// File: contracts/rfq/FastBridgeRouter.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.17;

import {DefaultRouter} from "../router/DefaultRouter.sol";
import {UniversalTokenLib} from "../router/libs/UniversalToken.sol";
import {ActionLib, LimitedToken} from "../router/libs/Structs.sol";
import {IFastBridge} from "./interfaces/IFastBridge.sol";
import {IFastBridgeRouter, SwapQuery} from "./interfaces/IFastBridgeRouter.sol";
import {ISwapQuoter} from "./interfaces/ISwapQuoter.sol";

import {Ownable} from "@openzeppelin/contracts-4.5.0/access/Ownable.sol";

contract FastBridgeRouter is DefaultRouter, Ownable, IFastBridgeRouter {
    using UniversalTokenLib for address;

    /// @notice Emitted when the swap quoter is set.
    /// @param newSwapQuoter The new swap quoter.
    event SwapQuoterSet(address newSwapQuoter);

    /// @notice Emitted when the new FastBridge contract is set.
    /// @param newFastBridge The new FastBridge contract.
    event FastBridgeSet(address newFastBridge);

    /// @inheritdoc IFastBridgeRouter
    bytes1 public constant GAS_REBATE_FLAG = 0x2A;

    /// @inheritdoc IFastBridgeRouter
    address public fastBridge;
    /// @inheritdoc IFastBridgeRouter
    address public swapQuoter;

    constructor(address owner_) {
        transferOwnership(owner_);
    }

    /// @inheritdoc IFastBridgeRouter
    function setFastBridge(address fastBridge_) external onlyOwner {
        fastBridge = fastBridge_;
        emit FastBridgeSet(fastBridge_);
    }

    /// @inheritdoc IFastBridgeRouter
    function setSwapQuoter(address swapQuoter_) external onlyOwner {
        swapQuoter = swapQuoter_;
        emit SwapQuoterSet(swapQuoter_);
    }

    /// @inheritdoc IFastBridgeRouter
    function bridge(
        address recipient,
        uint256 chainId,
        address token,
        uint256 amount,
        SwapQuery memory originQuery,
        SwapQuery memory destQuery
    ) external payable {
        if (originQuery.hasAdapter()) {
            // Perform a swap using the swap adapter, set this contract as recipient
            (token, amount) = _doSwap(address(this), token, amount, originQuery);
        } else {
            // Otherwise, pull the token from the user to this contract
            amount = _pullToken(address(this), token, amount);
        }
        IFastBridge.BridgeParams memory params = IFastBridge.BridgeParams({
            dstChainId: uint32(chainId),
            sender: msg.sender,
            to: recipient,
            originToken: token,
            destToken: destQuery.tokenOut,
            originAmount: amount,
            destAmount: destQuery.minAmountOut,
            sendChainGas: _chainGasRequested(destQuery.rawParams),
            deadline: destQuery.deadline
        });
        token.universalApproveInfinity(fastBridge, amount);
        uint256 msgValue = token == UniversalTokenLib.ETH_ADDRESS ? amount : 0;
        IFastBridge(fastBridge).bridge{value: msgValue}(params);
    }

    /// @inheritdoc IFastBridgeRouter
    function getOriginAmountOut(
        address tokenIn,
        address[] memory rfqTokens,
        uint256 amountIn
    ) external view returns (SwapQuery[] memory originQueries) {
        uint256 len = rfqTokens.length;
        originQueries = new SwapQuery[](len);
        for (uint256 i = 0; i < len; ++i) {
            originQueries[i] = ISwapQuoter(swapQuoter).getAmountOut(
                LimitedToken({actionMask: ActionLib.allActions(), token: tokenIn}),
                rfqTokens[i],
                amountIn
            );
            // Adjust the Adapter address if it exists
            if (originQueries[i].hasAdapter()) {
                originQueries[i].routerAdapter = address(this);
            }
        }
    }

    /// @dev Checks if the explicit instruction to send gas to the destination chain was provided.
    function _chainGasRequested(bytes memory rawParams) internal pure returns (bool) {
        return rawParams.length > 0 && rawParams[0] == GAS_REBATE_FLAG;
    }
}

// File: contracts/router/DefaultRouter.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.17;

import {DefaultAdapter} from "./adapters/DefaultAdapter.sol";
import {IRouterAdapter} from "./interfaces/IRouterAdapter.sol";
import {DeadlineExceeded, InsufficientOutputAmount, MsgValueIncorrect, TokenNotETH} from "./libs/Errors.sol";
import {Action, DefaultParams, SwapQuery} from "./libs/Structs.sol";
import {UniversalTokenLib} from "./libs/UniversalToken.sol";

import {SafeERC20, IERC20} from "@openzeppelin/contracts-4.5.0/token/ERC20/utils/SafeERC20.sol";

/// @title DefaultRouter
/// @notice Base contract for all Synapse Routers, that is able to natively work with Default Pools
/// due to the fact that it inherits from DefaultAdapter.
abstract contract DefaultRouter is DefaultAdapter {
    using SafeERC20 for IERC20;
    using UniversalTokenLib for address;

