//------------------------------------------------------------------------------
/*
    Copyright (c) 2011-2013, OpenCoin, Inc.
*/
//==============================================================================

SETUP_LOG (RPCServer)

// VFALCO TODO Make this a language constant
#ifndef RPC_MAXIMUM_QUERY
#define RPC_MAXIMUM_QUERY   (1024*1024)
#endif

class RPCServerImp
    : public RPCServer
{
public:
    typedef boost::shared_ptr<RPCServer> pointer;

    RPCServerImp (
        boost::asio::io_service& io_service,
        boost::asio::ssl::context& context,
        NetworkOPs* nopNetwork)
        : mNetOps (nopNetwork)
        , mSocket (io_service, context)
        , mStrand (io_service)
    {
        mRole = RPCHandler::GUEST;
    }

    //--------------------------------------------------------------------------

private:
    void handle_write (const boost::system::error_code& e)
    {
        //Log::out() << "async_write complete " << e;

        if (!e)
        {
            HTTPRequest::Action action = mHTTPRequest.requestDone (false);

            if (action == HTTPRequest::haCLOSE_CONN)
            {
                mSocket.async_shutdown (mStrand.wrap (boost::bind (
                    &RPCServerImp::handle_shutdown,
                    boost::static_pointer_cast <RPCServerImp> (shared_from_this()),
                    boost::asio::placeholders::error)));
            }
            else
            {
                boost::asio::async_read_until (
                    mSocket,
                    mLineBuffer,
                    "\r\n",
                    mStrand.wrap (boost::bind (
                        &RPCServerImp::handle_read_line,
                        boost::static_pointer_cast <RPCServerImp> (shared_from_this()),
                        boost::asio::placeholders::error)));
            }
        }

        if (e != boost::asio::error::operation_aborted)
        {
            //connection_manager_.stop(shared_from_this());
        }
    }

    //--------------------------------------------------------------------------

    void handle_read_line (const boost::system::error_code& e)
    {
        if (e)
            return;

        HTTPRequest::Action action = mHTTPRequest.consume (mLineBuffer);

        if (action == HTTPRequest::haDO_REQUEST)
        {
            // request with no body
            WriteLog (lsWARNING, RPCServer) << "RPC HTTP request with no body";

            mSocket.async_shutdown (mStrand.wrap (boost::bind (
                &RPCServerImp::handle_shutdown,
                boost::static_pointer_cast <RPCServerImp> (shared_from_this ()),
                boost::asio::placeholders::error)));

            return;
        }
        else if (action == HTTPRequest::haREAD_LINE)
        {
            boost::asio::async_read_until (
                mSocket,
                mLineBuffer,
                "\r\n",
                mStrand.wrap (boost::bind (
                    &RPCServerImp::handle_read_line,
                    boost::static_pointer_cast <RPCServerImp> (shared_from_this ()),
                    boost::asio::placeholders::error)));
        }
        else if (action == HTTPRequest::haREAD_RAW)
        {
            int rLen = mHTTPRequest.getDataSize ();

            if ((rLen < 0) || (rLen > RPC_MAXIMUM_QUERY))
            {
                WriteLog (lsWARNING, RPCServer) << "Illegal RPC request length " << rLen;

                mSocket.async_shutdown (mStrand.wrap (boost::bind (
                    &RPCServerImp::handle_shutdown,
                    boost::static_pointer_cast <RPCServerImp> (shared_from_this ()),
                    boost::asio::placeholders::error)));

                return;
            }

            int alreadyHave = mLineBuffer.size ();

            if (alreadyHave < rLen)
            {
                mQueryVec.resize (rLen - alreadyHave);

                boost::asio::async_read (
                    mSocket,
                    boost::asio::buffer (mQueryVec),
                    mStrand.wrap (boost::bind (
                        &RPCServerImp::handle_read_req,
                        boost::static_pointer_cast <RPCServerImp> (shared_from_this ()),
                        boost::asio::placeholders::error)));

                WriteLog (lsTRACE, RPCServer) << "Waiting for completed request: " << rLen;
            }
            else
            {
                // we have the whole thing
                mQueryVec.resize (0);
                handle_read_req (e);
            }
        }
        else
        {
            mSocket.async_shutdown (mStrand.wrap (boost::bind (
                &RPCServerImp::handle_shutdown,
                boost::static_pointer_cast <RPCServerImp> (shared_from_this ()),
                boost::asio::placeholders::error)));
        }
    }

