9 {
                        mstore(add(currentOutputPtr, mul(j, 32)), shl(amount0, amount1))
                    }
                    j := add(j, 1)
                }
                let finalPtr := add(currentOutputPtr, mul(9, 32))
                amount := mload(finalPtr)
                mstore(0x40, add(finalPtr, 32))
            }
            mstore(outputOffsetPtr, math(add(input, 32)))
        }
        outputOffsetPtr += 32;
        return outputOffsetPtr;
    }
    /// @dev Executes a comparison command.
    /// @param i The command data position.
    /// @param outputPtr The pointer to the output location in memory.
    /// @param outputOffsetPtr The pointer to the offset of the output in memory.
    /// @return New outputOffsetPtr position.
    function executeCommandComparison(
        uint256 i,
        uint256 outputPtr,
        uint256 outputOffsetPtr
    ) private view returns (uint256) {
        (bytes memory input, ) = getInput(i, outputPtr);
        assembly {
            function comparison(currentInputPtr) -> amount {
                let currentOutputPtr := mload(0x40)
                let j := 0
                let amount0 := 0
                let amount1 := 0
                let amount2 := 0
                let amount3 := 0
                let operator := 0
                for {
                } lt(j, 6) {
                } {
                    let pos := add(currentInputPtr, mul(j, 5))
                    let amount0Index := shr(248, mload(add(pos, 1)))
                    switch lt(amount0Index, 6)
                    case 1 {
                        amount0 := mload(add(currentOutputPtr, mul(amount0Index, 32)))
                    }
                    default {
                        amount0Index := sub(amount0Index, 6)
                        amount0 := mload(add(add(currentInputPtr, 32), mul(amount0Index, 32)))
                    }
                    let amount1Index := shr(248, mload(add(pos, 2)))
                    switch lt(amount1Index, 6)
                    case 1 {
                        amount1 := mload(add(currentOutputPtr, mul(amount1Index, 32)))
                    }
                    default {
                        amount1Index := sub(amount1Index, 6)
                        amount1 := mload(add(add(currentInputPtr, 32), mul(amount1Index, 32)))
                    }
                    let amount2Index := shr(248, mload(add(pos, 3)))
                    switch lt(amount2Index, 6)
                    case 1 {
                        amount2 := mload(add(currentOutputPtr, mul(amount2Index, 32)))
                    }
                    default {
                        amount2Index := sub(amount2Index, 6)
                        amount2 := mload(add(add(currentInputPtr, 32), mul(amount2Index, 32)))
                    }
                    let amount3Index := shr(248, mload(add(pos, 4)))
                    switch lt(amount3Index, 6)
                    case 1 {
                        amount3 := mload(add(currentOutputPtr, mul(amount3Index, 32)))
                    }
                    default {
                        amount3Index := sub(amount3Index, 6)
                        amount3 := mload(add(add(currentInputPtr, 32), mul(amount3Index, 32)))
                    }
                    operator := shr(248, mload(pos))
                    switch operator
                    // None
                    case 0 {
                        let finalPtr := add(currentOutputPtr, mul(sub(j, 1), 32))
                        amount := mload(finalPtr)
                        mstore(0x40, add(finalPtr, 32))
                        leave
                    }
                    // Lt
                    case 1 {
                        switch lt(amount0, amount1)
                        case 1 {
                            mstore(add(currentOutputPtr, mul(j, 32)), amount2)
                        }
                        default {
                            mstore(add(currentOutputPtr, mul(j, 32)), amount3)
                        }
                    }
                    // Lte
                    case 2 {
                        switch or(lt(amount0, amount1), eq(amount0, amount1))
                        case 1 {
                            mstore(add(currentOutputPtr, mul(j, 32)), amount2)
                        }
                        default {
                            mstore(add(currentOutputPtr, mul(j, 32)), amount3)
                        }
                    }
                    // Gt
                    case 3 {
                        switch gt(amount0, amount1)
                        case 1 {
                            mstore(add(currentOutputPtr, mul(j, 32)), amount2)
                        }
                        default {
                            mstore(add(currentOutputPtr, mul(j, 32)), amount3)
                        }
                    }
                    // Gte
                    case 4 {
                        switch or(gt(amount0, amount1), eq(amount0, amount1))
                        case 1 {
                            mstore(add(currentOutputPtr, mul(j, 32)), amount2)
                        }
                        default {
                            mstore(add(currentOutputPtr, mul(j, 32)), amount3)
                        }
                    }
                    // Eq
                    case 5 {
                        switch eq(amount0, amount1)
                        case 1 {
                            mstore(add(currentOutputPtr, mul(j, 32)), amount2)
                        }
                        default {
                            mstore(add(currentOutputPtr, mul(j, 32)), amount3)
                        }
                    }
                    // Ne
                    case 6 {
                        switch eq(amount0, amount1)
                        case 1 {
                            mstore(add(currentOutputPtr, mul(j, 32)), amount3)
                        }
                        default {
                            mstore(add(currentOutputPtr, mul(j, 32)), amount2)
                        }
                    }
                    j := add(j, 1)
                }
                let finalPtr := add(currentOutputPtr, mul(5, 32))
                amount := mload(finalPtr)
                mstore(0x40, add(finalPtr, 32))
            }
            mstore(outputOffsetPtr, comparison(add(input, 32)))
        }
        outputOffsetPtr += 32;
        return outputOffsetPtr;
    }
    /// @dev Handles the execution of the specified command commands for the swap operation.
    /// @param i The command data position.
    /// @param fromAddress The wallet / contract of the fromAssetAddress.
    /// @param fromAssetAddress The asset will be transfered from the user.
    /// @param outputPtr Starting position of the output memory pointer.
    /// @param outputOffsetPtr Current position of the output memory pointer.
    /// @param transferFromAmount Accumulated transferred amount.
    /// @param gasUsed Recorded gas between commands.
    function executeCommand(
        uint256 i,
        address fromAddress,
        address fromAssetAddress,
        uint256 outputPtr,
        uint256 outputOffsetPtr,
        uint256 transferFromAmount,
        uint256 gasUsed
    ) private returns (uint256, uint256, uint256) {
        CommandAction commandAction;
        assembly {
            commandAction := shr(248, calldataload(i))
        }
        if (commandAction == CommandAction.Call) {
            outputOffsetPtr = executeCommandCall(i, outputPtr, outputOffsetPtr);
