pragma solidity ^0.4.18;
/**
 * Libraries
 */
library SafeMath {
  /**
  * @dev Multiplies two numbers, throws on overflow.
  */
  function mul(uint256 a, uint256 b) internal pure returns (uint256) {
    if (a == 0) {
      return 0;
    }
    uint256 c = a * b;
    assert(c / a == b);
    return c;
  }
  /**
  * @dev Integer division of two numbers, truncating the quotient.
  */
  function div(uint256 a, uint256 b) internal pure 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;
  }

  /**
  * @dev Substracts two numbers, throws on overflow (i.e. if subtrahend is greater than minuend).
  */
  function sub(uint256 a, uint256 b) internal pure returns (uint256) {
    assert(b <= a);
    return a - b;
  }

  /**
  * @dev Adds two numbers, throws on overflow.
  */
  function add(uint256 a, uint256 b) internal pure returns (uint256) {
    uint256 c = a + b;
    assert(c >= a);
    return c;
  }
}

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() public {
    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) public onlyOwner {
    require(newOwner != address(0));
    OwnershipTransferred(owner, newOwner);
    owner = newOwner;
  }

}
/**
 * @title ERC20Basic
 * @dev Simpler version of ERC20 interface
 */
contract ERC20Basic {
  uint256 public totalSupply;
  function balanceOf(address who) public view returns (uint256);
  function transfer(address to, uint256 value) public returns (bool);
  event Transfer(address indexed from, address indexed to, uint256 value);
}

/**
 * @title ERC20 interface
 */
contract ERC20 is ERC20Basic {
  function allowance(address owner, address spender) public view 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 Contactable is Ownable{

    string public contactInformation;

    /**
     * @dev Allows the owner to set a string with their contact information.
     * @param info The contact information to attach to the contract.
     */
    function setContactInformation(string info) onlyOwner public {
         contactInformation = info;
     }
}

contract BurnableToken is ERC20, Ownable {
  using SafeMath for uint;
  event Burn(address indexed burner, uint256 value);
  
   mapping (address => uint) balances;

  /**
   * @dev Burns a specific amount of tokens.
   * @param _value The amount of token to be burned.
   */
  function burn(uint256 _value) public onlyOwner {
    require(_value <= balances[msg.sender]);
    address burner = msg.sender;
    balances[burner] = balances[burner].sub(_value);
    totalSupply = totalSupply.sub(_value);
    Burn(burner, _value);
  }
}

contract UNIToken is ERC20, Contactable,BurnableToken{
    using SafeMath for uint;

    string constant public name = "UNI Token";
    string constant public symbol = "UNI";
    uint constant public decimals = 4;

    bool public isActivated = false;

    //mapping (address => uint) balances;
    mapping (address => mapping (address => uint)) internal allowed;
    mapping (address => bool) public freezedList;

    address public minter;

    modifier whenActivated() {
        require(isActivated);
        _;
    }
	
    function UNIToken(uint256 _totalSupply) public {
        minter = msg.sender;
		
	    totalSupply = _totalSupply;
		// give money to us
        balances[minter] = totalSupply;

        // first event
        Transfer(0x0, minter, totalSupply);
    }

    /**
    * @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, uint _value) public returns (bool) {
        bytes memory empty;
        return transfer(_to, _value, empty);
    }

    /**
    * @dev transfer token for a specified address
    * @param _to The address to transfer to.
    * @param _value The amount to be transferred.
    * @param _data Optional metadata.
    */
    function transfer(address _to, uint _value, bytes _data) public whenActivated returns (bool) {
        require(_to != address(0));
        require(_value <= balances[msg.sender]);
        require(!freezedList[msg.sender]);

        // 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 uint representing the amount owned by the passed address.
    */
    function balanceOf(address _owner) public view returns (uint balance) {
        return balances[_owner];
    }

    /**
     * @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 uint the amount of tokens to be transferred
     */
    function transferFrom(address _from, address _to, uint _value) public returns (bool) {
        bytes memory empty;
        return transferFrom(_from, _to, _value, empty);
    }

    /**
     * @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 uint the amount of tokens to be transferred
     * @param _data Optional metadata.
     */
    function transferFrom(address _from, address _to, uint _value, bytes _data) public whenActivated returns (bool) {
        require(_to != address(0));
        require(_value <= balances[_from]);
        require(_value <= allowed[_from][msg.sender]);
        require(!freezedList[_from]);

        balances[_from] = balances[_from].sub(_value);
        balances[_to] = balances[_to].add(_value);
        allowed[_from][msg.sender] = allowed[_from][msg.sender].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, uint _value) public returns (bool) {
        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 uint specifying the amount of tokens still available for the spender.
     */
    function allowance(address _owner, address _spender) public view returns (uint) {
        return allowed[_owner][_spender];
    }

    /**
     * @dev Increase the amount of tokens that an owner allowed to a spender.
     * @param _spender The address which will spend the funds.
     * @param _addedValue The amount of tokens to increase the allowance by.
     */
    function increaseApproval(address _spender, uint _addedValue) public returns (bool) {
        allowed[msg.sender][_spender] = allowed[msg.sender][_spender].add(_addedValue);
        Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
        return true;
    }

    /**
     * @dev Decrease the amount of tokens that an owner allowed to a spender.
     * @param _spender The address which will spend the funds.
     * @param _subtractedValue The amount of tokens to decrease the allowance by.
     */
    function decreaseApproval(address _spender, uint _subtractedValue) public returns (bool) {
        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;
    }
    
    /**
     * Owner can unfreeze any address
     */
    function removeFromFreezedList(address user) external onlyOwner {
        freezedList[user] = false;
    }

    /**
     * Activation of the token allows all tokenholders to operate with the token
     */
    function activate() external onlyOwner returns (bool) {
        isActivated = true;
        return true;
    }
    
}