contract GpsFactRegistryAdapter is IQueryableFactRegistry, Identity {

    IQueryableFactRegistry public gpsContract;
    uint256 public programHash;

    constructor(
        IQueryableFactRegistry gpsStatementContract, uint256 programHash_)
        public
    {
        gpsContract = gpsStatementContract;
        programHash = programHash_;
    }

    function identify()
        external pure virtual override
        returns(string memory)
    {
        // TODO(ilya, 18/12/2020): Concat gpsContract identity.
        return "StarkWare_GpsFactRegistryAdapter_2020_1";
    }

    /*
      Checks if a fact has been verified.
    */
    function isValid(bytes32 fact)
        external view override
        returns(bool)
    {
        return gpsContract.isValid(keccak256(abi.encode(programHash, fact)));
    }


    /*
      Indicates whether at least one fact was registered.
    */
    function hasRegisteredFact()
        external view override
        returns(bool)
    {
        return gpsContract.hasRegisteredFact();
    }
}
/*
 The GpsFactRegistryAdapter contract is used as an adapter between a Dapp contract and a GPS fact
 registry. An isValid(fact) query is answered by querying the GPS contract about
 new_fact := keccak256(programHash, fact).
 
 The goal of this contract is to simplify the verifier upgradability logic in the Dapp contract
 by making the upgrade flow the same regardless of whether the update is to the program hash or
 the gpsContractAddress.
 */
function hasRegisteredFact()
        external view override
        returns(bool)
    {
        return gpsContract.hasRegisteredFact();
    }
/*
 Indicates whether at least one fact was registered.
 */