        } else if (commandAction == CommandAction.Approval) {
            executeCommandApproval(i, outputPtr);
        } else if (commandAction == CommandAction.TransferFrom) {
            transferFromAmount = executeCommandTransferFrom(
                i,
                outputPtr,
                fromAssetAddress,
                fromAddress,
                transferFromAmount
            );
        } else if (commandAction == CommandAction.Transfer) {
            executeCommandTransfer(i, outputPtr);
        } else if (commandAction == CommandAction.Wrap) {
            executeCommandWrap(i, outputPtr);
        } else if (commandAction == CommandAction.Unwrap) {
            executeCommandUnwrap(i, outputPtr);
        } else if (commandAction == CommandAction.Balance) {
            outputOffsetPtr = executeCommandBalance(i, outputPtr, outputOffsetPtr);
        } else if (commandAction == CommandAction.Math) {
            outputOffsetPtr = executeCommandMath(i, outputPtr, outputOffsetPtr);
        } else if (commandAction == CommandAction.Comparison) {
            outputOffsetPtr = executeCommandComparison(i, outputPtr, outputOffsetPtr);
        } else if (commandAction == CommandAction.EstimateGasStart) {
            gasUsed = gasleft();
        } else if (commandAction == CommandAction.EstimateGasEnd) {
            gasUsed -= gasleft();
        } else {
            revert InvalidCommand();
        }
        return (transferFromAmount, gasUsed, outputOffsetPtr);
    }
    /// @dev Used to receive ethers
    receive() external payable {}
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.24;
interface IMagpieRouterV3 {
    event UpdateInternalCaller(address indexed sender, address caller, bool value);
    /// @dev Allows the owner to update the whitelisted internal callers.
    /// @param caller Caller address.
    /// @param value Disable or enable the related caller.
    function updateInternalCaller(address caller, bool value) external;
    event UpdateBridge(address indexed sender, address caller, bool value);
    /// @dev Allows the owner to update the whitelisted bridges.
    /// @param caller Caller address.
    /// @param value Disable or enable the related caller.
    function updateBridge(address caller, bool value) external;
    /// @dev Allows the owner to update the swap fee receiver.
    /// @param value Swap fee receiver address.
    function updateSwapFeeAddress(address value) external;
    /// @dev Called by the owner to pause, triggers stopped state.
    function pause() external;
    /// @dev Called by the owner to unpause, returns to normal state.
    function unpause() external;
    event Swap(
        address indexed fromAddress,
        address indexed toAddress,
        address fromAssetAddress,
        address toAssetAddress,
        uint256 amountIn,
        uint256 amountOut
    );
    /// @dev Makes it possible to execute multiple functions in the same transaction.
    function multicall(bytes[] calldata data) external returns (bytes[] memory results);
    /// @dev Provides an external interface to estimate the gas cost of the last hop in a route.
    /// @return amountOut The amount received after swapping.
    /// @return gasUsed The cost of gas while performing the swap.
    function estimateSwapGas(bytes calldata swapArgs) external payable returns (uint256 amountOut, uint256 gasUsed);
    /// @dev Performs token swap with magpie signature.
    /// @return amountOut The amount received after swapping.
    function swapWithMagpieSignature(bytes calldata swapArgs) external payable returns (uint256 amountOut);
    /// @dev Performs token swap with a user signature.
    /// @return amountOut The amount received after swapping.
    function swapWithUserSignature(bytes calldata swapArgs) external payable returns (uint256 amountOut);
    /// @dev Performs token swap without a signature (data will be validated in the bridge) without triggering event.
    /// @return amountOut The amount received after swapping.
    function swapWithoutSignature(bytes calldata swapArgs) external payable returns (uint256 amountOut);
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.24;
interface IWETH {
    function deposit() external payable;
    function transfer(address to, uint256 value) external returns (bool);
    function withdraw(uint256) external;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.24;
import "../interfaces/IWETH.sol";
error AssetNotReceived();
error ApprovalFailed();
error TransferFromFailed();
error TransferFailed();
error FailedWrap();
error FailedUnwrap();
library LibAsset {
    using LibAsset for address;
    address constant NATIVE_ASSETID = address(0);
    /// @dev Checks if the given address (self) represents a native asset (Ether).
    /// @param self The asset that will be checked for a native token.
    /// @return Flag to identify if the asset is native or not.
    function isNative(address self) internal pure returns (bool) {
        return self == NATIVE_ASSETID;
    }
    /// @dev Wraps the specified asset.
    /// @param self The asset that will be wrapped.
    function wrap(address self, uint256 amount) internal {
        uint256 ptr;
        assembly {
            ptr := mload(0x40)
            mstore(0x40, add(ptr, 4))
            mstore(ptr, 0xd0e30db000000000000000000000000000000000000000000000000000000000)
        }
        if (!execute(self, amount, ptr, 4, 0, 0)) {
            revert FailedWrap();
        }
    }
    /// @dev Unwraps the specified asset.
    /// @param self The asset that will be unwrapped.
    function unwrap(address self, uint256 amount) internal {
        uint256 ptr;
        assembly {
            ptr := mload(0x40)
            mstore(0x40, add(ptr, 36))
            mstore(ptr, 0x2e1a7d4d00000000000000000000000000000000000000000000000000000000)
            mstore(add(ptr, 4), amount)
        }
        if (!execute(self, 0, ptr, 36, 0, 0)) {
            revert FailedUnwrap();
        }
    }
    /// @dev Retrieves the balance of the current contract for a given asset (self).
    /// @param self Asset whose balance needs to be found.
    /// @return Balance of the specific asset.
    function getBalance(address self) internal view returns (uint256) {
        return getBalanceOf(self, address(this));
    }
    /// @dev Retrieves the balance of the target address for a given asset (self).
    /// @param self Asset whose balance needs to be found.
    /// @param targetAddress The address where the balance is checked from.
    /// @return amount Balance of the specific asset.
    function getBalanceOf(address self, address targetAddress) internal view returns (uint256 amount) {
        assembly {
            switch self
            case 0 {
                amount := balance(targetAddress)
            }
            default {
                let currentInputPtr := mload(0x40)
                mstore(0x40, add(currentInputPtr, 68))
                mstore(currentInputPtr, 0x70a0823100000000000000000000000000000000000000000000000000000000)
                mstore(add(currentInputPtr, 4), targetAddress)
                let currentOutputPtr := add(currentInputPtr, 36)
                if iszero(staticcall(gas(), self, currentInputPtr, 36, currentOutputPtr, 32)) {
                    returndatacopy(0, 0, returndatasize())
                    revert(0, returndatasize())
                }
                amount := mload(currentOutputPtr)
            }
        }
    }
    /// @dev Performs a safe transferFrom operation for a given asset (self) from one address (from) to another address (to).
