/////////////////////////////////////////////////////////////////////////////////
//
//  Copyright (C) 2019-     Equinor ASA
//
//  ResInsight is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  ResInsight is distributed in the hope that it will be useful, but WITHOUT ANY
//  WARRANTY; without even the implied warranty of MERCHANTABILITY or
//  FITNESS FOR A PARTICULAR PURPOSE.
//
//  See the GNU General Public License at <http://www.gnu.org/licenses/gpl.html>
//  for more details.
//
//////////////////////////////////////////////////////////////////////////////////

inline RiaGrpcCallbackInterface::RiaGrpcCallbackInterface()
    : m_state(CREATE_HANDLER)
    , m_status(Status::OK)
{
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
RiaGrpcCallbackInterface::CallState RiaGrpcCallbackInterface::callState() const
{
    return m_state;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
const Status& RiaGrpcCallbackInterface::status() const
{
    return m_status;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
inline void RiaGrpcCallbackInterface::setNextCallState(CallState state)
{
    m_state = state;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
template<typename ServiceT, typename RequestT, typename ReplyT>
RiaGrpcServiceCallback<ServiceT, RequestT, ReplyT>::RiaGrpcServiceCallback(ServiceT* service)
    : m_service(service)
{
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
template<typename ServiceT, typename RequestT, typename ReplyT>
QString RiaGrpcServiceCallback<ServiceT, RequestT, ReplyT>::name() const
{
    QString fullName = QString("%1:%2(%3, %4)")
                           .arg(typeid(ServiceT).name())
                           .arg(methodType())
                           .arg(typeid(RequestT).name())
                           .arg(typeid(ReplyT).name());
    return fullName;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
template<typename ServiceT, typename RequestT, typename ReplyT>
const RequestT& RiaGrpcServiceCallback<ServiceT, RequestT, ReplyT>::request() const
{
    return m_request;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
template<typename ServiceT, typename RequestT, typename ReplyT>
ReplyT& RiaGrpcServiceCallback<ServiceT, RequestT, ReplyT>::reply()
{
    return m_reply;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
template<typename ServiceT, typename RequestT, typename ReplyT>
RiaGrpcUnaryCallback<ServiceT, RequestT, ReplyT>::RiaGrpcUnaryCallback(ServiceT*      service,
                                                             MethodImplT    methodImpl,
                                                             MethodRequestT methodRequest)
    : RiaGrpcServiceCallback<ServiceT, RequestT, ReplyT>(service)
    , m_responder(&m_context)
    , m_methodImpl(methodImpl)
    , m_methodRequest(methodRequest)
{
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
template<typename ServiceT, typename RequestT, typename ReplyT>
RiaGrpcCallbackInterface* RiaGrpcUnaryCallback<ServiceT, RequestT, ReplyT>::createNewFromThis() const
{
    return new RiaGrpcUnaryCallback<ServiceT, RequestT, ReplyT>(this->m_service, this->m_methodImpl, this->m_methodRequest);
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
template<typename ServiceT, typename RequestT, typename ReplyT>
void RiaGrpcUnaryCallback<ServiceT, RequestT, ReplyT>::createRequestHandler(ServerCompletionQueue* completionQueue)
{
    // The Request-method is where the service gets registered to respond to a given request.
    m_methodRequest(*this->m_service, &m_context, &this->m_request, &m_responder, completionQueue, completionQueue, this);
    // Simple unary requests don't need initialisation, so proceed to process as soon as a request turns up.
    this->setNextCallState(RiaGrpcCallbackInterface::PROCESS_REQUEST);
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
template<typename ServiceT, typename RequestT, typename ReplyT>
void RiaGrpcUnaryCallback<ServiceT, RequestT, ReplyT>::onProcessRequest()
{
    // Call request handler method
    this->m_status = m_methodImpl(*this->m_service, &m_context, &this->m_request, &this->m_reply);
    // Simply unary requests are finished as soon as you've done any processing.
    // So next time we receive a new tag on the command queue we should proceed to finish.
    this->setNextCallState(RiaGrpcCallbackInterface::FINISH_REQUEST);
    // Finish will push this callback back on the command queue (now with Finish as the call state).
    m_responder.Finish(this->m_reply, this->m_status, this);
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
template<typename ServiceT, typename RequestT, typename ReplyT>
QString RiaGrpcUnaryCallback<ServiceT, RequestT, ReplyT>::methodType() const
{
    return "RegularMethod";
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
template<typename ServiceT, typename RequestT, typename ReplyT, typename StateHandlerT>
RiaGrpcServerStreamCallback<ServiceT, RequestT, ReplyT, StateHandlerT>::RiaGrpcServerStreamCallback(ServiceT*      service,
                                                                                        MethodImplT    methodImpl,
                                                                                        MethodRequestT methodRequest,
                                                                                        StateHandlerT* stateHandler)
    : RiaGrpcServiceCallback<ServiceT, RequestT, ReplyT>(service)
    , m_responder(&m_context)
    , m_methodImpl(methodImpl)
    , m_methodRequest(methodRequest)
    , m_stateHandler(stateHandler)
{
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
template<typename ServiceT, typename RequestT, typename ReplyT, typename StateHandlerT>
RiaGrpcCallbackInterface* RiaGrpcServerStreamCallback<ServiceT, RequestT, ReplyT, StateHandlerT>::createNewFromThis() const
{
    return new RiaGrpcServerStreamCallback<ServiceT, RequestT, ReplyT, StateHandlerT>(
        this->m_service, m_methodImpl, m_methodRequest, new StateHandlerT);
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
template<typename ServiceT, typename RequestT, typename ReplyT, typename StateHandlerT>
void RiaGrpcServerStreamCallback<ServiceT, RequestT, ReplyT, StateHandlerT>::createRequestHandler(
    ServerCompletionQueue* completionQueue)
{
    // The Request-method is where the service gets registered to respond to a given request.
    m_methodRequest(*this->m_service, &m_context, &this->m_request, &m_responder, completionQueue, completionQueue, this);
    // Server->Client Streaming requests require initialisation. However, we receive the complete request immediately.
    // So can proceed directly to completion of the init request.
    this->setNextCallState(RiaGrpcCallbackInterface::INIT_REQUEST_COMPLETED);
}

