contract MVCStaking is Ownable {
  using SafeMath for uint256;
  using SafeMath for uint16;

  /**
   *
   * @dev User reflects the info of each user
   *
   *
   * @param {total_invested} how many tokens the user staked
   * @param {total_withdrawn} how many tokens withdrawn so far
   * @param {lastPayout} time at which last claim was done
   * @param {depositTime} Time of last deposit
   * @param {totalClaimed} Total claimed by the user
   *
   */
  struct User {
    uint256 total_invested;
    uint256 total_withdrawn;
    uint256 lastPayout;
    uint256 depositTime;
    uint256 totalClaimed;
  }

  /**
   *
   * @dev PoolInfo reflects the info of each pools
   *
   * To improve precision, we provide APY with an additional zero. So if APY is 12%, we provide
   * 120 as input.lockPeriodInDays would be the number of days which the unstake is locked. So if we want to
   * lock unstake for 1 month, lockPeriodInDays would be 30.
   *
   * @param {apy} Percentage of yield produced by the pool
   * @param {lockPeriodInDays} Amount of time unstake will be locked
   * @param {totalDeposit} Total deposit in the pool
   * @param {startDate} starting time of pool
   * @param {endDate} ending time of pool in unix timestamp
   *
   */

  struct Pool {
    uint16 apy;
    uint16 lockPeriodInDays;
    uint256 totalDeposit;
    uint256 startDate;
    uint256 endDate;
  }

  IERC20 private token = IERC20(0x5aC525D33fFDA012eA2Fe246a0Ee698F861304D7); //MVC Token address
  address private feeAddress; //Address which receives fee
  uint8 private feePercent; //Percentage of fee deducted (/1000)

  mapping(uint256 => mapping(address => User)) public users;

  Pool[] public poolInfo;

  event Stake(address indexed addr, uint256 amount);
  event Claim(address indexed addr, uint256 amount);

  constructor() {
    feeAddress = msg.sender;
    feePercent = 0;

    poolInfo.push(
      Pool({
        apy: 330,
        lockPeriodInDays: 30,
        totalDeposit: 0,
        startDate: block.timestamp,
        endDate: block.timestamp + 365 days //1 year
      })
    );

    poolInfo.push(
      Pool({
        apy: 660,
        lockPeriodInDays: 90,
        totalDeposit: 0,
        startDate: block.timestamp,
        endDate: block.timestamp + 365 days //1 year
      })
    );
  }

  receive() external payable {
    revert("BNB deposit not supported");
  }

  /**
   *
   * @dev get length of the pools
   *
   * @return {uint256} length of the pools
   *
   */
  function poolLength() public view returns (uint256) {
    return poolInfo.length;
  }

  /**
   *
   * @dev get info of all pools
   *
   * @return {PoolInfo[]} Pool info struct
   *
   */
  function getPools() public view returns (Pool[] memory) {
    return poolInfo;
  }

  /**
   *
   * @dev add new pool, only available for owner
   *
   */
  function add(
    uint16 _apy,
    uint16 _lockPeriodInDays,
    uint256 _endDate
  ) public onlyOwner {
    poolInfo.push(
      Pool({
        apy: _apy,
        lockPeriodInDays: _lockPeriodInDays,
        totalDeposit: 0,
        startDate: block.timestamp,
        endDate: _endDate
      })
    );
  }

  /**
   *
   * @dev update the given pool's Info
   *
   */
  function set(
    uint256 _pid,
    uint16 _apy,
    uint16 _lockPeriodInDays,
    uint256 _endDate
  ) public onlyOwner {
    require(_pid < poolLength(),"Invalid pool Id");
    
    poolInfo[_pid].apy = _apy;
    poolInfo[_pid].lockPeriodInDays = _lockPeriodInDays;
    poolInfo[_pid].endDate = _endDate;
  }

  /**
   *
   * @dev depsoit tokens to staking for token allocation
   *
   * @param {_pid} Id of the pool
   * @param {_amount} Amount to be staked
   *
   * @return {bool} Status of stake
   *
   */
  function stake(uint8 _pid, uint256 _amount) external returns (bool) {
    require(
      token.allowance(msg.sender, address(this)) >= _amount,
      "Set allowance first!"
    );

    bool success = token.transferFrom(msg.sender, address(this), _amount);
    require(success, "Transfer failed");

