Cryo Explorer Ethereum Mainnet

pragma solidity 0.5.16;

interface IERC20 {
  /**
   * @dev Returns the amount of tokens in existence.
   */
  function totalSupply() external view returns (uint256);

  /**
   * @dev Returns the token decimals.
   */
  function decimals() external view returns (uint8);

  /**
   * @dev Returns the token symbol.
   */
  function symbol() external view returns (string memory);

  /**
  * @dev Returns the token name.
  */
  function name() external view returns (string memory);

  /**
   * @dev Returns the bep token owner.
   */
  function getOwner() external view returns (address);

  /**
   * @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 `recipient`.
   *
   * Returns a boolean value indicating whether the operation succeeded.
   *
   * Emits a {Transfer} event.
   */
  function transfer(address recipient, 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 `sender` to `recipient` 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 sender, address recipient, uint256 amount) external returns (bool);

  /**
   * @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 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 GSN 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.
 */
contract Context {
  // Empty internal constructor, to prevent people from mistakenly deploying
  // an instance of this contract, which should be used via inheritance.
  constructor () internal { }

  function _msgSender() internal view returns (address payable) {
    return msg.sender;
  }

  function _msgData() internal view returns (bytes memory) {
    this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
    return msg.data;
  }
}

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
  /**
   * @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) {
    uint256 c = a + b;
    require(c >= a, "SafeMath: addition overflow");

    return c;
  }

  /**
   * @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 sub(a, b, "SafeMath: subtraction overflow");
  }

  /**
   * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
   * overflow (when the result is negative).
   *
   * Counterpart to Solidity's `-` operator.
   *
   * Requirements:
   * - Subtraction cannot overflow.
   */
  function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
    require(b <= a, errorMessage);
    uint256 c = a - b;

    return c;
  }

  /**
   * @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) {
    // 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 0;
    }

    uint256 c = a * b;
    require(c / a == b, "SafeMath: multiplication overflow");

    return c;
  }

  /**
   * @dev Returns the integer division of two unsigned integers. Reverts 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) internal pure returns (uint256) {
    return div(a, b, "SafeMath: division by zero");
  }

  /**
   * @dev Returns the integer division of two unsigned integers. Reverts 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) {
    // 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;
  }

  /**
   * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
   * Reverts 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 mod(a, b, "SafeMath: modulo by zero");
  }

  /**
   * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
   * Reverts with custom message 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, string memory errorMessage) internal pure returns (uint256) {
    require(b != 0, errorMessage);
    return a % b;
  }
}

/**
 * @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.
 */
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 () internal {
    address msgSender = _msgSender();
    _owner = msgSender;
    emit OwnershipTransferred(address(0), msgSender);
  }

  /**
   * @dev Returns the address of the current owner.
   */
  function owner() public view returns (address) {
    return _owner;
  }

  /**
   * @dev Throws if called by any account other than the owner.
   */
  modifier onlyOwner() {
    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() external onlyOwner {
    emit OwnershipTransferred(_owner, address(0));
    _owner = 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) external onlyOwner {
    _transferOwnership(newOwner);
  }

  /**
   * @dev Transfers ownership of the contract to a new account (`newOwner`).
   */
  function _transferOwnership(address newOwner) internal {
    require(newOwner != address(0), "Ownable: new owner is the zero address");
    emit OwnershipTransferred(_owner, newOwner);
    _owner = newOwner;
  }
}

contract LGEWhitelisted is Context {
    
    using SafeMath for uint256;
    
    struct WhitelistRound {
        uint256 duration;
        uint256 amountMax;
        mapping(address => bool) addresses;
        mapping(address => uint256) purchased;
    }
  
    WhitelistRound[] public _lgeWhitelistRounds;
    
    uint256 public _lgeTimestamp;
    address public _lgePairAddress;
    
    address public _whitelister;
    
    event WhitelisterTransferred(address indexed previousWhitelister, address indexed newWhitelister);
    
    constructor () internal {
        _whitelister = _msgSender();
    }
    
    modifier onlyWhitelister() {
        require(_whitelister == _msgSender(), "Caller is not the whitelister");
        _;
    }
    
    function renounceWhitelister() external onlyWhitelister {
        emit WhitelisterTransferred(_whitelister, address(0));
        _whitelister = address(0);
    }
    
    function transferWhitelister(address newWhitelister) external onlyWhitelister {
        _transferWhitelister(newWhitelister);
    }
    
    function _transferWhitelister(address newWhitelister) internal {
        require(newWhitelister != address(0), "New whitelister is the zero address");
        emit WhitelisterTransferred(_whitelister, newWhitelister);
        _whitelister = newWhitelister;
    }
    
