pragma solidity ^0.4.11;

/**
 * Различные валидаторы
 */

contract ValidationUtil {
    function requireValidAddress(address value){
        require(isAddressNotEmpty(value));
    }

    function isAddressNotEmpty(address value) internal returns (bool result){
        return value != 0;
    }
}

/**
 * @title SafeMath
 * @dev Math operations with safety checks that throw on error
 */
library SafeMath {
  function mul(uint256 a, uint256 b) internal constant returns (uint256) {
    uint256 c = a * b;
    assert(a == 0 || c / a == b);
    return c;
  }

  function div(uint256 a, uint256 b) internal constant returns (uint256) {
    // assert(b > 0); // Solidity automatically throws when dividing by 0
    uint256 c = a / b;
    // assert(a == b * c + a % b); // There is no case in which this doesn't hold
    return c;
  }

  function sub(uint256 a, uint256 b) internal constant returns (uint256) {
    assert(b <= a);
    return a - b;
  }

  function add(uint256 a, uint256 b) internal constant returns (uint256) {
    uint256 c = a + b;
    assert(c >= a);
    return c;
  }
}

/**
 * @title Ownable
 * @dev The Ownable contract has an owner address, and provides basic authorization control
 * functions, this simplifies the implementation of "user permissions".
 */
contract Ownable {
  address public owner;


  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);


  /**
   * @dev The Ownable constructor sets the original `owner` of the contract to the sender
   * account.
   */
  function Ownable() {
    owner = msg.sender;
  }


  /**
   * @dev Throws if called by any account other than the owner.
   */
  modifier onlyOwner() {
    require(msg.sender == owner);
    _;
  }


  /**
   * @dev Allows the current owner to transfer control of the contract to a newOwner.
   * @param newOwner The address to transfer ownership to.
   */
  function transferOwnership(address newOwner) onlyOwner {
    require(newOwner != address(0));      
    OwnershipTransferred(owner, newOwner);
    owner = newOwner;
  }

}

/**
 * @title ERC20Basic
 * @dev Simpler version of ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/179
 */
contract ERC20Basic {
  uint256 public totalSupply;
  function balanceOf(address who) constant returns (uint256);
  function transfer(address to, uint256 value) returns (bool);
  event Transfer(address indexed from, address indexed to, uint256 value);
}

/**
 * @title Basic token
 * @dev Basic version of StandardToken, with no allowances. 
 */
contract BasicToken is ERC20Basic {
  using SafeMath for uint256;

  mapping(address => uint256) balances;

  /**
  * @dev transfer token for a specified address
  * @param _to The address to transfer to.
  * @param _value The amount to be transferred.
  */
  function transfer(address _to, uint256 _value) returns (bool) {
    require(_to != address(0));

    // SafeMath.sub will throw if there is not enough balance.
    balances[msg.sender] = balances[msg.sender].sub(_value);
    balances[_to] = balances[_to].add(_value);
    Transfer(msg.sender, _to, _value);
    return true;
  }

  /**
  * @dev Gets the balance of the specified address.
  * @param _owner The address to query the the balance of. 
  * @return An uint256 representing the amount owned by the passed address.
  */
  function balanceOf(address _owner) constant returns (uint256 balance) {
    return balances[_owner];
  }

}

/**
 * @title ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/20
 */
contract ERC20 is ERC20Basic {
  function allowance(address owner, address spender) constant returns (uint256);
  function transferFrom(address from, address to, uint256 value) returns (bool);
  function approve(address spender, uint256 value) returns (bool);
  event Approval(address indexed owner, address indexed spender, uint256 value);
}

/**
 * @title Standard ERC20 token
 *
 * @dev Implementation of the basic standard token.
 * @dev https://github.com/ethereum/EIPs/issues/20
 * @dev Based on code by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
 */
contract StandardToken is ERC20, BasicToken {

  mapping (address => mapping (address => uint256)) allowed;


  /**
   * @dev Transfer tokens from one address to another
   * @param _from address The address which you want to send tokens from
   * @param _to address The address which you want to transfer to
   * @param _value uint256 the amount of tokens to be transferred
   */
  function transferFrom(address _from, address _to, uint256 _value) returns (bool) {
    require(_to != address(0));

    var _allowance = allowed[_from][msg.sender];

    // Check is not needed because sub(_allowance, _value) will already throw if this condition is not met
    // require (_value <= _allowance);

    balances[_from] = balances[_from].sub(_value);
    balances[_to] = balances[_to].add(_value);
    allowed[_from][msg.sender] = _allowance.sub(_value);
    Transfer(_from, _to, _value);
    return true;
  }

  /**
   * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
   * @param _spender The address which will spend the funds.
   * @param _value The amount of tokens to be spent.
   */
  function approve(address _spender, uint256 _value) returns (bool) {

    // To change the approve amount you first have to reduce the addresses`
    //  allowance to zero by calling `approve(_spender, 0)` if it is not
    //  already 0 to mitigate the race condition described here:
    //  https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
    require((_value == 0) || (allowed[msg.sender][_spender] == 0));

    allowed[msg.sender][_spender] = _value;
    Approval(msg.sender, _spender, _value);
    return true;
  }