    /// @param self Asset that will be transferred.
    /// @param from Address that will send the asset.
    /// @param to Address that will receive the asset.
    /// @param amount Transferred amount.
    function transferFrom(address self, address from, address to, uint256 amount) internal {
        uint256 ptr;
        assembly {
            ptr := mload(0x40)
            mstore(0x40, add(ptr, 100))
            mstore(ptr, 0x23b872dd00000000000000000000000000000000000000000000000000000000)
            mstore(add(ptr, 4), from)
            mstore(add(ptr, 36), to)
            mstore(add(ptr, 68), amount)
        }
        if (!execute(self, 0, ptr, 100, 0, 0)) {
            revert TransferFromFailed();
        }
    }
    /// @dev Transfers a given amount of an asset (self) to a recipient address (recipient).
    /// @param self Asset that will be transferred.
    /// @param recipient Address that will receive the transferred asset.
    /// @param amount Transferred amount.
    function transfer(address self, address recipient, uint256 amount) internal {
        if (self.isNative()) {
            (bool success, ) = payable(recipient).call{value: amount}("");
            if (!success) {
                revert TransferFailed();
            }
        } else {
            uint256 ptr;
            assembly {
                ptr := mload(0x40)
                mstore(0x40, add(ptr, 68))
                mstore(ptr, 0xa9059cbb00000000000000000000000000000000000000000000000000000000)
                mstore(add(ptr, 4), recipient)
                mstore(add(ptr, 36), amount)
            }
            if (!execute(self, 0, ptr, 68, 0, 0)) {
                revert TransferFailed();
            }
        }
    }
    /// @dev Approves a spender address (spender) to spend a specified amount of an asset (self).
    /// @param self The asset that will be approved.
    /// @param spender Address of a contract that will spend the owners asset.
    /// @param amount Asset amount that can be spent.
    function approve(address self, address spender, uint256 amount) internal {
        uint256 ptr;
        assembly {
            ptr := mload(0x40)
            mstore(0x40, add(ptr, 68))
            mstore(ptr, 0x095ea7b300000000000000000000000000000000000000000000000000000000)
            mstore(add(ptr, 4), spender)
            mstore(add(ptr, 36), amount)
        }
        if (!execute(self, 0, ptr, 68, 0, 0)) {
            assembly {
                mstore(add(ptr, 36), 0)
            }
            if (!execute(self, 0, ptr, 68, 0, 0)) {
                revert ApprovalFailed();
            }
            assembly {
                mstore(add(ptr, 36), amount)
            }
            if (!execute(self, 0, ptr, 68, 0, 0)) {
                revert ApprovalFailed();
            }
        }
    }
    function permit(
        address self,
        address owner,
        address spender,
        uint256 amount,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal {
        assembly {
            let ptr := mload(0x40)
            mstore(0x40, add(ptr, 228))
            mstore(ptr, 0xd505accf00000000000000000000000000000000000000000000000000000000)
            mstore(add(ptr, 4), owner)
            mstore(add(ptr, 36), spender)
            mstore(add(ptr, 68), amount)
            mstore(add(ptr, 100), deadline)
            mstore(add(ptr, 132), v)
            mstore(add(ptr, 164), r)
            mstore(add(ptr, 196), s)
            let success := call(gas(), self, 0, ptr, 228, 0, 0)
        }
    }
    /// @dev Determines if a call was successful.
    /// @param target Address of the target contract.
    /// @param success To check if the call to the contract was successful or not.
    /// @param data The data was sent while calling the target contract.
    /// @return result The success of the call.
    function isSuccessful(address target, bool success, bytes memory data) private view returns (bool result) {
        if (success) {
            if (data.length == 0) {
                // isContract
                if (target.code.length > 0) {
                    result = true;
                }
            } else {
                assembly {
                    result := mload(add(data, 32))
                }
            }
        }
    }
    /// @dev Executes a low level call.
    function execute(
        address self,
        uint256 currentNativeAmount,
        uint256 currentInputPtr,
        uint256 currentInputLength,
        uint256 currentOutputPtr,
        uint256 outputLength
    ) internal returns (bool result) {
        assembly {
            function isSuccessfulCall(targetAddress) -> isSuccessful {
                switch iszero(returndatasize())
                case 1 {
                    if gt(extcodesize(targetAddress), 0) {
                        isSuccessful := 1
                    }
                }
                case 0 {
                    returndatacopy(0, 0, 32)
                    isSuccessful := gt(mload(0), 0)
                }
            }
            if iszero(
                call(
                    gas(),
                    self,
                    currentNativeAmount,
                    currentInputPtr,
                    currentInputLength,
                    currentOutputPtr,
                    outputLength
                )
            ) {
                returndatacopy(0, 0, returndatasize())
                revert(0, returndatasize())
            }
            result := isSuccessfulCall(self)
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.24;
import {LibAsset} from "../libraries/LibAsset.sol";
struct SwapData {
    address toAddress;
    address fromAssetAddress;
    address toAssetAddress;
    uint256 deadline;
    uint256 amountOutMin;
    uint256 swapFee;
    uint256 amountIn;
    bool hasPermit;
    bool hasAffiliate;
    address affiliateAddress;
    uint256 affiliateFee;
}
error InvalidSignature();
error ExpiredTransaction();
library LibRouter {
    using LibAsset for address;
    /// @dev Prepares SwapData from calldata
    function getData() internal view returns (SwapData memory swapData) {
        // dataOffset: 68 + 2
        assembly {
            let deadline := shr(
                shr(248, calldataload(132)), // dataOffset + 62
                calldataload(shr(240, calldataload(133))) // dataOffset + 62 + 1
            )
            if lt(deadline, timestamp()) {
                // ExpiredTransaction
                mstore(0, 0x931997cf00000000000000000000000000000000000000000000000000000000)
                revert(0, 4)
            }
            mstore(swapData, shr(96, calldataload(72))) // toAddress / dataOffset + 2
            mstore(add(swapData, 32), shr(96, calldataload(92))) // fromAssetAddress / dataOffset + 22
            mstore(add(swapData, 64), shr(96, calldataload(112))) // toAssetAddress / dataOffset + 42
            mstore(add(swapData, 96), deadline)
            mstore(
                add(swapData, 128),
                shr(
                    shr(248, calldataload(135)), // dataOffset + 62 + 3
                    calldataload(shr(240, calldataload(136))) // dataOffset + 62 + 4
                )
            ) // amountOutMin
            mstore(
                add(swapData, 160),
                shr(
                    shr(248, calldataload(138)), // dataOffset + 62 + 6
                    calldataload(shr(240, calldataload(139))) // dataOffset + 62 + 7
                )
            ) // swapFee
            mstore(
                add(swapData, 192),
                shr(