    /*
     * createLGEWhitelist - Call this after initial Token Generation Event (TGE) 
     * 
     * pairAddress - address generated from createPair() event on DEX
     * durations - array of durations (seconds) for each whitelist rounds
     * amountsMax - array of max amounts (TOKEN decimals) for each whitelist round
     * 
     */
  
    function createLGEWhitelist(address pairAddress, uint256[] calldata durations, uint256[] calldata amountsMax) external onlyWhitelister() {
        require(durations.length == amountsMax.length, "Invalid whitelist(s)");
        
        _lgePairAddress = pairAddress;
        
        if(durations.length > 0) {
            
            delete _lgeWhitelistRounds;
        
            for (uint256 i = 0; i < durations.length; i++) {
                _lgeWhitelistRounds.push(WhitelistRound(durations[i], amountsMax[i]));
            }
        
        }
    }
    
    /*
     * modifyLGEWhitelistAddresses - Define what addresses are included/excluded from a whitelist round
     * 
     * index - 0-based index of round to modify whitelist
     * duration - period in seconds from LGE event or previous whitelist round
     * amountMax - max amount (TOKEN decimals) for each whitelist round
     * 
     */
    
    function modifyLGEWhitelist(uint256 index, uint256 duration, uint256 amountMax, address[] calldata addresses, bool enabled) external onlyWhitelister() {
        require(index < _lgeWhitelistRounds.length, "Invalid index");
        require(amountMax > 0, "Invalid amountMax");

        if(duration != _lgeWhitelistRounds[index].duration)
            _lgeWhitelistRounds[index].duration = duration;
        
        if(amountMax != _lgeWhitelistRounds[index].amountMax)  
            _lgeWhitelistRounds[index].amountMax = amountMax;
        
        for (uint256 i = 0; i < addresses.length; i++) {
            _lgeWhitelistRounds[index].addresses[addresses[i]] = enabled;
        }
    }
    
    /*
     *  getLGEWhitelistRound
     *
     *  returns:
     *
     *  1. whitelist round number ( 0 = no active round now )
     *  2. duration, in seconds, current whitelist round is active for
     *  3. timestamp current whitelist round closes at
     *  4. maximum amount a whitelister can purchase in this round
     *  5. is caller whitelisted
     *  6. how much caller has purchased in current whitelist round
     *
     */
    
    function getLGEWhitelistRound() public view returns (uint256, uint256, uint256, uint256, bool, uint256) {
        
        if(_lgeTimestamp > 0) {
            
            uint256 wlCloseTimestampLast = _lgeTimestamp;
        
            for (uint256 i = 0; i < _lgeWhitelistRounds.length; i++) {
                
                WhitelistRound storage wlRound = _lgeWhitelistRounds[i];
                
                wlCloseTimestampLast = wlCloseTimestampLast.add(wlRound.duration);
                if(now <= wlCloseTimestampLast)
                    return (i.add(1), wlRound.duration, wlCloseTimestampLast, wlRound.amountMax, wlRound.addresses[_msgSender()], wlRound.purchased[_msgSender()]);
            }
        
        }
        
        return (0, 0, 0, 0, false, 0);
    }
    
    /*
     * _applyLGEWhitelist - internal function to be called initially before any transfers
     * 
     */
    
    function _applyLGEWhitelist(address sender, address recipient, uint256 amount) internal {
        
        if(_lgePairAddress == address(0) || _lgeWhitelistRounds.length == 0)
            return;
        
        if(_lgeTimestamp == 0 && sender != _lgePairAddress && recipient == _lgePairAddress && amount > 0)
            _lgeTimestamp = now;
        
        if(sender == _lgePairAddress && recipient != _lgePairAddress) {
            //buying
            
            (uint256 wlRoundNumber,,,,,) = getLGEWhitelistRound();
        
            if(wlRoundNumber > 0) {
                
                WhitelistRound storage wlRound = _lgeWhitelistRounds[wlRoundNumber.sub(1)];
                
                require(wlRound.addresses[recipient], "LGE - Buyer is not whitelisted");
                
                uint256 amountRemaining = 0;
                
                if(wlRound.purchased[recipient] < wlRound.amountMax)
                    amountRemaining = wlRound.amountMax.sub(wlRound.purchased[recipient]);
    
                require(amount <= amountRemaining, "LGE - Amount exceeds whitelist maximum");
                wlRound.purchased[recipient] = wlRound.purchased[recipient].add(amount);
                
