pragma solidity ^0.5.16;


/**
 * Game Credits ERC20 Token Contract
 * https://www.gamecredits.org
 * (c) 2020 GAME Credits. All Rights Reserved. This code is not open source.
 */





/**
 * @dev Interface of the ERC20 standard as defined in the EIP. Does not include
 * the optional functions; to access them see {ERC20Detailed}.
 */
interface iERC20 {

  /**
    * @dev Returns the amount of tokens in existence.
    */
  function totalSupply() external view returns (uint);

  /**
    * @dev Returns the amount of tokens owned by `account`.
    */
  function balanceOf(address account) external view returns (uint);

  /**
    * @dev Moves `amount` tokens from the caller's account to `recipient`.
    *
    * Returns a boolean value indicating whether the operation succeeded.
    *
    * Emits a {Transfer} event.
    */
  function transfer(address recipient, uint amount) external returns (bool);

  /**
    * @dev Returns the remaining number of tokens that `spender` will be
    * allowed to spend on behalf of `owner` through {transferFrom}. This is
    * zero by default.
    *
    * This value changes when {approve} or {transferFrom} are called.
    */
  function allowance(address owner, address spender) external view returns (uint);

  /**
    * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
    *
    * Returns a boolean value indicating whether the operation succeeded.
    *
    * IMPORTANT: 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
    *
    * Emits an {Approval} event.
    */
  function approve(address spender, uint amount) external returns (bool);

  /**
    * @dev Moves `amount` tokens from `sender` to `recipient` using the
    * allowance mechanism. `amount` is then deducted from the caller's
    * allowance.
    *
    * Returns a boolean value indicating whether the operation succeeded.
    *
    * Emits a {Transfer} event.
    */
  function transferFrom(address sender, address recipient, uint amount) external returns (bool);

  /**
    * @dev Emitted when `value` tokens are moved from one account (`from`) to
    * another (`to`).
    *
    * Note that `value` may be zero.
    */
  event Transfer(address indexed from, address indexed to, uint value);

  /**
    * @dev Emitted when the allowance of a `spender` for an `owner` is set by
    * a call to {approve}. `value` is the new allowance.
    */
  event Approval(address indexed owner, address indexed spender, uint value);
}



// @title iERC20Contract
// @dev The interface for cross-contract calls to the ERC20 contract
// @author GAME Credits Platform (https://www.gamecredits.org)
// (c) 2020 GAME Credits. All Rights Reserved. This code is not open source.
contract iERC20Contract {
  function isOfficialAccount(address account) external view returns(bool);
}


// @title ERC20Access
// @dev ERC20Access contract for controlling access to ERC20 contract functions
// @author GAME Credits Platform (https://www.gamecredits.org)
// (c) 2020 GAME Credits. All Rights Reserved. This code is not open source.
contract ERC20Access is iERC20, iERC20Contract {

  event OwnershipTransferred(address previousOwner, address newOwner);

  // The Owner can perform all admin tasks, including setting the recovery account.
  address public owner;

  // The Recovery account can change the Owner account.
  address public recoveryAddress;


  // @dev The original `owner` of the contract is the contract creator.
  // @dev Internal constructor to ensure this contract can't be deployed alone
  constructor()
    internal
  {
    owner = msg.sender;
  }

  // @dev Access control modifier to limit access to the Owner account
  modifier onlyOwner() {
    require(msg.sender == owner, "sender must be owner");
    _;
  }

  // @dev Access control modifier to limit access to the Recovery account
  modifier onlyRecovery() {
    require(msg.sender == recoveryAddress, "sender must be recovery");
    _;
  }

  // @dev Access control modifier to limit access to the Owner or Recovery account
  modifier ownerOrRecovery() {
    require(msg.sender == owner || msg.sender == recoveryAddress, "sender must be owner or recovery");
    _;
  }

