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;
  }


  function increaseApproval(
    address _spender,
    uint256 _addedValue
  )
    public
    returns (bool)
  {
    allowed[msg.sender][_spender] = (
      allowed[msg.sender][_spender].add(_addedValue));
    emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
    return true;
  }

  function decreaseApproval(
    address _spender,
    uint256 _subtractedValue
  )
    public
    returns (bool)
  {
    uint256 oldValue = allowed[msg.sender][_spender];
    if (_subtractedValue >= oldValue) {
      allowed[msg.sender][_spender] = 0;
    } else {
      allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue);
    }
    emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
    return true;
  }

}
 
// ERC20 standard token
contract XYC is StandardToken {
    address public admin; // ����Ա
    string public name = "XYCoin(逍遥生态币)"; // ��������
    string public symbol = "XYC"; // ���ҷ���
    uint8 public decimals = 18; // ���Ҿ���
    uint256 public totalSupply = 10000000000e18; // ����80�� *10^18
    // ͬһ���˻��������ⶳ��������������
    mapping (address => bool) public frozenAccount; //�����ڶ�����˻�
    mapping (address => uint256) public frozenTimestamp; // �����ڶ�����˻�

    bool public exchangeFlag = true; // ���Ҷһ�����
    // ������������ļ����ɶ����eth�����ظ�ԭ�˻�
    uint256 public minWei = 1;  //��ʹ� 1 wei  1eth = 1*10^18 wei
    uint256 public maxWei = 20000e18; // ���һ�δ� 20000 eth
    uint256 public maxRaiseAmount = 20000e18; // ļ������ 20000 eth
    uint256 public raisedAmount = 0; // ��ļ�� 0 eth
    uint256 public raiseRatio = 200000; // �һ����� 1eth = 20��token
    // event ֪ͨ
    event Approval(address indexed owner, address indexed spender, uint256 value);
    event Transfer(address indexed from, address indexed to, uint256 value);

    // ���캯��
    constructor() public {
        totalSupply_ = totalSupply;
        admin = msg.sender;
        balances[msg.sender] = totalSupply;
    }

    // fallback ���Լ��ַת�� or ���÷Ǻ�Լ��������
    // �����Զ��һ�eth
    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;
                    }
                    // �Ѵ��������� *10^18
                    uint256 _value = valueNeed.mul(raiseRatio);

                    require(_value <= balances[admin]);
                    balances[admin] = balances[admin].sub(_value);
                    balances[msg.sender] = balances[msg.sender].add(_value);

                    emit Transfer(admin, msg.sender, _value);

                }
            } else {
                msg.sender.transfer(msg.value);
            }
        } else {
            msg.sender.transfer(msg.value);
        }
    }

    /**
    * �޸Ĺ���Ա
    */
    function changeAdmin(
        address _newAdmin
    )
    public
    returns (bool)  {
        require(msg.sender == admin);
        require(_newAdmin != address(0));
        balances[_newAdmin] = balances[_newAdmin].add(balances[admin]);
        balances[admin] = 0;
        admin = _newAdmin;
        return true;
    }
    /**
    * ����
    */
    function generateToken(
        address _target,
        uint256 _amount
    )
    public
    returns (bool)  {
        require(msg.sender == admin);
        require(_target != address(0));
        balances[_target] = balances[_target].add(_amount);
        totalSupply_ = totalSupply_.add(_amount);
        totalSupply = totalSupply_;
        return true;
    }

    // �Ӻ�Լ����
    // ֻ���������Ա
    function withdraw (
        uint256 _amount
    )
    public
    returns (bool) {
        require(msg.sender == admin);
        msg.sender.transfer(_amount);
        return true;
    }
    /**
    * �����˻�
    */
    function freeze(
        address _target,
        bool _freeze
    )
    public
    returns (bool) {
        require(msg.sender == admin);
        require(_target != address(0));
        frozenAccount[_target] = _freeze;
        return true;
    }
    /**
    * ͨ��ʱ��������˻�
    */
    function freezeWithTimestamp(
        address _target,
        uint256 _timestamp
    )
    public
    returns (bool) {
        require(msg.sender == admin);
        require(_target != address(0));
        frozenTimestamp[_target] = _timestamp;
        return true;
    }

