// Copyright (c) Facebook, Inc. and its affiliates.
//
// 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.

#include "rsocket/benchmarks/Fixture.h"
#include "rsocket/benchmarks/Latch.h"

#include <folly/Benchmark.h>
#include <folly/portability/GFlags.h>

#include "rsocket/RSocket.h"

using namespace rsocket;

DEFINE_int32(server_threads, 8, "number of server threads to run");
DEFINE_int32(
    override_client_threads,
    0,
    "control the number of client threads (defaults to the number of clients)");
DEFINE_int32(clients, 10, "number of clients to run");
DEFINE_int32(items, 1000000, "number of items to fire-and-forget, in total");

namespace {

class Responder : public RSocketResponder {
 public:
  Responder(Latch& latch) : latch_{latch} {}

  void handleFireAndForget(Payload, StreamId) override {
    latch_.post();
  }

 private:
  Latch& latch_;
};
} // namespace

BENCHMARK(FireForgetThroughput, n) {
  (void)n;

  Latch latch{static_cast<size_t>(FLAGS_items)};

  std::unique_ptr<Fixture> fixture;
  Fixture::Options opts;

  BENCHMARK_SUSPEND {
    auto responder = std::make_shared<Responder>(latch);

    opts.serverThreads = FLAGS_server_threads;
    opts.clients = FLAGS_clients;
    if (FLAGS_override_client_threads > 0) {
      opts.clientThreads = FLAGS_override_client_threads;
    }

    fixture = std::make_unique<Fixture>(opts, std::move(responder));

    LOG(INFO) << "Running:";
    LOG(INFO) << "  Server with " << opts.serverThreads << " threads.";
    LOG(INFO) << "  " << opts.clients << " clients across "
              << fixture->workers.size() << " threads.";
    LOG(INFO) << "  Running " << FLAGS_items << " requests in total.";
  }

  for (int i = 0; i < FLAGS_items; ++i) {
    for (auto& client : fixture->clients) {
      client->getRequester()
          ->fireAndForget(Payload("TcpFireAndForget"))
          ->subscribe(
              std::make_shared<yarpl::single::SingleObserverBase<void>>());
    }
  }

  constexpr std::chrono::minutes timeout{5};
  if (!latch.timed_wait(timeout)) {
    LOG(ERROR) << "Timed out!";
  }
}