/*

    Copyright 2020 DODO ZOO.
    SPDX-License-Identifier: Apache-2.0

*/

pragma solidity 0.6.9;
pragma experimental ABIEncoderV2;

contract MultiSigWalletWithTimelock {
    uint256 public constant MAX_OWNER_COUNT = 50;
    uint256 public lockSeconds = 86400;

    event Confirmation(address indexed sender, uint256 indexed transactionId);
    event Revocation(address indexed sender, uint256 indexed transactionId);
    event Submission(uint256 indexed transactionId);
    event Execution(uint256 indexed transactionId);
    event ExecutionFailure(uint256 indexed transactionId);
    event Deposit(address indexed sender, uint256 value);
    event OwnerAddition(address indexed owner);
    event OwnerRemoval(address indexed owner);
    event RequirementChange(uint256 required);
    event UnlockTimeSet(uint256 indexed transactionId, uint256 confirmationTime);
    event LockSecondsChange(uint256 lockSeconds);

    mapping(uint256 => Transaction) public transactions;
    mapping(uint256 => mapping(address => bool)) public confirmations;
    mapping(address => bool) public isOwner;
    mapping(uint256 => uint256) public unlockTimes;

    address[] public owners;
    uint256 public required;
    uint256 public transactionCount;

    struct Transaction {
        address destination;
        uint256 value;
        bytes data;
        bool executed;
    }

    modifier onlyWallet() {
        if (msg.sender != address(this)) revert("ONLY_WALLET_ERROR");
        _;
    }

    modifier ownerDoesNotExist(address owner) {
        if (isOwner[owner]) revert("OWNER_DOES_NOT_EXIST_ERROR");
        _;
    }

    modifier ownerExists(address owner) {
        if (!isOwner[owner]) revert("OWNER_EXISTS_ERROR");
        _;
    }

    modifier transactionExists(uint256 transactionId) {
        if (transactions[transactionId].destination == address(0))
            revert("TRANSACTION_EXISTS_ERROR");
        _;
    }

    modifier confirmed(uint256 transactionId, address owner) {
        if (!confirmations[transactionId][owner]) revert("CONFIRMED_ERROR");
        _;
    }

    modifier notConfirmed(uint256 transactionId, address owner) {
        if (confirmations[transactionId][owner]) revert("NOT_CONFIRMED_ERROR");
        _;
    }

    modifier notExecuted(uint256 transactionId) {
        if (transactions[transactionId].executed) revert("NOT_EXECUTED_ERROR");
        _;
    }

    modifier notNull(address _address) {
        if (_address == address(0)) revert("NOT_NULL_ERROR");
        _;
    }

    modifier validRequirement(uint256 ownerCount, uint256 _required) {
        if (
            ownerCount > MAX_OWNER_COUNT ||
            _required > ownerCount ||
            _required == 0 ||
            ownerCount == 0
        ) revert("VALID_REQUIREMENT_ERROR");
        _;
    }

    /** @dev Fallback function allows to deposit ether. */
    fallback() external payable {
        if (msg.value > 0) {
            emit Deposit(msg.sender, msg.value);
        }
    }

    receive() external payable {
        if (msg.value > 0) {
            emit Deposit(msg.sender, msg.value);
        }
    }

    /** @dev Contract constructor sets initial owners and required number of confirmations.
     * @param _owners List of initial owners.
     * @param _required Number of required confirmations.
     */
    constructor(address[] memory _owners, uint256 _required)
        public
        validRequirement(_owners.length, _required)
    {
        for (uint256 i = 0; i < _owners.length; i++) {
            if (isOwner[_owners[i]] || _owners[i] == address(0)) {
                revert("OWNER_ERROR");
            }

            isOwner[_owners[i]] = true;
        }

        owners = _owners;
        required = _required;
    }

    /** @dev Allows to add a new owner. Transaction has to be sent by wallet.
     * @param owner Address of new owner.
     */
    function addOwner(address owner)
        external
        onlyWallet
        ownerDoesNotExist(owner)
        notNull(owner)
        validRequirement(owners.length + 1, required)
    {
        isOwner[owner] = true;
        owners.push(owner);
        emit OwnerAddition(owner);
    }

    /** @dev Allows to remove an owner. Transaction has to be sent by wallet.
     * @param owner Address of owner.
     */
    function removeOwner(address owner) external onlyWallet ownerExists(owner) {
        isOwner[owner] = false;
        for (uint256 i = 0; i < owners.length - 1; i++) {
            if (owners[i] == owner) {
                owners[i] = owners[owners.length - 1];
                break;
            }
        }

        owners.pop;

        if (required > owners.length) {
            changeRequirement(owners.length);
        }

        emit OwnerRemoval(owner);
    }

    /** @dev Allows to replace an owner with a new owner. Transaction has to be sent by wallet.
     * @param owner Address of owner to be replaced.
     * @param owner Address of new owner.
     */
    function replaceOwner(address owner, address newOwner)
        external
        onlyWallet
        ownerExists(owner)
        ownerDoesNotExist(newOwner)
    {
        for (uint256 i = 0; i < owners.length; i++) {
            if (owners[i] == owner) {
                owners[i] = newOwner;
                break;
            }
        }

        isOwner[owner] = false;
        isOwner[newOwner] = true;
        emit OwnerRemoval(owner);
        emit OwnerAddition(newOwner);
    }

