pragma solidity ^0.4.13;

library SafeMath {
  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;
  }

  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;
  }

  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 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;
  }

}

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);
}

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) public returns (bool) {
    require(_to != address(0));
    require(_value <= balances[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 uint256 representing the amount owned by the passed address.
  */
  function balanceOf(address _owner) public view returns (uint256 balance) {
    return balances[_owner];
  }

}

contract BurnableToken is BasicToken {

    event Burn(address indexed burner, uint256 value);

    /**
     * @dev Burns a specific amount of tokens.
     * @param _value The amount of token to be burned.
     */
    function burn(uint256 _value) public {
        require(_value <= balances[msg.sender]);
        // no need to require value <= totalSupply, since that would imply the
        // sender's balance is greater than the totalSupply, which *should* be an assertion failure

        address burner = msg.sender;
        balances[burner] = balances[burner].sub(_value);
        totalSupply = totalSupply.sub(_value);
        Burn(burner, _value);
    }
}

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 StandardToken is ERC20, BasicToken {

  mapping (address => mapping (address => uint256)) internal 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) public returns (bool) {
    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);
    Transfer(_from, _to, _value);
    return true;
  }

  /**
   * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
   *
   * Beware that changing an allowance with this method brings the risk that someone may use both the old
   * and the new allowance by unfortunate transaction ordering. One possible solution to mitigate this
   * race condition is to first reduce the spender's allowance to 0 and set the desired value afterwards:
   * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
   * @param _spender The address which will spend the funds.
   * @param _value The amount of tokens to be spent.
   */
  function approve(address _spender, uint256 _value) public returns (bool) {
    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) public view returns (uint256) {
    return allowed[_owner][_spender];
  }

  /**
   * @dev Increase the amount of tokens that an owner allowed to a 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
   * @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.
   *
   * approve should be called when allowed[_spender] == 0. To decrement
   * allowed value is better to use this function to avoid 2 calls (and wait until
   * the first transaction is mined)
   * From MonolithDAO Token.sol
   * @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;
  }

}

contract MintableToken is StandardToken, Ownable {
  event Mint(address indexed to, uint256 amount);
  event MintFinished();

  bool public mintingFinished = false;


  modifier canMint() {
    require(!mintingFinished);
    _;
  }

  /**
   * @dev Function to mint tokens
   * @param _to The address that will receive the minted tokens.
   * @param _amount The amount of tokens to mint.
   * @return A boolean that indicates if the operation was successful.
   */
  function mint(address _to, uint256 _amount) onlyOwner canMint public returns (bool) {
    totalSupply = totalSupply.add(_amount);
    balances[_to] = balances[_to].add(_amount);
    Mint(_to, _amount);
    Transfer(address(0), _to, _amount);
    return true;
  }

  /**
   * @dev Function to stop minting new tokens.
   * @return True if the operation was successful.
   */
  function finishMinting() onlyOwner canMint public returns (bool) {
    mintingFinished = true;
    MintFinished();
    return true;
  }
}

contract ApprovedBurnableToken is BurnableToken, StandardToken {

        /**
           Sent when `burner` burns some `value` of `owners` tokens.
        */
        event BurnFrom(address indexed owner, // The address whose tokens were burned.
                       address indexed burner, // The address that executed the `burnFrom` call
                       uint256 value           // The amount of tokens that were burned.
                );

        /**
           @dev Burns a specific amount of tokens of another account that `msg.sender`
           was approved to burn tokens for using `approveBurn` earlier.
           @param _owner The address to burn tokens from.
           @param _value The amount of token to be burned.
        */
        function burnFrom(address _owner, uint256 _value) public {
                require(_value > 0);
                require(_value <= balances[_owner]);
                require(_value <= allowed[_owner][msg.sender]);
                // no need to require value <= totalSupply, since that would imply the
                // sender's balance is greater than the totalSupply, which *should* be an assertion failure

                address burner = msg.sender;
                balances[_owner] = balances[_owner].sub(_value);
                allowed[_owner][burner] = allowed[_owner][burner].sub(_value);
                totalSupply = totalSupply.sub(_value);

                BurnFrom(_owner, burner, _value);
                Burn(_owner, _value);
        }
}

contract FintechCoin is MintableToken, ApprovedBurnableToken {
        /**
           @dev We do not expect this to change ever after deployment,
           @dev but it is a way to identify different versions of the FintechCoin during development.
        */
        uint8 public constant contractVersion = 1;

        /**
           @dev The name of the FintechCoin, specified as indicated in ERC20.
         */
        string public constant name = "FintechCoin";

        /**
           @dev The abbreviation FINC, specified as indicated in ERC20.
        */
        string public constant symbol = "FINC";

        /**
           @dev The smallest denomination of the FintechCoin is 1 * 10^(-18) FINC. `decimals` is specified as indicated in ERC20.
        */
        uint8 public constant decimals = 18;
}

contract UnlockedAfterMintingToken is MintableToken {

    /**
       Ensures certain calls can only be made when minting is finished.

       The calls that are restricted are any calls that allow direct or indirect transferral of funds.
       Only the owner is allowed to perform these calls during the minting time as well.
     */
    modifier whenMintingFinished() {
      require(mintingFinished || (msg.sender == owner));
        _;
    }

    function transfer(address _to, uint256 _value) public whenMintingFinished returns (bool) {
        return super.transfer(_to, _value);
    }

    /**
      @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) public whenMintingFinished returns (bool) {
        return super.transferFrom(_from, _to, _value);
    }

    /**
      @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
      @dev NOTE: This call is considered deprecated, and only included for proper compliance with ERC20.
      @dev Rather than use this call, use `increaseApproval` and `decreaseApproval` instead, whenever possible.
      @dev The reason for this, is that using `approve` directly when your allowance is nonzero results in an exploitable situation:
      @dev https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729

      @param _spender The address which will spend the funds.
      @param _value The amount of tokens to be spent.
     */
    function approve(address _spender, uint256 _value) public whenMintingFinished returns (bool) {
        return super.approve(_spender, _value);
    }

    /**
      @dev approve should only be called when allowed[_spender] == 0. To alter the
      @dev allowed value it is better to use this function, because it is safer.
      @dev (And making `approve` safe manually would require making two calls made in separate blocks.)

      This method was adapted from the one in use by the MonolithDAO Token.
     */
    function increaseApproval(address _spender, uint _addedValue) public whenMintingFinished returns (bool success) {
        return super.increaseApproval(_spender, _addedValue);
    }

    /**
       @dev approve should only be called when allowed[_spender] == 0. To alter the
       @dev allowed value it is better to use this function, because it is safer.
       @dev (And making `approve` safe manually would require making two calls made in separate blocks.)

       This method was adapted from the one in use by the MonolithDAO Token.
    */
    function decreaseApproval(address _spender, uint _subtractedValue) public whenMintingFinished returns (bool success) {
        return super.decreaseApproval(_spender, _subtractedValue);
    }

}