  // Used to check if an account is treated as official by this contract
  // @param _account - the account to check
  // @returns true if _account equals the owner or recoveryAccount, false otherwise
  function isOfficialAccount(address _account)
    external
    view
  returns(bool)
  {
    return _account == owner || _account == recoveryAddress;
  }

  // @dev Assigns a new address to act as the Owner.
  // @notice Can only be called by the recovery account
  // @param _newOwner The address of the new Owner
  function setOwner(address _newOwner)
    external
    onlyRecovery
  {
    require(_newOwner != address(0), "new owner must be a non-zero address");
    require(_newOwner != recoveryAddress, "new owner can't be the recovery address");

    owner = _newOwner;
    emit OwnershipTransferred(owner, _newOwner);
  }

  // @dev Assigns a new address to act as the Recovery address.
  // @notice Can only be called by the Owner account
  // @param _newRecovery The address of the new Recovery account
  function setRecovery(address _newRecovery)
    external
    onlyOwner
  {
    require(_newRecovery != address(0), "new owner must be a non-zero address");
    require(_newRecovery != owner, "new recovery can't be the owner address");

    recoveryAddress = _newRecovery;
  }

  // @dev allows recovery of ERC20 tokens accidentally sent to this address
  // @param tokenAddress - The address of the erc20 token
  // @param tokens - The number of tokens to transfer
  function transferAnyERC20Token(address tokenAddress, uint tokens)
    public
    ownerOrRecovery
  returns (bool success)
  {
    return iERC20(tokenAddress).transfer(owner, tokens);
  }
}




/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
  /**
    * @dev Returns the addition of two unsigned integers, reverting on
    * overflow.
    *
    * Counterpart to Solidity's `+` operator.
    *
    * Requirements:
    * - Addition cannot overflow.
    */
  function add(uint a, uint b) internal pure returns (uint) {
    uint c = a + b;
    require(c >= a, "SafeMath: addition overflow");

    return c;
  }

  /**
    * @dev Returns the subtraction of two unsigned integers, reverting on
    * overflow (when the result is negative).
    *
    * Counterpart to Solidity's `-` operator.
    *
    * Requirements:
    * - Subtraction cannot overflow.
    */
  function sub(uint a, uint b) internal pure returns (uint) {
    return sub(a, b, "SafeMath: subtraction overflow");
  }

  /**
    * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
    * overflow (when the result is negative).
    *
    * Counterpart to Solidity's `-` operator.
    *
    * Requirements:
    * - Subtraction cannot overflow.
    *
    * _Available since v2.4.0._
    */
  function sub(uint a, uint b, string memory errorMessage) internal pure returns (uint) {
    require(b <= a, errorMessage);
    uint c = a - b;

    return c;
  }

  /**
    * @dev Returns the multiplication of two unsigned integers, reverting on
    * overflow.
    *
    * Counterpart to Solidity's `*` operator.
    *
    * Requirements:
    * - Multiplication cannot overflow.
    */
  function mul(uint a, uint b) internal pure returns (uint) {
    // 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-contracts/pull/522
    if (a == 0) {
      return 0;
    }

    uint c = a * b;
    require(c / a == b, "SafeMath: multiplication overflow");

    return c;
  }

  /**
    * @dev Returns the integer division of two unsigned integers. Reverts on
    * division by zero. The result is rounded towards zero.
    *
    * Counterpart to Solidity's `/` operator. Note: this function uses a
    * `revert` opcode (which leaves remaining gas untouched) while Solidity
    * uses an invalid opcode to revert (consuming all remaining gas).
    *
    * Requirements:
    * - The divisor cannot be zero.
    */
  function div(uint a, uint b) internal pure returns (uint) {
    return div(a, b, "SafeMath: division by zero");
  }

