// File: @openzeppelin/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (access/Ownable.sol)

pragma solidity ^0.8.0;

import "../utils/Context.sol";

/**
 * @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. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby disabling 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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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/Context.sol



// SPDX-License-Identifier: MIT
// 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: @uniswap/v2-core/contracts/interfaces/IUniswapV2Pair.sol



pragma solidity >=0.5.0;

interface IUniswapV2Pair {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    function MINIMUM_LIQUIDITY() external pure returns (uint);
    function factory() external view returns (address);
    function token0() external view returns (address);
    function token1() external view returns (address);
    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
    function price0CumulativeLast() external view returns (uint);
    function price1CumulativeLast() external view returns (uint);
    function kLast() external view returns (uint);

    function mint(address to) external returns (uint liquidity);
    function burn(address to) external returns (uint amount0, uint amount1);
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
    function skim(address to) external;
    function sync() external;

    function initialize(address, address) external;
}

// File: @uniswap/v2-periphery/contracts/interfaces/IUniswapV2Router01.sol



pragma solidity >=0.6.2;

interface IUniswapV2Router01 {
    function factory() external pure returns (address);
    function WETH() external pure returns (address);

    function addLiquidity(
        address tokenA,
        address tokenB,
        uint amountADesired,
        uint amountBDesired,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns (uint amountA, uint amountB, uint liquidity);
    function addLiquidityETH(
        address token,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external payable returns (uint amountToken, uint amountETH, uint liquidity);
    function removeLiquidity(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns (uint amountA, uint amountB);
    function removeLiquidityETH(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns (uint amountToken, uint amountETH);
    function removeLiquidityWithPermit(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountA, uint amountB);
    function removeLiquidityETHWithPermit(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountToken, uint amountETH);
    function swapExactTokensForTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
    function swapTokensForExactTokens(
        uint amountOut,
        uint amountInMax,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
    function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        payable
        returns (uint[] memory amounts);
    function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)
        external
        payable
        returns (uint[] memory amounts);

    function quote(uint amountA, uint reserveA, uint reserveB) external pure returns (uint amountB);
    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) external pure returns (uint amountOut);
    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) external pure returns (uint amountIn);
    function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts);
    function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts);
}

// File: @uniswap/v2-periphery/contracts/interfaces/IUniswapV2Router02.sol



pragma solidity >=0.6.2;

import './IUniswapV2Router01.sol';

interface IUniswapV2Router02 is IUniswapV2Router01 {
    function removeLiquidityETHSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns (uint amountETH);
    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountETH);

    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external payable;
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
}

// File: contracts/LottyStaking.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.21;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@uniswap/v2-core/contracts/interfaces/IUniswapV2Pair.sol";
import "@uniswap/v2-periphery/contracts/interfaces/IUniswapV2Router02.sol";

/**
 * @title LOTTY Staking Contract
 * @author @Xirynx
 */
contract LottyStaking is Ownable {
    //============================================//
    //                Definitions                 //
    //============================================//

    struct StakePosition {
        address owner;
        uint256 timestamp;
        uint256 liquidity;
        uint256 timeLocked;
    }

    //============================================//
    //                  Errors                    //
    //============================================//

    error BalanceTransferFailed();
    error CallerNotOrigin();
    error CallerDoesNotOwnPosition();
    error PositionLocked();

    //============================================//
    //                  Events                    //
    //============================================//

    event Stake(
        address indexed owner,
        uint256 indexed positionNonce,
        uint256 timestamp,
        uint256 timelock,
        uint256 liquidity
    );
    event Unstake(
        address indexed owner,
        uint256 indexed positionNonce,
        uint256 timestamp,
        uint256 liquidity
    );

    //============================================//
    //                 Constants                  //
    //============================================//

    IUniswapV2Pair uniswapV2Pair;
    IUniswapV2Router02 uniswapV2Router;
    IERC20 lotty;

    //============================================//
    //              State Variables               //
    //============================================//

    uint256 public totalLiquidity;
    uint256 public stakeNonce;
    mapping(uint256 => StakePosition) public positions;

