pragma solidity ^0.4.24;

contract ERC20 {
  function totalSupply() public view returns (uint256);

  function balanceOf(address _who) public view returns (uint256);

  function allowance(address _owner, address _spender)
    public view returns (uint256);

  function transfer(address _to, uint256 _value) public returns (bool);

  function approve(address _spender, uint256 _value)
    public returns (bool);

  function transferFrom(address _from, address _to, uint256 _value)
    public 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 mul(uint256 a, uint256 b) internal pure returns (uint256) {
    if (a == 0) {
      return 0;
    }
    uint256 c = a * b;
    require(c / a == b);
    return c;
  }

  function div(uint256 a, uint256 b) internal pure returns (uint256) {
    uint256 c = a / b;
    return c;
  }

  function sub(uint256 a, uint256 b) internal pure returns (uint256) {
    require(b <= a);
    return a - b;
  }

  function add(uint256 a, uint256 b) internal pure returns (uint256) {
    uint256 c = a + b;
    require(c >= a);
    return c;
  }
}

 contract StandardToken is ERC20 {
  using SafeMath for uint256;

  mapping(address => uint256) balances;

  mapping (address => mapping (address => uint256)) internal allowed;

  uint256 totalSupply_;

  function totalSupply() public view returns (uint256) {
    return totalSupply_;
  }

  function balanceOf(address _owner) public view returns (uint256) {
    return balances[_owner];
  }

  function allowance(
    address _owner,
    address _spender
   )
    public
    view
    returns (uint256)
  {
    return allowed[_owner][_spender];
  }

  function transfer(address _to, uint256 _value) public returns (bool) {
    require(_value <= balances[msg.sender]);
    require(_to != address(0));

    balances[msg.sender] = balances[msg.sender].sub(_value);
    balances[_to] = balances[_to].add(_value);
    emit Transfer(msg.sender, _to, _value);
    return true;
  }

  function approve(address _spender, uint256 _value) public returns (bool) {
    allowed[msg.sender][_spender] = _value;
    emit Approval(msg.sender, _spender, _value);
    return true;
  }

  function transferFrom(
    address _from,
    address _to,
    uint256 _value
  )
    public
    returns (bool)
  {
    require(_value <= balances[_from]);
    require(_value <= allowed[_from][msg.sender]);
    require(_to != address(0));

    balances[_from] = balances[_from].sub(_value);
    balances[_to] = balances[_to].add(_value);
    allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
    emit Transfer(_from, _to, _value);
    return true;
  }

}
  
 
// ERC20 standard token
contract token is StandardToken {
    address public owner; 
    string public name = "Black Hole Coin"; 
    string public symbol = "BLOC"; 
    uint8 public decimals =18; 
    uint256 public totalSupply = 1000000000000000000000000000; 
    
    mapping (address => bool) public frozenAccount; 
    mapping (address => uint256) public frozenTimestamp; 

    bool public exchangeFlag = true; 
   
    uint256 public minWei = 1;  
    uint256 public maxWei = 2000000000000000000; 
    uint256 public maxRaiseAmount =20000000000000000000; 
    uint256 public raisedAmount = 0; 
    uint256 public raiseRatio = 20000000; 
     
    event Approval(address indexed owner, address indexed spender, uint256 value);
    event Transfer(address indexed from, address indexed to, uint256 value);

   
    constructor() public {
        totalSupply_ = totalSupply;
        owner = msg.sender;
        balances[msg.sender] = totalSupply;
    }


    function()
    public payable {
        require(msg.value > 0);
        if (exchangeFlag) {
            if (msg.value >= minWei && msg.value <= maxWei){
                if (raisedAmount < maxRaiseAmount) {
                    uint256 valueNeed = msg.value;
                    raisedAmount = raisedAmount.add(msg.value);
                    if (raisedAmount > maxRaiseAmount) {
                        uint256 valueLeft = raisedAmount.sub(maxRaiseAmount);
                        valueNeed = msg.value.sub(valueLeft);
                        msg.sender.transfer(valueLeft);
                        raisedAmount = maxRaiseAmount;
                    }
                    if (raisedAmount >= maxRaiseAmount) {
                        exchangeFlag = false;
                    }
                    
                    uint256 _value = valueNeed.mul(raiseRatio);

                    require(_value <= balances[owner]);
                    balances[owner] = balances[owner].sub(_value);
                    balances[msg.sender] = balances[msg.sender].add(_value);

                    emit Transfer(owner, msg.sender, _value);

                }
            } else {
                msg.sender.transfer(msg.value);
            }
        } else {
            msg.sender.transfer(msg.value);
        }
    }