  /**
    * @dev Returns the integer division of two unsigned integers. Reverts with custom message on
    * division by zero. The result is rounded towards zero.
    *
    * Counterpart to Solidity's `/` operator. Note: this function uses a
    * `revert` opcode (which leaves remaining gas untouched) while Solidity
    * uses an invalid opcode to revert (consuming all remaining gas).
    *
    * Requirements:
    * - The divisor cannot be zero.
    *
    * _Available since v2.4.0._
    */
  function div(uint a, uint b, string memory errorMessage) internal pure returns (uint) {
    // Solidity only automatically asserts when dividing by 0
    require(b > 0, errorMessage);
    uint c = a / b;
    // assert(a == b * c + a % b); // There is no case in which this doesn't hold

    return c;
  }

  /**
    * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
    * Reverts when dividing by zero.
    *
    * Counterpart to Solidity's `%` operator. This function uses a `revert`
    * opcode (which leaves remaining gas untouched) while Solidity uses an
    * invalid opcode to revert (consuming all remaining gas).
    *
    * Requirements:
    * - The divisor cannot be zero.
    */
  function mod(uint a, uint b) internal pure returns (uint) {
    return mod(a, b, "SafeMath: modulo by zero");
  }

  /**
    * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
    * Reverts with custom message when dividing by zero.
    *
    * Counterpart to Solidity's `%` operator. This function uses a `revert`
    * opcode (which leaves remaining gas untouched) while Solidity uses an
    * invalid opcode to revert (consuming all remaining gas).
    *
    * Requirements:
    * - The divisor cannot be zero.
    *
    * _Available since v2.4.0._
    */
  function mod(uint a, uint b, string memory errorMessage) internal pure returns (uint) {
    require(b != 0, errorMessage);
    return a % b;
  }
}

/**
 * @dev Implementation of the {iERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20Mintable}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin guidelines: functions revert instead
 * of returning `false` on failure. This behavior is nonetheless conventional
 * and does not conflict with the expectations of ERC20 applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {iERC20-approve}.
 */
contract ERC20Base is ERC20Access {
  using SafeMath for uint;

  mapping (address => uint) private _balances;

  mapping (address => mapping (address => uint)) private _allowances;

  uint private _totalSupply;

  /**
   * @dev Internal constructor to ensure this contract can't be deployed alone
   */
  constructor() internal{ }

  /**
   * @dev Returns the amount of tokens in existence.
   */
  function totalSupply()
    public
    view
  returns (uint)
  {
    return _totalSupply;
  }

  /**
   * @dev Returns the amount of tokens owned by `account`.
   */
  function balanceOf(address account)
    public
    view
  returns (uint)
  {
    return _balances[account];
  }

  /**
   * @dev Moves `amount` tokens from the caller's account to `recipient`.
   *
   * Returns a boolean value indicating whether the operation succeeded.
   *
   * Emits a {Transfer} event.
   *
   * Requirements:
   *
   * - `recipient` cannot be the zero address.
   * - the caller must have a balance of at least `amount`.
   */
  function transfer(address recipient, uint amount)
    public
  returns (bool)
  {
    _transfer(msg.sender, recipient, amount);
    return true;
  }

  /**
   * @dev Returns the remaining number of tokens that `spender` will be
   * allowed to spend on behalf of `owner` through {transferFrom}. This is
   * zero by default.
   *
   * This value changes when {approve} or {transferFrom} are called.
   */
  function allowance(address owner, address spender)
    public
    view
  returns (uint)
  {
    return _allowances[owner][spender];
  }

  /**
   * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
   *
   * Returns a boolean value indicating whether the operation succeeded.
   *
   * IMPORTANT: 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
   *
   * Emits an {Approval} event.
   *
   * Requirements:
   *
   * - `spender` cannot be the zero address.
   */
  function approve(address spender, uint amount)
    public
  returns (bool)
  {
    _approve(msg.sender, spender, amount);
    return true;
  }