//--------------------------------------------------------------------------------------------------
/// Perform initialisation tasks at the time of receiving a complete request
//--------------------------------------------------------------------------------------------------
template<typename ServiceT, typename RequestT, typename ReplyT, typename StateHandlerT>
void RiaGrpcServerStreamCallback<ServiceT, RequestT, ReplyT, StateHandlerT>::onInitRequestCompleted()
{
    // Initialise streaming state handler
    this->m_status = m_stateHandler->init(&this->m_request);

    if (!this->m_status.ok())
    {
        // We have an error. Proceed to finish and report the status
        this->setNextCallState(RiaGrpcCallbackInterface::FINISH_REQUEST);
        m_responder.Finish(this->m_status, this);
        return;
    }

    // Move on to processing and perform the first processing immediately since the client will
    // not request anything more.
    this->setNextCallState(RiaGrpcCallbackInterface::PROCESS_REQUEST);
    this->onProcessRequest();
}

//--------------------------------------------------------------------------------------------------
/// Process a streaming request and send one package
//--------------------------------------------------------------------------------------------------
template<typename ServiceT, typename RequestT, typename ReplyT, typename StateHandlerT>
void RiaGrpcServerStreamCallback<ServiceT, RequestT, ReplyT, StateHandlerT>::onProcessRequest()
{
    this->m_reply = ReplyT(); // Make sure it is reset
   
    // Call request handler method
    this->m_status = m_methodImpl(*this->m_service, &m_context, &this->m_request, &this->m_reply, m_stateHandler.get());

    if (this->m_status.ok())
    {
        // The write call will send data to client AND put this callback back on the command queue
        // so that this method gets called again to send the next stream package.
        m_responder.Write(this->m_reply, this);
    }
    else
    {
        this->setNextCallState(RiaGrpcCallbackInterface::FINISH_REQUEST);
        // Out of range means we're finished but it isn't an error
        if (this->m_status.error_code() == grpc::OUT_OF_RANGE)
        {
            this->m_status = Status::OK;
        }
        // Finish will put this callback back on the command queue, now with a finish state.
        m_responder.Finish(this->m_status, this);
    }
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
template<typename ServiceT, typename RequestT, typename ReplyT, typename StateHandlerT>
QString RiaGrpcServerStreamCallback<ServiceT, RequestT, ReplyT, StateHandlerT>::methodType() const
{
    return "StreamingMethod";
}


