// Contract: BaseWallet
// Target function: function init(address _owner, address[] calldata _modules) external
pragma solidity ^0.6.12;
// Copyright (C) 2018  Argent Labs Ltd. <https://argent.xyz>

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

// SPDX-License-Identifier: GPL-3.0-only


/**
 * @title IModule
 * @notice Interface for a module.
 * A module MUST implement the addModule() method to ensure that a wallet with at least one module
 * can never end up in a "frozen" state.
 * @author Julien Niset - <julien@argent.xyz>
 */
interface IModule {
    /**
     * @notice Inits a module for a wallet by e.g. setting some wallet specific parameters in storage.
     * @param _wallet The wallet.
     */
    function init(address _wallet) external;

    /**	
     * @notice Adds a module to a wallet. Cannot execute when wallet is locked (or under recovery)	
     * @param _wallet The target wallet.	
     * @param _module The modules to authorise.	
     */	
    function addModule(address _wallet, address _module) external;
}


/**
 * @title IWallet
 * @notice Interface for the BaseWallet
 */
interface IWallet {
    /**
     * @notice Returns the wallet owner.
     * @return The wallet owner address.
     */
    function owner() external view returns (address);

    /**
     * @notice Returns the number of authorised modules.
     * @return The number of authorised modules.
     */
    function modules() external view returns (uint);

    /**
     * @notice Sets a new owner for the wallet.
     * @param _newOwner The new owner.
     */
    function setOwner(address _newOwner) external;

    /**
     * @notice Checks if a module is authorised on the wallet.
     * @param _module The module address to check.
     * @return `true` if the module is authorised, otherwise `false`.
     */
    function authorised(address _module) external view returns (bool);

    /**
     * @notice Returns the module responsible for a static call redirection.
     * @param _sig The signature of the static call.
     * @return the module doing the redirection
     */
    function enabled(bytes4 _sig) external view returns (address);

    /**
     * @notice Enables/Disables a module.
     * @param _module The target module.
     * @param _value Set to `true` to authorise the module.
     */
    function authoriseModule(address _module, bool _value) external;

    /**
    * @notice Enables a static method by specifying the target module to which the call must be delegated.
    * @param _module The target module.
    * @param _method The static method signature.
    */
    function enableStaticCall(address _module, bytes4 _method) external;
}



/**
 * @title BaseWallet
 * @notice Simple modular wallet that authorises modules to call its invoke() method.
 * @author Julien Niset - <julien@argent.xyz>
 */
contract BaseWallet is IWallet {

    // The implementation of the proxy
    address public implementation;
    // The owner
    address public override owner;
    // The authorised modules
    mapping (address => bool) public override authorised;
    // The enabled static calls
    mapping (bytes4 => address) public override enabled;
    // The number of modules
    uint public override modules;

    event AuthorisedModule(address indexed module, bool value);
    event EnabledStaticCall(address indexed module, bytes4 indexed method);
    event Invoked(address indexed module, address indexed target, uint indexed value, bytes data);
    event Received(uint indexed value, address indexed sender, bytes data);
    event OwnerChanged(address owner);

    /**
     * @notice Throws if the sender is not an authorised module.
     */
    modifier moduleOnly {
        require(authorised[msg.sender], "BW: msg.sender not an authorized module");
        _;
    }