UnifiedExecutorV4

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.21;

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

// OpenZeppelin Contracts (last updated v5.0.1) (utils/Context.sol)

/**
 * @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;
    }

    function _contextSuffixLength() internal view virtual returns (uint256) {
        return 0;
    }
}

// File: @openzeppelin/contracts/access/Ownable.sol


// OpenZeppelin Contracts (last updated v5.0.0) (access/Ownable.sol)

pragma solidity ^0.8.20;


/**
 * @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.
 *
 * The initial owner is set to the address provided by the deployer. 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;

    /**
     * @dev The caller account is not authorized to perform an operation.
     */
    error OwnableUnauthorizedAccount(address account);

    /**
     * @dev The owner is not a valid owner account. (eg. `address(0)`)
     */
    error OwnableInvalidOwner(address owner);

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

    /**
     * @dev Initializes the contract setting the address provided by the deployer as the initial owner.
     */
    constructor(address initialOwner) {
        if (initialOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(initialOwner);
    }

    /**
     * @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 {
        if (owner() != _msgSender()) {
            revert OwnableUnauthorizedAccount(_msgSender());
        }
    }

    /**
     * @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 {
        if (newOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _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: @openzeppelin/contracts/security/ReentrancyGuard.sol


// OpenZeppelin Contracts (last updated v4.9.0) (security/ReentrancyGuard.sol)

pragma solidity ^0.8.0;

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuard {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    constructor() {
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and making it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        _nonReentrantBefore();
        _;
        _nonReentrantAfter();
    }

    function _nonReentrantBefore() private {
        // On the first call to nonReentrant, _status will be _NOT_ENTERED
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;
    }

    function _nonReentrantAfter() private {
        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Returns true if the reentrancy guard is currently set to "entered", which indicates there is a
     * `nonReentrant` function in the call stack.
     */
    function _reentrancyGuardEntered() internal view returns (bool) {
        return _status == _ENTERED;
    }
}

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


// OpenZeppelin Contracts (last updated v5.4.0) (token/ERC20/IERC20.sol)

pragma solidity >=0.4.16;

/**
 * @dev Interface of the ERC-20 standard as defined in the ERC.
 */
interface IERC20 {
    /**
     * @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);

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

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

    /**
     * @dev Moves a `value` amount of 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 value) 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 a `value` amount of tokens 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 value) external returns (bool);

    /**
     * @dev Moves a `value` amount of tokens from `from` to `to` using the
     * allowance mechanism. `value` 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 value) external returns (bool);
}

// File: @openzeppelin/contracts/interfaces/IERC20.sol


// OpenZeppelin Contracts (last updated v5.4.0) (interfaces/IERC20.sol)

pragma solidity >=0.4.16;


// File: @openzeppelin/contracts/utils/introspection/IERC165.sol


// OpenZeppelin Contracts (last updated v5.4.0) (utils/introspection/IERC165.sol)

pragma solidity >=0.4.16;

/**
 * @dev Interface of the ERC-165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[ERC].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165 {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[ERC section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

// File: @openzeppelin/contracts/interfaces/IERC165.sol


// OpenZeppelin Contracts (last updated v5.4.0) (interfaces/IERC165.sol)

pragma solidity >=0.4.16;


// File: @openzeppelin/contracts/interfaces/IERC1363.sol


// OpenZeppelin Contracts (last updated v5.4.0) (interfaces/IERC1363.sol)

pragma solidity >=0.6.2;



/**
 * @title IERC1363
 * @dev Interface of the ERC-1363 standard as defined in the https://eips.ethereum.org/EIPS/eip-1363[ERC-1363].
 *
 * Defines an extension interface for ERC-20 tokens that supports executing code on a recipient contract
 * after `transfer` or `transferFrom`, or code on a spender contract after `approve`, in a single transaction.
 */
interface IERC1363 is IERC20, IERC165 {
    /*
     * Note: the ERC-165 identifier for this interface is 0xb0202a11.
     * 0xb0202a11 ===
     *   bytes4(keccak256('transferAndCall(address,uint256)')) ^
     *   bytes4(keccak256('transferAndCall(address,uint256,bytes)')) ^
     *   bytes4(keccak256('transferFromAndCall(address,address,uint256)')) ^
     *   bytes4(keccak256('transferFromAndCall(address,address,uint256,bytes)')) ^
     *   bytes4(keccak256('approveAndCall(address,uint256)')) ^
     *   bytes4(keccak256('approveAndCall(address,uint256,bytes)'))
     */