                    shr(248, calldataload(141)), // dataOffset + 62 + 9
                    calldataload(shr(240, calldataload(142))) // dataOffset + 62 + 10
                )
            ) // amountIn
            // calldataload(144) // r
            // calldataload(176) // s
            // shr(248, calldataload(208)) // v
            let hasPermit := gt(shr(248, calldataload(209)), 0) // permit v
            mstore(add(swapData, 224), hasPermit) // hasPermit
            // calldataload(210) // permit r
            // calldataload(242) // permit s
            // calldataload(274) // permit deadline
            switch hasPermit
            case 1 {
                let hasAffiliate := shr(248, calldataload(277))
                mstore(add(swapData, 256), hasAffiliate) // hasAffiliate
                if eq(hasAffiliate, 1) {
                    mstore(add(swapData, 288), shr(96, calldataload(278))) // affiliateAddress
                    mstore(
                        add(swapData, 320),
                        shr(shr(248, calldataload(298)), calldataload(shr(240, calldataload(299))))
                    ) // affiliateFee
                }
            }
            default {
                let hasAffiliate := shr(248, calldataload(210))
                mstore(add(swapData, 256), hasAffiliate) // hasAffiliate
                if eq(hasAffiliate, 1) {
                    mstore(add(swapData, 288), shr(96, calldataload(211))) // affiliateAddress
                    mstore(
                        add(swapData, 320),
                        shr(shr(248, calldataload(231)), calldataload(shr(240, calldataload(232))))
                    ) // affiliateFee
                }
            }
        }
    }
    /// @dev Transfers the required fees for the swap operation from the user's account.
    /// @param swapData The data structure containing the details of the swap operation, including fee information.
    /// @param fromAddress The address of the user from whom the fees will be deducted.
    /// @param swapFeeAddress The address of the swap fee receiver.
    function transferFees(SwapData memory swapData, address fromAddress, address swapFeeAddress) internal {
        if (swapData.swapFee > 0) {
            if (swapData.fromAssetAddress.isNative()) {
                swapData.fromAssetAddress.transfer(swapFeeAddress, swapData.swapFee);
            } else {
                swapData.fromAssetAddress.transferFrom(fromAddress, swapFeeAddress, swapData.swapFee);
            }
        }
        if (swapData.affiliateFee > 0) {
            if (swapData.fromAssetAddress.isNative()) {
                swapData.fromAssetAddress.transfer(swapData.affiliateAddress, swapData.affiliateFee);
            } else {
                swapData.fromAssetAddress.transferFrom(fromAddress, swapData.affiliateAddress, swapData.affiliateFee);
            }
        }
    }
    /// @dev Grants permission for the user's asset to be used in a swap operation.
    /// @param swapData The data structure containing the details of the swap operation.
    /// @param fromAddress The address of the user who is granting permission for their asset to be used.
    function permit(SwapData memory swapData, address fromAddress) internal {
        uint8 v;
        bytes32 r;
        bytes32 s;
        uint256 deadline;
        assembly {
            v := shr(248, calldataload(209))
            r := calldataload(210)
            s := calldataload(242)
            deadline := shr(shr(248, calldataload(274)), calldataload(shr(240, calldataload(275))))
        }
        swapData.fromAssetAddress.permit(
            fromAddress,
            address(this),
            swapData.amountIn + swapData.swapFee + swapData.affiliateFee,
            deadline,
            v,
            r,
            s
        );
    }
    /// @dev Recovers the signer's address from a hashed message and signature components.
    /// @param hash The hash of the message that was signed.
    /// @param r The `r` component of the signature.
    /// @param s The `s` component of the signature.
    /// @param v The `v` component of the signature.
    /// @return signer The address of the signer recovered from the signature.
    function recoverSigner(bytes32 hash, bytes32 r, bytes32 s, uint8 v) private pure returns (address signer) {
        // 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 (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): 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 InvalidSignature();
        }
        if (v != 27 && v != 28) {
            revert InvalidSignature();
        }
        signer = ecrecover(hash, v, r, s);
        if (signer == address(0)) {
            revert InvalidSignature();
        }
    }
    function getDomainSeparator(bytes32 name, bytes32 version) private view returns (bytes32) {
        uint256 chainId;
        assembly {
            chainId := chainid()
        }
        return
            keccak256(
                abi.encode(
                    // keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)")
                    0x8b73c3c69bb8fe3d512ecc4cf759cc79239f7b179b0ffacaa9a75d522b39400f,
                    name,
                    version,
                    chainId,
                    address(this)
                )
            );
    }
    /// @dev Verifies the signature for a swap operation.
    /// @param swapData The SwapData struct containing swap details.
    /// @param messagePtr Pointer to the message data in memory.
    /// @param messageLength Length of the message data.
    /// @param useCaller Flag indicating whether to use the caller's address for verification.
    /// @param internalCallersSlot Slot in the internal callers storage for verification.
    /// @return fromAddress The address of the signer / or caller if the signature is valid.
    function verifySignature(
        bytes32 name,
        bytes32 version,
        SwapData memory swapData,
        uint256 messagePtr,
        uint256 messageLength,
        bool useCaller,
        uint8 internalCallersSlot
    ) internal view returns (address fromAddress) {
        bytes32 domainSeparator = getDomainSeparator(name, version);
        bytes32 digest;
        bytes32 r;
        bytes32 s;
        uint8 v;
        assembly {
            mstore(add(messagePtr, 32), address())
            mstore(add(messagePtr, 64), caller())
            mstore(add(messagePtr, 96), mload(swapData))
            mstore(add(messagePtr, 128), mload(add(swapData, 32)))
            mstore(add(messagePtr, 160), mload(add(swapData, 64)))
            mstore(add(messagePtr, 192), mload(add(swapData, 96)))
            mstore(add(messagePtr, 224), mload(add(swapData, 128)))
            mstore(add(messagePtr, 256), mload(add(swapData, 160)))
            mstore(add(messagePtr, 288), mload(add(swapData, 192)))
            // hasAffiliate
            if eq(mload(add(swapData, 256)), 1) {
                mstore(add(messagePtr, 320), mload(add(swapData, 288)))
                mstore(add(messagePtr, 352), mload(add(swapData, 320)))
            }
            let hash := keccak256(messagePtr, messageLength)
            messagePtr := mload(0x40)
            mstore(0x40, add(messagePtr, 66))
            mstore(messagePtr, "\\x19\\x01")
            mstore(add(messagePtr, 2), domainSeparator)
            mstore(add(messagePtr, 34), hash)
            digest := keccak256(messagePtr, 66)
            r := calldataload(144)
            s := calldataload(176)
            v := shr(248, calldataload(208))
        }
        if (useCaller) {
