contract YGYPool is LPTokenWrapper, OwnableUpgradeSafe {
  using SafeERC20 for IERC20;

  IERC20 public rewardToken;
  IMultiplier public multiplier;
  IStorageV1 public storage_;
  uint256 public DURATION;
  uint256 public periodFinish;
  uint256 public lastUpdateTime;
  uint256 public rewardRate;
  uint256 public rewardPerTokenStored;
  uint256 public deployedTime;
  address public devFund;

  address public ram;
  address public ramVault;

  mapping(address => uint256) public userRewardPerTokenPaid;
  mapping(address => uint256) public rewards;

  event RewardAdded(uint256 reward);
  event Withdrawn(address indexed user, uint256 amount);
  event Staked(address indexed user, uint256 amount);
  event RewardPaid(address indexed user, uint256 reward);
  event Boost(address _token, uint256 level);

  constructor(
    uint256 _duration,
    address _stakingToken,
    address _rewardToken,
    address _multiplier,
    address _treasury,
    address _ram,
    address _ramVault,
    address _storage
  ) public LPTokenWrapper() {
    __Ownable_init();
    setStakingToken(_stakingToken);
    multiplier = IMultiplier(_multiplier);
    treasury = _treasury;
    devFee = 20; // 2%
    rewardToken = IERC20(_rewardToken);
    deployedTime = block.timestamp;
    DURATION = _duration;
    ram = _ram;
    ramVault = _ramVault;
    storage_ = IStorageV1(_storage);
  }

  function setNewTreasury(address _treasury) external onlyOwner {
    treasury = _treasury;
  }

  function lastTimeRewardsActive() public view returns (uint256) {
    return Math.min(block.timestamp, periodFinish);
  }

  /* @dev Returns the current rate of rewards per token (doh) */
  function rewardPerToken() public view returns (uint256) {
    // Do not distribute rewards before startTime.
    if (block.timestamp < startTime) {
      return 0;
    }
    if (_totalSupply == 0) {
      return rewardPerTokenStored;
    }
    // Effective total supply takes into account all the multipliers bought by userbase.
    uint256 effectiveTotalSupply = _totalSupply.add(_totalSupplyAccounting);
    // The returrn value is time-based on last time the contract had rewards active multipliede by the reward-rate.
    // It's evened out with a division of bonus effective supply.
    return rewardPerTokenStored.add(lastTimeRewardsActive().sub(lastUpdateTime).mul(rewardRate).mul(1e18).div(effectiveTotalSupply));
  }

  /** @dev Returns the claimable tokens for user.*/
  function earned(address account) public view returns (uint256) {
    // Do a lookup for the multiplier on the view - it's necessary for correct reward distribution.
    uint256 totalMultiplier = multiplier.getTotalValueForUser(address(this), account);
    uint256 effectiveBalance = _balances[account].add(_balances[account].mul(totalMultiplier).div(1000));
    return effectiveBalance.mul(rewardPerToken().sub(userRewardPerTokenPaid[account])).div(1e18).add(rewards[account]);
  }

  /** @dev Staking function which updates the user balances in the parent contract */
  function stake(uint256 amount) public override {
    updateReward(msg.sender);
    require(amount > 0, "Cannot stake 0!");

    // Call the parent to adjust the balances.
    super.stake(amount);

    // Get users multiplier.
    uint256 userTotalMultiplier = multiplier.getTotalValueForUser(address(this), msg.sender);

    // Adjust the bonus effective stake according to the multiplier.
    adjustEffectiveStake(msg.sender, userTotalMultiplier, false);
    emit Staked(msg.sender, amount);
  }

  /** @dev Withdraw function, this pool contains a tax which is defined in the constructor */
  function withdraw(uint256 amount) public override {
    require(amount > 0, "Cannot withdraw 0");
    updateReward(msg.sender);

    // Calculate the withdraw tax (it's 2% of the amount)
    uint256 tax = amount.mul(devFee).div(1000);

    // Transfer the tokens to user
    stakingToken.safeTransfer(msg.sender, amount.sub(tax));
    // Tax to treasury
    stakingToken.safeTransfer(treasury, tax);

    // Adjust regular balances
    super.withdraw(amount);

    // And the bonus balances
    uint256 userTotalMultiplier = multiplier.getTotalValueForUser(address(this), msg.sender);
    adjustEffectiveStake(msg.sender, userTotalMultiplier, true);
    emit Withdrawn(msg.sender, amount);
  }