    /**
     * @dev Moves a `value` amount of tokens from the caller's account to `to`
     * and then calls {IERC1363Receiver-onTransferReceived} on `to`.
     * @param to The address which you want to transfer to.
     * @param value The amount of tokens to be transferred.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function transferAndCall(address to, uint256 value) external returns (bool);

    /**
     * @dev Moves a `value` amount of tokens from the caller's account to `to`
     * and then calls {IERC1363Receiver-onTransferReceived} on `to`.
     * @param to The address which you want to transfer to.
     * @param value The amount of tokens to be transferred.
     * @param data Additional data with no specified format, sent in call to `to`.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function transferAndCall(address to, uint256 value, bytes calldata data) external returns (bool);

    /**
     * @dev Moves a `value` amount of tokens from `from` to `to` using the allowance mechanism
     * and then calls {IERC1363Receiver-onTransferReceived} on `to`.
     * @param from The address which you want to send tokens from.
     * @param to The address which you want to transfer to.
     * @param value The amount of tokens to be transferred.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function transferFromAndCall(address from, address to, uint256 value) external returns (bool);

    /**
     * @dev Moves a `value` amount of tokens from `from` to `to` using the allowance mechanism
     * and then calls {IERC1363Receiver-onTransferReceived} on `to`.
     * @param from The address which you want to send tokens from.
     * @param to The address which you want to transfer to.
     * @param value The amount of tokens to be transferred.
     * @param data Additional data with no specified format, sent in call to `to`.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function transferFromAndCall(address from, address to, uint256 value, bytes calldata data) external returns (bool);

    /**
     * @dev Sets a `value` amount of tokens as the allowance of `spender` over the
     * caller's tokens and then calls {IERC1363Spender-onApprovalReceived} on `spender`.
     * @param spender The address which will spend the funds.
     * @param value The amount of tokens to be spent.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function approveAndCall(address spender, uint256 value) external returns (bool);

    /**
     * @dev Sets a `value` amount of tokens as the allowance of `spender` over the
     * caller's tokens and then calls {IERC1363Spender-onApprovalReceived} on `spender`.
     * @param spender The address which will spend the funds.
     * @param value The amount of tokens to be spent.
     * @param data Additional data with no specified format, sent in call to `spender`.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function approveAndCall(address spender, uint256 value, bytes calldata data) external returns (bool);
}

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


// OpenZeppelin Contracts (last updated v5.3.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.20;



/**
 * @title SafeERC20
 * @dev Wrappers around ERC-20 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 {
    /**
     * @dev An operation with an ERC-20 token failed.
     */
    error SafeERC20FailedOperation(address token);

    /**
     * @dev Indicates a failed `decreaseAllowance` request.
     */
    error SafeERC20FailedDecreaseAllowance(address spender, uint256 currentAllowance, uint256 requestedDecrease);

    /**
     * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeCall(token.transfer, (to, value)));
    }

    /**
     * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
     * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
     */
    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeCall(token.transferFrom, (from, to, value)));
    }

    /**
     * @dev Variant of {safeTransfer} that returns a bool instead of reverting if the operation is not successful.
     */
    function trySafeTransfer(IERC20 token, address to, uint256 value) internal returns (bool) {
        return _callOptionalReturnBool(token, abi.encodeCall(token.transfer, (to, value)));
    }

    /**
     * @dev Variant of {safeTransferFrom} that returns a bool instead of reverting if the operation is not successful.
     */
    function trySafeTransferFrom(IERC20 token, address from, address to, uint256 value) internal returns (bool) {
        return _callOptionalReturnBool(token, abi.encodeCall(token.transferFrom, (from, to, value)));
    }