            address internalCaller = recoverSigner(digest, r, s, v);
            assembly {
                fromAddress := caller()
                mstore(0, internalCaller)
                mstore(0x20, internalCallersSlot)
                if iszero(eq(sload(keccak256(0, 0x40)), 1)) {
                    // InvalidSignature
                    mstore(0, 0x8baa579f00000000000000000000000000000000000000000000000000000000)
                    revert(0, 4)
                }
            }
        } else {
            fromAddress = recoverSigner(digest, r, s, v);
            if (fromAddress == address(this)) {
                revert InvalidSignature();
            }
        }
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)
pragma solidity ^0.8.0;
import "../utils/Context.sol";
/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }
    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }
    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }
    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }
    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby disabling any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }
    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }
    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (access/Ownable2Step.sol)
pragma solidity ^0.8.0;
import "./Ownable.sol";
/**
 * @dev Contract module which provides access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership} and {acceptOwnership}.
 *
 * This module is used through inheritance. It will make available all functions
 * from parent (Ownable).
 */
abstract contract Ownable2Step is Ownable {
    address private _pendingOwner;
    event OwnershipTransferStarted(address indexed previousOwner, address indexed newOwner);
    /**
     * @dev Returns the address of the pending owner.
     */
    function pendingOwner() public view virtual returns (address) {
        return _pendingOwner;
    }
    /**
     * @dev Starts the ownership transfer of the contract to a new account. Replaces the pending transfer if there is one.
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual override onlyOwner {
        _pendingOwner = newOwner;
        emit OwnershipTransferStarted(owner(), newOwner);
    }
    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`) and deletes any pending owner.
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual override {
        delete _pendingOwner;
        super._transferOwnership(newOwner);
    }
    /**
     * @dev The new owner accepts the ownership transfer.
     */
    function acceptOwnership() public virtual {
        address sender = _msgSender();
        require(pendingOwner() == sender, "Ownable2Step: caller is not the new owner");
        _transferOwnership(sender);
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (security/Pausable.sol)
pragma solidity ^0.8.0;
import "../utils/Context.sol";
/**
 * @dev Contract module which allows children to implement an emergency stop
 * mechanism that can be triggered by an authorized account.
 *
 * This module is used through inheritance. It will make available the
 * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
 * the functions of your contract. Note that they will not be pausable by
 * simply including this module, only once the modifiers are put in place.
 */
abstract contract Pausable is Context {
    /**
     * @dev Emitted when the pause is triggered by `account`.
     */
    event Paused(address account);
    /**
     * @dev Emitted when the pause is lifted by `account`.
     */
    event Unpaused(address account);
    bool private _paused;
    /**
     * @dev Initializes the contract in unpaused state.
     */
    constructor() {
        _paused = false;
    }
    /**
     * @dev Modifier to make a function callable only when the contract is not paused.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    modifier whenNotPaused() {
        _requireNotPaused();
        _;
    }
    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    modifier whenPaused() {
        _requirePaused();
        _;
    }
    /**
     * @dev Returns true if the contract is paused, and false otherwise.
     */
    function paused() public view virtual returns (bool) {
        return _paused;
    }
    /**
     * @dev Throws if the contract is paused.
     */
    function _requireNotPaused() internal view virtual {
        require(!paused(), "Pausable: paused");
    }
    /**
     * @dev Throws if the contract is not paused.
     */
    function _requirePaused() internal view virtual {
        require(paused(), "Pausable: not paused");
    }
    /**
     * @dev Triggers stopped state.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    function _pause() internal virtual whenNotPaused {
        _paused = true;
        emit Paused(_msgSender());
    }
    /**
     * @dev Returns to normal state.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    function _unpause() internal virtual whenPaused {
        _paused = false;
        emit Unpaused(_msgSender());
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/Address.sol)
pragma solidity ^0.8.1;
/**
 * @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
     *
     * Furthermore, `isContract` will also return true if the target contract within
     * the same transaction is already scheduled for destruction by `SELFDESTRUCT`,
     * which only has an effect at the end of a transaction.
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.
        return account.code.length > 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://consensys.net/diligence/blog/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/v0.8.0/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");
        (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 functionCallWithValue(target, data, 0, "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");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResultFromTarget(target, 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) {
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResultFromTarget(target, 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) {
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }
    /**
     * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
     * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
     *
     * _Available since v4.8._
     */
    function verifyCallResultFromTarget(
        address target,
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        if (success) {
            if (returndata.length == 0) {
                // only check isContract if the call was successful and the return data is empty
                // otherwise we already know that it was a contract
                require(isContract(target), "Address: call to non-contract");
            }
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }
    /**
     * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason or using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }
    function _revert(bytes memory returndata, string memory errorMessage) private pure {
        // 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
            /// @solidity memory-safe-assembly
            assembly {
                let returndata_size := mload(returndata)
                revert(add(32, returndata), returndata_size)
            }
        } else {
            revert(errorMessage);
        }
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;
/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }
    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