    _stake(_pid, msg.sender, _amount);

    return success;
  }

  function _stake(
    uint8 _pid,
    address _sender,
    uint256 _amount
  ) internal {
    User storage user = users[_pid][_sender];
    Pool storage pool = poolInfo[_pid];

    uint256 stopDepo = pool.endDate.sub(pool.lockPeriodInDays.mul(1 days));

    require(block.timestamp <= stopDepo, "Staking is disabled for this pool");

    user.total_invested = user.total_invested.add(_amount);
    pool.totalDeposit = pool.totalDeposit.add(_amount);
    user.lastPayout = block.timestamp;
    user.depositTime = block.timestamp;

    emit Stake(_sender, _amount);
  }

  /**
   *
   * @dev claim accumulated token reward for a single pool
   *
   * @param {_pid} pool identifier
   *
   * @return {bool} status of claim
   */

  function claim(uint8 _pid) public returns (bool) {

    _claim(_pid, msg.sender);

    return true;
  }

  /**
   *
   * @dev claim accumulated token reward from all pools
   *
   * Beware of gas fee!
   *
   */
  function claimAll() public returns (bool) {
    uint256 length = poolInfo.length;

    for (uint8 pid = 0; pid < length; ++pid) {
        _claim(pid, msg.sender);
    }

    return true;
  }

  /**
   *
   * @dev check whether user can Unstake or not
   *
   * @param {_pid}  id of the pool
   * @param {_addr} address of the user
   *
   * @return {bool} Status of unstake
   *
   */

  function canUnstake(uint8 _pid, address _addr) public view returns (bool) {
    User storage user = users[_pid][_addr];
    Pool storage pool = poolInfo[_pid];

    return (block.timestamp >=
      user.depositTime.add(pool.lockPeriodInDays.mul(1 days)));
  }

  /**
   *
   * @dev withdraw tokens from Staking
   *
   * @param {_pid} id of the pool
   * @param {_amount} amount to be unstaked
   *
   * @return {bool} Status of unstake
   *
   */
  function unStake(uint8 _pid, uint256 _amount) external returns (bool) {
    User storage user = users[_pid][msg.sender];
    Pool storage pool = poolInfo[_pid];

    require(user.total_invested >= _amount, "You don't have enough funds");

    require(canUnstake(_pid, msg.sender), "Stake still in locked state");

    _claim(_pid, msg.sender);

    pool.totalDeposit = pool.totalDeposit.sub(_amount);
    user.total_invested = user.total_invested.sub(_amount);
    
    safeTokenTransfer(msg.sender, _amount);

    return true;
  }

  function _claim(uint8 _pid, address _addr) internal {
    User storage user = users[_pid][_addr];

    uint256 amount = payout(_pid, _addr);

    if (amount > 0) {
      user.total_withdrawn = user.total_withdrawn.add(amount);

      uint256 feeAmount = amount.mul(feePercent).div(1000);

      safeTokenTransfer(feeAddress, feeAmount);

      amount = amount.sub(feeAmount);

      safeTokenTransfer(_addr, amount);

      user.lastPayout = block.timestamp;

      user.totalClaimed = user.totalClaimed.add(amount);
    }

    emit Claim(_addr, amount);
  }

  function payout(uint8 _pid, address _addr)
    public
    view
    returns (uint256 value)
  {
    User storage user = users[_pid][_addr];
    Pool storage pool = poolInfo[_pid];

    uint256 from = user.lastPayout > user.depositTime
      ? user.lastPayout
      : user.depositTime;
    uint256 to = block.timestamp > pool.endDate
      ? pool.endDate
      : block.timestamp;

    if (from < to) {
      value = value.add(
        user.total_invested.mul(to.sub(from)).mul(pool.apy).div(365 days * 1000)
      );
    }

    return value;
  }

  /**
   *
   * @dev safe token transfer function, require to have enough token to transfer
   *
   */
  function safeTokenTransfer(address _to, uint256 _amount) internal {
    uint256 tokenBal = token.balanceOf(address(this));
    if (_amount > tokenBal) {
      token.transfer(_to, tokenBal);
    } else {
      token.transfer(_to, _amount);
    }
  }

  /**
   *
   * @dev update fee values
   *
   */
  function updateFeeValues(uint8 _feePercent, address _feeWallet)
    public
    onlyOwner
  {
    feePercent = _feePercent;
    feeAddress = _feeWallet;
  }
}
function poolLength() public view returns (uint256) {
  return poolInfo.length;
}

/**
 *
 * @dev get length of the pools
 *
 * @return {uint256} length of the pools
 *
 */