    /**
     * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     *
     * IMPORTANT: If the token implements ERC-7674 (ERC-20 with temporary allowance), and if the "client"
     * smart contract uses ERC-7674 to set temporary allowances, then the "client" smart contract should avoid using
     * this function. Performing a {safeIncreaseAllowance} or {safeDecreaseAllowance} operation on a token contract
     * that has a non-zero temporary allowance (for that particular owner-spender) will result in unexpected behavior.
     */
    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 oldAllowance = token.allowance(address(this), spender);
        forceApprove(token, spender, oldAllowance + value);
    }

    /**
     * @dev Decrease the calling contract's allowance toward `spender` by `requestedDecrease`. If `token` returns no
     * value, non-reverting calls are assumed to be successful.
     *
     * IMPORTANT: If the token implements ERC-7674 (ERC-20 with temporary allowance), and if the "client"
     * smart contract uses ERC-7674 to set temporary allowances, then the "client" smart contract should avoid using
     * this function. Performing a {safeIncreaseAllowance} or {safeDecreaseAllowance} operation on a token contract
     * that has a non-zero temporary allowance (for that particular owner-spender) will result in unexpected behavior.
     */
    function safeDecreaseAllowance(IERC20 token, address spender, uint256 requestedDecrease) internal {
        unchecked {
            uint256 currentAllowance = token.allowance(address(this), spender);
            if (currentAllowance < requestedDecrease) {
                revert SafeERC20FailedDecreaseAllowance(spender, currentAllowance, requestedDecrease);
            }
            forceApprove(token, spender, currentAllowance - requestedDecrease);
        }
    }

    /**
     * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful. Meant to be used with tokens that require the approval
     * to be set to zero before setting it to a non-zero value, such as USDT.
     *
     * NOTE: If the token implements ERC-7674, this function will not modify any temporary allowance. This function
     * only sets the "standard" allowance. Any temporary allowance will remain active, in addition to the value being
     * set here.
     */
    function forceApprove(IERC20 token, address spender, uint256 value) internal {
        bytes memory approvalCall = abi.encodeCall(token.approve, (spender, value));

        if (!_callOptionalReturnBool(token, approvalCall)) {
            _callOptionalReturn(token, abi.encodeCall(token.approve, (spender, 0)));
            _callOptionalReturn(token, approvalCall);
        }
    }

    /**
     * @dev Performs an {ERC1363} transferAndCall, with a fallback to the simple {ERC20} transfer if the target has no
     * code. This can be used to implement an {ERC721}-like safe transfer that rely on {ERC1363} checks when
     * targeting contracts.
     *
     * Reverts if the returned value is other than `true`.
     */
    function transferAndCallRelaxed(IERC1363 token, address to, uint256 value, bytes memory data) internal {
        if (to.code.length == 0) {
            safeTransfer(token, to, value);
        } else if (!token.transferAndCall(to, value, data)) {
            revert SafeERC20FailedOperation(address(token));
        }
    }

    /**
     * @dev Performs an {ERC1363} transferFromAndCall, with a fallback to the simple {ERC20} transferFrom if the target
     * has no code. This can be used to implement an {ERC721}-like safe transfer that rely on {ERC1363} checks when
     * targeting contracts.
     *
     * Reverts if the returned value is other than `true`.
     */
    function transferFromAndCallRelaxed(
        IERC1363 token,
        address from,
        address to,
        uint256 value,
        bytes memory data
    ) internal {
        if (to.code.length == 0) {
            safeTransferFrom(token, from, to, value);
        } else if (!token.transferFromAndCall(from, to, value, data)) {
            revert SafeERC20FailedOperation(address(token));
        }
    }