            }
            
        }
        
    }
    
}

contract X22Token is Context, IERC20, Ownable, LGEWhitelisted {
    
    using SafeMath for uint256;
    
    mapping (address => uint256) private _balances;
    
    mapping (address => mapping (address => uint256)) private _allowances;
    
    uint256 private _totalSupply;
    uint8 private _decimals;
    string private _symbol;
    string private _name;
    
    constructor() public {
        _name = "X22";
        _symbol = "X22";
        _decimals = 18;
        _totalSupply = 20000022 * 10 ** 18;
        _balances[_msgSender()] = _totalSupply;
        
        emit Transfer(address(0), _msgSender(), _totalSupply);
    }

    /**
    * @dev Returns the bep token owner.
    */
    
    function getOwner() external view returns (address) {
        return owner();
    }
    
    /**
    * @dev Returns the token decimals.
    */
    function decimals() external view returns (uint8) {
        return _decimals;
    }
    
    /**
    * @dev Returns the token symbol.
    */
    function symbol() external view returns (string memory) {
        return _symbol;
    }
    
    /**
    * @dev Returns the token name.
    */
    function name() external view returns (string memory) {
        return _name;
    }
    
    /**
    * @dev See {ERC20-totalSupply}.
    */
    function totalSupply() external view returns (uint256) {
        return _totalSupply;
    }
    
    /**
    * @dev See {ERC20-balanceOf}.
    */
    function balanceOf(address account) external view returns (uint256) {
        return _balances[account];
    }
    
    /**
    * @dev See {ERC20-transfer}.
    *
    * Requirements:
    *
    * - `recipient` cannot be the zero address.
    * - the caller must have a balance of at least `amount`.
    */
    function transfer(address recipient, uint256 amount) external returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }
    
    /**
    * @dev See {ERC20-allowance}.
    */
    function allowance(address owner, address spender) external view returns (uint256) {
        return _allowances[owner][spender];
    }
    
    /**
    * @dev See {ERC20-approve}.
    *
    * Requirements:
    *
    * - `spender` cannot be the zero address.
    */
    function approve(address spender, uint256 amount) external returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }
    
    /**
    * @dev See {ERC20-transferFrom}.
    *
    * Emits an {Approval} event indicating the updated allowance. This is not
    * required by the EIP. See the note at the beginning of {ERC20};
    *
    * Requirements:
    * - `sender` and `recipient` cannot be the zero address.
    * - `sender` must have a balance of at least `amount`.
    * - the caller must have allowance for `sender`'s tokens of at least
    * `amount`.
    */
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool) {
        _transfer(sender, recipient, amount);
        _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
        return true;
    }
    
    /**
    * @dev Atomically increases the allowance granted to `spender` by the caller.
    *
    * This is an alternative to {approve} that can be used as a mitigation for
    * problems described in {ERC20-approve}.
    *
    * Emits an {Approval} event indicating the updated allowance.
    *
    * Requirements:
    *
    * - `spender` cannot be the zero address.
    */
    function increaseAllowance(address spender, uint256 addedValue) external returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
        return true;
    }
    
    /**
    * @dev Atomically decreases the allowance granted to `spender` by the caller.
    *
    * This is an alternative to {approve} that can be used as a mitigation for
    * problems described in {BEP20-approve}.
    *
    * Emits an {Approval} event indicating the updated allowance.
    *
    * Requirements:
    *
    * - `spender` cannot be the zero address.
    * - `spender` must have allowance for the caller of at least
    * `subtractedValue`.
    */
    function decreaseAllowance(address spender, uint256 subtractedValue) external returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
        return true;
    }
    
    /**
    * @dev Moves tokens `amount` from `sender` to `recipient`.
    *
    * This is internal function is equivalent to {transfer}, and can be used to
    * e.g. implement automatic token fees, slashing mechanisms, etc.
    *
    * Emits a {Transfer} event.
    *
    * Requirements:
    *
    * - `sender` cannot be the zero address.
    * - `recipient` cannot be the zero address.
    * - `sender` must have a balance of at least `amount`.
    */
    function _transfer(address sender, address recipient, uint256 amount) internal {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");
        
        _applyLGEWhitelist(sender, recipient, amount);
        
        _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(sender, recipient, amount);
    }
    
    /**
    * @dev Sets `amount` as the allowance of `spender` over the `owner`s tokens.
    *
    * This is internal function is equivalent to `approve`, and can be used to
    * e.g. set automatic allowances for certain subsystems, etc.
    *
    * Emits an {Approval} event.
    *
    * Requirements:
    *
    * - `owner` cannot be the zero address.
    * - `spender` cannot be the zero address.
    */
    function _approve(address owner, address spender, uint256 amount) internal {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");
        
        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }
    
}