    /// @dev Performs a "swap from tokenIn" following instructions from `query`.
    /// `query` will include the router adapter to use, and the exact type of "tokenIn -> tokenOut swap"
    /// should be encoded in `query.rawParams`.
    function _doSwap(
        address recipient,
        address tokenIn,
        uint256 amountIn,
        SwapQuery memory query
    ) internal returns (address tokenOut, uint256 amountOut) {
        // First, check the deadline for the swap
        // solhint-disable-next-line not-rely-on-time
        if (block.timestamp > query.deadline) revert DeadlineExceeded();
        // Pull initial token from the user to specified router adapter
        amountIn = _pullToken(query.routerAdapter, tokenIn, amountIn);
        tokenOut = query.tokenOut;
        address routerAdapter = query.routerAdapter;
        if (routerAdapter == address(this)) {
            // If the router adapter is this contract, we can perform the swap directly and trust the result
            amountOut = _adapterSwap(recipient, tokenIn, amountIn, tokenOut, query.rawParams);
        } else {
            // Otherwise, we need to call the router adapter. Adapters are permissionless, so we verify the result
            // Record tokenOut balance before swap
            amountOut = tokenOut.universalBalanceOf(recipient);
            IRouterAdapter(routerAdapter).adapterSwap{value: msg.value}({
                recipient: recipient,
                tokenIn: tokenIn,
                amountIn: amountIn,
                tokenOut: tokenOut,
                rawParams: query.rawParams
            });
            // Use the difference between the recorded balance and the current balance as the amountOut
            amountOut = tokenOut.universalBalanceOf(recipient) - amountOut;
        }
        // Finally, check that the recipient received at least as much as they wanted
        if (amountOut < query.minAmountOut) revert InsufficientOutputAmount();
    }

    /// @dev Pulls a requested token from the user to the requested recipient.
    /// Or, if msg.value was provided, check that ETH_ADDRESS was used and msg.value is correct.
    function _pullToken(
        address recipient,
        address token,
        uint256 amount
    ) internal returns (uint256 amountPulled) {
        if (msg.value == 0) {
            token.assertIsContract();
            // Record token balance before transfer
            amountPulled = IERC20(token).balanceOf(recipient);
            // Token needs to be pulled only if msg.value is zero
            // This way user can specify WETH as the origin asset
            IERC20(token).safeTransferFrom(msg.sender, recipient, amount);
            // Use the difference between the recorded balance and the current balance as the amountPulled
            amountPulled = IERC20(token).balanceOf(recipient) - amountPulled;
        } else {
            // Otherwise, we need to check that ETH was specified
            if (token != UniversalTokenLib.ETH_ADDRESS) revert TokenNotETH();
            // And that amount matches msg.value
            if (amount != msg.value) revert MsgValueIncorrect();
            // We will forward msg.value in the external call later, if recipient is not this contract
            amountPulled = msg.value;
        }
    }
}

// File: contracts/router/libs/UniversalToken.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.17;

import {TokenNotContract} from "./Errors.sol";
import {SafeERC20, IERC20} from "@openzeppelin/contracts-4.5.0/token/ERC20/utils/SafeERC20.sol";

library UniversalTokenLib {
    using SafeERC20 for IERC20;

    address internal constant ETH_ADDRESS = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;

    /// @notice Transfers tokens to the given account. Reverts if transfer is not successful.
    /// @dev This might trigger fallback, if ETH is transferred to the contract.
    /// Make sure this can not lead to reentrancy attacks.
    function universalTransfer(
        address token,
        address to,
        uint256 value
    ) internal {
        // Don't do anything, if need to send tokens to this address
        if (to == address(this)) return;
        if (token == ETH_ADDRESS) {
            /// @dev Note: this can potentially lead to executing code in `to`.
            // solhint-disable-next-line avoid-low-level-calls
            (bool success, ) = to.call{value: value}("");
            require(success, "ETH transfer failed");
        } else {
            IERC20(token).safeTransfer(to, value);
        }
    }

    /// @notice Issues an infinite allowance to the spender, if the current allowance is insufficient
    /// to spend the given amount.
    function universalApproveInfinity(
        address token,
        address spender,
        uint256 amountToSpend
    ) internal {
        // ETH Chad doesn't require your approval
        if (token == ETH_ADDRESS) return;
        // No-op if allowance is already sufficient
        uint256 allowance = IERC20(token).allowance(address(this), spender);
        if (allowance >= amountToSpend) return;
        // Otherwise, reset approval to 0 and set to max allowance
        if (allowance > 0) IERC20(token).safeApprove(spender, 0);
        IERC20(token).safeApprove(spender, type(uint256).max);
    }

    /// @notice Returns the balance of the given token (or native ETH) for the given account.
    function universalBalanceOf(address token, address account) internal view returns (uint256) {
        if (token == ETH_ADDRESS) {
            return account.balance;
        } else {
            return IERC20(token).balanceOf(account);
        }
    }