    /** @dev Allows to change the number of required confirmations. Transaction has to be sent by wallet.
     * @param _required Number of required confirmations.
     */
    function changeRequirement(uint256 _required)
        public
        onlyWallet
        validRequirement(owners.length, _required)
    {
        required = _required;
        emit RequirementChange(_required);
    }

    /** @dev Changes the duration of the time lock for transactions.
     * @param _lockSeconds Duration needed after a transaction is confirmed and before it becomes executable, in seconds.
     */
    function changeLockSeconds(uint256 _lockSeconds) external onlyWallet {
        lockSeconds = _lockSeconds;
        emit LockSecondsChange(_lockSeconds);
    }

    /** @dev Allows an owner to submit and confirm a transaction.
     * @param destination Transaction target address.
     * @param value Transaction ether value.
     * @param data Transaction data payload.
     * @return transactionId Returns transaction ID.
     */
    function submitTransaction(
        address destination,
        uint256 value,
        bytes calldata data
    ) external ownerExists(msg.sender) notNull(destination) returns (uint256 transactionId) {
        transactionId = transactionCount;
        transactions[transactionId] = Transaction({
            destination: destination,
            value: value,
            data: data,
            executed: false
        });
        transactionCount += 1;
        emit Submission(transactionId);
        confirmTransaction(transactionId);
    }

    /** @dev Allows an owner to confirm a transaction.
     * @param transactionId Transaction ID.
     */
    function confirmTransaction(uint256 transactionId)
        public
        ownerExists(msg.sender)
        transactionExists(transactionId)
        notConfirmed(transactionId, msg.sender)
    {
        confirmations[transactionId][msg.sender] = true;
        emit Confirmation(msg.sender, transactionId);

        if (isConfirmed(transactionId) && unlockTimes[transactionId] == 0) {
            uint256 unlockTime = block.timestamp + lockSeconds;
            unlockTimes[transactionId] = unlockTime;
            emit UnlockTimeSet(transactionId, unlockTime);
        }
    }

    /** @dev Allows an owner to revoke a confirmation for a transaction.
     * @param transactionId Transaction ID.
     */
    function revokeConfirmation(uint256 transactionId)
        external
        ownerExists(msg.sender)
        confirmed(transactionId, msg.sender)
        notExecuted(transactionId)
    {
        confirmations[transactionId][msg.sender] = false;
        emit Revocation(msg.sender, transactionId);
    }

    /** @dev Allows anyone to execute a confirmed transaction.
     * @param transactionId Transaction ID.
     */
    function executeTransaction(uint256 transactionId)
        external
        ownerExists(msg.sender)
        notExecuted(transactionId)
    {
        require(block.timestamp >= unlockTimes[transactionId], "TRANSACTION_NEED_TO_UNLOCK");

        if (isConfirmed(transactionId)) {
            Transaction storage transaction = transactions[transactionId];
            transaction.executed = true;
            (bool success, ) = transaction.destination.call{value: transaction.value}(
                transaction.data
            );
            if (success) emit Execution(transactionId);
            else {
                emit ExecutionFailure(transactionId);
                transaction.executed = false;
            }
        }
    }

    /** @dev Returns the confirmation status of a transaction.
     * @param transactionId Transaction ID.
     * @return Confirmation status.
     */
    function isConfirmed(uint256 transactionId) public view returns (bool) {
        uint256 count = 0;

        for (uint256 i = 0; i < owners.length; i++) {
            if (confirmations[transactionId][owners[i]]) {
                count += 1;
            }

            if (count >= required) {
                return true;
            }
        }

        return false;
    }

    /* Web3 call functions */

    /** @dev Returns number of confirmations of a transaction.
     * @param transactionId Transaction ID.
     * @return count Number of confirmations.
     */
    function getConfirmationCount(uint256 transactionId) external view returns (uint256 count) {
        for (uint256 i = 0; i < owners.length; i++) {
            if (confirmations[transactionId][owners[i]]) {
                count += 1;
            }
        }
    }

    /** @dev Returns total number of transactions after filers are applied.
     * @param pending Include pending transactions.
     * @param executed Include executed transactions.
     * @return count Total number of transactions after filters are applied.
     */
    function getTransactionCount(bool pending, bool executed)
        external
        view
        returns (uint256 count)
    {
        for (uint256 i = 0; i < transactionCount; i++) {
            if ((pending && !transactions[i].executed) || (executed && transactions[i].executed)) {
                count += 1;
            }
        }
    }

    /** @dev Returns list of owners.
     * @return List of owner addresses.
     */
    function getOwners() external view returns (address[] memory) {
        return owners;
    }

    /** @dev Returns array with owner addresses, which confirmed transaction.
     * @param transactionId Transaction ID.
     * @return _confirmations Returns array of owner addresses.
     */
    function getConfirmations(uint256 transactionId)
        external
        view
        returns (address[] memory _confirmations)
    {
        address[] memory confirmationsTemp = new address[](owners.length);
        uint256 count = 0;
        uint256 i;

        for (i = 0; i < owners.length; i++) {
            if (confirmations[transactionId][owners[i]]) {
                confirmationsTemp[count] = owners[i];
                count += 1;
            }
        }

        _confirmations = new address[](count);

        for (i = 0; i < count; i++) {
            _confirmations[i] = confirmationsTemp[i];
        }
    }
}