pragma solidity ^0.4.20;

library SafeMath {
  function mul(uint256 a, uint256 b) internal pure returns (uint256) {
    uint256 c = a * b;
    assert(a == 0 || 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) {
    assert(b <= a);
    return a - b;
  }

  function add(uint256 a, uint256 b) internal pure returns (uint256) {
    uint256 c = a + b;
    assert(c >= a);
    return c;
  }
}

contract ERC20Basic {
    uint256 public totalSupply;
    function balanceOf(address who) public constant returns (uint256);
    function transfer(address to, uint256 value) public returns (bool);
    event Transfer(address indexed from, address indexed to, uint256 value);
}

contract ERC20 is ERC20Basic {
    function allowance(address owner, address spender) public constant returns (uint256);
    function transferFrom(address from, address to, uint256 value) public returns (bool);
    function approve(address spender, uint256 value) public returns (bool);
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

contract UBlockChain is ERC20 {
    
    using SafeMath for uint256; 
    address owner1 = msg.sender; 
    address owner2; 

    mapping (address => uint256) balances; 
    mapping (address => mapping (address => uint256)) allowed;
    mapping (address => bool) public frozenAccount;
    mapping (address => bool) public blacklist;

    string public constant name = "UBlockChain";
    string public constant symbol = "UBCoin";
    uint public constant decimals = 18;
    
    uint256 public totalSupply = 32000000000e18;

    uint256 public totalDistributed = 0;
    uint256 public totalRemaining = totalSupply.sub(totalDistributed);
    uint256 public value;
    bool public distributionClosed = true;

    event Transfer(address indexed _from, address indexed _to, uint256 _value);
    event Approval(address indexed _owner, address indexed _spender, uint256 _value);
    event FrozenFunds(address target, bool frozen);
    event Distr(address indexed to, uint256 amount);
    event DistrClosed(bool Closed);

    modifier onlyOwner() {
        require(msg.sender == owner1 || msg.sender == owner2);
        _;
    }

    modifier onlyPayloadSize(uint size) {
        assert(msg.data.length >= size + 4);
        _;
    }

     function UBlockChain (address _owner) public {
        owner1 = msg.sender;
        owner2 = _owner;
        value = 200e18;
    }

    function transferOwnership(address newOwner) onlyOwner public {
        if (newOwner != address(0) && newOwner != owner1 && newOwner != owner2) {
            if(msg.sender == owner1){
             owner1 = newOwner;   
            }
            if(msg.sender == owner2){
             owner2 = newOwner;   
            }
        }
    }

    function closeDistribution(bool Closed) onlyOwner public returns (bool) {
        distributionClosed = Closed;
        DistrClosed(Closed);
        return true;
    }

    function distr(address _to, uint256 _amount) private returns (bool) {
        totalDistributed = totalDistributed.add(_amount);
        totalRemaining = totalRemaining.sub(_amount);
        balances[_to] = balances[_to].add(_amount);

        if (_amount > 0) {
            blacklist[_to] = true;
        }
        if (totalDistributed >= totalSupply) {
            distributionClosed = true;
        }        
        Distr(_to, _amount);
        Transfer(address(0), _to, _amount);
        return true;
        

    }

    function airdrop(address[] addresses) onlyOwner public {
        
        require(addresses.length <= 255);
        require(value <= totalRemaining);
        
        for (uint i = 0; i < addresses.length; i++) {
            require(value <= totalRemaining);
            distr(addresses[i], value);
        }
    }
 
    function distribute(address[] addresses, uint256[] amounts) onlyOwner public {

        require(addresses.length <= 255);
        require(addresses.length == amounts.length);
        
        for (uint8 i = 0; i < addresses.length; i++) {
            require(amounts[i] <= totalRemaining);
            distr(addresses[i], amounts[i]);
        }
    }

    function () external payable {
            getTokens();
     }

    function getTokens() payable public {
        if(!distributionClosed){
        if (value > totalRemaining) {
            value = totalRemaining;
        }
        address investor = msg.sender;
        uint256 toGive = value;
        require(value <= totalRemaining);
        
        if(!blacklist[investor]){
          distr(investor, toGive);   
        }
        }
    }
    //
    function freeze(address[] addresses,bool locked) onlyOwner public {
        
        require(addresses.length <= 255);
        
        for (uint i = 0; i < addresses.length; i++) {
            freezeAccount(addresses[i], locked);
        }
    }
    
    function freezeAccount(address target, bool B) private {
        frozenAccount[target] = B;
        FrozenFunds(target, B);
    }

    function balanceOf(address _owner) constant public returns (uint256) {
	    return balances[_owner];
    }

    function transfer(address _to, uint256 _amount) onlyPayloadSize(2 * 32) public returns (bool success) {

        require(_to != address(0));
        require(_amount <= balances[msg.sender]);
        require(!frozenAccount[msg.sender]);                     
        require(!frozenAccount[_to]);                      
        balances[msg.sender] = balances[msg.sender].sub(_amount);
        balances[_to] = balances[_to].add(_amount);
        Transfer(msg.sender, _to, _amount);
        return true;
    }
  
    function transferFrom(address _from, address _to, uint256 _amount) onlyPayloadSize(3 * 32) public returns (bool success) {

        require(_to != address(0));
        require(_amount <= balances[_from]);
        require(_amount <= allowed[_from][msg.sender]);
        
        balances[_from] = balances[_from].sub(_amount);
        allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_amount);
        balances[_to] = balances[_to].add(_amount);
        Transfer(_from, _to, _amount);
        return true;
    }

    function approve(address _spender, uint256 _value) public returns (bool success) {
        if (_value != 0 && allowed[msg.sender][_spender] != 0) { return false; }
        allowed[msg.sender][_spender] = _value;
        Approval(msg.sender, _spender, _value);
        return true;
    }

    function allowance(address _owner, address _spender) constant public returns (uint256) {
        return allowed[_owner][_spender];
    }

    function withdraw() onlyOwner public {
        uint256 etherBalance = this.balance;
        address owner = msg.sender;
        owner.transfer(etherBalance);
    }
}