    /// @dev Checks that token is a contract and not ETH_ADDRESS.
    function assertIsContract(address token) internal view {
        // Check that ETH_ADDRESS was not used (in case this is a predeploy on any of the chains)
        if (token == UniversalTokenLib.ETH_ADDRESS) revert TokenNotContract();
        // Check that token is not an EOA
        if (token.code.length == 0) revert TokenNotContract();
    }
}

// File: contracts/router/libs/Structs.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.8.13; // "using A for B global" requires 0.8.13 or higher

// ══════════════════════════════════════════ TOKEN AND POOL DESCRIPTION ═══════════════════════════════════════════════

/// @notice Struct representing a bridge token. Used as the return value in view functions.
/// @param symbol   Bridge token symbol: unique token ID consistent among all chains
/// @param token    Bridge token address
struct BridgeToken {
    string symbol;
    address token;
}

/// @notice Struct used by IPoolHandler to represent a token in a pool
/// @param index    Token index in the pool
/// @param token    Token address
struct IndexedToken {
    uint8 index;
    address token;
}

/// @notice Struct representing a token, and the available Actions for performing a swap.
/// @param actionMask   Bitmask representing what actions (see ActionLib) are available for swapping a token
/// @param token        Token address
struct LimitedToken {
    uint256 actionMask;
    address token;
}

/// @notice Struct representing how pool tokens are stored by `SwapQuoter`.
/// @param isWeth   Whether the token represents Wrapped ETH.
/// @param token    Token address.
struct PoolToken {
    bool isWeth;
    address token;
}

/// @notice Struct representing a liquidity pool. Used as the return value in view functions.
/// @param pool         Pool address.
/// @param lpToken      Address of pool's LP token.
/// @param tokens       List of pool's tokens.
struct Pool {
    address pool;
    address lpToken;
    PoolToken[] tokens;
}

// ════════════════════════════════════════════════ ROUTER STRUCTS ═════════════════════════════════════════════════════

/// @notice Struct representing a quote request for swapping a bridge token.
/// Used in destination chain's SynapseRouter, hence the name "Destination Request".
/// @dev tokenOut is passed externally.
/// @param symbol   Bridge token symbol: unique token ID consistent among all chains
/// @param amountIn Amount of bridge token to start with, before the bridge fee is applied
struct DestRequest {
    string symbol;
    uint256 amountIn;
}

/// @notice Struct representing a swap request for SynapseRouter.
/// @dev tokenIn is supplied separately.
/// @param routerAdapter    Contract that will perform the swap for the Router. Address(0) specifies a "no swap" query.
/// @param tokenOut         Token address to swap to.
/// @param minAmountOut     Minimum amount of tokens to receive after the swap, or tx will be reverted.
/// @param deadline         Latest timestamp for when the transaction needs to be executed, or tx will be reverted.
/// @param rawParams        ABI-encoded params for the swap that will be passed to `routerAdapter`.
///                         Should be DefaultParams for swaps via DefaultAdapter.
struct SwapQuery {
    address routerAdapter;
    address tokenOut;
    uint256 minAmountOut;
    uint256 deadline;
    bytes rawParams;
}

using SwapQueryLib for SwapQuery global;

library SwapQueryLib {
    /// @notice Checks whether the router adapter was specified in the query.
    /// Query without a router adapter specifies that no action needs to be taken.
    function hasAdapter(SwapQuery memory query) internal pure returns (bool) {
        return query.routerAdapter != address(0);
    }

    /// @notice Fills `routerAdapter` and `deadline` fields in query, if it specifies one of the supported Actions,
    /// and if a path for this action was found.
    function fillAdapterAndDeadline(SwapQuery memory query, address routerAdapter) internal pure {
        // Fill the fields only if some path was found.
        if (query.minAmountOut == 0) return;
        // Empty params indicates no action needs to be done, thus no adapter is needed.
        query.routerAdapter = query.rawParams.length == 0 ? address(0) : routerAdapter;
        // Set default deadline to infinity. Not using the value of 0,
        // which would lead to every swap to revert by default.
        query.deadline = type(uint256).max;
    }
}

// ════════════════════════════════════════════════ ADAPTER STRUCTS ════════════════════════════════════════════════════

/// @notice Struct representing parameters for swapping via DefaultAdapter.
/// @param action           Action that DefaultAdapter needs to perform.
/// @param pool             Liquidity pool that will be used for Swap/AddLiquidity/RemoveLiquidity actions.
/// @param tokenIndexFrom   Token index to swap from. Used for swap/addLiquidity actions.
/// @param tokenIndexTo     Token index to swap to. Used for swap/removeLiquidity actions.
struct DefaultParams {
    Action action;
    address pool;
    uint8 tokenIndexFrom;
    uint8 tokenIndexTo;
}

/// @notice All possible actions that DefaultAdapter could perform.
enum Action {
    Swap, // swap between two pools tokens
    AddLiquidity, // add liquidity in a form of a single pool token
    RemoveLiquidity, // remove liquidity in a form of a single pool token
    HandleEth // ETH <> WETH interaction
}

using ActionLib for Action global;

/// @notice Library for dealing with bit masks which describe what set of Actions is available.
library ActionLib {
    /// @notice Returns a bitmask with all possible actions set to True.
    function allActions() internal pure returns (uint256 actionMask) {
        actionMask = type(uint256).max;
    }

