contract MasterChef is Ownable, ReentrancyGuard {
    using SafeMath for uint256;
    using SafeBEP20 for IBEP20;

    // Info of each user.
    struct UserInfo {
        uint256 amount;
        uint256 rewardDebt;
    }

    // Info of each pool.
    struct PoolInfo {
        IBEP20 lpToken;
        uint256 allocPoint;
        uint256 lastRewardBlock;
        uint256 accCoinagePerShare;
        uint16 depositFeeBP;
        bool isActive;
    }

    // The Coinage TOKEN!
    Coinage public coinage;

    // Dev address.
    address public devaddr;

    // Deposit Fee address
    address public feeAddress;

    // coinage tokens created per block.
    uint256 public coinagePerBlock;

    // Bonus multiplier for early coinage makers.
    uint256 public constant BONUS_MULTIPLIER = 1;

    // Info of each pool.
    PoolInfo[] public poolInfo;

    // Info of each user that stakes LP tokens.
    mapping(uint256 => mapping(address => UserInfo)) public userInfo;

    // Total allocation points. Must be the sum of all allocation points in all pools.
    uint256 public totalAllocPoint = 0;

    // The block number when coinage mining starts.
    uint256 public startBlock;

    event Deposit(address indexed user, uint256 indexed pid, uint256 amount);
    event Withdraw(address indexed user, uint256 indexed pid, uint256 amount);
    event EmergencyWithdraw(address indexed user, uint256 indexed pid, uint256 amount);
    event SetFeeAddress(address indexed user, address indexed newAddress);
    event SetDevAddress(address indexed user, address indexed newAddress);
    event UpdateEmissionRate(address indexed user, uint256 goosePerBlock);
	
    constructor(
        Coinage _coinage,
        address _devaddr,
        address _feeAddress,
        uint256 _coinagePerBlock,
        uint256 _startBlock
    ) public {
        coinage = _coinage;
        devaddr = _devaddr;
        feeAddress = _feeAddress;
        coinagePerBlock = _coinagePerBlock;
        startBlock = _startBlock;
    }

    function poolLength() external view returns (uint256) {
        return poolInfo.length;
    }

    mapping(IBEP20 => bool) public poolExistence;
    modifier nonDuplicated(IBEP20 _lpToken) {
        require(poolExistence[_lpToken] == false, "nonDuplicated: duplicated");
        _;
    }

    // Add a new lp to the pool. Can only be called by the owner.
    function add(uint256 _allocPoint, IBEP20 _lpToken, uint16 _depositFeeBP, bool _withUpdate, bool _isActive) public onlyOwner nonDuplicated(_lpToken) {
        require(_depositFeeBP <= 500, "add: invalid deposit fee basis points");
        if (_withUpdate) {
            massUpdatePools();
        }
        uint256 lastRewardBlock = block.number > startBlock ? block.number : startBlock;
        totalAllocPoint = totalAllocPoint.add(_allocPoint);
        poolExistence[_lpToken] = true;
        poolInfo.push(PoolInfo({
        lpToken : _lpToken,
        allocPoint : _allocPoint,
        lastRewardBlock : lastRewardBlock,
        accCoinagePerShare : 0,
        depositFeeBP : _depositFeeBP,
        isActive: _isActive
        }));
    }

    // Update the given pool's coinage allocation point and deposit fee. Can only be called by the owner.
    function set(uint256 _pid, uint256 _allocPoint, uint16 _depositFeeBP, bool _withUpdate, bool _isActive) public onlyOwner {
        require(_depositFeeBP <= 500, "set: invalid deposit fee basis points");
        if (_withUpdate) {
            massUpdatePools();
        }
        totalAllocPoint = totalAllocPoint.sub(poolInfo[_pid].allocPoint).add(_allocPoint);
        poolInfo[_pid].allocPoint = _allocPoint;
        poolInfo[_pid].depositFeeBP = _depositFeeBP;
        poolInfo[_pid].isActive = _isActive;
    }

    // Return reward multiplier over the given _from to _to block.
    function getMultiplier(uint256 _from, uint256 _to) public pure returns (uint256) {
        return _to.sub(_from).mul(BONUS_MULTIPLIER);
    }

    // View function to see pending COINAGE on frontend.
    function pendingCoinage(uint256 _pid, address _user) external view returns (uint256) {
        PoolInfo storage pool = poolInfo[_pid];
        UserInfo storage user = userInfo[_pid][_user];
        uint256 accCoinagePerShare = pool.accCoinagePerShare;
        uint256 lpSupply = pool.lpToken.balanceOf(address(this));
        if (block.number > pool.lastRewardBlock && lpSupply != 0) {
            uint256 multiplier = getMultiplier(pool.lastRewardBlock, block.number);
            uint256 coinageReward = multiplier.mul(coinagePerBlock).mul(pool.allocPoint).div(totalAllocPoint);
            accCoinagePerShare = accCoinagePerShare.add(coinageReward.mul(1e12).div(lpSupply));
        }
        return user.amount.mul(accCoinagePerShare).div(1e12).sub(user.rewardDebt);
    }

    // Update reward variables for all pools. Be careful of gas spending!
    function massUpdatePools() public {
        uint256 length = poolInfo.length;
        for (uint256 pid = 0; pid < length; ++pid) {
            updatePool(pid);
        }
    }

