// SPDX-License-Identifier: MIT

pragma solidity ^0.6.12;
pragma experimental ABIEncoderV2;

import { Governance } from "../../v1/Governance.sol";
import { SafeMath } from "@openzeppelin/contracts/math/SafeMath.sol";
import { ITornadoVault } from "../interfaces/ITornadoVault.sol";

/// @title Version 2 Governance contract of the tornado.cash governance
contract GovernanceVaultUpgrade is Governance {
  using SafeMath for uint256;

  // vault which stores user TORN
  ITornadoVault public immutable userVault;

  // call Governance v1 constructor
  constructor(address _userVault) public Governance() {
    userVault = ITornadoVault(_userVault);
  }

  /// @notice Withdraws TORN from governance if conditions permit
  /// @param amount the amount of TORN to withdraw
  function unlock(uint256 amount) public virtual override {
    require(getBlockTimestamp() > canWithdrawAfter[msg.sender], "Governance: tokens are locked");
    lockedBalance[msg.sender] = lockedBalance[msg.sender].sub(amount, "Governance: insufficient balance");
    userVault.withdrawTorn(msg.sender, amount);
  }

  /// @notice checker for success on deployment
  /// @return returns precise version of governance
  function version() external pure virtual returns (string memory) {
    return "2.vault-migration";
  }

  /// @notice transfers tokens from the contract to the vault, withdrawals are unlock()
  /// @param owner account/contract which (this) spender will send to the user vault
  /// @param amount amount which spender will send to the user vault
  function _transferTokens(address owner, uint256 amount) internal virtual override {
    require(torn.transferFrom(owner, address(userVault), amount), "TORN: transferFrom failed");
    lockedBalance[owner] = lockedBalance[owner].add(amount);
  }
}