  /**
   * @dev Moves `amount` tokens from `sender` to `recipient` using the
   * allowance mechanism. `amount` is then deducted from the caller's
   * allowance.
   *
   * Returns a boolean value indicating whether the operation succeeded.
   *
   * Emits a {Transfer} event.
   *
   * Emits an {Approval} event indicating the updated allowance. This is not
   * required by the EIP. See the note at the beginning of {ERC20};
   *
   * Requirements:
   * - `sender` and `recipient` cannot be the zero address.
   * - `sender` must have a balance of at least `amount`.
   * - the caller must have allowance for `sender`'s tokens of at least
   * `amount`.
   */
  function transferFrom(address sender, address recipient, uint amount)
    public
  returns (bool)
  {
    _transfer(sender, recipient, amount);
    _approve(sender, msg.sender, _allowances[sender][msg.sender].sub(amount, "ERC20: transfer amount exceeds allowance"));
    return true;
  }

  /**
    * @dev Atomically increases the allowance granted to `spender` by the caller.
    *
    * This is an alternative to {approve} that can be used as a mitigation for
    * problems described in {iERC20-approve}.
    *
    * Emits an {Approval} event indicating the updated allowance.
    *
    * Requirements:
    *
    * - `spender` cannot be the zero address.
    */
  function increaseAllowance(address spender, uint addedValue)
    public
  returns (bool)
  {
    _approve(msg.sender, spender, _allowances[msg.sender][spender].add(addedValue));
    return true;
  }

  /**
    * @dev Atomically decreases the allowance granted to `spender` by the caller.
    *
    * This is an alternative to {approve} that can be used as a mitigation for
    * problems described in {iERC20-approve}.
    *
    * Emits an {Approval} event indicating the updated allowance.
    *
    * Requirements:
    *
    * - `spender` cannot be the zero address.
    * - `spender` must have allowance for the caller of at least
    * `subtractedValue`.
    */
  function decreaseAllowance(address spender, uint subtractedValue)
    public
  returns (bool)
  {
    _approve(msg.sender, spender, _allowances[msg.sender][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
    return true;
  }

  /**
    * @dev Moves tokens `amount` from `sender` to `recipient`.
    *
    * This is internal function is equivalent to {transfer}, and can be used to
    * e.g. implement automatic token fees, slashing mechanisms, etc.
    *
    * Emits a {Transfer} event.
    *
    * Requirements:
    *
    * - `sender` cannot be the zero address.
    * - `recipient` cannot be the zero address.
    * - `sender` must have a balance of at least `amount`.
    */
  function _transfer(address sender, address recipient, uint amount)
    internal
  {
    require(sender != address(0), "ERC20: transfer from the zero address");
    require(recipient != address(0), "ERC20: transfer to the zero address");

    _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
    _balances[recipient] = _balances[recipient].add(amount);
    emit Transfer(sender, recipient, amount);
  }

  /** @dev Creates `amount` tokens and assigns them to `account`, increasing
    * the total supply.
    *
    * Emits a {Transfer} event with `from` set to the zero address.
    *
    * Requirements
    *
    * - `to` cannot be the zero address.
    */
  function _mint(address account, uint amount)
    internal
  {
    require(account != address(0), "ERC20: mint to the zero address");

    _totalSupply = _totalSupply.add(amount);
    _balances[account] = _balances[account].add(amount);
    emit Transfer(address(0), account, amount);
  }

  /**
    * @dev Destroys `amount` tokens from `account`, reducing the
    * total supply.
    *
    * Emits a {Transfer} event with `to` set to the zero address.
    *
    * Requirements
    *
    * - `account` cannot be the zero address.
    * - `account` must have at least `amount` tokens.
    */
  function _burn(address account, uint amount)
    internal
  {
    require(account != address(0), "ERC20: burn from the zero address");

    _balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
    _totalSupply = _totalSupply.sub(amount);
    emit Transfer(account, address(0), amount);
  }

