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contracts...MultisigPlugin.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.10;

import {Plugin} from "https://github.com/aragon/core/blob/develop/packages/contracts/contracts/core/plugin/Plugin.sol";
import {IDAO} from "https://github.com/aragon/core/blob/develop/packages/contracts/contracts/core/IDAO.sol";

contract MultisigPlugin is Plugin {
    /* ====================================================================== */
    /*                              Permissions                               */
    /* ====================================================================== */

    bytes32 public constant SIGNER_PERMISSION_ID = keccak256("SIGNER_PERMISSION");

    /* ====================================================================== */
    /*                              Events                                    */
    /* ====================================================================== */

    event NewTransfer(address indexed creator, uint256 transferId);
    event SignedTransfer(address indexed signer, uint256 transferId);
    event ExecutedTransfer(uint256 transferId);
    event UpdateThreshold(uint8 oldThreshold, uint8 newThreshold);

    /* ====================================================================== */
    /*                              State                                     */
    /* ====================================================================== */

    struct Transfer {
        address to;
        uint256 value;
        uint8 signersRemaining;
        bool executed;
    }

    uint8 public threshold;
    uint256 transferId;
    mapping(uint256 => Transfer) public transfers;


    constructor(uint8 _threshold, address _dao) Plugin(IDAO(_dao)) {
        assert(_threshold > 0);

        transferId = 0;
        threshold = _threshold;
    }

    /* ====================================================================== */
    /*                              Functions                                 */
    /* ====================================================================== */


    function newTransfer(address _to, uint256 _value) external auth(SIGNER_PERMISSION_ID) {
        transfers[transferId] = Transfer({
            to: _to,
            value: _value,
            signersRemaining: threshold - 1,
            executed: false
        });
        emit NewTransfer(_msgSender(), transferId);
        transferId++;

        if (threshold == 1) _executeTransfer(transferId);
    }

    function signTransfer(uint256 _transferId) external auth(SIGNER_PERMISSION_ID) {
        assert(_transferId < transferId);
        assert(!transfers[_transferId].executed);

        transfers[_transferId].signersRemaining--;
        emit SignedTransfer(_msgSender(), _transferId);

        if (transfers[_transferId].signersRemaining == 0) _executeTransfer(transferId);
    }

    function _executeTransfer(uint256 _transferId) internal {
        transfers[_transferId].executed = true;
        dao.withdraw(
            address(0),
            transfers[_transferId].to,
            transfers[_transferId].value,
            "MultiSig Plugin"
        );

        emit ExecutedTransfer(_transferId);
    }
}