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

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

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

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

pragma solidity ^0.4.18;

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

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

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

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

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

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

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

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

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

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

        Transfer(src, dst, wad);

        return true;
    }
}


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

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

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GNU General Public License for most of our software; it applies also to
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  When we speak of free software, we are referring to freedom, not
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  Developers that use the GNU GPL protect your rights with two steps:
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*/

// File: contracts/uniswapv2/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 migrator() 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;
    function setMigrator(address) external;
}

// File: contracts/uniswapv2/libraries/SafeMath.sol

pragma solidity =0.6.12;

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

library SafeMathUniswap {
    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/uniswapv2/UniswapV2ERC20.sol

pragma solidity =0.6.12;


contract UniswapV2ERC20 {
    using SafeMathUniswap for uint;

    string public constant name = 'SushiSwap LP Token';
    string public constant symbol = 'SLP';
    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/uniswapv2/libraries/Math.sol

pragma solidity =0.6.12;

// 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/uniswapv2/libraries/UQ112x112.sol

pragma solidity =0.6.12;

// 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/uniswapv2/interfaces/IERC20.sol

pragma solidity >=0.5.0;

interface IERC20Uniswap {
    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/uniswapv2/interfaces/IUniswapV2Callee.sol

pragma solidity >=0.5.0;

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

// File: contracts/uniswapv2/UniswapV2Pair.sol

pragma solidity =0.6.12;








interface IMigrator {
    // Return the desired amount of liquidity token that the migrator wants.
    function desiredLiquidity() external view returns (uint256);
}

contract UniswapV2Pair is UniswapV2ERC20 {
    using SafeMathUniswap  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 = IERC20Uniswap(token0).balanceOf(address(this));
        uint balance1 = IERC20Uniswap(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) {
            address migrator = IUniswapV2Factory(factory).migrator();
            if (msg.sender == migrator) {
                liquidity = IMigrator(migrator).desiredLiquidity();
                require(liquidity > 0 && liquidity != uint256(-1), "Bad desired liquidity");
            } else {
                require(migrator == address(0), "Must not have migrator");
                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 = IERC20Uniswap(_token0).balanceOf(address(this));
        uint balance1 = IERC20Uniswap(_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 = IERC20Uniswap(_token0).balanceOf(address(this));
        balance1 = IERC20Uniswap(_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 = IERC20Uniswap(_token0).balanceOf(address(this));
        balance1 = IERC20Uniswap(_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, IERC20Uniswap(_token0).balanceOf(address(this)).sub(reserve0));
        _safeTransfer(_token1, to, IERC20Uniswap(_token1).balanceOf(address(this)).sub(reserve1));
    }

    // force reserves to match balances
    function sync() external lock {
        _update(IERC20Uniswap(token0).balanceOf(address(this)), IERC20Uniswap(token1).balanceOf(address(this)), reserve0, reserve1);
    }
}

// Sources flattened with hardhat v2.0.2 https://hardhat.org

// File @openzeppelin/contracts/GSN/[email protected]

// SPDX-License-Identifier: MIT

pragma solidity ^0.7.0;

/*
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with GSN meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address payable) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}


// File @openzeppelin/contracts/token/ERC20/[email protected]

pragma solidity ^0.7.0;

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

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

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

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

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

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

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

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


// File @openzeppelin/contracts/math/[email protected]

pragma solidity ^0.7.0;

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

        return c;
    }

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

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

        return c;
    }

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

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

        return c;
    }

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

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

        return c;
    }

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

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


// File @openzeppelin/contracts/token/ERC20/[email protected]

pragma solidity ^0.7.0;



/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin guidelines: functions revert instead
 * of returning `false` on failure. This behavior is nonetheless conventional
 * and does not conflict with the expectations of ERC20 applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20 {
    using SafeMath for uint256;

    mapping (address => uint256) private _balances;

    mapping (address => mapping (address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;
    uint8 private _decimals;