    /**
     * @dev Performs an {ERC1363} approveAndCall, with a fallback to the simple {ERC20} approve if the target has no
     * code. This can be used to implement an {ERC721}-like safe transfer that rely on {ERC1363} checks when
     * targeting contracts.
     *
     * NOTE: When the recipient address (`to`) has no code (i.e. is an EOA), this function behaves as {forceApprove}.
     * Opposedly, when the recipient address (`to`) has code, this function only attempts to call {ERC1363-approveAndCall}
     * once without retrying, and relies on the returned value to be true.
     *
     * Reverts if the returned value is other than `true`.
     */
    function approveAndCallRelaxed(IERC1363 token, address to, uint256 value, bytes memory data) internal {
        if (to.code.length == 0) {
            forceApprove(token, to, value);
        } else if (!token.approveAndCall(to, value, data)) {
            revert SafeERC20FailedOperation(address(token));
        }
    }

    /**
     * @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).
     *
     * This is a variant of {_callOptionalReturnBool} that reverts if call fails to meet the requirements.
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        uint256 returnSize;
        uint256 returnValue;
        assembly ("memory-safe") {
            let success := call(gas(), token, 0, add(data, 0x20), mload(data), 0, 0x20)
            // bubble errors
            if iszero(success) {
                let ptr := mload(0x40)
                returndatacopy(ptr, 0, returndatasize())
                revert(ptr, returndatasize())
            }
            returnSize := returndatasize()
            returnValue := mload(0)
        }

        if (returnSize == 0 ? address(token).code.length == 0 : returnValue != 1) {
            revert SafeERC20FailedOperation(address(token));
        }
    }

    /**
     * @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).
     *
     * This is a variant of {_callOptionalReturn} that silently catches all reverts and returns a bool instead.
     */
    function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
        bool success;
        uint256 returnSize;
        uint256 returnValue;
        assembly ("memory-safe") {
            success := call(gas(), token, 0, add(data, 0x20), mload(data), 0, 0x20)
            returnSize := returndatasize()
            returnValue := mload(0)
        }
        return success && (returnSize == 0 ? address(token).code.length > 0 : returnValue == 1);
    }
}

// File: contracts/UnifiedExecutorV4.sol


pragma solidity ^0.8.21;
/// File: @openzeppelin/contracts/utils/Context.sol
// OpenZeppelin Contracts (last updated v5.0.1) (utils/Context.sol)
/* -----------------------------------------
* Security hardening applied (V4, Option A)
* - ReentrancyGuard on flashloan handler
* - Checks-Effects-Interactions ordering
* - SafeERC20 for every token transfer/approve
* - Slippage & deadline checks on all swaps
* - Whitelisted routers/pools only
* - Curve index (i,j) validation (i != j, i>=0, j>=0)
* - Payout fixed to owner; no external setter
* ----------------------------------------- */





/** -------- Aave V3 minimal interfaces -------- */
interface IFlashLoanSimpleReceiver {
 function executeOperation(
     address asset,
     uint256 amount,
     uint256 premium,
     address initiator,
     bytes calldata params
 ) external returns (bool);
}

interface IPoolAddressesProvider {
 function getPool() external view returns (address);
}

interface IPool {
 function flashLoanSimple(
     address receiverAddress,
     address asset,
     uint256 amount,
     bytes calldata params,
     uint16 referralCode
 ) external;
}

/** -------- Uniswap V2 / Sushiswap router -------- */
interface IUniswapV2RouterLike {
 function swapExactTokensForTokens(
     uint amountIn,
     uint amountOutMin,
     address[] calldata path,
     address to,
     uint deadline
 ) external returns (uint[] memory amounts);
}

/** -------- Curve (common minimal) -------- */
interface ICurvePoolLike {
 function exchange(int128 i, int128 j, uint256 dx, uint256 min_dy) external returns (uint256);
 function exchange_underlying(int128 i, int128 j, uint256 dx, uint256 min_dy) external returns (uint256);
}