  /** @dev Adjust the bonus effective stakee for user and whole userbase */
  function adjustEffectiveStake(
    address self,
    uint256 _totalMultiplier,
    bool _isWithdraw
  ) private {
    uint256 prevBalancesAccounting = _balancesAccounting[self];
    if (_totalMultiplier > 0) {
      // Calculate and set self's new accounting balance
      uint256 newBalancesAccounting = _balances[self].mul(_totalMultiplier).div(1000);

      // Adjust total accounting supply accordingly - Subtracting previous balance from new balance on withdraws
      // On deposits it's vice-versa.
      if (_isWithdraw) {
        uint256 diffBalancesAccounting = prevBalancesAccounting.sub(newBalancesAccounting);
        _balancesAccounting[self] = _balancesAccounting[self].sub(diffBalancesAccounting);
        _totalSupplyAccounting = _totalSupplyAccounting.sub(diffBalancesAccounting);
      } else {
        uint256 diffBalancesAccounting = newBalancesAccounting.sub(prevBalancesAccounting);
        _balancesAccounting[self] = _balancesAccounting[self].add(diffBalancesAccounting);
        _totalSupplyAccounting = _totalSupplyAccounting.add(diffBalancesAccounting);
      }
    } else {
      _balancesAccounting[self] = 0;
      _totalSupplyAccounting = _totalSupplyAccounting.sub(prevBalancesAccounting);
    }
  }

  // Ease-of-access function for user to remove assets from the pool.
  function exit() external {
    getReward();
    withdraw(balanceOf(msg.sender));
  }

  // Sends out the reward tokens to the user.
  function getReward() public {
    updateReward(msg.sender);
    uint256 reward = earned(msg.sender);
    if (reward > 0) {
      uint256 tax = reward.mul(devFee).div(1000);
      rewards[msg.sender] = 0;
      rewardToken.safeTransfer(msg.sender, reward.sub(tax));
      rewardToken.safeTransfer(treasury, tax);
      emit RewardPaid(msg.sender, reward);
    }
  }

  // Called to start the pool with the reward amount it should distribute
  // The reward period will be the duration of the pool.
  function notifyRewardAmount(uint256 reward) external onlyOwner {
    // Pull the funds from the owner
    rewardToken.safeTransferFrom(msg.sender, address(this), reward);
    // Update reward values
    updateRewardPerTokenStored();

    // Rewardrate must stay at a constant since it's used by end-users claiming rewards after the reward period has finished.
    if (block.timestamp >= periodFinish) {
      rewardRate = reward.div(DURATION);
    } else {
      // Remaining time for the pool
      uint256 remainingTime = periodFinish.sub(block.timestamp);
      // And the rewards
      uint256 rewardsRemaining = remainingTime.mul(rewardRate);
      // Set the current rate
      rewardRate = reward.add(rewardsRemaining).div(DURATION);
    }

    // Set the last updated
    lastUpdateTime = block.timestamp;
    startTime = block.timestamp;
    // Add the period to be equal to duration set.s
    periodFinish = block.timestamp.add(DURATION);
    emit RewardAdded(reward);
  }

  // Notify a reward amount without updating time,
  function notifyRewardAmountWithoutUpdateTime(uint256 reward) external onlyOwner {
    rewardToken.safeTransferFrom(msg.sender, address(this), reward);
    updateRewardPerTokenStored();
    if (block.timestamp >= periodFinish) {
      rewardRate = reward.div(DURATION);
    } else {
      uint256 remaining = periodFinish.sub(block.timestamp);
      uint256 leftover = remaining.mul(rewardRate);
      rewardRate = reward.add(leftover).div(DURATION);
    }
    emit RewardAdded(reward);
  }

  // Returns the users current multiplier level
  function getTotalLevel(address _user) external view returns (uint256) {
    return multiplier.getTotalLevel(address(this), _user);
  }

  // Return the amount spent on multipliers, used for subtracting for future purchases.
  function getSpent(address _token, address _user) external view returns (uint256) {
    return multiplier.getTokensSpentPerContract(address(this), _token, _user);
  }

