// File: openzeppelin-solidity/contracts/math/SafeMath.sol

pragma solidity ^0.5.0;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SafeMath: subtraction overflow");
        uint256 c = a - b;

        return c;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        // Solidity only automatically asserts when dividing by 0
        require(b > 0, "SafeMath: division by zero");
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b != 0, "SafeMath: modulo by zero");
        return a % b;
    }
}

// File: openzeppelin-solidity/contracts/token/ERC20/IERC20.sol

pragma solidity ^0.5.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP. Does not include
 * the optional functions; to access them see `ERC20Detailed`.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a `Transfer` event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through `transferFrom`. This is
     * zero by default.
     *
     * This value changes when `approve` or `transferFrom` are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * > Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an `Approval` event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a `Transfer` event.
     */
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to `approve`. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

// File: openzeppelin-solidity/contracts/token/ERC20/ERC20Detailed.sol

pragma solidity ^0.5.0;


/**
 * @dev Optional functions from the ERC20 standard.
 */
contract ERC20Detailed is IERC20 {
    string private _name;
    string private _symbol;
    uint8 private _decimals;

    /**
     * @dev Sets the values for `name`, `symbol`, and `decimals`. All three of
     * these values are immutable: they can only be set once during
     * construction.
     */
    constructor (string memory name, string memory symbol, uint8 decimals) public {
        _name = name;
        _symbol = symbol;
        _decimals = decimals;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5,05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei.
     *
     * > Note that this information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * `IERC20.balanceOf` and `IERC20.transfer`.
     */
    function decimals() public view returns (uint8) {
        return _decimals;
    }
}

// File: contracts/MultisigVaultERC20.sol

pragma solidity ^0.5.0;



/**
 * @title Basic token
 * @dev Basic version of StandardToken, with no allowances.
 */
contract MultisigVaultERC20 {

    using SafeMath for uint256;

    struct Approval {
        uint256 nonce;
        uint256 coincieded;
        address[] coinciedeParties;
    }

    uint256 private participantsAmount;
    uint256 private signatureMinThreshold;
    uint256 private nonce;

    ERC20Detailed token;
    address public currencyAddress;

    string  private _symbol;
    uint8   private _decimals;



    mapping(address => bool) public parties;

    mapping(
        // Destination
        address => mapping(
            // Amount
            uint256 => Approval
        )
    ) public approvals;

    mapping(uint256 => bool) public finished;

    event ConfirmationReceived(address indexed from, address indexed destination, address currency, uint256 amount);
    event ConsensusAchived(address indexed destination, address currency, uint256 amount);

    /**
      * @dev Construcor.
      *
      * Requirements:
      * - `_signatureMinThreshold` .
      * - `_parties`.
      */
    constructor(
        uint256 _signatureMinThreshold,
        address[] memory _parties,
        address _currencyAddress
    ) public {
        require(_parties.length > 0 && _parties.length <= 10);
        require(_signatureMinThreshold > 0 && _signatureMinThreshold <= _parties.length);

        signatureMinThreshold = _signatureMinThreshold;
        currencyAddress = _currencyAddress;
        token = ERC20Detailed(currencyAddress);

        _symbol = token.symbol();
        _decimals = token.decimals();

        for (uint256 i = 0; i < _parties.length; i++) parties[_parties[i]] = true;
    }

    modifier isMember() {
        require(parties[msg.sender]);
        _;
    }

    modifier sufficient(uint256 _amount) {


        require(token.balanceOf(address(this)) >= _amount);
        _;
    }

    function getNonce(
        address _destination,
        uint256 _amount
    ) public view returns (uint256) {
        Approval storage approval = approvals[_destination][_amount];

        return approval.nonce;
    }

    function partyCoincieded(
        address _destination,
        uint256 _amount,
        uint256 _nonce,
        address _partyAddress
    ) public view returns (bool) {
        if ( finished[_nonce] ) {
          return true;
        } else {
          Approval storage approval = approvals[_destination][_amount];

          for (uint i=0; i<approval.coinciedeParties.length; i++) {
             if (approval.coinciedeParties[i] == _partyAddress) return true;
          }

          return false;
        }
    }


    function approve(
        address _destination,
        uint256 _amount
    ) public isMember sufficient(_amount) returns (bool) {
        Approval storage approval = approvals[_destination][_amount]; // Create new project

        bool coinciedeParties = false;
        for (uint i=0; i<approval.coinciedeParties.length; i++) {
           if (approval.coinciedeParties[i] == msg.sender) coinciedeParties = true;
        }

        require(!coinciedeParties);

        if (approval.coincieded == 0) {
            nonce += 1;
            approval.nonce = nonce;
        }

        approval.coinciedeParties.push(msg.sender);
        approval.coincieded += 1;

        emit ConfirmationReceived(msg.sender, _destination, currencyAddress, _amount);

        if ( approval.coincieded >= signatureMinThreshold ) {
            token.transfer(_destination, _amount); // Release funds

            finished[approval.nonce] = true;
            delete approvals[_destination][_amount];

            emit ConsensusAchived(_destination, currencyAddress, _amount);
        }

       return false;
    }

    function symbol() public view returns (string memory) {
        return _symbol;
    }

    function decimals() public view returns (uint8) {
        return _decimals;
    }
}