//Have an idea for a studio? Email: admin[at]EtherPornStars.com
pragma solidity ^0.4.24;


/**
 * @title ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/20
 */
contract ERC20 {
  function totalSupply() public view returns (uint256);

  function balanceOf(address _who) public view returns (uint256);

  function allowance(address _owner, address _spender)
    public view returns (uint256);

  function transfer(address _to, uint256 _value) public returns (bool);

  function approve(address _spender, uint256 _value)
    public returns (bool);

  function transferFrom(address _from, address _to, uint256 _value)
    public returns (bool);

  event Transfer(
    address indexed from,
    address indexed to,
    uint256 value
  );

  event Approval(
    address indexed owner,
    address indexed spender,
    uint256 value
  );
}








/**
 * @title SafeMath
 * @dev Math operations with safety checks that revert on error
 */
library SafeMath {

  /**
  * @dev Multiplies two numbers, reverts on overflow.
  */
  function mul(uint256 _a, uint256 _b) internal pure returns (uint256) {
    // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
    // benefit is lost if 'b' is also tested.
    // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
    if (_a == 0) {
      return 0;
    }

    uint256 c = _a * _b;
    require(c / _a == _b);

    return c;
  }

  /**
  * @dev Integer division of two numbers truncating the quotient, reverts on division by zero.
  */
  function div(uint256 _a, uint256 _b) internal pure returns (uint256) {
    require(_b > 0); // Solidity only automatically asserts 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 Subtracts two numbers, reverts on overflow (i.e. if subtrahend is greater than minuend).
  */
  function sub(uint256 _a, uint256 _b) internal pure returns (uint256) {
    require(_b <= _a);
    uint256 c = _a - _b;

    return c;
  }

  /**
  * @dev Adds two numbers, reverts on overflow.
  */
  function add(uint256 _a, uint256 _b) internal pure returns (uint256) {
    uint256 c = _a + _b;
    require(c >= _a);

    return c;
  }

  /**
  * @dev Divides two numbers and returns the remainder (unsigned integer modulo),
  * reverts when dividing by zero.
  */
  function mod(uint256 a, uint256 b) internal pure returns (uint256) {
    require(b != 0);
    return a % b;
  }
}

/**
 * @title Standard ERC20 token
 *
 * @dev Implementation of the basic standard token.
 * https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20.md
 * Based on code by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
 */
contract StandardToken is ERC20 {
  using SafeMath for uint256;

  mapping (address => uint256) balances;

  mapping (address => mapping (address => uint256)) allowed;

  uint256 totalSupply_;

  /**
  * @dev Total number of tokens in existence
  */
  function totalSupply() public view returns (uint256) {
    return totalSupply_;
  }

  /**
  * @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) {
    return balances[_owner];
  }

  /**
   * @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 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(_value <= balances[msg.sender]);
    require(_to != address(0));

    balances[msg.sender] = balances[msg.sender].sub(_value);
    balances[_to] = balances[_to].add(_value);
    emit Transfer(msg.sender, _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;
    emit Approval(msg.sender, _spender, _value);
    return true;
  }

  /**
   * @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(_value <= balances[_from]);
    require(_value <= allowed[_from][msg.sender]);
    require(_to != address(0));

    balances[_from] = balances[_from].sub(_value);
    balances[_to] = balances[_to].add(_value);
    allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
    emit Transfer(_from, _to, _value);
    return true;
  }

  /**
   * @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,
    uint256 _addedValue
  )
    public
    returns (bool)
  {
    allowed[msg.sender][_spender] = (
      allowed[msg.sender][_spender].add(_addedValue));
    emit 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,
    uint256 _subtractedValue
  )
    public
    returns (bool)
  {
    uint256 oldValue = allowed[msg.sender][_spender];
    if (_subtractedValue >= oldValue) {
      allowed[msg.sender][_spender] = 0;
    } else {
      allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue);
    }
    emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
    return true;
  }

  /**
   * @dev Internal function that mints an amount of the token and assigns it to
   * an account. This encapsulates the modification of balances such that the
   * proper events are emitted.
   * @param _account The account that will receive the created tokens.
   * @param _amount The amount that will be created.
   */
  function _mint(address _account, uint256 _amount) internal {
    require(_account != 0);
    totalSupply_ = totalSupply_.add(_amount);
    balances[_account] = balances[_account].add(_amount);
    emit Transfer(address(0), _account, _amount);
  }

