contract MasterChef is Ownable {
	using SafeMath for uint256;
	using SafeERC20 for IERC20;
	// Info of each user.
	struct UserInfo {
		uint256 amount; // How many LP tokens the user has provided.
		uint256 rewardDebt; // Reward debt. See explanation below.
		//
		// We do some fancy math here. Basically, any point in time, the amount of SUSHIs
		// entitled to a user but is pending to be distributed is:
		//
		//   pending reward = (user.amount * pool.accSushiPerShare) - user.rewardDebt
		//
		// Whenever a user deposits or withdraws LP tokens to a pool. Here's what happens:
		//   1. The pool's `accSushiPerShare` (and `lastRewardBlock`) gets updated.
		//   2. User receives the pending reward sent to his/her address.
		//   3. User's `amount` gets updated.
		//   4. User's `rewardDebt` gets updated.
	}
	// Info of each pool.
	struct PoolInfo {
		IERC20 lpToken; // Address of LP token contract.
		uint256 allocPoint; // How many allocation points assigned to this pool. SUSHIs to distribute per block.
		uint256 lastRewardBlock; // Last block number that SUSHIs distribution occurs.
		uint256 accSushiPerShare; // Accumulated SUSHIs per share, times 1e12. See below.
	}
	// The SUSHI TOKEN!
	SushiToken public sushi;
	// Dev address.
	address public devaddr;
	// Block number when bonus SUSHI period ends.
	uint256 public bonusEndBlock;
	// SUSHI tokens created per block.
	uint256 public sushiPerBlock;
	// Bonus muliplier for early sushi makers.
	uint256 public constant BONUS_MULTIPLIER = 10;
	// The migrator contract. It has a lot of power. Can only be set through governance (owner).
	IMigratorChef public migrator;
	// Info of each pool.
	PoolInfo[] public poolInfo;
	// Info of each user that stakes LP tokens.
	mapping(uint256 => mapping(address => UserInfo)) public userInfo;
	// Total allocation poitns. Must be the sum of all allocation points in all pools.
	uint256 public totalAllocPoint = 0;
	// The block number when SUSHI 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);

	constructor(
		SushiToken _sushi,
		address _devaddr,
		uint256 _sushiPerBlock,
		uint256 _startBlock,
		uint256 _bonusEndBlock
	) public {
		sushi = _sushi;
		devaddr = _devaddr;
		sushiPerBlock = _sushiPerBlock;
		bonusEndBlock = _bonusEndBlock;
		startBlock = _startBlock;
	}

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

	// Add a new lp to the pool. Can only be called by the owner.
	// XXX DO NOT add the same LP token more than once. Rewards will be messed up if you do.
	function add(
		uint256 _allocPoint,
		IERC20 _lpToken,
		bool _withUpdate
	) public onlyOwner {
		if (_withUpdate) {
			massUpdatePools();
		}
		uint256 lastRewardBlock = block.number > startBlock ? block.number : startBlock;
		totalAllocPoint = totalAllocPoint.add(_allocPoint);
		poolInfo.push(
			PoolInfo({ lpToken: _lpToken, allocPoint: _allocPoint, lastRewardBlock: lastRewardBlock, accSushiPerShare: 0 })
		);
	}

	// Update the given pool's SUSHI allocation point. Can only be called by the owner.
	function set(
		uint256 _pid,
		uint256 _allocPoint,
		bool _withUpdate
	) public onlyOwner {
		if (_withUpdate) {
			massUpdatePools();
		}
		totalAllocPoint = totalAllocPoint.sub(poolInfo[_pid].allocPoint).add(_allocPoint);
		poolInfo[_pid].allocPoint = _allocPoint;
	}

	// Set the migrator contract. Can only be called by the owner.
	function setMigrator(IMigratorChef _migrator) public onlyOwner {
		migrator = _migrator;
	}

	// Migrate lp token to another lp contract. Can be called by anyone. We trust that migrator contract is good.
	function migrate(uint256 _pid) public {
		require(address(migrator) != address(0), "migrate: no migrator");
		PoolInfo storage pool = poolInfo[_pid];
		IERC20 lpToken = pool.lpToken;
		uint256 bal = lpToken.balanceOf(address(this));
		lpToken.safeApprove(address(migrator), bal);
		IERC20 newLpToken = migrator.migrate(lpToken);
		require(bal == newLpToken.balanceOf(address(this)), "migrate: bad");
		pool.lpToken = newLpToken;
	}