    /// @notice Returns whether the given action is set to True in the bitmask.
    function isIncluded(Action action, uint256 actionMask) internal pure returns (bool) {
        return actionMask & mask(action) != 0;
    }

    /// @notice Returns a bitmask with only the given action set to True.
    function mask(Action action) internal pure returns (uint256) {
        return 1 << uint256(action);
    }

    /// @notice Returns a bitmask with only two given actions set to True.
    function mask(Action a, Action b) internal pure returns (uint256) {
        return mask(a) | mask(b);
    }
}

// File: contracts/rfq/interfaces/IFastBridge.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

// TODO: This should be pulled from the sanguine repo (requires publish and relaxing the ^0.8.20 pragma)
interface IFastBridge {
    struct BridgeTransaction {
        uint32 originChainId;
        uint32 destChainId;
        address originSender; // user (origin)
        address destRecipient; // user (dest)
        address originToken;
        address destToken;
        uint256 originAmount; // amount in on origin bridge less originFeeAmount
        uint256 destAmount;
        uint256 originFeeAmount;
        bool sendChainGas;
        uint256 deadline;
        uint256 nonce;
    }

    struct BridgeProof {
        uint96 timestamp;
        address relayer;
    }

    // ============ Events ============

    event BridgeRequested(bytes32 transactionId, address sender, bytes request);
    event BridgeRelayed(
        bytes32 transactionId,
        address relayer,
        address to,
        address token,
        uint256 amount,
        uint256 chainGasAmount
    );
    event BridgeProofProvided(bytes32 transactionId, address relayer, bytes32 transactionHash);
    event BridgeProofDisputed(bytes32 transactionId, address relayer);
    event BridgeDepositClaimed(bytes32 transactionId, address relayer, address to, address token, uint256 amount);
    event BridgeDepositRefunded(bytes32 transactionId, address to, address token, uint256 amount);

    // ============ Methods ============

    struct BridgeParams {
        uint32 dstChainId;
        address sender;
        address to;
        address originToken;
        address destToken;
        uint256 originAmount; // should include protocol fee (if any)
        uint256 destAmount; // should include relayer fee
        bool sendChainGas;
        uint256 deadline;
    }

    /// @notice Initiates bridge on origin chain to be relayed by off-chain relayer
    /// @param params The parameters required to bridge
    function bridge(BridgeParams memory params) external payable;

    /// @notice Relays destination side of bridge transaction by off-chain relayer
    /// @param request The encoded bridge transaction to relay on destination chain
    function relay(bytes memory request) external payable;

    /// @notice Provides proof on origin side that relayer provided funds on destination side of bridge transaction
    /// @param request The encoded bridge transaction to prove on origin chain
    /// @param destTxHash The destination tx hash proving bridge transaction was relayed
    function prove(bytes memory request, bytes32 destTxHash) external;

    /// @notice Completes bridge transaction on origin chain by claiming originally deposited capital
    /// @param request The encoded bridge transaction to claim on origin chain
    /// @param to The recipient address of the funds
    function claim(bytes memory request, address to) external;

    /// @notice Disputes an outstanding proof in case relayer provided dest chain tx is invalid
    /// @param transactionId The transaction id associated with the encoded bridge transaction to dispute
    function dispute(bytes32 transactionId) external;

    /// @notice Refunds an outstanding bridge transaction in case optimistic bridging failed
    /// @param request The encoded bridge transaction to refund
    /// @param to The recipient address of the funds
    function refund(bytes memory request, address to) external;

    // ============ Views ============

    /// @notice Decodes bridge request into a bridge transaction
    /// @param request The bridge request to decode
    function getBridgeTransaction(bytes memory request) external pure returns (BridgeTransaction memory);

    /// @notice Checks if the dispute period has passed so bridge deposit can be claimed
    /// @param transactionId The transaction id associated with the encoded bridge transaction to check
    /// @param relayer The address of the relayer attempting to claim
    function canClaim(bytes32 transactionId, address relayer) external view returns (bool);
}

// File: contracts/rfq/interfaces/IFastBridgeRouter.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import {SwapQuery} from "../../router/libs/Structs.sol";

interface IFastBridgeRouter {
    /// @notice Sets the address of the FastBridge contract
    /// @dev This function is only callable by the owner
    /// @param fastBridge_      The address of the FastBridge contract
    function setFastBridge(address fastBridge_) external;

    /// @notice Sets the address of the SwapQuoter contract
    /// @dev This function is only callable by the owner
    /// @param swapQuoter_      The address of the SwapQuoter contract
    function setSwapQuoter(address swapQuoter_) external;