/** -------- Balancer (optional minimal exact in single) -------- */
interface IBalancerVault {
 enum SwapKind { GIVEN_IN, GIVEN_OUT }
 struct SingleSwap {
     bytes32 poolId;
     uint8 kind;
     address assetIn;
     address assetOut;
     uint256 amount;
     bytes userData;
 }
 struct FundManagement {
     address sender;
     bool fromInternalBalance;
     address payable recipient;
     bool toInternalBalance;
 }
 function swap(
     SingleSwap calldata singleSwap,
     FundManagement calldata funds,
     uint256 limit,
     uint256 deadline
 ) external payable returns (uint256);
}

contract UnifiedExecutorV4 is IFlashLoanSimpleReceiver, Ownable, ReentrancyGuard {
 using SafeERC20 for IERC20;

 enum LegType { UNI_V2, SUSHI, CURVE, CURVE_UNDERLYING, BALANCER }

 struct Leg {
     LegType legType;
     address routerOrPool;
     address[] path;
     int128 i;
     int128 j;
     bytes32 balancerPoolId;
 }

 struct FlashParams {
     address asset;
     uint256 amount;
     uint256 minOut;
     uint256 deadline;
     Leg[] legs;
 }

 IPool public immutable POOL;
 address public immutable WETH;

 mapping(address => bool) public trustedRouterOrPool;

 event TrustedSet(address target, bool allowed);
 event FlashExecuted(address asset, uint256 amount, uint256 premium, uint256 profit);
 event SwapExecuted(uint8 legType, address routerOrPool, uint256 inAmt, uint256 outAmt);

 constructor(
     address _addressesProvider,
     address _weth,
     address[] memory initialTrusted
 ) Ownable(msg.sender) {
     require(_addressesProvider != address(0) && _weth != address(0), "bad addr");
     POOL = IPool(IPoolAddressesProvider(_addressesProvider).getPool());
     WETH = _weth;
     for (uint i = 0; i < initialTrusted.length; i++) {
         trustedRouterOrPool[ initialTrusted[i] ] = true;
         emit TrustedSet(initialTrusted[i], true);
     }
 }

 function setTrusted(address target, bool allowed) external onlyOwner {
     require(target != address(0), "zero addr");
     trustedRouterOrPool[target] = allowed;
     emit TrustedSet(target, allowed);
 }

 function requestFlashLoan(FlashParams calldata fp) external onlyOwner {
     require(fp.asset != address(0), "asset=0");
     require(fp.amount > 0, "amount=0");
     require(fp.deadline >= block.timestamp, "deadline passed");
     bytes memory params = abi.encode(fp);
     POOL.flashLoanSimple(address(this), fp.asset, fp.amount, params, 0);
 }

 function executeOperation(
     address asset,
     uint256 amount,
     uint256 premium,
     address initiator,
     bytes calldata params
 ) external override nonReentrant returns (bool) {
     require(msg.sender == address(POOL), "only pool");
     require(initiator == address(this), "bad initiator");

     FlashParams memory fp = abi.decode(params, (FlashParams));
     require(fp.asset == asset, "asset mismatch");
     require(fp.deadline >= block.timestamp, "dl");

     uint256 currentAmount = amount;
     address currentToken = asset;

     for (uint i = 0; i < fp.legs.length; i++) {
         currentAmount = _executeLeg(fp, currentToken, currentAmount, fp.legs[i]);
         currentToken = _outTokenOfLeg(currentToken, fp.legs[i]);
     }

     require(currentToken == asset, "final token mismatch");

     uint256 afterBal = IERC20(asset).balanceOf(address(this));
     uint256 repay = amount + premium;
     require(afterBal >= repay + fp.minOut, "no profit");
     uint256 profit = afterBal - repay;

     _forceApprove(IERC20(asset), address(POOL), repay);

