// File: @openzeppelin/contracts/utils/Context.sol


// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

// File: @openzeppelin/contracts/access/Ownable.sol


// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)

pragma solidity ^0.8.0;


/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol


// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);

    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `from` to `to` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) external returns (bool);
}

// File: @openzeppelin/contracts/utils/math/SafeMath.sol


// OpenZeppelin Contracts (last updated v4.6.0) (utils/math/SafeMath.sol)

pragma solidity ^0.8.0;

// CAUTION
// This version of SafeMath should only be used with Solidity 0.8 or later,
// because it relies on the compiler's built in overflow checks.

/**
 * @dev Wrappers over Solidity's arithmetic operations.
 *
 * NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler
 * now has built in overflow checking.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            uint256 c = a + b;
            if (c < a) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b > a) return (false, 0);
            return (true, a - b);
        }
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
            // benefit is lost if 'b' is also tested.
            // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
            if (a == 0) return (true, 0);
            uint256 c = a * b;
            if (c / a != b) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a / b);
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a % b);
        }
    }

    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        return a + b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return a - b;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        return a * b;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator.
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return a % b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b <= a, errorMessage);
            return a - b;
        }
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a / b;
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a % b;
        }
    }
}

// File: FALIStaking.sol


pragma solidity >=0.8.4;



contract FALIStake is Ownable {
    
    using SafeMath for uint256;
    // 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 CAKEs
        // entitled to a user but is pending to be distributed is:
        //
        //   pending reward = (user.amount * accPhxPerShare) - user.rewardDebt
        //
        // Whenever a user deposits or withdraws LP tokens to a pool. Here's what happens:
        //   1. The pool's `accPhxPerShare` (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. CAKEs to distribute per block.
    //     uint256 lastRewardBlock;  // Last block number that CAKEs distribution occurs.
    //     uint256 accPhxPerShare; // Accumulated CAKEs per share, times 1e12. See below.
    // }
    // The PHX TOKEN!

    IERC20 public phx;
    //The lpToken TOKEN!
    IERC20 public lpToken;
    // PHX tokens created per block.
    uint256 public phxPerBlock;
    // Bonus muliplier for early cake makers.
    uint256 public BONUS_MULTIPLIER = 1;
    // Info of each user that stakes LP tokens.
    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 PHX mining starts.
    uint256 public startBlock;
    // How many allocation points assigned to pool.
    uint256 public allocPoint;
    // Accumulated PHX per share, times 1e12.
    uint256 public accPhxPerShare;
    //Last block number that CAKEs distribution occurs.
    uint256 public lastRewardBlock; 

    event Deposit(
        address indexed user, 
        uint256 amount
        );

    event Withdraw(
        address indexed user, 
        uint256 amount
        );

    event EmergencyWithdraw(
        address indexed user, 
        uint256 amount
        );

    constructor(
        IERC20 _phx,
        IERC20 _lpToken,
        uint256 _phxPerBlock
  
    ) public {
        phx = _phx;
        lpToken = _lpToken;
        phxPerBlock = _phxPerBlock;
        startBlock = block.number;
        allocPoint = 1000;
        lastRewardBlock = startBlock;
        accPhxPerShare= 0;
        totalAllocPoint = 1000;
    }

    function updateMultiplier(uint256 multiplierNumber) public onlyOwner {
        BONUS_MULTIPLIER = multiplierNumber;
    }
    function setPhxPerBlock(uint256 _phxPerBlock) external onlyOwner{
        phxPerBlock = _phxPerBlock;
    }

    // Update the pool's allocation point. Can only be called by the owner.
    function set(uint256 _allocPoint) public onlyOwner {
        uint256 prevAllocPoint = allocPoint;
        allocPoint = _allocPoint;
        if (prevAllocPoint != _allocPoint) {
            totalAllocPoint = totalAllocPoint.sub(prevAllocPoint).add(_allocPoint);
            updatePool();
        }
    }

