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

    /// @dev Set a new owner.
    function setOwner(address newOwner) external;

    /// @dev Set up this wallet by assigning an original owner and a
    ///      list of initial modules. For each module, its `init` method
    ///      will be called with `address(this)` as the parameter.
    ///
    ///      Note that calling this method more than once will throw.
    ///
    /// @param _controller The Controller instance.
    /// @param _owner The owner of this wallet, must not be address(0).
    /// @param _boostrapModule The bootstrap module.
    function setup(address _controller, address _owner, address _boostrapModule) external;

    /// @dev Adds a new module. The `init` method of the module
    ///      will be called with `address(this)` as the parameter.
    ///      This method must throw if the module has already been added.
    /// @param _module The module's address.
    function addModule(address _module) external;

    /// @dev Removes an existing module. This method must throw if the module
    ///      has NOT been added or the module is the wallet's only module.
    /// @param _module The module's address.
    function removeModule(address _module) external;

    /// @dev Returns the list of modules added to this wallet in the order
    ///      they were added.
    /// @return _modules The list of modules added to this wallet.
    function modules() external view returns (address[] memory _modules);

    /// @dev Checks if a module has been added to this wallet.
    /// @param _module The module to check.
    /// @return True if the module exists; False otherwise.
    function hasModule(address _module) external view returns (bool);

    /// @dev Binds a method from the given module to this
    ///      wallet so the method can be invoked using this wallet's default
    ///      function.
    ///      Note that this method must throw when the given module has
    ///      not been added to this wallet.
    /// @param _method The method's 4-byte selector.
    /// @param _module The module's address. Use address(0) to unbind the method.
    function bindMethod(bytes4 _method, address _module) external;

    /// @dev Returns the module the given method has been bound to.
    /// @param _method The method's 4-byte selector.
    /// @return _module The address of the bound module. If no binding exists,
    ///                 returns address(0) instead.
    function boundMethodModule(bytes4 _method) external view returns (address _module);

    /// @dev Performs generic transactions. Any module that has been added to this
    ///      wallet can use this method to transact on any third-party contract with
    ///      msg.sender as this wallet itself.
    ///
    ///      This method will emit `Transacted` event if it doesn't throw.
    ///
    ///      Note: this method must ONLY allow invocations from a module that has
    ///      been added to this wallet. The wallet owner shall NOT be permitted
    ///      to call this method directly.
    ///
    /// @param mode The transaction mode, 1 for CALL, 2 for DELEGATECALL.
    /// @param to The desitination address.
    /// @param value The amount of Ether to transfer.
    /// @param data The data to send over using `to.call{value: value}(data)`
    /// @return returnData The transaction's return value.
    function transact(
        uint8    mode,
        address  to,
        uint     value,
        bytes    calldata data
        )
        external
        returns (bytes memory returnData);
}
/// @title Wallet
/// @dev Base contract for smart wallets.
///      Sub-contracts must NOT use non-default constructor to initialize
///      wallet states, instead, `init` shall be used. This is to enable
///      proxies to be deployed in front of the real wallet contract for
///      saving gas.
///
/// @author Daniel Wang - <daniel@loopring.org>
///
/// The design of this contract is inspired by Argent's contract codebase:
/// https://github.com/argentlabs/argent-contracts
function hasModule(address _module) external view returns (bool);

/// @dev Checks if a module has been added to this wallet.
/// @param _module The module to check.
/// @return True if the module exists; False otherwise.