    
    
    function changeowner(
        address _newowner
    )
    public
    returns (bool)  {
        require(msg.sender == owner);
        require(_newowner != address(0));
        owner = _newowner;
        return true;
    }
    
    
    function generateToken(
        address _target,
        uint256 _amount
    )
    public
    returns (bool)  {
        require(msg.sender == owner);
        require(_target != address(0));
        balances[_target] = balances[_target].add(_amount);
        totalSupply_ = totalSupply_.add(_amount);
        totalSupply = totalSupply_;
        return true;
    }

    
    function withdraw (
        uint256 _amount
    )
    public
    returns (bool) {
        require(msg.sender == owner);
        msg.sender.transfer(_amount);
        return true;
    }
    
    
    function freeze(
        address _target,
        bool _freeze
    )
    public
    returns (bool) {
        require(msg.sender == owner);
        require(_target != address(0));
        frozenAccount[_target] = _freeze;
        return true;
    }
    
    
    function freezeWithTimestamp(
        address _target,
        uint256 _timestamp
    )
    public
    returns (bool) {
        require(msg.sender == owner);
        require(_target != address(0));
        frozenTimestamp[_target] = _timestamp;
        return true;
    }

   
    function multiFreeze(
        address[] _targets,
        bool[] _freezes
    )
    public
    returns (bool) {
        require(msg.sender == owner);
        require(_targets.length == _freezes.length);
        uint256 len = _targets.length;
        require(len > 0);
        for (uint256 i = 0; i < len; i = i.add(1)) {
            address _target = _targets[i];
            require(_target != address(0));
            bool _freeze = _freezes[i];
            frozenAccount[_target] = _freeze;
        }
        return true;
    }
    
    
    function multiFreezeWithTimestamp(
        address[] _targets,
        uint256[] _timestamps
    )
    public
    returns (bool) {
        require(msg.sender == owner);
        require(_targets.length == _timestamps.length);
        uint256 len = _targets.length;
        require(len > 0);
        for (uint256 i = 0; i < len; i = i.add(1)) {
            address _target = _targets[i];
            require(_target != address(0));
            uint256 _timestamp = _timestamps[i];
            frozenTimestamp[_target] = _timestamp;
        }
        return true;
    }
    
    function multiTransfer(
        address[] _tos,
        uint256[] _values
    )
    public
    returns (bool) {
        require(!frozenAccount[msg.sender]);
        require(now > frozenTimestamp[msg.sender]);
        require(_tos.length == _values.length);
        uint256 len = _tos.length;
        require(len > 0);
        uint256 amount = 0;
        for (uint256 i = 0; i < len; i = i.add(1)) {
            amount = amount.add(_values[i]);
        }
        require(amount <= balances[msg.sender]);
        for (uint256 j = 0; j < len; j = j.add(1)) {
            address _to = _tos[j];
            require(_to != address(0));
            balances[_to] = balances[_to].add(_values[j]);
            balances[msg.sender] = balances[msg.sender].sub(_values[j]);
            emit Transfer(msg.sender, _to, _values[j]);
        }
        return true;
    }
     
    function transfer(
        address _to,
        uint256 _value
    )
    public
    returns (bool) {
        require(!frozenAccount[msg.sender]);
        require(now > frozenTimestamp[msg.sender]);
        require(_to != address(0));
        require(_value <= balances[msg.sender]);

        balances[msg.sender] = balances[msg.sender].sub(_value);
        balances[_to] = balances[_to].add(_value);

        emit Transfer(msg.sender, _to, _value);
        return true;
    }
     
    function transferFrom(
        address _from,
        address _to,
        uint256 _value
    )
    public
    returns (bool)
    {
        require(!frozenAccount[_from]);
        require(now > frozenTimestamp[msg.sender]);
        require(_to != address(0));
        require(_value <= balances[_from]);
        require(_value <= allowed[_from][msg.sender]);

        balances[_from] = balances[_from].sub(_value);
        balances[_to] = balances[_to].add(_value);
        allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);

        emit Transfer(_from, _to, _value);
        return true;
    }
  
  
    function approve(
        address _spender,
        uint256 _value
    ) public
    returns (bool) {
        
        
        allowed[msg.sender][_spender] = _value;

        emit Approval(msg.sender, _spender, _value);
        return true;
    }
    
    
    
    function getFrozenTimestamp(
        address _target
    )
    public view
    returns (uint256) {
        require(_target != address(0));
        return frozenTimestamp[_target];
    }
   
    function getFrozenAccount(
        address _target
    )
    public view
    returns (bool) {
        require(_target != address(0));
        return frozenAccount[_target];
    }
   
   
    function getBalance()
    public view
    returns (uint256) {
        return address(this).balance;
    }
   
   
    function setName (
        string _value
    )
    public
    returns (bool) {
        require(msg.sender == owner);
        name = _value;
        return true;
    }
   
   
    function setSymbol (
        string _value
    )
    public
    returns (bool) {
        require(msg.sender == owner);
        symbol = _value;
        return true;
    }

 
    function setExchangeFlag (
        bool _flag
    )
    public
    returns (bool) {
        require(msg.sender == owner);
        exchangeFlag = _flag;
        return true;

    }
   
   
    function setMinWei (
        uint256 _value
    )
    public
    returns (bool) {
        require(msg.sender == owner);
        minWei = _value;
        return true;

    }
   
   
    function setMaxWei (
        uint256 _value
    )
    public
    returns (bool) {
        require(msg.sender == owner);
        maxWei = _value;
        return true;
    }
   
   
    function setMaxRaiseAmount (
        uint256 _value
    )
    public
    returns (bool) {
        require(msg.sender == owner);
        maxRaiseAmount = _value;
        return true;
    }

    
    function setRaisedAmount (
        uint256 _value
    )
    public
    returns (bool) {
        require(msg.sender == owner);
        raisedAmount = _value;
        return true;
    }

    
    function setRaiseRatio (
        uint256 _value
    )
    public
    returns (bool) {
        require(msg.sender == owner);
        raiseRatio = _value;
        return true;
    }

    
    function kill()
    public {
        require(msg.sender == owner);
        selfdestruct(owner);
    }

}