     IERC20(asset).safeTransfer(owner(), profit);

     emit FlashExecuted(asset, amount, premium, profit);
     return true;
 }

 function _executeLeg(
     FlashParams memory fp,
     address inToken,
     uint256 inAmount,
     Leg memory L
 ) internal returns (uint256 outAmount) {
     require(trustedRouterOrPool[L.routerOrPool], "untrusted router/pool");

     if (L.legType == LegType.UNI_V2 || L.legType == LegType.SUSHI) {
         require(L.path.length >= 2, "bad path");
         require(L.path[0] == inToken, "path[0]!=in");
         _forceApprove(IERC20(inToken), L.routerOrPool, inAmount);
         uint[] memory amounts = IUniswapV2RouterLike(L.routerOrPool).swapExactTokensForTokens(
             inAmount,
             fp.minOut,
             L.path,
             address(this),
             block.timestamp + 300
         );
         outAmount = amounts[amounts.length - 1];
         require(outAmount >= fp.minOut, "slippage");
         emit SwapExecuted(uint8(L.legType), L.routerOrPool, inAmount, outAmount);
         return outAmount;
     }

     if (L.legType == LegType.CURVE) {
         require(L.i != L.j && L.i >= 0 && L.j >= 0, "bad ij");
         _forceApprove(IERC20(inToken), L.routerOrPool, inAmount);
         uint256 dy = ICurvePoolLike(L.routerOrPool).exchange(L.i, L.j, inAmount, fp.minOut);
         require(dy >= fp.minOut, "slippage");
         outAmount = dy;
         emit SwapExecuted(uint8(L.legType), L.routerOrPool, inAmount, outAmount);
         return outAmount;
     }

     if (L.legType == LegType.CURVE_UNDERLYING) {
         require(L.i != L.j && L.i >= 0 && L.j >= 0, "bad ij");
         _forceApprove(IERC20(inToken), L.routerOrPool, inAmount);
         uint256 dy = ICurvePoolLike(L.routerOrPool).exchange_underlying(L.i, L.j, inAmount, fp.minOut);
         require(dy >= fp.minOut, "slippage");
         outAmount = dy;
         emit SwapExecuted(uint8(L.legType), L.routerOrPool, inAmount, outAmount);
         return outAmount;
     }

     if (L.legType == LegType.BALANCER) {
         IBalancerVault.SingleSwap memory s = IBalancerVault.SingleSwap({
             poolId: L.balancerPoolId,
             kind: uint8(IBalancerVault.SwapKind.GIVEN_IN),
             assetIn: inToken,
             assetOut: _expectOutToken(inToken, L),
             amount: inAmount,
             userData: ""
         });
         IBalancerVault.FundManagement memory fm = IBalancerVault.FundManagement({
             sender: address(this),
             fromInternalBalance: false,
             recipient: payable(address(this)),
             toInternalBalance: false
         });
         _forceApprove(IERC20(inToken), L.routerOrPool, inAmount);
         uint256 got = IBalancerVault(L.routerOrPool).swap(
             s, fm, fp.minOut, block.timestamp + 300
         );
         require(got >= fp.minOut, "slippage");
         outAmount = got;
         emit SwapExecuted(uint8(L.legType), L.routerOrPool, inAmount, outAmount);
         return outAmount;
     }

     revert("unknown leg");
 }

 function _outTokenOfLeg(address inToken, Leg memory L) internal pure returns (address) {
     if (L.legType == LegType.UNI_V2 || L.legType == LegType.SUSHI) {
         return L.path[L.path.length - 1];
     }
     if (L.legType == LegType.CURVE || L.legType == LegType.CURVE_UNDERLYING) {
         if (L.path.length > 0) return L.path[L.path.length - 1];
         return inToken;
     }
     if (L.legType == LegType.BALANCER) {
         if (L.path.length > 0) return L.path[L.path.length - 1];
         return inToken;
     }
     return inToken;
 }

 function _expectOutToken(address inToken, Leg memory L) internal pure returns (address) {
     if (L.path.length > 0) return L.path[L.path.length - 1];
     return inToken;
 }

 // Safe approve helper: replace deprecated safeApprove with forceApprove (OZ v5)
 function _forceApprove(IERC20 token, address spender, uint256 value) internal {
     uint256 current = token.allowance(address(this), spender);
     if (current < value) {
         if (current != 0) {
             token.forceApprove(spender, 0);
         }
         token.forceApprove(spender, value);
     }
 }
}