    /**
     * @dev Sets the values for {name} and {symbol}, initializes {decimals} with
     * a default value of 18.
     *
     * To select a different value for {decimals}, use {_setupDecimals}.
     *
     * All three of these values are immutable: they can only be set once during
     * construction.
     */
    constructor (string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
        _decimals = 18;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5,05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is
     * called.
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view returns (uint8) {
        return _decimals;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view override returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view override returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `recipient` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * Requirements:
     *
     * - `sender` and `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     * - the caller must have allowance for ``sender``'s tokens of at least
     * `amount`.
     */
    function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(sender, recipient, amount);
        _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
        return true;
    }

    /**
     * @dev Moves tokens `amount` from `sender` to `recipient`.
     *
     * This is internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `sender` cannot be the zero address.
     * - `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     */
    function _transfer(address sender, address recipient, uint256 amount) internal virtual {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(sender, recipient, amount);

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

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

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

        _totalSupply = _totalSupply.add(amount);
        _balances[account] = _balances[account].add(amount);
        emit Transfer(address(0), account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

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

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

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(address owner, address spender, uint256 amount) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

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

    /**
     * @dev Sets {decimals} to a value other than the default one of 18.
     *
     * WARNING: This function should only be called from the constructor. Most
     * applications that interact with token contracts will not expect
     * {decimals} to ever change, and may work incorrectly if it does.
     */
    function _setupDecimals(uint8 decimals_) internal {
        _decimals = decimals_;
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be to transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual { }
}


// File @openzeppelin/contracts/token/ERC20/[email protected]

pragma solidity ^0.7.0;


/**
 * @dev Extension of {ERC20} that allows token holders to destroy both their own
 * tokens and those that they have an allowance for, in a way that can be
 * recognized off-chain (via event analysis).
 */
abstract contract ERC20Burnable is Context, ERC20 {
    using SafeMath for uint256;

    /**
     * @dev Destroys `amount` tokens from the caller.
     *
     * See {ERC20-_burn}.
     */
    function burn(uint256 amount) public virtual {
        _burn(_msgSender(), amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, deducting from the caller's
     * allowance.
     *
     * See {ERC20-_burn} and {ERC20-allowance}.
     *
     * Requirements:
     *
     * - the caller must have allowance for ``accounts``'s tokens of at least
     * `amount`.
     */
    function burnFrom(address account, uint256 amount) public virtual {
        uint256 decreasedAllowance = allowance(account, _msgSender()).sub(amount, "ERC20: burn amount exceeds allowance");

        _approve(account, _msgSender(), decreasedAllowance);
        _burn(account, amount);
    }
}


// File @openzeppelin/contracts/cryptography/[email protected]

pragma solidity ^0.7.0;

/**
 * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
 *
 * These functions can be used to verify that a message was signed by the holder
 * of the private keys of a given address.
 */
library ECDSA {
    /**
     * @dev Returns the address that signed a hashed message (`hash`) with
     * `signature`. This address can then be used for verification purposes.
     *
     * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
     * this function rejects them by requiring the `s` value to be in the lower
     * half order, and the `v` value to be either 27 or 28.
     *
     * IMPORTANT: `hash` _must_ be the result of a hash operation for the
     * verification to be secure: it is possible to craft signatures that
     * recover to arbitrary addresses for non-hashed data. A safe way to ensure
     * this is by receiving a hash of the original message (which may otherwise
     * be too long), and then calling {toEthSignedMessageHash} on it.
     */
    function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
        // Check the signature length
        if (signature.length != 65) {
            revert("ECDSA: invalid signature length");
        }

        // Divide the signature in r, s and v variables
        bytes32 r;
        bytes32 s;
        uint8 v;

        // ecrecover takes the signature parameters, and the only way to get them
        // currently is to use assembly.
        // solhint-disable-next-line no-inline-assembly
        assembly {
            r := mload(add(signature, 0x20))
            s := mload(add(signature, 0x40))
            v := byte(0, mload(add(signature, 0x60)))
        }

        // 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.
        require(uint256(s) <= 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0, "ECDSA: invalid signature 's' value");
        require(v == 27 || v == 28, "ECDSA: invalid signature 'v' value");

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

        return signer;
    }

    /**
     * @dev Returns an Ethereum Signed Message, created from a `hash`. This
     * replicates the behavior of the
     * https://github.com/ethereum/wiki/wiki/JSON-RPC#eth_sign[`eth_sign`]
     * JSON-RPC method.
     *
     * See {recover}.
     */
    function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32) {
        // 32 is the length in bytes of hash,
        // enforced by the type signature above
        return keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n32", hash));
    }
}


// File contracts/governance/Governed.sol

pragma solidity ^0.7.3;

/**
 * @title Graph Governance contract
 * @dev All contracts that will be owned by a Governor entity should extend this contract.
 */
contract Governed {
    // -- State --

    address public governor;
    address public pendingGovernor;

    // -- Events --

    event NewPendingOwnership(address indexed from, address indexed to);
    event NewOwnership(address indexed from, address indexed to);

    /**
     * @dev Check if the caller is the governor.
     */
    modifier onlyGovernor {
        require(msg.sender == governor, "Only Governor can call");
        _;
    }

    /**
     * @dev Initialize the governor to the contract caller.
     */
    function _initialize(address _initGovernor) internal {
        governor = _initGovernor;
    }

    /**
     * @dev Admin function to begin change of governor. The `_newGovernor` must call
     * `acceptOwnership` to finalize the transfer.
     * @param _newGovernor Address of new `governor`
     */
    function transferOwnership(address _newGovernor) external onlyGovernor {
        require(_newGovernor != address(0), "Governor must be set");

        address oldPendingGovernor = pendingGovernor;
        pendingGovernor = _newGovernor;

        emit NewPendingOwnership(oldPendingGovernor, pendingGovernor);
    }

    /**
     * @dev Admin function for pending governor to accept role and update governor.
     * This function must called by the pending governor.
     */
    function acceptOwnership() external {
        require(
            pendingGovernor != address(0) && msg.sender == pendingGovernor,
            "Caller must be pending governor"
        );

        address oldGovernor = governor;
        address oldPendingGovernor = pendingGovernor;

        governor = pendingGovernor;
        pendingGovernor = address(0);

        emit NewOwnership(oldGovernor, governor);
        emit NewPendingOwnership(oldPendingGovernor, pendingGovernor);
    }
}