    // Update reward variables of the given pool to be up-to-date.
    function updatePool(uint256 _pid) public {
        PoolInfo storage pool = poolInfo[_pid];

        if (!pool.isActive) {
            return;
        }
        if (block.number <= pool.lastRewardBlock) {
            return;
        }
        uint256 lpSupply = pool.lpToken.balanceOf(address(this));
        if (lpSupply == 0 || pool.allocPoint == 0) {
            pool.lastRewardBlock = block.number;
            return;
        }
        uint256 multiplier = getMultiplier(pool.lastRewardBlock, block.number);
        uint256 coinageReward = multiplier.mul(coinagePerBlock).mul(pool.allocPoint).div(totalAllocPoint);
        coinage.mint(devaddr, coinageReward.div(10));
        coinage.mint(address(this), coinageReward);
        pool.accCoinagePerShare = pool.accCoinagePerShare.add(coinageReward.mul(1e12).div(lpSupply));
        pool.lastRewardBlock = block.number;
    }

    // Deposit LP tokens to MasterChef for coinage allocation.
    function deposit(uint256 _pid, uint256 _amount) public nonReentrant {
        PoolInfo storage pool = poolInfo[_pid];
        UserInfo storage user = userInfo[_pid][msg.sender];
        updatePool(_pid);
        if (user.amount > 0) {
            uint256 pending = user.amount.mul(pool.accCoinagePerShare).div(1e12).sub(user.rewardDebt);
            if (pending > 0) {
                safeCoinageTransfer(msg.sender, pending);
            }
        }
        if (_amount > 0) {
            pool.lpToken.safeTransferFrom(address(msg.sender), address(this), _amount);
            if (address(pool.lpToken) == address(coinage) && !coinage.isExcludeTaxFee(msg.sender)) {
                uint256 transferTax = _amount.mul(coinage.transferTaxRate()).div(10000);
                _amount = _amount.sub(transferTax);
            }
            if (pool.depositFeeBP > 0) {
                uint256 depositFee = _amount.mul(pool.depositFeeBP).div(10000);
                pool.lpToken.safeTransfer(feeAddress, depositFee);
                user.amount = user.amount.add(_amount).sub(depositFee);
            } else {
                user.amount = user.amount.add(_amount);
            }
        }
        user.rewardDebt = user.amount.mul(pool.accCoinagePerShare).div(1e12);
		
        emit Deposit(msg.sender, _pid, _amount);
    }

    // Withdraw LP tokens from MasterChef.
    function withdraw(uint256 _pid, uint256 _amount) public nonReentrant {
        PoolInfo storage pool = poolInfo[_pid];
        UserInfo storage user = userInfo[_pid][msg.sender];
        require(user.amount >= _amount, "withdraw: not good");
        updatePool(_pid);
        uint256 pending = user.amount.mul(pool.accCoinagePerShare).div(1e12).sub(user.rewardDebt);
        if (pending > 0) {
            safeCoinageTransfer(msg.sender, pending);
        }
        if (_amount > 0) {
            user.amount = user.amount.sub(_amount);
            pool.lpToken.safeTransfer(address(msg.sender), _amount);
        }
        user.rewardDebt = user.amount.mul(pool.accCoinagePerShare).div(1e12);
        emit Withdraw(msg.sender, _pid, _amount);
    }

    // Withdraw without caring about rewards. EMERGENCY ONLY.
    function emergencyWithdraw(uint256 _pid) public nonReentrant {
        PoolInfo storage pool = poolInfo[_pid];
        UserInfo storage user = userInfo[_pid][msg.sender];
        uint256 amount = user.amount;
        user.amount = 0;
        user.rewardDebt = 0;
        pool.lpToken.safeTransfer(address(msg.sender), amount);
        emit EmergencyWithdraw(msg.sender, _pid, amount);
    }

    // Safe coinage transfer function, just in case if rounding error causes pool to not have enough COINAGE.
    function safeCoinageTransfer(address _to, uint256 _amount) internal {
        uint256 coinageBalance = coinage.balanceOf(address(this));
        bool transferSuccess = false;
        if (_amount > coinageBalance) {
            transferSuccess = coinage.transfer(_to, coinageBalance);
        } else {
            transferSuccess = coinage.transfer(_to, _amount);
        }
        require(transferSuccess, "safeCoinageTransfer: transfer failed");
    }

    // Update dev address by the previous dev.
    function dev(address _devaddr) public {
        require(msg.sender == devaddr, "dev: wut?");
        devaddr = _devaddr;
        emit SetDevAddress(msg.sender, _devaddr);
    }

    function setFeeAddress(address _feeAddress) public {
        require(msg.sender == feeAddress, "setFeeAddress: FORBIDDEN");
        feeAddress = _feeAddress;
        emit SetFeeAddress(msg.sender, _feeAddress);
    }

    //Pancake has to add hidden dummy pools inorder to alter the emission, here we make it simple and transparent to all.
    function updateEmissionRate(uint256 _coinagePerBlock) public onlyOwner {
        massUpdatePools();
        coinagePerBlock = _coinagePerBlock;
        emit UpdateEmissionRate(msg.sender, _coinagePerBlock);
    }
}
function safeCoinageTransfer(address _to, uint256 _amount) internal {
        uint256 coinageBalance = coinage.balanceOf(address(this));
        bool transferSuccess = false;
        if (_amount > coinageBalance) {
            transferSuccess = coinage.transfer(_to, coinageBalance);
        } else {
            transferSuccess = coinage.transfer(_to, _amount);
        }
        require(transferSuccess, "safeCoinageTransfer: transfer failed");
    }
// Safe coinage transfer function, just in case if rounding error causes pool to not have enough COINAGE.