    /**
     * @notice Make the deployment network agnostic by requiring to specify prerequisite addresses
     * @param _uniswapV2Pair: Uniswap pool pair address
     * @param _uniswapV2Router: UniswapV2Router address
     * @param _lotty: ERC20 Lotty token address
     */
    constructor(
        IUniswapV2Pair _uniswapV2Pair,
        IUniswapV2Router02 _uniswapV2Router,
        IERC20 _lotty
    ) {
        uniswapV2Pair = IUniswapV2Pair(_uniswapV2Pair);
        uniswapV2Router = IUniswapV2Router02(_uniswapV2Router);
        lotty = IERC20(_lotty);
    }

    //============================================//
    //                 Read Only                  //
    //============================================//
    /**
     * @notice Returns staking position indexed at `_nonce`
     * @param _nonce: Index of the staking position being queried.
     */
    function checkPosition(
        uint256 _nonce
    ) public view returns (StakePosition memory _position) {
        _position = positions[_nonce];
    }

    //============================================//
    //                Core Methods                //
    //============================================//

    /**
     * @notice Stakes Lotty and ETH and locks liquidity for duration of _timeLocked
     * @dev Caller must be not be contract
     * @dev Caller must have approved at least `_amountLottyDesired` tokens before staking
     * @param _amountLottyDesired: Ideal amount of Lotty tokens to stake
     * @param _amountLottyMin: Bounds the extent to which the ETH/Lotty price can go up before the transaction reverts. Must be <= _amountLottyDesired
     * @param _amountETHMin: Bounds the extent to which the Lotty/ETH price can go up before the transaction reverts. Must be <= `msg.value`
     * @param _deadline: Unix timestamp after which the transaction will revert
     * @param _timeLocked: Duration (seconds) for which the position will be unstakeable
     */
    function stake(
        uint256 _amountLottyDesired,
        uint256 _amountLottyMin,
        uint256 _amountETHMin,
        uint256 _deadline,
        uint256 _timeLocked
    ) public payable {
        if (msg.sender != tx.origin) revert CallerNotOrigin();

        lotty.transferFrom(msg.sender, address(this), _amountLottyDesired);
        lotty.approve(address(uniswapV2Router), _amountLottyDesired);
        stakeNonce += 1;

        (, , uint256 liquidity) = uniswapV2Router.addLiquidityETH{
            value: msg.value
        }(
            address(lotty),
            _amountLottyDesired,
            _amountLottyMin,
            _amountETHMin,
            address(this),
            _deadline
        );

        totalLiquidity += liquidity;
        positions[stakeNonce] = StakePosition(
            msg.sender,
            block.timestamp,
            liquidity,
            _timeLocked
        );

        uint256 balance = address(this).balance;
        if (balance > 0) {
            (bool callSuccess, ) = payable(msg.sender).call{value: balance}("");
            if (!callSuccess) revert BalanceTransferFailed();
        }

        uint256 lottyBalance = lotty.balanceOf(address(this));
        if (lottyBalance > 0) {
            lotty.transfer(msg.sender, lottyBalance);
        }

        emit Stake(
            msg.sender,
            stakeNonce,
            block.timestamp,
            _timeLocked,
            liquidity
        );
    }

    /**
     * @notice Burns the position's liquidity tokens and returns the equivalent Lotty and ETH back to the staker
     * @dev Caller must own the position
     * @dev `block.timestamp` must be greater than the position's unlock time
     * @param _positionNonce: Nonce by which to identify the position for unstaking
     * @param _amountLottyMin: The minimum amount of Lotty that must be received for the transaction not to revert
     * @param _amountETHMin: The minimum amount of ETH that must be received for the transaction not to revert.
     * @param _deadline: Unix timestamp after which the transaction will revert
     */
    function unstake(
        uint256 _positionNonce,
        uint256 _amountLottyMin,
        uint256 _amountETHMin,
        uint256 _deadline
    ) public {
        StakePosition memory position = positions[_positionNonce];
        if (position.owner != msg.sender) revert CallerDoesNotOwnPosition();
        if (block.timestamp - position.timestamp < position.timeLocked)
            revert PositionLocked();

        totalLiquidity -= position.liquidity;
        positions[_positionNonce].owner = address(0);

        uniswapV2Pair.approve(address(uniswapV2Router), position.liquidity);

        uniswapV2Router.removeLiquidityETH(
            address(lotty),
            position.liquidity,
            _amountLottyMin,
            _amountETHMin,
            msg.sender,
            _deadline
        );

        emit Unstake(
            msg.sender,
            _positionNonce,
            block.timestamp,
            position.liquidity
        );
    }

    receive() external payable {}
}