    // Return reward multiplier over the given _from to _to block.
    function getMultiplier(uint256 _from, uint256 _to) public view returns (uint256) {
        return _to.sub(_from).mul(BONUS_MULTIPLIER);
    }

    // View function to see pending pheonix on frontend.
    function pendingPHX(address _user) 
        external 
        view 
        returns (uint256) 
        {
        UserInfo storage user = userInfo[_user];
        uint256 lpSupply = lpToken.balanceOf(address(this));
        uint256 accPhx = accPhxPerShare;
        if (block.number > lastRewardBlock && lpSupply != 0) {
            uint256 multiplier = getMultiplier(lastRewardBlock, block.number);
            
            uint256 phxReward = multiplier.mul(phxPerBlock).mul(allocPoint).div(totalAllocPoint);
            accPhx = accPhx.add(phxReward.mul(1e12).div(lpSupply));
        }
        return (user.amount.mul(accPhx).div(1e12).sub(user.rewardDebt));
    }

    // Update reward variables of the given pool to be up-to-date.
    function updatePool() public {
        if (block.number <= lastRewardBlock) {
            return;
        }
        uint256 lpSupply = lpToken.balanceOf(address(this));
        if (lpSupply == 0) {
            lastRewardBlock = block.number;
            return;
        }
        uint256 multiplier = getMultiplier(lastRewardBlock, block.number);
        uint256 phxReward = multiplier.mul(phxPerBlock).mul(allocPoint).div(totalAllocPoint);
        accPhxPerShare = accPhxPerShare.add(phxReward.mul(1e12).div(lpSupply));
        lastRewardBlock = block.number;
    }

    // Deposit LP tokens to MasterChef for CAKE allocation.
    function deposit( uint256 _amount) public {
        UserInfo storage user = userInfo[msg.sender];
        updatePool();
        if (user.amount > 0) {
            uint256 pending = user.amount.mul(accPhxPerShare).div(1e12).sub(user.rewardDebt);
            if(pending > 0) {
                phx.transfer(msg.sender, pending);
            }
        }
        if (_amount > 0) {
            lpToken.transferFrom(address(msg.sender), address(this), _amount);
            user.amount = user.amount.add(_amount);
        }
        user.rewardDebt = user.amount.mul(accPhxPerShare).div(1e12);
        emit Deposit(msg.sender, _amount);
    }
    function lpTokenSupply() public view returns(uint256){
        return lpToken.balanceOf(address(this));
    }
    // function acc() public view returns(uint256){
    //     return accPhxPerShare;
    // }
    // function userInf() public view returns(uint256,uint256){
    //     return (userInfo[msg.sender].amount,userInfo[msg.sender].rewardDebt);
    // }
    // function utils() public view returns(uint256){
    //     return (block.number);
    // }
    // function getPhx() public view returns(uint256){
    //     uint256 multiplier = getMultiplier(lastRewardBlock, block.number);
    //     uint256 phxReward = multiplier.mul(phxPerBlock).mul(allocPoint).div(totalAllocPoint);
    //     return phxReward;
    // }
    // Withdraw LP tokens from MasterChef.
    function withdraw(uint256 _amount) public {

        UserInfo storage user = userInfo[msg.sender];
        require(user.amount >= _amount, "withdraw: not good");

        updatePool();
        uint256 pending = user.amount.mul(accPhxPerShare).div(1e12).sub(user.rewardDebt);
        if(pending > 0) {
           phx.transfer(msg.sender, pending);
        }
        if(_amount > 0) {
            user.amount = user.amount.sub(_amount);
            lpToken.transfer(address(msg.sender), _amount);
        }
        user.rewardDebt = user.amount.mul(accPhxPerShare).div(1e12);
        emit Withdraw(msg.sender, _amount);
    }
     // Withdraw without caring about rewards. EMERGENCY ONLY.
    function emergencyWithdraw() public {
        // hi
        UserInfo storage user = userInfo[msg.sender];
        lpToken.transfer(address(msg.sender), user.amount);
        emit EmergencyWithdraw(msg.sender, user.amount);
        user.amount = 0;
        user.rewardDebt = 0;
    }
}