//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
template<typename ServiceT, typename RequestT, typename ReplyT, typename StateHandlerT>
RiaGrpcClientStreamCallback<ServiceT, RequestT, ReplyT, StateHandlerT>::RiaGrpcClientStreamCallback(ServiceT*      service,
                                                                                                    MethodImplT    methodImpl,
                                                                                                    MethodRequestT methodRequest,
                                                                                                    StateHandlerT* stateHandler)
    : RiaGrpcServiceCallback<ServiceT, RequestT, ReplyT>(service)
    , m_reader(&m_context)
    , m_methodImpl(methodImpl)
    , m_methodRequest(methodRequest)
    , m_stateHandler(stateHandler)
{
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
template<typename ServiceT, typename RequestT, typename ReplyT, typename StateHandlerT>
RiaGrpcCallbackInterface* RiaGrpcClientStreamCallback<ServiceT, RequestT, ReplyT, StateHandlerT>::createNewFromThis() const
{
    return new RiaGrpcClientStreamCallback<ServiceT, RequestT, ReplyT, StateHandlerT>(
        this->m_service, m_methodImpl, m_methodRequest, new StateHandlerT(true));
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
template<typename ServiceT, typename RequestT, typename ReplyT, typename StateHandlerT>
void RiaGrpcClientStreamCallback<ServiceT, RequestT, ReplyT, StateHandlerT>::createRequestHandler(
    ServerCompletionQueue* completionQueue)
{
    // The Request-method is where the service gets registered to respond to a given request.
    m_methodRequest(*this->m_service, &m_context, &this->m_reader, completionQueue, completionQueue, this);
    // The client->server streaming requires initialisation and each request package is streamed asynchronously
    // So we need to start and complete the init request.
    this->setNextCallState(RiaGrpcCallbackInterface::INIT_REQUEST_STARTED);
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
template<typename ServiceT, typename RequestT, typename ReplyT, typename StateHandlerT>
void RiaGrpcClientStreamCallback<ServiceT, RequestT, ReplyT, StateHandlerT>::onInitRequestStarted()
{
    this->setNextCallState(RiaGrpcCallbackInterface::INIT_REQUEST_COMPLETED);
    // The read call will start reading the request data and push this callback back onto the command queue
    // when the read call is completed.
    m_reader.Read(&this->m_request, this);
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
template<typename ServiceT, typename RequestT, typename ReplyT, typename StateHandlerT>
void RiaGrpcClientStreamCallback<ServiceT, RequestT, ReplyT, StateHandlerT>::onInitRequestCompleted()
{
    this->setNextCallState(RiaGrpcCallbackInterface::PROCESS_REQUEST); 
    // Fully received the stream package so can now init
    this->m_status = m_stateHandler->init(&this->m_request);

    if (!this->m_status.ok())
    {
        // We have an error. Proceed to finish and report the status
        m_reader.FinishWithError(this->m_status, this);
        this->setNextCallState(RiaGrpcCallbackInterface::FINISH_REQUEST);
        return;
    }

    // Start reading and push this back onto the command queue.
    m_reader.Read(&this->m_request, this);
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
template<typename ServiceT, typename RequestT, typename ReplyT, typename StateHandlerT>
void RiaGrpcClientStreamCallback<ServiceT, RequestT, ReplyT, StateHandlerT>::onProcessRequest()
{
    this->m_reply = ReplyT(); // Make sure it is reset
  
    // Call request handler method
    this->m_status = m_methodImpl(*this->m_service, &m_context, &this->m_request, &this->m_reply, m_stateHandler.get());
    
    if (!this->m_status.ok())
    {
        this->setNextCallState(RiaGrpcCallbackInterface::FINISH_REQUEST);
        if (this->m_status.error_code() == grpc::OUT_OF_RANGE)
        {
            m_reader.Finish(this->m_reply, grpc::Status::OK, this);
        }
        else
        {
            m_reader.FinishWithError(this->m_status, this);
        }
    }
    else
    {
        m_reader.Read(&this->m_request, this);
    }
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
template<typename ServiceT, typename RequestT, typename ReplyT, typename StateHandlerT>
void RiaGrpcClientStreamCallback<ServiceT, RequestT, ReplyT, StateHandlerT>::onFinishRequest()
{
    m_stateHandler->finish();
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
template<typename ServiceT, typename RequestT, typename ReplyT, typename StateHandlerT>
QString RiaGrpcClientStreamCallback<ServiceT, RequestT, ReplyT, StateHandlerT>::methodType() const
{
    return "ClientStreamingMethod";
}