    /// @notice Initiate an RFQ transaction with an optional swap on origin chain,
    /// and an optional gas rebate on destination chain.
    /// @dev Note that method is payable.
    /// If token is ETH_ADDRESS, this method should be invoked with `msg.value = amountIn`.
    /// If token is ERC20, the tokens will be pulled from msg.sender (use `msg.value = 0`).
    /// Make sure to approve this contract for spending `token` beforehand.
    ///
    /// `originQuery` is supposed to be fetched using FastBridgeRouter.getOriginAmountOut().
    /// Alternatively one could use an external adapter for more complex swaps on the origin chain.
    /// `destQuery.rawParams` signals whether the user wants to receive a gas rebate on the destination chain:
    /// - If the first byte of `destQuery.rawParams` is GAS_REBATE_FLAG, the user wants to receive a gas rebate.
    /// - Otherwise, the user does not want to receive a gas rebate.
    ///
    /// Cross-chain RFQ swap will be performed between tokens: `originQuery.tokenOut` and `destQuery.tokenOut`.
    /// Note: both tokens could be ETH_ADDRESS or ERC20.
    /// Full proceeds of the origin swap are considered the bid for the cross-chain swap.
    /// `destQuery.minAmountOut` is considered the ask for the cross-chain swap.
    /// Note: applying slippage to `destQuery.minAmountOut` will result in a worse price for the user,
    /// the full Relayer quote should be used instead.
    /// @param recipient        Address to receive tokens on destination chain
    /// @param chainId          Destination chain id
    /// @param token            Initial token to be pulled from the user
    /// @param amount           Amount of the initial tokens to be pulled from the user
    /// @param originQuery      Origin swap query (see above)
    /// @param destQuery        Destination swap query (see above)
    function bridge(
        address recipient,
        uint256 chainId,
        address token,
        uint256 amount,
        SwapQuery memory originQuery,
        SwapQuery memory destQuery
    ) external payable;

    // ═══════════════════════════════════════════════════ VIEWS ═══════════════════════════════════════════════════════

    /// @notice Finds the best path between `tokenIn` and every RFQ token from the given list,
    /// treating the swap as "origin swap", without putting any restrictions on the swap.
    /// @dev Check (query.minAmountOut != 0): this is true only if the swap is possible.
    /// The returned queries with minAmountOut != 0 could be used as `originQuery` with FastBridgeRouter.
    /// Note: it is possible to form a SwapQuery off-chain using alternative SwapAdapter for the origin swap.
    /// @param tokenIn          Initial token that user wants to bridge/swap
    /// @param rfqTokens        List of RFQ tokens
    /// @param amountIn         Amount of tokens user wants to bridge/swap
    /// @return originQueries   List of structs that could be used as `originQuery` in FastBridgeRouter.
    ///                         minAmountOut and deadline fields will need to be adjusted based on the user settings.
    function getOriginAmountOut(
        address tokenIn,
        address[] memory rfqTokens,
        uint256 amountIn
    ) external view returns (SwapQuery[] memory originQueries);

    /// @notice Magic value that indicates that the user wants to receive gas rebate on the destination chain.
    /// This is the answer to the ultimate question of life, the universe, and everything.
    function GAS_REBATE_FLAG() external view returns (bytes1);

    /// @notice Address of the FastBridge contract, used to initiate cross-chain RFQ swaps.
    function fastBridge() external view returns (address);

    /// @notice Address of the SwapQuoter contract, used to fetch quotes for the origin swap.
    function swapQuoter() external view returns (address);
}

// File: contracts/rfq/interfaces/ISwapQuoter.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import {LimitedToken, SwapQuery} from "../../router/libs/Structs.sol";

interface ISwapQuoter {
    function getAmountOut(
        LimitedToken memory tokenIn,
        address tokenOut,
        uint256 amountIn
    ) external view returns (SwapQuery memory query);
}

// File: node_modules/@openzeppelin/contracts-4.5.0/access/Ownable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (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 Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

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

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing 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);
    }
}

// File: contracts/router/adapters/DefaultAdapter.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.17;

import {IDefaultPool, IDefaultExtendedPool} from "../interfaces/IDefaultExtendedPool.sol";
import {IRouterAdapter} from "../interfaces/IRouterAdapter.sol";
import {IWETH9} from "../interfaces/IWETH9.sol";
import {MsgValueIncorrect, PoolNotFound, TokenAddressMismatch, TokensIdentical} from "../libs/Errors.sol";
import {Action, DefaultParams} from "../libs/Structs.sol";
import {UniversalTokenLib} from "../libs/UniversalToken.sol";

import {SafeERC20, IERC20} from "@openzeppelin/contracts-4.5.0/token/ERC20/utils/SafeERC20.sol";

contract DefaultAdapter is IRouterAdapter {
    using SafeERC20 for IERC20;
    using UniversalTokenLib for address;

    /// @notice Enable this contract to receive Ether when withdrawing from WETH.
    /// @dev Consider implementing rescue functions to withdraw Ether from this contract.
    receive() external payable {}

    /// @inheritdoc IRouterAdapter
    function adapterSwap(
        address recipient,
        address tokenIn,
        uint256 amountIn,
        address tokenOut,
        bytes memory rawParams
    ) external payable returns (uint256 amountOut) {
        return _adapterSwap(recipient, tokenIn, amountIn, tokenOut, rawParams);
    }

    /// @dev Internal logic for doing a tokenIn -> tokenOut swap.
    /// Note: `tokenIn` is assumed to have already been transferred to this contract.
    function _adapterSwap(
        address recipient,
        address tokenIn,
        uint256 amountIn,
        address tokenOut,
        bytes memory rawParams
    ) internal virtual returns (uint256 amountOut) {
        // We define a few phases for the whole Adapter's swap process.
        // (?) means the phase is optional.
        // (!) means the phase is mandatory.