// File contracts/token/GraphToken.sol

pragma solidity ^0.7.3;




/**
 * @title GraphToken contract
 * @dev This is the implementation of the ERC20 Graph Token.
 * The implementation exposes a Permit() function to allow for a spender to send a signed message
 * and approve funds to a spender following EIP2612 to make integration with other contracts easier.
 *
 * The token is initially owned by the deployer address that can mint tokens to create the initial
 * distribution. For convenience, an initial supply can be passed in the constructor that will be
 * assigned to the deployer.
 *
 * The governor can add the RewardsManager contract to mint indexing rewards.
 *
 */
contract GraphToken is Governed, ERC20, ERC20Burnable {
    using SafeMath for uint256;

    // -- EIP712 --
    // https://github.com/ethereum/EIPs/blob/master/EIPS/eip-712.md#definition-of-domainseparator

    bytes32 private constant DOMAIN_TYPE_HASH = keccak256(
        "EIP712Domain(string name,string version,uint256 chainId,address verifyingContract,bytes32 salt)"
    );
    bytes32 private constant DOMAIN_NAME_HASH = keccak256("Graph Token");
    bytes32 private constant DOMAIN_VERSION_HASH = keccak256("0");
    bytes32
        private constant DOMAIN_SALT = 0x51f3d585afe6dfeb2af01bba0889a36c1db03beec88c6a4d0c53817069026afa; // Randomly generated salt
    bytes32 private constant PERMIT_TYPEHASH = keccak256(
        "Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)"
    );

    // -- State --

    bytes32 private DOMAIN_SEPARATOR;
    mapping(address => bool) private _minters;
    mapping(address => uint256) public nonces;

    // -- Events --

    event MinterAdded(address indexed account);
    event MinterRemoved(address indexed account);

    modifier onlyMinter() {
        require(isMinter(msg.sender), "Only minter can call");
        _;
    }

    /**
     * @dev Graph Token Contract Constructor.
     * @param _initialSupply Initial supply of GRT
     */
    constructor(uint256 _initialSupply) ERC20("Graph Token", "GRT") {
        Governed._initialize(msg.sender);

        // The Governor has the initial supply of tokens
        _mint(msg.sender, _initialSupply);

        // The Governor is the default minter
        _addMinter(msg.sender);

        // EIP-712 domain separator
        DOMAIN_SEPARATOR = keccak256(
            abi.encode(
                DOMAIN_TYPE_HASH,
                DOMAIN_NAME_HASH,
                DOMAIN_VERSION_HASH,
                _getChainID(),
                address(this),
                DOMAIN_SALT
            )
        );
    }

    /**
     * @dev Approve token allowance by validating a message signed by the holder.
     * @param _owner Address of the token holder
     * @param _spender Address of the approved spender
     * @param _value Amount of tokens to approve the spender
     * @param _deadline Expiration time of the signed permit
     * @param _v Signature version
     * @param _r Signature r value
     * @param _s Signature s value
     */
    function permit(
        address _owner,
        address _spender,
        uint256 _value,
        uint256 _deadline,
        uint8 _v,
        bytes32 _r,
        bytes32 _s
    ) external {
        bytes32 digest = keccak256(
            abi.encodePacked(
                "\x19\x01",
                DOMAIN_SEPARATOR,
                keccak256(
                    abi.encode(
                        PERMIT_TYPEHASH,
                        _owner,
                        _spender,
                        _value,
                        nonces[_owner],
                        _deadline
                    )
                )
            )
        );
        nonces[_owner] = nonces[_owner].add(1);

        address recoveredAddress = ECDSA.recover(digest, abi.encodePacked(_r, _s, _v));
        require(_owner == recoveredAddress, "GRT: invalid permit");
        require(_deadline == 0 || block.timestamp <= _deadline, "GRT: expired permit");

        _approve(_owner, _spender, _value);
    }

    /**
     * @dev Add a new minter.
     * @param _account Address of the minter
     */
    function addMinter(address _account) external onlyGovernor {
        _addMinter(_account);
    }

    /**
     * @dev Remove a minter.
     * @param _account Address of the minter
     */
    function removeMinter(address _account) external onlyGovernor {
        _removeMinter(_account);
    }

    /**
     * @dev Renounce to be a minter.
     */
    function renounceMinter() external {
        _removeMinter(msg.sender);
    }

    /**
     * @dev Mint new tokens.
     * @param _to Address to send the newly minted tokens
     * @param _amount Amount of tokens to mint
     */
    function mint(address _to, uint256 _amount) external onlyMinter {
        _mint(_to, _amount);
    }

    /**
     * @dev Return if the `_account` is a minter or not.
     * @param _account Address to check
     * @return True if the `_account` is minter
     */
    function isMinter(address _account) public view returns (bool) {
        return _minters[_account];
    }

    /**
     * @dev Add a new minter.
     * @param _account Address of the minter
     */
    function _addMinter(address _account) private {
        _minters[_account] = true;
        emit MinterAdded(_account);
    }

    /**
     * @dev Remove a minter.
     * @param _account Address of the minter
     */
    function _removeMinter(address _account) private {
        _minters[_account] = false;
        emit MinterRemoved(_account);
    }

    /**
     * @dev Get the running network chain ID.
     * @return The chain ID
     */
    function _getChainID() private pure returns (uint256) {
        uint256 id;
        assembly {
            id := chainid()
        }
        return id;
    }
}