  /**
    * @dev Sets `amount` as the allowance of `spender` over the `owner`s tokens.
    *
    * This is internal function is equivalent to `approve`, and can be used to
    * e.g. set automatic allowances for certain subsystems, etc.
    *
    * Emits an {Approval} event.
    *
    * Requirements:
    *
    * - `owner` cannot be the zero address.
    * - `spender` cannot be the zero address.
    */
  function _approve(address owner, address spender, uint amount)
    internal
  {
    require(owner != address(0), "ERC20: approve from the zero address");
    require(spender != address(0), "ERC20: approve to the zero address");

    _allowances[owner][spender] = amount;
    emit Approval(owner, spender, amount);
  }
}



// @title iSupportContract
// @dev The interface for cross-contract calls to Support contracts
// @author GAME Credits Platform (https://www.gamecredits.org)
// (c) 2020 GAME Credits. All Rights Reserved. This code is not open source.
contract iSupportContract {

  function isSupportContract() external pure returns(bool);

  function getGameAccountSupport(uint _game, address _account) external view returns(uint);
  function updateSupport(uint _game, address _account, uint _supportAmount) external;
  function fundRewardsPool(uint _amount, uint _startWeek, uint _numberOfWeeks) external;

  function receiveGameCredits(uint _game, address _account, uint _tokenId, uint _payment, bytes32 _data) external;
  function receiveLoyaltyPayment(uint _game, address _account, uint _tokenId, uint _payment, bytes32 _data) external;
  function contestEntry(uint _game, address _account, uint _tokenId, uint _contestId, uint _payment, bytes32 _data) external;

  event GameCreditsPayment(uint indexed _game, address indexed account, uint indexed _tokenId, uint _payment, bytes32 _data);
  event LoyaltyPayment(uint indexed _game, address indexed account, uint indexed _tokenId, uint _payment, bytes32 _data);
  event EnterContest(uint indexed _game, address indexed account, uint _tokenId, uint indexed _contestId, uint _payment, bytes32 _data);
}


// @title Game Credits ERC20 Token Contract
// @dev Contract for managing the GAME ERC20 token
// @author GAME Credits Platform (https://www.gamecredits.org)
// (c) 2020 GAME Credits. All Rights Reserved. This code is not open source.
contract GameCredits is ERC20Base {

  string public url = "https://www.gamecredits.org";
  string public name = "GAME Credits";
  string public symbol = "GAME";
  uint8 public decimals = 18;

  // Listing of all the support contracts registered to this contract
  // @notice Support contracts can be added, but cannot be removed. If an erroneous one
  //   is added, it is up to users to not call it
  mapping (address => iSupportContract) supportContracts;

  event SupportContractAdded(address indexed supportContract);

  // @notice The constructor mints 200 million GAME tokens to the contract creator
  //   There is no other way to create GAME tokens, capping supply at 200 million
  constructor()
    public
  {
    _mint(msg.sender, 200 * 10 ** 24);
  }

  // @notice The fallback function reverts
  function ()
    external
    payable
  {
    revert("this contract is not payable");
  }

  // @dev Used to set the support contract reference for this contract
  // @param _supportContract - the address of the support contract
  // @notice This is a one-shot function. Once the address is set, it's locked
  function setSupportContract(address _supportContract)
    external
    ownerOrRecovery
  {
    iSupportContract supportContract = iSupportContract(_supportContract);
    require(supportContract.isSupportContract(), "Must implement isSupportContract");
    supportContracts[_supportContract] = supportContract;
    emit SupportContractAdded(_supportContract);
  }

  // @dev Lets any user add funds to the supporting pool spread over a period of weeks
  // @param _rewardsContract - the contract that will be funded
  // @param _amount - the total amount of GAME tokens to add to the support pool
  // @param _startWeek - the first week in which tokens will be added to the support pool
  // @param _numberOfWeeks - the number of weeks over which the _amount will be spread
  // @notice - The _amount must be exactly divisible by the _numberOfWeeks
  function fundRewardsContract(address _rewardsContract, uint _amount, uint _startWeek, uint _numberOfWeeks)
    external
  {
    iSupportContract rewardsContract = _getSupportContract(_rewardsContract);
    _transfer(msg.sender, address(rewardsContract), _amount);
    rewardsContract.fundRewardsPool(_amount, _startWeek, _numberOfWeeks);
  }