        // PHASE 0(!): CHECK ALL THE PARAMS
        DefaultParams memory params = _checkParams(tokenIn, tokenOut, rawParams);

        // PHASE 1(?): WRAP RECEIVED ETH INTO WETH
        tokenIn = _wrapReceivedETH(tokenIn, amountIn, tokenOut, params);
        // After PHASE 1 this contract has `amountIn` worth of `tokenIn`, tokenIn != ETH_ADDRESS

        // PHASE 2(?): PREPARE TO UNWRAP SWAPPED WETH
        address tokenSwapTo = _deriveTokenSwapTo(tokenIn, tokenOut, params);
        // We need to perform tokenIn -> tokenSwapTo action in PHASE 3.
        // if tokenOut == ETH_ADDRESS, we need to unwrap WETH in PHASE 4.
        // Recipient will receive `tokenOut` in PHASE 5.

        // PHASE 3(?): PERFORM A REQUESTED SWAP
        amountOut = _performPoolAction(tokenIn, amountIn, tokenSwapTo, params);
        // After PHASE 3 this contract has `amountOut` worth of `tokenSwapTo`, tokenSwapTo != ETH_ADDRESS

        // PHASE 4(?): UNWRAP SWAPPED WETH
        // Check if the final token is native ETH
        if (tokenOut == UniversalTokenLib.ETH_ADDRESS) {
            // PHASE 2: WETH address was stored as `tokenSwapTo`
            _unwrapETH(tokenSwapTo, amountOut);
        }

        // PHASE 5(!): TRANSFER SWAPPED TOKENS TO RECIPIENT
        // Note: this will transfer native ETH, if tokenOut == ETH_ADDRESS
        // Note: this is a no-op if recipient == address(this)
        tokenOut.universalTransfer(recipient, amountOut);
    }

    /// @dev Checks the params and decodes them into a struct.
    function _checkParams(
        address tokenIn,
        address tokenOut,
        bytes memory rawParams
    ) internal pure returns (DefaultParams memory params) {
        if (tokenIn == tokenOut) revert TokensIdentical();
        // Decode params for swapping via a Default pool
        params = abi.decode(rawParams, (DefaultParams));
        // Swap pool should exist, if action other than HandleEth was requested
        if (params.pool == address(0) && params.action != Action.HandleEth) revert PoolNotFound();
    }

    /// @dev Wraps native ETH into WETH, if requested.
    /// Returns the address of the token this contract ends up with.
    function _wrapReceivedETH(
        address tokenIn,
        uint256 amountIn,
        address tokenOut,
        DefaultParams memory params
    ) internal returns (address wrappedTokenIn) {
        // tokenIn was already transferred to this contract, check if we start from native ETH
        if (tokenIn == UniversalTokenLib.ETH_ADDRESS) {
            // Determine WETH address: this is either tokenOut (if no swap is needed),
            // or a pool token with index `tokenIndexFrom` (if swap is needed).
            wrappedTokenIn = _deriveWethAddress({token: tokenOut, params: params, isTokenFromWeth: true});
            // Wrap ETH into WETH and leave it in this contract
            _wrapETH(wrappedTokenIn, amountIn);
        } else {
            wrappedTokenIn = tokenIn;
            // For ERC20 tokens msg.value should be zero
            if (msg.value != 0) revert MsgValueIncorrect();
        }
    }

    /// @dev Derives the address of token to be received after an action defined in `params`.
    function _deriveTokenSwapTo(
        address tokenIn,
        address tokenOut,
        DefaultParams memory params
    ) internal view returns (address tokenSwapTo) {
        // Check if swap to native ETH was requested
        if (tokenOut == UniversalTokenLib.ETH_ADDRESS) {
            // Determine WETH address: this is either tokenIn (if no swap is needed),
            // or a pool token with index `tokenIndexTo` (if swap is needed).
            tokenSwapTo = _deriveWethAddress({token: tokenIn, params: params, isTokenFromWeth: false});
        } else {
            tokenSwapTo = tokenOut;
        }
    }

    /// @dev Performs an action defined in `params` and returns the amount of `tokenSwapTo` received.
    function _performPoolAction(
        address tokenIn,
        uint256 amountIn,
        address tokenSwapTo,
        DefaultParams memory params
    ) internal returns (uint256 amountOut) {
        // Determine if we need to perform a swap
        if (params.action == Action.HandleEth) {
            // If no swap is required, amountOut doesn't change
            amountOut = amountIn;
        } else {
            // Record balance before the swap
            amountOut = IERC20(tokenSwapTo).balanceOf(address(this));
            // Approve the pool for spending exactly `amountIn` of `tokenIn`
            IERC20(tokenIn).safeIncreaseAllowance(params.pool, amountIn);
            if (params.action == Action.Swap) {
                _swap(params.pool, params, amountIn, tokenSwapTo);
            } else if (params.action == Action.AddLiquidity) {
                _addLiquidity(params.pool, params, amountIn, tokenSwapTo);
            } else {
                // The only remaining action is RemoveLiquidity
                _removeLiquidity(params.pool, params, amountIn, tokenSwapTo);
            }
            // Use the difference between the balance after the swap and the recorded balance as `amountOut`
            amountOut = IERC20(tokenSwapTo).balanceOf(address(this)) - amountOut;
        }
    }