  /**
   * @dev Function to check the amount of tokens that an owner allowed to a spender.
   * @param _owner address The address which owns the funds.
   * @param _spender address The address which will spend the funds.
   * @return A uint256 specifying the amount of tokens still available for the spender.
   */
  function allowance(address _owner, address _spender) constant returns (uint256 remaining) {
    return allowed[_owner][_spender];
  }
  
  /**
   * approve should be called when allowed[_spender] == 0. To increment
   * allowed value is better to use this function to avoid 2 calls (and wait until 
   * the first transaction is mined)
   * From MonolithDAO Token.sol
   */
  function increaseApproval (address _spender, uint _addedValue) 
    returns (bool success) {
    allowed[msg.sender][_spender] = allowed[msg.sender][_spender].add(_addedValue);
    Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
    return true;
  }

  function decreaseApproval (address _spender, uint _subtractedValue) 
    returns (bool success) {
    uint oldValue = allowed[msg.sender][_spender];
    if (_subtractedValue > oldValue) {
      allowed[msg.sender][_spender] = 0;
    } else {
      allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue);
    }
    Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
    return true;
  }

}

/**
 * Шаблон для токена, который можно сжечь
 *
 */

contract BurnableToken is StandardToken, Ownable, ValidationUtil {
    using SafeMath for uint;

    address public tokenOwnerBurner;

    /** Событие, сколько токенов мы сожгли */
    event Burned(address burner, uint burnedAmount);

    function setOwnerBurner(address _tokenOwnerBurner) public onlyOwner invalidOwnerBurner{
        // Проверка, что адрес не пустой
        requireValidAddress(_tokenOwnerBurner);

        tokenOwnerBurner = _tokenOwnerBurner;
    }

    /**
     * Сжигаем токены на балансе burner'а
     */
    function internalBurnTokens(address burner, uint burnAmount) internal {
        balances[burner] = balances[burner].sub(burnAmount);
        totalSupply = totalSupply.sub(burnAmount);

        // Вызываем событие
        Burned(burner, burnAmount);
    }

    /**
     * Сжигаем токены на балансе владельца токенов может только адрес tokenOwnerBurner
     */
    function burnOwnerTokens(uint burnAmount) public onlyTokenOwnerBurner validOwnerBurner{
        internalBurnTokens(tokenOwnerBurner, burnAmount);
    }

    /** Модификаторы
     */
    modifier onlyTokenOwnerBurner() {
        require(msg.sender == tokenOwnerBurner);

        _;
    }

    modifier validOwnerBurner() {
        // Проверка, что адрес не пустой
        requireValidAddress(tokenOwnerBurner);

        _;
    }

    modifier invalidOwnerBurner() {
        // Проверка, что адрес не пустой
        require(!isAddressNotEmpty(tokenOwnerBurner));

        _;
    }
}

/**
 * Токен продаж
 *
 * ERC-20 токен, для ICO
 *
 * - Токен может быть с верхним лимитом или без него
 *
 */

contract CrowdsaleToken is StandardToken, Ownable {

    /* Описание см. в конструкторе */
    string public name;
    string public symbol;
    uint public decimals;

    bool public isInitialSupplied = false;

    /** Событие обновления токена (имя и символ) */
    event UpdatedTokenInformation(string name, string symbol);

    /**
     * Конструктор
     *
     * Токен должен быть создан только владельцем через кошелек (либо с мультиподписью, либо без нее)
     *
     * @param _name - имя токена
     * @param _symbol - символ токена
     * @param _initialSupply - со сколькими токенами мы стартуем
     * @param _decimals - кол-во знаков после запятой
     */
    function CrowdsaleToken(string _name, string _symbol, uint _initialSupply, uint _decimals) {
        require(_initialSupply != 0);

        name = _name;
        symbol = _symbol;
        decimals = _decimals;

        totalSupply = _initialSupply;
    }

    /**
     * Владелец должен вызвать эту функцию, чтобы присвоить начальный баланс
     */
    function initialSupply(address _toAddress) external onlyOwner {
        require(!isInitialSupplied);

        // Создаем начальный баланс токенов на кошельке
        balances[_toAddress] = totalSupply;

        isInitialSupplied = true;
    }

    /**
     * Владелец может обновить инфу по токену
     */
    function setTokenInformation(string _name, string _symbol) external onlyOwner {
        name = _name;
        symbol = _symbol;

        // Вызываем событие
        UpdatedTokenInformation(name, symbol);
    }

}

/**
 * Шаблон для продаж токена, который можно сжечь
 *
 */
contract BurnableCrowdsaleToken is BurnableToken, CrowdsaleToken {

    function BurnableCrowdsaleToken(string _name, string _symbol, uint _initialSupply, uint _decimals) CrowdsaleToken(_name, _symbol, _initialSupply, _decimals) BurnableToken(){

    }

}