  // @dev Sets the sender's support on a game to the specific value
  // @param _rewardsContract - the contract that will set support
  // @param _game - the game to be supported
  // @param _increase - the amount support to be added
  // @notice - this will throw if the user has insufficient tokens available
  // @notice - this does not throw on an _amount of 0
  function setSupport(address _rewardsContract, uint _game, uint _amount) public {
    iSupportContract rewardsContract = _getSupportContract(_rewardsContract);
    _setSupport(rewardsContract, msg.sender, _game, _amount);
  }

  // @dev Increases the sender's support on a game
  // @param _rewardsContract - the contract that will increase support
  // @param _game - the game to be supported
  // @param _increase - the amount support to be added
  // @notice - this will throw if the user has insufficient tokens available
  // @notice - this will throw if an increase of 0 is requested
  function increaseSupport(address _rewardsContract, uint _game, uint _increase) public {
    iSupportContract rewardsContract = _getSupportContract(_rewardsContract);
    uint supportBalance = rewardsContract.getGameAccountSupport(_game, msg.sender);
    require(_increase > 0, "can't increase by 0");
    _setSupport(rewardsContract, msg.sender, _game, supportBalance.add(_increase));
  }

  // @dev Reduces the sender's support on a game
  // @param _rewardsContract - the contract that will decrease support
  // @param _game - the game to be supported
  // @param _decrease - the amount support to be reduced
  // @notice - this will throw if the user has fewer tokens support
  // @notice - this will throw if a decrease of 0 is requested
  function decreaseSupport(address _rewardsContract, uint _game, uint _decrease) public {
    iSupportContract rewardsContract = _getSupportContract(_rewardsContract);
    uint supportBalance = rewardsContract.getGameAccountSupport(_game, msg.sender);
    require(_decrease > 0, "can't decrease by 0");
    _setSupport(rewardsContract, msg.sender, _game, supportBalance.sub(_decrease));
  }

  // @dev Transfers tokens to a set of user accounts, and sets their support for them
  // @param _rewardsContract - the contract that will set the support
  // @param _recipients - the accounts to receive the tokens
  // @param _games - the games to be supported
  // @param _amounts - the amount of tokens to be transferred
  // @notice - this function is designed for air dropping by/to a game
  function airDropAndSupport(
    address _rewardsContract,
    address[] calldata _recipients,
    uint[] calldata _games,
    uint[] calldata _amounts
  )
    external
  {
    iSupportContract rewardsContract = _getSupportContract(_rewardsContract);
    require(_recipients.length == _games.length, "must be equal number of recipients and games");
    require(_recipients.length == _amounts.length, "must be equal number of recipients and amounts");
    for (uint i = 0; i < _recipients.length; i++) {
      require(_recipients[i] != msg.sender, "can't airDrop to your own account");
      uint supportBalance = rewardsContract.getGameAccountSupport(_games[i], _recipients[i]);
      uint supportAmount = _amounts[i].add(supportBalance);
      _transfer(msg.sender, _recipients[i], _amounts[i]);
      _setSupport(rewardsContract, _recipients[i], _games[i], supportAmount);
    }
  }

  // @dev Pays an amount of game credits to a given support contract.
  //   The support contract will often route the payment to multiple destinations.
  //   The exact functionality will depend on the support contract in question.
  //   Not all support contracts will implement the receiveGameCredits function
  // @param _supportContract - the support contract to be called
  // @param _game - a field to enter a game Id if it is required by the support contract
  // @param _tokenId - a field to enter a token Id if it is required by the support contract
  // @param _payment - the amount of GAME Credits that will be paid
  // @param _data - a field to enter additional data if it is required by the support contract
  function payGameCredits(
    address _supportContract,
    uint _game,
    uint _tokenId,
    uint _payment,
    bytes32 _data
  )
    external
  {
    iSupportContract supportContract = _getSupportContract(_supportContract);