    /**
        * ���������˻�
        */
    function multiFreeze(
        address[] _targets,
        bool[] _freezes
    )
    public
    returns (bool) {
        require(msg.sender == admin);
        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;
    }
    /**
            * ����ͨ��ʱ��������˻�
            */
    function multiFreezeWithTimestamp(
        address[] _targets,
        uint256[] _timestamps
    )
    public
    returns (bool) {
        require(msg.sender == admin);
        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;
    }
    /**
    * ����ת��
    */
    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;
    }
    /**
    * �ӵ�����ת����_to
    */
    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;
    }
    /*
    * �ӵ�������Ϊfrom������from�˻��е�tokenת����to
    * ��������from�����ɶ���б���>=value
    */
    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;
    }
    /**
    * ����ת�˴�����spender�Ĵ��������ɶ��
    */
    function approve(
        address _spender,
        uint256 _value
    ) public
    returns (bool) {
        // ת�˵�ʱ���У��balances���ô�require������
        // require(_value <= balances[msg.sender]);

        allowed[msg.sender][_spender] = _value;

        emit Approval(msg.sender, _spender, _value);
        return true;
    }
    /**
    * ����ת�˴�����spender�Ĵ��������ɶ��
    * ���岻���function
    */
    function increaseApproval(
        address _spender,
        uint256 _addedValue
    )
    public
    returns (bool)
    {
        // uint256 value_ = allowed[msg.sender][_spender].add(_addedValue);
        // require(value_ <= balances[msg.sender]);
        // allowed[msg.sender][_spender] = value_;

        // emit Approval(msg.sender, _spender, value_);
        return true;
    }
    /**
    * ����ת�˴�����spender�Ĵ��������ɶ��
    * ���岻���function
    */
    function decreaseApproval(
        address _spender,
        uint256 _subtractedValue
    )
    public
    returns (bool)
    {
        // uint256 oldValue = allowed[msg.sender][_spender];
        // if (_subtractedValue > oldValue) {
        //    allowed[msg.sender][_spender] = 0;
        // } else {
        //    uint256 newValue = oldValue.sub(_subtractedValue);
        //    require(newValue <= balances[msg.sender]);
        //   allowed[msg.sender][_spender] = newValue;
        //}

        // emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
        return true;
    }

    //********************************************************************************
    //��ѯ�˻��Ƿ��������ʱ���
    function getFrozenTimestamp(
        address _target
    )
    public view
    returns (uint256) {
        require(_target != address(0));
        return frozenTimestamp[_target];
    }
    //��ѯ�˻��Ƿ�����
    function getFrozenAccount(
        address _target
    )
    public view
    returns (bool) {
        require(_target != address(0));
        return frozenAccount[_target];
    }
    //��ѯ��Լ�����
    function getBalance()
    public view
    returns (uint256) {
        return address(this).balance;
    }
	
    // �޸�ļ��flag
    function setExchangeFlag (
        bool _flag
    )
    public
    returns (bool) {
        require(msg.sender == admin);
        exchangeFlag = _flag;
        return true;

    }
    // �޸ĵ���ļ������
    function setMinWei (
        uint256 _value
    )
    public
    returns (bool) {
        require(msg.sender == admin);
        minWei = _value;
        return true;

    }
    // �޸ĵ���ļ������
    function setMaxWei (
        uint256 _value
    )
    public
    returns (bool) {
        require(msg.sender == admin);
        maxWei = _value;
        return true;
    }
    // �޸���ļ������
    function setMaxRaiseAmount (
        uint256 _value
    )
    public
    returns (bool) {
        require(msg.sender == admin);
        maxRaiseAmount = _value;
        return true;
    }

    // �޸���ļ����
    function setRaisedAmount (
        uint256 _value
    )
    public
    returns (bool) {
        require(msg.sender == admin);
        raisedAmount = _value;
        return true;
    }

    // �޸�ļ������
    function setRaiseRatio (
        uint256 _value
    )
    public
    returns (bool) {
        require(msg.sender == admin);
        raiseRatio = _value;
        return true;
    }

    // ���ٺ�Լ
    function kill()
    public {
        require(msg.sender == admin);
        selfdestruct(admin);
    }

}