// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly { size := extcodesize(account) }
        return size > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (bool success, ) = recipient.call{ value: amount }("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain`call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
      return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    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");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    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");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{ value: value }(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.staticcall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

library SafeERC20 {
    using SafeMath for uint256;
    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));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
     
    function safeApprove(IERC20 token, address spender, uint256 value) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        // solhint-disable-next-line max-line-length
        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).add(value);
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) { // Return data is optional
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}
contract Context {

    function _msgSender() internal view virtual returns (address payable) {
        return payable(msg.sender);
    }
    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}


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);
}


library SafeMath {
    function add(uint256 a, uint256 b) internal pure returns (uint256) 
    
    {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        // Solidity only automatically asserts when dividing by 0
        require(b > 0, errorMessage);
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
    }
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}

contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    constructor ()  {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

    function owner() public view returns (address) {
        return _owner;
    }
    modifier onlyOwner() {
        require(_owner == _msgSender(), "Ownable: caller is not the owner");
        _;
    }
    function renounceOwnership() public virtual onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}





contract DOBKPresale is Ownable {
    using SafeMath for uint256;
    using SafeERC20 for IERC20;



    IERC20 public USDT;
    IERC20 public USDC;
    IERC20 public token;

    uint256 public TokenPricePerUsdt; 
    uint256 public USDTPricePerETH;  
    uint256 public TokenSold; 
    uint256 public maxTokeninPresale;

    mapping (address => bool) public isBlacklist;

    bool public presaleStatus;
    bool public CanClaim;

 
  

 
    mapping(address => uint256) public Claimable;
    event Recovered(address token, uint256 amount);
   

    constructor(IERC20 _USDT, IERC20 _USDC,IERC20 _token)  {
       TokenPricePerUsdt=2000000000000000000;  //1$=2token
       maxTokeninPresale=2333000000*(1E18);
       USDTPricePerETH=2200000000;  //1ETH= 2200$
       USDT=_USDT;
       USDC=_USDC;
       token=_token;
    }

     receive() external payable {
            // React to receiving ETH
        }


    

    function BuyWithETH() external payable 
    {
        require(TokenSold.add(getValuePerETH(msg.value))<=maxTokeninPresale,"Hardcap Reached!");
        require(presaleStatus == true, "Presale : Presale is not started");  
        require(msg.value > 0, "Presale : Unsuitable Amount"); 
        require(isBlacklist[msg.sender]==false,"Presale : you are blacklisted");
        require(tx.origin == msg.sender,"Presale : caller is a contract");
        Claimable[msg.sender]+=getValuePerETH(msg.value);
        TokenSold =TokenSold.add(getValuePerETH(msg.value)); 
    }

   


    function BuyWithUSDT(uint256 _amt) external {

        require(TokenSold.add(getValuePerUsdt(_amt))<=maxTokeninPresale,"Hardcap Reached!");
        require(presaleStatus == true, "Presale : Presale is not started");  
        require(_amt > 0, "Presale : Unsuitable Amount"); 
        require(isBlacklist[msg.sender]==false,"Presale : you are blacklisted");
        require(tx.origin == msg.sender,"Presale : caller is a contract");
        IERC20(USDT).safeTransferFrom(msg.sender,address(this),_amt);
        Claimable[msg.sender]+=getValuePerUsdt(_amt);
        TokenSold =TokenSold.add(getValuePerUsdt(_amt)); 
    }



    function BuyWithUSDC(uint256 _amt) external {

        require(TokenSold.add(getValuePerUsdt(_amt))<=maxTokeninPresale,"Hardcap Reached!");
        require(presaleStatus == true, "Presale : Presale is not started");  
        require(_amt > 0, "Presale : Unsuitable Amount"); 
        require(isBlacklist[msg.sender]==false,"Presale : you are blacklisted");
        require(tx.origin == msg.sender,"Presale : caller is a contract");
        IERC20(USDC).safeTransferFrom(msg.sender,address(this),_amt);
        Claimable[msg.sender]+=getValuePerUsdt(_amt);
        TokenSold =TokenSold.add(getValuePerUsdt(_amt)); 
    }

    function claim() external {
        require(CanClaim==true,"Claim is not open yet");
        require(isBlacklist[msg.sender]==false,"Presale : you are blacklisted");
        require(tx.origin == msg.sender,"Presale : caller is a contract");
        uint256 claimable=Claimable[msg.sender];
        require(claimable>0,"no claimable found");
        token.transfer(msg.sender, claimable);
        Claimable[msg.sender]=0;
    }


   

    function getValuePerETH(uint256 _ethvalue) public view returns(uint256){
        uint256 usdtamount=(USDTPricePerETH.mul(_ethvalue)).div(1e18);
       return   (TokenPricePerUsdt.mul(usdtamount)).div(1e6);
    }


    function getValuePerUsdt(uint256 _amt) public view returns(uint256){
    
       return   (TokenPricePerUsdt.mul(_amt)).div(1e6);
    }

   

    function setRewardPricePerUsdt(uint256 _count) external onlyOwner {
        TokenPricePerUsdt = _count;
    }
    
    function SetUSDTpricePerETH(uint256 _count) external onlyOwner{
        USDTPricePerETH=_count;
    }

    function stopPresale() external onlyOwner {
        presaleStatus = false;
    }

    function StartClaim() external onlyOwner{
        CanClaim=true;
    }

       function StopClaim() external onlyOwner{
        CanClaim=false;
    }

    function resumePresale() external onlyOwner {
        presaleStatus = true;
    }

    function setmaxTokeninPresale(uint256 _value) external onlyOwner{
        maxTokeninPresale=_value;
    }

    


    function contractbalance() public view returns(uint256)
    {
      return address(this).balance;
    }



    function recoverERC20(address tokenAddress, uint256 tokenAmount) external onlyOwner {
        IERC20(tokenAddress).transfer(this.owner(), tokenAmount);
        emit Recovered(tokenAddress, tokenAmount);
    }

     function EmergencyUSDT( address _usdt ,uint256 tokenAmount) external onlyOwner {
        IERC20(_usdt).safeTransfer(this.owner(),tokenAmount);

        emit Recovered(address(_usdt), tokenAmount);
    }


    function settoken(IERC20 _token) external onlyOwner{
        token=_token;
    }

    function setUSDT(IERC20 _usdt) external onlyOwner{
        USDT=_usdt;
    }

    function setUSDC(IERC20 _usdc) external onlyOwner{
        USDC=_usdc;
    }



    function setBlacklist(address _addr,bool _state) external onlyOwner{
        isBlacklist[_addr]=_state;
    }


       function releaseFunds() external onlyOwner 
    {
        payable(msg.sender).transfer(address(this).balance);
    }


}


// Testnet

// DOBK: 0xFeB00c5fbb12081fb755Aa747F485DC2a76c99aD

//USDT:  0x42c3C3d4102eC19BaBa2B4d3011019E0C5ABfEFa

//USDC: 0x6faeE24f6Cf32a7afc43B2ee4EA963AcadBC2B3d




// Mainnnet

// USDT: 0xdAC17F958D2ee523a2206206994597C13D831ec7

// USDC:  0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48

// Token: 0x2662D294abf0A6DD82F882E626376123AC4DE0be