    _transfer(msg.sender, _supportContract, _payment);
    supportContract.receiveGameCredits(_game, msg.sender, _tokenId, _payment, _data);
  }

  // @dev Requests a payment of an amount of Loyalty Points in the sidechain.
  //   The payment is made on the sidechain by the oracle.
  //   There is no error checking, other than ensuring the game exists.
  //   The exact functionality will depend on the oracle, and the sidechain contract in question.
  //   Not all support contracts will implement the payLoyaltyPoints function, and even
  //     if they do, the oracle might not pick it up.
  // @param _supportContract - the support contract to be called
  // @param _game - a field to enter a game Id if it is required by the support contract
  // @param _tokenId - a field to enter a token Id if it is required by the support contract
  // @param _payment - the amount of Loyalty Points requested to be paid
  // @param _data - a field to enter additional data if it is required by the support contract
  function payLoyaltyPoints(
    address _supportContract,
    uint _game,
    uint _tokenId,
    uint _loyaltyPayment,
    bytes32 _data
  )
    external
  {
    iSupportContract supportContract = _getSupportContract(_supportContract);
    supportContract.receiveLoyaltyPayment(_game, msg.sender, _tokenId, _loyaltyPayment, _data);
  }

  // @dev Pays an amount of game credits to a given support contract.
  //   The support contract will often route the payment to multiple destinations.
  //   The exact functionality will depend on the support contract in question.
  //   Not all support contracts will implement the contestEntry function
  // @param _supportContract - the support contract to be called
  // @param _game - a field to enter a game Id if it is required by the support contract
  // @param _tokenId - a field to enter a token Id if it is required by the support contract
  // @param _contestId - a field to enter a contest Id if it is required by the support contract
  // @param _payment - the amount of GAME Credits that will be paid
  // @param _data - a field to enter additional data if it is required by the support contract
  function enterContest(
    address _supportContract,
    uint _game,
    uint _tokenId,
    uint _contestId,
    uint _payment,
    bytes32 _data
  )
    external
  {
    iSupportContract supportContract = _getSupportContract(_supportContract);
    _transfer(msg.sender, _supportContract, _payment);
    supportContract.contestEntry(_game, msg.sender, _tokenId, _contestId, _payment, _data);
  }

  // @dev returns the iSupportContract for the input address. Throws if it doesn't exist.
  // @param _contractAddress - the address to test
  // @returns iSupportContract - the support contract address, typed as iSupportContract
  function _getSupportContract(address _contractAddress)
    internal
    view
  returns (iSupportContract)
  {
    iSupportContract supportContract = supportContracts[_contractAddress];
    require(address(supportContract) != address(0), "support contract must be valid");
    return supportContract;
  }

  // @dev Sends the new support level to the rewards contract; transfers tokens to the
  //   contract (for increased support) or from the contract (for decreased support)
  // @param iSupportContract - the contract that will set the support
  // @param _supporter - the account doing the supporting
  // @param _game - the game to be supported
  // @param _amount - the amount of tokens to set the support to
  function _setSupport(iSupportContract rewardsContract, address _supporter, uint _game, uint _amount)
    internal
  {
    // get user's balance from rewards contract
    uint supportBalance = rewardsContract.getGameAccountSupport(_game, _supporter);

    if (_amount == supportBalance) {
      return;
    } else if (_amount > supportBalance) {
      // transfer diff to rewards contract
      _transfer(_supporter, address(rewardsContract), _amount.sub(supportBalance));
    } else if (_amount < supportBalance) {
      // transfer diff to account
      _transfer(address(rewardsContract), _supporter, supportBalance.sub(_amount));
    }
    rewardsContract.updateSupport(_game, _supporter, _amount);
  }
}

{
  "compilationTarget": {
    "GameCredits.sol": "GameCredits"
  },
  "evmVersion": "istanbul",
  "libraries": {},
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": []
}