/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserve.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License. */

#pragma once

#include "paddle/framework/lod_tensor.h"
#include "paddle/framework/scope.h"
#include "paddle/framework/selected_rows.h"
#include "paddle/framework/var_type.h"
#include "paddle/operators/detail/simple_block_queue.h"

#include "paddle/operators/detail/send_recv.grpc.pb.h"
#include "paddle/operators/detail/send_recv.pb.h"

#include <grpc++/grpc++.h>
#include <grpc/support/log.h>
#include <thread>
#include "paddle/operators/detail/sendrecvop_utils.h"

namespace paddle {
namespace operators {
namespace detail {

typedef std::pair<std::string, sendrecv::VariableMessage> MessageWithName;
class RequestBase;

class AsyncGRPCServer final : public sendrecv::SendRecvService::Service {
 public:
  explicit AsyncGRPCServer(const std::string &address) : address_(address) {}

  void RunSyncUpdate();

  void Reset();

  void Done();

  void SetScope(framework::Scope *scope) { scope_ = scope; }

  void SetDevCtx(const platform::DeviceContext *dev_ctx) { dev_ctx_ = dev_ctx; }

  const MessageWithName Get() { return this->var_recv_queue_.Pop(); }

  void Push(const MessageWithName &msg) { this->var_recv_queue_.Push(msg); }

  void ShutDown();

 protected:
  void Wait();
  void HandleRequest(bool wait, grpc::ServerCompletionQueue *cq,
                     std::string cq_name,
                     std::function<void()> TryToRegisterNewOne);
  void TryToRegisterNewSendOne();
  void TryToRegisterNewGetOne();
  void SetFinishOrDelete(RequestBase *&last);
  void ShutdownQueue();

 private:
  std::mutex cq_mutex_;
  volatile bool is_shut_down_ = false;
  std::unique_ptr<grpc::ServerCompletionQueue> cq_send_;
  std::unique_ptr<grpc::ServerCompletionQueue> cq_get_;

  sendrecv::SendRecvService::AsyncService service_;
  std::unique_ptr<grpc::Server> server_;

  std::string address_;
  framework::Scope *scope_;
  const platform::DeviceContext *dev_ctx_;
  // received variable from RPC, operators fetch variable from this queue.
  SimpleBlockQueue<MessageWithName> var_recv_queue_;

  // condition of the sub program
  std::mutex mutex_;
  volatile mutable bool done_;
  std::condition_variable condition_;

  std::unique_ptr<std::thread> t_send_;
  std::unique_ptr<std::thread> t_get_;
};

};  // namespace detail
};  // namespace operators
};  // namespace paddle