    // ═══════════════════════════════════════ INTERNAL LOGIC: SWAP ACTIONS ════════════════════════════════════════════

    /// @dev Performs a swap through the given pool.
    /// Note: The pool should be already approved for spending `tokenIn`.
    function _swap(
        address pool,
        DefaultParams memory params,
        uint256 amountIn,
        address tokenOut
    ) internal {
        // tokenOut should match the "swap to" token
        if (IDefaultPool(pool).getToken(params.tokenIndexTo) != tokenOut) revert TokenAddressMismatch();
        // amountOut and deadline are not checked in RouterAdapter
        IDefaultPool(pool).swap({
            tokenIndexFrom: params.tokenIndexFrom,
            tokenIndexTo: params.tokenIndexTo,
            dx: amountIn,
            minDy: 0,
            deadline: type(uint256).max
        });
    }

    /// @dev Adds liquidity in a form of a single token to the given pool.
    /// Note: The pool should be already approved for spending `tokenIn`.
    function _addLiquidity(
        address pool,
        DefaultParams memory params,
        uint256 amountIn,
        address tokenOut
    ) internal {
        uint256 numTokens = _getPoolNumTokens(pool);
        address lpToken = _getPoolLPToken(pool);
        // tokenOut should match the LP token
        if (lpToken != tokenOut) revert TokenAddressMismatch();
        uint256[] memory amounts = new uint256[](numTokens);
        amounts[params.tokenIndexFrom] = amountIn;
        // amountOut and deadline are not checked in RouterAdapter
        IDefaultExtendedPool(pool).addLiquidity({amounts: amounts, minToMint: 0, deadline: type(uint256).max});
    }

    /// @dev Removes liquidity in a form of a single token from the given pool.
    /// Note: The pool should be already approved for spending `tokenIn`.
    function _removeLiquidity(
        address pool,
        DefaultParams memory params,
        uint256 amountIn,
        address tokenOut
    ) internal {
        // tokenOut should match the "swap to" token
        if (IDefaultPool(pool).getToken(params.tokenIndexTo) != tokenOut) revert TokenAddressMismatch();
        // amountOut and deadline are not checked in RouterAdapter
        IDefaultExtendedPool(pool).removeLiquidityOneToken({
            tokenAmount: amountIn,
            tokenIndex: params.tokenIndexTo,
            minAmount: 0,
            deadline: type(uint256).max
        });
    }

    // ═════════════════════════════════════════ INTERNAL LOGIC: POOL LENS ═════════════════════════════════════════════

    /// @dev Returns the LP token address of the given pool.
    function _getPoolLPToken(address pool) internal view returns (address lpToken) {
        (, , , , , , lpToken) = IDefaultExtendedPool(pool).swapStorage();
    }

    /// @dev Returns the number of tokens in the given pool.
    function _getPoolNumTokens(address pool) internal view returns (uint256 numTokens) {
        // Iterate over all tokens in the pool until the end is reached
        for (uint8 index = 0; ; ++index) {
            try IDefaultPool(pool).getToken(index) returns (address) {} catch {
                // End of pool reached
                numTokens = index;
                break;
            }
        }
    }

    /// @dev Returns the tokens in the given pool.
    function _getPoolTokens(address pool) internal view returns (address[] memory tokens) {
        uint256 numTokens = _getPoolNumTokens(pool);
        tokens = new address[](numTokens);
        for (uint8 i = 0; i < numTokens; ++i) {
            // This will not revert because we already know the number of tokens in the pool
            tokens[i] = IDefaultPool(pool).getToken(i);
        }
    }

    /// @dev Returns the quote for a swap through the given pool.
    /// Note: will return 0 on invalid swaps.
    function _getPoolSwapQuote(
        address pool,
        uint8 tokenIndexFrom,
        uint8 tokenIndexTo,
        uint256 amountIn
    ) internal view returns (uint256 amountOut) {
        try IDefaultPool(pool).calculateSwap(tokenIndexFrom, tokenIndexTo, amountIn) returns (uint256 dy) {
            amountOut = dy;
        } catch {
            // Return 0 instead of reverting
            amountOut = 0;
        }
    }

    // ════════════════════════════════════════ INTERNAL LOGIC: ETH <> WETH ════════════════════════════════════════════

    /// @dev Wraps ETH into WETH.
    function _wrapETH(address weth, uint256 amount) internal {
        if (amount != msg.value) revert MsgValueIncorrect();
        // Deposit in order to have WETH in this contract
        IWETH9(weth).deposit{value: amount}();
    }