    //--------------------------------------------------------------------------

    void handle_read_req (const boost::system::error_code& ec)
    {
        std::string req;

        if (mLineBuffer.size ())
        {
            req.assign (boost::asio::buffer_cast<const char*> (mLineBuffer.data ()), mLineBuffer.size ());
            mLineBuffer.consume (mLineBuffer.size ());
        }

        req += strCopy (mQueryVec);

        if (!HTTPAuthorized (mHTTPRequest.peekHeaders ()))
            mReplyStr = HTTPReply (403, "Forbidden");
        else
            mReplyStr = handleRequest (req);

        boost::asio::async_write (
            mSocket,
            boost::asio::buffer (mReplyStr),
            mStrand.wrap (boost::bind (
                &RPCServerImp::handle_write,
                boost::static_pointer_cast <RPCServerImp> (shared_from_this ()),
                boost::asio::placeholders::error)));
    }

    //--------------------------------------------------------------------------

    void handle_shutdown (const boost::system::error_code& ec)
    {
        // nothing to do, we just keep the object alive
    }

    //--------------------------------------------------------------------------

    std::string handleRequest (const std::string& requestStr)
    {
        WriteLog (lsTRACE, RPCServer) << "handleRequest " << requestStr;

        Json::Value id;

        // Parse request
        Json::Value     jvRequest;
        Json::Reader    reader;

        if (!reader.parse (requestStr, jvRequest) || jvRequest.isNull () || !jvRequest.isObject ())
            return (HTTPReply (400, "unable to parse request"));

        // Parse id now so errors from here on will have the id
        id = jvRequest["id"];

        // Parse method
        Json::Value valMethod = jvRequest["method"];

        if (valMethod.isNull ())
            return (HTTPReply (400, "null method"));

        if (!valMethod.isString ())
            return (HTTPReply (400, "method is not string"));

        std::string strMethod = valMethod.asString ();

        // Parse params
        Json::Value valParams = jvRequest["params"];

        if (valParams.isNull ())
        {
            valParams = Json::Value (Json::arrayValue);
        }
        else if (!valParams.isArray ())
        {
            return HTTPReply (400, "params unparseable");
        }

        try
        {
            mRole   = iAdminGet (jvRequest, mSocket.PlainSocket ().remote_endpoint ().address ().to_string ());
        }
        catch (...)
        {
            // endpoint already disconnected
            return "";
        }

        if (RPCHandler::FORBID == mRole)
        {
            // XXX This needs rate limiting to prevent brute forcing password.
            return HTTPReply (403, "Forbidden");
        }

        RPCHandler mRPCHandler (mNetOps);

        WriteLog (lsINFO, RPCServer) << valParams;
        LoadType loadType = LT_RPCReference;
        Json::Value result = mRPCHandler.doRpcCommand (strMethod, valParams, mRole, &loadType);

        // VFALCO NOTE We discard loadType since there is no endpoint to punish

        WriteLog (lsINFO, RPCServer) << result;

        std::string strReply = JSONRPCReply (result, Json::Value (), id);

        return HTTPReply (200, strReply);
    }

    //--------------------------------------------------------------------------

    AutoSocket& getSocket ()
    {
        return mSocket;
    }

    //--------------------------------------------------------------------------

    boost::asio::ip::tcp::socket& getRawSocket ()
    {
        return mSocket.PlainSocket ();
    }

    //--------------------------------------------------------------------------

    void connected ()
    {
        //Log::out() << "RPC request";
        boost::asio::async_read_until (
            mSocket,
            mLineBuffer,
            "\r\n",
            mStrand.wrap (boost::bind (
                &RPCServerImp::handle_read_line,
                boost::static_pointer_cast <RPCServerImp> (shared_from_this ()),
                boost::asio::placeholders::error)));
    }

    //--------------------------------------------------------------------------

    std::string getRemoteAddressText ()
    {
        std::string address;

        address = mSocket.PlainSocket ().remote_endpoint ().address ().to_string ();

        return address;
    }

private:
    NetworkOPs* const mNetOps;

    AutoSocket mSocket;
    boost::asio::io_service::strand mStrand;

    boost::asio::streambuf mLineBuffer;
    Blob mQueryVec;
    std::string mReplyStr;

    HTTPRequest mHTTPRequest;

    int mRole;
};

//------------------------------------------------------------------------------

RPCServer::pointer RPCServer::New (
    boost::asio::io_service& io_service,
    boost::asio::ssl::context& context,
    NetworkOPs* mNetOps)
{
    return pointer (new RPCServerImp (io_service, context, mNetOps));
}