  /**
   * @dev Internal function that burns an amount of the token of a given
   * account.
   * @param _account The account whose tokens will be burnt.
   * @param _amount The amount that will be burnt.
   */
  function _burn(address _account, uint256 _amount) internal {
    require(_account != 0);
    require(_amount <= balances[_account]);

    totalSupply_ = totalSupply_.sub(_amount);
    balances[_account] = balances[_account].sub(_amount);
    emit Transfer(_account, address(0), _amount);
  }

  /**
   * @dev Internal function that burns an amount of the token of a given
   * account, deducting from the sender's allowance for said account. Uses the
   * internal _burn function.
   * @param _account The account whose tokens will be burnt.
   * @param _amount The amount that will be burnt.
   */
  function _burnFrom(address _account, uint256 _amount) internal {
    require(_amount <= allowed[_account][msg.sender]);

    // Should https://github.com/OpenZeppelin/zeppelin-solidity/issues/707 be accepted,
    // this function needs to emit an event with the updated approval.
    allowed[_account][msg.sender] = allowed[_account][msg.sender].sub(_amount);
    _burn(_account, _amount);
  }
}

/**
 * @title ERC20 token receiver interface
 * @dev Interface for any contract that wants to support safeTransfers
 *  from ERC20 asset contracts.
 */

/**
 * @title SafeMath
 * @dev Math operations with safety checks that revert on error
 */



contract Ownable {
  address public owner;


  event OwnershipRenounced(address indexed previousOwner);
  event OwnershipTransferred(
    address indexed previousOwner,
    address indexed newOwner
  );


  /**
   * @dev The Ownable constructor sets the original `owner` of the contract to the sender
   * account.
   */
  constructor() public {
    owner = msg.sender;
  }

  /**
   * @dev Throws if called by any account other than the owner.
   */
  modifier onlyOwner() {
    require(msg.sender == owner);
    _;
  }
}


contract StarCoin is Ownable, StandardToken {
    using SafeMath for uint;
    address gateway;
    string public name = "EtherPornStars Coin";
    string public symbol = "EPS";
    uint8 public decimals = 18;
    mapping (uint8 => address) public studioContracts;
    mapping (address => bool) public isMinter;
    event Withdrawal(address indexed to, uint256 value);
    event Burn(address indexed from, uint256 value);
    modifier onlyMinters {
      require(msg.sender == owner || isMinter[msg.sender]);
      _;
    }

    constructor () public {
  }
  /**
   * @dev Future sidechain integration for studios.
   */
    function setGateway(address _gateway) external onlyOwner {
        gateway = _gateway;
    }


    function _mintTokens(address _user, uint256 _amount) private {
        require(_user != 0x0);
        balances[_user] = balances[_user].add(_amount);
        totalSupply_ = totalSupply_.add(_amount);
        emit Transfer(address(this), _user, _amount);
    }

    function rewardTokens(address _user, uint256 _tokens) external   { 
        require(msg.sender == owner || isMinter[msg.sender]);
        _mintTokens(_user, _tokens);
    }
    function buyStudioStake(address _user, uint256 _tokens) external   { 
        require(msg.sender == owner || isMinter[msg.sender]);
        _burn(_user, _tokens);
    }
    function transferFromStudio(
      address _from,
      address _to,
      uint256 _value
    )
      external
      returns (bool)
    {
      require(msg.sender == owner || isMinter[msg.sender]);
      require(_value <= balances[_from]);
      require(_to != address(0));

      balances[_from] = balances[_from].sub(_value);
      balances[_to] = balances[_to].add(_value);
      emit Transfer(_from, _to, _value);
      return true;
  }

    function() payable public {
        // Intentionally left empty, for use by studios
    }

    function accountAuth(uint256 /*_challenge*/) external {
        // Does nothing by design
    }

    function burn(uint256 _amount) external {
        require(balances[msg.sender] >= _amount);
        balances[msg.sender] = balances[msg.sender].sub(_amount);
        totalSupply_ = totalSupply_.sub(_amount);
        emit Burn(msg.sender, _amount);
    }

    function withdrawBalance(uint _amount) external {
        require(balances[msg.sender] >= _amount);
        balances[msg.sender] = balances[msg.sender].sub(_amount);
        totalSupply_ = totalSupply_.sub(_amount);
        uint ethexchange = _amount.div(2);
        msg.sender.transfer(ethexchange);
    }

    function setIsMinter(address _address, bool _value) external onlyOwner {
        isMinter[_address] = _value;
    }

    function depositToGateway(uint256 amount) external {
        transfer(gateway, amount);
    }
}