    /// @dev Unwraps WETH into ETH.
    function _unwrapETH(address weth, uint256 amount) internal {
        // Withdraw ETH to this contract
        IWETH9(weth).withdraw(amount);
    }

    /// @dev Derives WETH address from swap parameters.
    function _deriveWethAddress(
        address token,
        DefaultParams memory params,
        bool isTokenFromWeth
    ) internal view returns (address weth) {
        if (params.action == Action.HandleEth) {
            // If we only need to wrap/unwrap ETH, WETH address should be specified as the other token
            weth = token;
        } else {
            // Otherwise, we need to get WETH address from the liquidity pool
            weth = address(
                IDefaultPool(params.pool).getToken(isTokenFromWeth ? params.tokenIndexFrom : params.tokenIndexTo)
            );
        }
    }
}

// File: contracts/router/interfaces/IRouterAdapter.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.17;

interface IRouterAdapter {
    /// @notice Performs a tokenIn -> tokenOut swap, according to the provided params.
    /// If tokenIn is ETH_ADDRESS, this method should be invoked with `msg.value = amountIn`.
    /// If tokenIn is ERC20, the tokens should be already transferred to this contract (using `msg.value = 0`).
    /// If tokenOut is ETH_ADDRESS, native ETH will be sent to the recipient (be aware of potential reentrancy).
    /// If tokenOut is ERC20, the tokens will be transferred to the recipient.
    /// @dev Contracts implementing {IRouterAdapter} interface are required to enforce the above restrictions.
    /// On top of that, they must ensure that exactly `amountOut` worth of `tokenOut` is transferred to the recipient.
    /// Swap deadline and slippage is checked outside of this contract.
    /// @param recipient    Address to receive the swapped token
    /// @param tokenIn      Token to sell (use ETH_ADDRESS to start from native ETH)
    /// @param amountIn     Amount of tokens to sell
    /// @param tokenOut     Token to buy (use ETH_ADDRESS to end with native ETH)
    /// @param rawParams    Additional swap parameters
    /// @return amountOut   Amount of bought tokens
    function adapterSwap(
        address recipient,
        address tokenIn,
        uint256 amountIn,
        address tokenOut,
        bytes calldata rawParams
    ) external payable returns (uint256 amountOut);
}

// File: contracts/router/libs/Errors.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.17;

error DeadlineExceeded();
error InsufficientOutputAmount();

error MsgValueIncorrect();
error PoolNotFound();
error TokenAddressMismatch();
error TokenNotContract();
error TokenNotETH();
error TokensIdentical();

// File: node_modules/@openzeppelin/contracts-4.5.0/token/ERC20/utils/SafeERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";
import "../../../utils/Address.sol";

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

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

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

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

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

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

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

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

// File: node_modules/@openzeppelin/contracts-4.5.0/utils/Context.sol



// 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;
    }
}

// File: contracts/router/interfaces/IDefaultExtendedPool.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.17;

import {IDefaultPool} from "./IDefaultPool.sol";

interface IDefaultExtendedPool is IDefaultPool {
    function addLiquidity(
        uint256[] calldata amounts,
        uint256 minToMint,
        uint256 deadline
    ) external returns (uint256);

    function removeLiquidityOneToken(
        uint256 tokenAmount,
        uint8 tokenIndex,
        uint256 minAmount,
        uint256 deadline
    ) external returns (uint256);

    // ═══════════════════════════════════════════════════ VIEWS ═══════════════════════════════════════════════════════

    function calculateRemoveLiquidity(uint256 amount) external view returns (uint256[] memory);

    function calculateRemoveLiquidityOneToken(uint256 tokenAmount, uint8 tokenIndex)
        external
        view
        returns (uint256 availableTokenAmount);

    function getAPrecise() external view returns (uint256);

    function getTokenBalance(uint8 index) external view returns (uint256);

    function swapStorage()
        external
        view
        returns (
            uint256 initialA,
            uint256 futureA,
            uint256 initialATime,
            uint256 futureATime,
            uint256 swapFee,
            uint256 adminFee,
            address lpToken
        );
}

// File: contracts/router/interfaces/IWETH9.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.17;

interface IWETH9 {
    function deposit() external payable;

    function withdraw(uint256 wad) external;
}

// File: node_modules/@openzeppelin/contracts-4.5.0/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

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

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

    /**
     * @dev Moves `amount` tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, 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 `from` to `to` 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 from,
        address to,
        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: node_modules/@openzeppelin/contracts-4.5.0/utils/Address.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (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
     * ====
     *
     * [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://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

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

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

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

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

        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason 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 {
            // 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

                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// File: contracts/router/interfaces/IDefaultPool.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.17;

interface IDefaultPool {
    function swap(
        uint8 tokenIndexFrom,
        uint8 tokenIndexTo,
        uint256 dx,
        uint256 minDy,
        uint256 deadline
    ) external returns (uint256 amountOut);

    function calculateSwap(
        uint8 tokenIndexFrom,
        uint8 tokenIndexTo,
        uint256 dx
    ) external view returns (uint256 amountOut);

    function getToken(uint8 index) external view returns (address token);
}