pragma solidity ^0.4.20;


/**
 * @title SafeMath
 * @dev Math operations with safety checks that throw on error
 */
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;
    }
}


/**
 * @title ERC20Basic
 * @dev Simpler version of ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/179
 */
contract ERC20Basic {
    function totalSupply() public view returns (uint256);
    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
 * @dev see https://github.com/ethereum/EIPs/issues/20
 */
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);
}


/**
 * @title Basic token
 * @dev Basic version of StandardToken, with no allowances.
 */
contract BasicToken is ERC20Basic {
    using SafeMath for uint256;

    mapping(address => uint256) balances;

    uint256 totalSupply_;

    /**
    * @dev total number of tokens in existence
    */
    function totalSupply() public view returns (uint256) {
        return 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, 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];
    }

}

/**
 * @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)) 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;
    }

}


/**
 * @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() 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 Pausable
 * @dev Base contract which allows children to implement an emergency stop mechanism.
 */
contract Pausable is Ownable {
    event Pause();

    event Unpause();

    bool public paused = false;


    /**
     * @dev Modifier to make a function callable only when the contract is not paused.
     */
    modifier whenNotPaused() {
        require(!paused);
        _;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     */
    modifier whenPaused() {
        require(paused);
        _;
    }

    /**
     * @dev called by the owner to pause, triggers stopped state
     */
    function pause() onlyOwner whenNotPaused public {
        paused = true;
        Pause();
    }

    /**
     * @dev called by the owner to unpause, returns to normal state
     */
    function unpause() onlyOwner whenPaused public {
        paused = false;
        Unpause();
    }
}


contract MintableToken is StandardToken, Ownable, Pausable {

    event Mint(address indexed to, uint256 amount);

    event MintFinished();

    bool public mintingFinished = false;

    uint256 public maxTokensToMint = 25000000 ether;

    uint8 public currentRound = 1;

    struct Round {
    uint256 total;
    bool finished;
    bool active;
    uint256 issuedTokens;
    uint256 startMinimumTime;
    }

    Round[] rounds;

    modifier canMint() {
        require(!mintingFinished);
        require(rounds[currentRound-1].active);
        _;
    }

    /**
    * @dev Function to mint tokens
    * @param _to The address that will recieve 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) whenNotPaused onlyOwner returns (bool) {
        require(mintInternal(_to, _amount));
        return true;
    }

    /**
    * @dev Function to stop minting new tokens.
    * @return True if the operation was successful.
    */
    function finishMinting() whenNotPaused onlyOwner returns (bool) {
        mintingFinished = true;
        MintFinished();
        return true;
    }

    function mintInternal(address _to, uint256 _amount) internal canMint returns (bool) {
        require(rounds[currentRound-1].issuedTokens.add(_amount) <= rounds[currentRound-1].total);
        require(totalSupply_.add(_amount) <= maxTokensToMint);
        totalSupply_ = totalSupply_.add(_amount);
        rounds[currentRound-1].issuedTokens = rounds[currentRound-1].issuedTokens.add(_amount);
        balances[_to] = balances[_to].add(_amount);
        Mint(_to, _amount);
        Transfer(address(0), _to, _amount);
        return true;
    }
}


contract Rock is MintableToken {

    string public constant name = "Rocket Token";

    string public constant symbol = "ROCK";

    bool public transferEnabled = false;

    uint8 public constant decimals = 18;

    event TokenPurchase(address indexed purchaser, address indexed beneficiary, uint256 amount);

    function Rock(){
        Round memory roundone = Round({total : 4170000 ether, active: true, finished: false, issuedTokens : 0, startMinimumTime: 0});
        Round memory roundtwo = Round({total : 6945000 ether, active: false, finished: false, issuedTokens : 0, startMinimumTime: 1534291200 });
        Round memory roundthree = Round({total : 13885000 ether, active: false, finished: false, issuedTokens : 0, startMinimumTime: 0});
        rounds.push(roundone);
        rounds.push(roundtwo);
        rounds.push(roundthree);
    }

    /**
    * @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) whenNotPaused canTransfer returns (bool) {
        require(_to != address(this));
        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 amout of tokens to be transfered
    */
    function transferFrom(address _from, address _to, uint _value) whenNotPaused canTransfer returns (bool) {
        require(_to != address(this));
        return super.transferFrom(_from, _to, _value);
    }

    /**
     * @dev Aprove 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) whenNotPaused returns (bool) {
        return super.approve(_spender, _value);
    }

    /**
     * @dev Modifier to make a function callable only when the transfer is enabled.
     */
    modifier canTransfer() {
        require(transferEnabled);
        _;
    }

    /**
    * @dev Function to start transfering tokens.
    * @return True if the operation was successful.
    */
    function enableTransfer() onlyOwner returns (bool) {
        transferEnabled = true;
        return true;
    }

    /**
    * @dev Function to stop current round.
    * @return True if the operation was successful.
    */
    function finishRound() onlyOwner returns (bool) {
        require(currentRound - 1 < 3);
        require(rounds[currentRound-1].active);

        uint256 tokensToBurn = rounds[currentRound-1].total.sub(rounds[currentRound-1].issuedTokens);

        rounds[currentRound-1].active = false;
        rounds[currentRound-1].finished = true;
        maxTokensToMint = maxTokensToMint.sub(tokensToBurn);

        return true;
    }

    /**
    * @dev Function to start new round.
    * @return True if the operation was successful.
    */
    function startRound() onlyOwner returns (bool) {
        require(currentRound - 1 < 2);
        require(rounds[currentRound-1].finished);
        if(rounds[currentRound].startMinimumTime > 0){
            require(block.timestamp >= rounds[currentRound].startMinimumTime);
        }

        currentRound ++;
        rounds[currentRound-1].active = true;

        return true;
    }

    function getCurrentRoundTotal() constant returns (uint256 total) {
        return rounds[currentRound-1].total;
    }

    function getCurrentRoundIsFinished() constant returns (bool) {
        return rounds[currentRound-1].finished;
    }

    function getCurrentRoundIsActive() constant returns (bool) {
        return rounds[currentRound-1].active;
    }

    function getCurrentRoundMinimumTime() constant returns (uint256) {
        return rounds[currentRound-1].startMinimumTime;
    }

    function getCurrentRoundIssued() constant returns (uint256 issued) {
        return rounds[currentRound-1].issuedTokens;
    }

}