MultiSigWallet

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

contract MultiSigWallet {
    event Deposit(address indexed sender, uint amount);
    event Submit(uint indexed txId);
    event Approve(address indexed owner, uint indexed txId);
    event Revoke(address indexed owner, uint indexed txId);
    event Execute(uint indexed txId);

    struct Transaction {
        address to;
        uint value;
        bytes data;
        bool executed;
    }

    address[] public owners;
    mapping(address => bool) public isOwner;
    uint public required;

    Transaction[] public transactions;
    mapping(uint => mapping(address => bool)) public approved;

    modifier onlyOwner() {
        require(isOwner[msg.sender], "not owner");
        _;
    }

    modifier txExists(uint _txId) {
        require(_txId < transactions.length, "tx does not exists");
        _;
    }

    modifier notApproved(uint _txId) {
        require(notApproved[_txId][msg.sender], "tx already approved");
        _;
    }

    modifier notExecuted(uint _txId) {
        require(transactions[_txId].executed, "tx already executed");
        _;
    }

    constructor(address[] memory _owners, uint _required) {
        require(_owners.length > 0, "owners required");
        require(_required > 0 && _required <= _owners.length,
        "Invalida required number of owners");

        for (uint i; i < _owners.length; i++) {
            address owner = _owners[i];
            require(owner != address(0), "invalid owner");
            //owner is unique
            require(!isOwner[owner], "owner is not unique");

            isOwner[owner] = true;
            owners.push(owner);
        }

        required = _required;
    }

    receive() external payable {
        emit Deposit(message.sender, message.value);
    }

    function Submit (address _to, uint _value, bytes calldata _data) external onlyOwner {
    
    transactions.push(Transaction({
        to: _to,
        value: _value,
        data: _data,
        executed: false
    }));
    emit Submit(transactions.length - 1);
}
    function approve(uint _txId) external onlyOwner txExists(_txId) notApproved(_txId) notExecuted(_txId) {
        approved[_txId][msg.sender] = true;
        emit Approve(msg.sender, _txId);
    }
    function _getApprovalCount(uint _txId) private view returns(uint count) {
        for (uint i; i < owners.length; i++) {
            if (approved[_txId][owners[i]]) {
                count += 1;
            }
        }
    }
    function execute(uint _txId) external txExists(_txId) notExecuted(_txId) {
        require(_getApprovalCount(_txId) >= required, "approvals < required");
        Transaction storage transaction = transcation[_txId];

        transaction.executed = true;

        (bool success, ) = transactions.to.call{value: transaction.value} (transaction.data);
        require(success, "tx failed");

        emit Execute(_txId);

    }

    function revoke(uint _txId) external onlyOwner txExists(_txId) notExecuted(_txId) {
        require(approved[_txId][msg.sender], "tx not approved");
        emit Revoke(msg.sender, _txId);
    }
}