	// Return reward multiplier over the given _from to _to block.
	function getMultiplier(uint256 _from, uint256 _to) public view returns (uint256) {
		if (_to <= bonusEndBlock) {
			return _to.sub(_from).mul(BONUS_MULTIPLIER);
		} else if (_from >= bonusEndBlock) {
			return _to.sub(_from);
		} else {
			return bonusEndBlock.sub(_from).mul(BONUS_MULTIPLIER).add(_to.sub(bonusEndBlock));
		}
	}

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

	// Update reward vairables 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 (block.number <= pool.lastRewardBlock) {
			return;
		}
		uint256 lpSupply = pool.lpToken.balanceOf(address(this));
		if (lpSupply == 0) {
			pool.lastRewardBlock = block.number;
			return;
		}
		uint256 multiplier = getMultiplier(pool.lastRewardBlock, block.number);
		uint256 sushiReward = multiplier.mul(sushiPerBlock).mul(pool.allocPoint).div(totalAllocPoint);
		sushi.mint(devaddr, sushiReward.div(10));
		sushi.mint(address(this), sushiReward);
		pool.accSushiPerShare = pool.accSushiPerShare.add(sushiReward.mul(1e12).div(lpSupply));
		pool.lastRewardBlock = block.number;
	}

	// Deposit LP tokens to MasterChef for SUSHI allocation.
	function deposit(uint256 _pid, uint256 _amount) public {
		PoolInfo storage pool = poolInfo[_pid];
		UserInfo storage user = userInfo[_pid][msg.sender];
		updatePool(_pid);
		if (user.amount > 0) {
			uint256 pending = user.amount.mul(pool.accSushiPerShare).div(1e12).sub(user.rewardDebt);
			safeSushiTransfer(msg.sender, pending);
		}
		pool.lpToken.safeTransferFrom(address(msg.sender), address(this), _amount);
		user.amount = user.amount.add(_amount);
		user.rewardDebt = user.amount.mul(pool.accSushiPerShare).div(1e12);
		emit Deposit(msg.sender, _pid, _amount);
	}

	// Withdraw LP tokens from MasterChef.
	function withdraw(uint256 _pid, uint256 _amount) public {
		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.accSushiPerShare).div(1e12).sub(user.rewardDebt);
		safeSushiTransfer(msg.sender, pending);
		user.amount = user.amount.sub(_amount);
		user.rewardDebt = user.amount.mul(pool.accSushiPerShare).div(1e12);
		pool.lpToken.safeTransfer(address(msg.sender), _amount);
		emit Withdraw(msg.sender, _pid, _amount);
	}

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

	// Safe sushi transfer function, just in case if rounding error causes pool to not have enough SUSHIs.
	function safeSushiTransfer(address _to, uint256 _amount) internal {
		uint256 sushiBal = sushi.balanceOf(address(this));
		if (_amount > sushiBal) {
			sushi.transfer(_to, sushiBal);
		} else {
			sushi.transfer(_to, _amount);
		}
	}

	// Update dev address by the previous dev.
	function dev(address _devaddr) public {
		require(msg.sender == devaddr, "dev: wut?");
		devaddr = _devaddr;
	}
}
// MasterChef is the master of Sushi. He can make Sushi and he is a fair guy.
//
// Note that it's ownable and the owner wields tremendous power. The ownership
// will be transferred to a governance smart contract once SUSHI is sufficiently
// distributed and the community can show to govern itself.
//
// Have fun reading it. Hopefully it's bug-free. God bless.
function updatePool(uint256 _pid) public {
		PoolInfo storage pool = poolInfo[_pid];
		if (block.number <= pool.lastRewardBlock) {
			return;
		}
		uint256 lpSupply = pool.lpToken.balanceOf(address(this));
		if (lpSupply == 0) {
			pool.lastRewardBlock = block.number;
			return;
		}
		uint256 multiplier = getMultiplier(pool.lastRewardBlock, block.number);
		uint256 sushiReward = multiplier.mul(sushiPerBlock).mul(pool.allocPoint).div(totalAllocPoint);
		sushi.mint(devaddr, sushiReward.div(10));
		sushi.mint(address(this), sushiReward);
		pool.accSushiPerShare = pool.accSushiPerShare.add(sushiReward.mul(1e12).div(lpSupply));
		pool.lastRewardBlock = block.number;
	}
// Update reward variables of the given pool to be up-to-date.