  // Calculate the cost for purchasing a boost.
  function calculateCost(
    address _user,
    address _token,
    uint256 _level
  ) public view returns (uint256) {
    // Users last level, no cost for levels lower than current (doh)
    uint256 lastLevel = multiplier.getLastTokenLevelForUser(address(this), _user, _token);
    if (lastLevel >= _level) {
      return 0;
    } else {
      return multiplier.getSpendableCostPerTokenForUser(address(this), _user, _token, _level);
    }
  }

  // Purchase a multiplier level, same level cannot be purchased twice.
  function purchase(address _token, uint256 _newLevel) external {
    // Must be a spendable token
    require(multiplier.isSpendableTokenInContract(address(this), _token), "Not a spendable!");

    // What's the last level for the user?
    uint256 lastLevel = multiplier.getLastTokenLevelForUser(address(this), msg.sender, _token);
    require(lastLevel < _newLevel, "Cannot downgrade level or same level");

    // Get the subtracted cost for the new level.
    uint256 cost = calculateCost(msg.sender, _token, _newLevel);

    // Ram token is sent to vault
    if (_token == ram) {
      IERC20(_token).safeTransferFrom(msg.sender, ramVault, cost);
      // Notify the vault about it
      storage_.addPendingRewards(cost);
    } else {
      // Other tokens go to YGY treasury.
      IERC20(_token).safeTransferFrom(msg.sender, treasury, cost);
    }

    // Update balances and level in the multiplier contarct
    multiplier.purchase(address(this), msg.sender, _token, _newLevel);

    // Adjust new level
    uint256 userTotalMultiplier = multiplier.getTotalValueForUser(address(this), msg.sender);
    adjustEffectiveStake(msg.sender, userTotalMultiplier, false);

    emit Boost(_token, _newLevel);
  }

  // Returns the multiplier for user.
  function getTotalMultiplier(address _account) public view returns (uint256) {
    return multiplier.getTotalValueForUser(address(this), _account);
  }

  // Ejects any remaining tokens from the pool.
  // Callable only after the pool has started and the pools reward distribution period has finished.
  function eject() external onlyOwner {
    require(startTime < block.timestamp && block.timestamp >= periodFinish, "Cannot eject before period finishes or pool has started");
    uint256 currBalance = rewardToken.balanceOf(address(this));
    rewardToken.safeTransfer(msg.sender, currBalance);
  }

  // Forcefully retire a pool
  // Only sets the period finish to 0
  // This will prevent more rewards from being disbursed
  function kill() external onlyOwner {
    periodFinish = block.timestamp;
  }

  function updateRewardPerTokenStored() internal {
    rewardPerTokenStored = rewardPerToken();
    lastUpdateTime = lastTimeRewardsActive();
  }

  function updateReward(address account) internal {
    updateRewardPerTokenStored();
    rewards[account] = earned(account);
    userRewardPerTokenPaid[account] = rewardPerTokenStored;
  }
}
/**
 * @dev This contract is a time-based yield farming pool with effective-staking multiplier mechanics.
 *
 * * * NOTE: A withdrawal fee of 2% is included which is sent to either 1) the treasury address. 2) burn address 3) the ram vault * * *
 */
function purchase(address _token, uint256 _newLevel) external {
    // Must be a spendable token
    require(multiplier.isSpendableTokenInContract(address(this), _token), "Not a spendable!");

    // What's the last level for the user?
    uint256 lastLevel = multiplier.getLastTokenLevelForUser(address(this), msg.sender, _token);
    require(lastLevel < _newLevel, "Cannot downgrade level or same level");

    // Get the subtracted cost for the new level.
    uint256 cost = calculateCost(msg.sender, _token, _newLevel);

    // Ram token is sent to vault
    if (_token == ram) {
      IERC20(_token).safeTransferFrom(msg.sender, ramVault, cost);
      // Notify the vault about it
      storage_.addPendingRewards(cost);
    } else {
      // Other tokens go to YGY treasury.
      IERC20(_token).safeTransferFrom(msg.sender, treasury, cost);
    }

    // Update balances and level in the multiplier contarct
    multiplier.purchase(address(this), msg.sender, _token, _newLevel);

    // Adjust new level
    uint256 userTotalMultiplier = multiplier.getTotalValueForUser(address(this), msg.sender);
    adjustEffectiveStake(msg.sender, userTotalMultiplier, false);

    emit Boost(_token, _newLevel);
  }
// Purchase a multiplier level, same level cannot be purchased twice.