////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2016 ArangoDB GmbH, Cologne, Germany
///
/// 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.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Simon Grätzer
////////////////////////////////////////////////////////////////////////////////

#ifndef ARANGODB_PREGEL_FEATURE_H
#define ARANGODB_PREGEL_FEATURE_H 1

#include <cstdint>
#include "ApplicationFeatures/ApplicationFeature.h"
#include "Basics/Common.h"
#include "Basics/Mutex.h"

struct TRI_vocbase_t;
namespace arangodb {
namespace pregel {

class Conductor;
class IWorker;
class RecoveryManager;

class PregelFeature final : public application_features::ApplicationFeature {
 public:
  explicit PregelFeature(application_features::ApplicationServer* server);
  ~PregelFeature();

  static PregelFeature* instance();
  static size_t availableParallelism();

  void start() override final;
  void beginShutdown() override final;

  uint64_t createExecutionNumber();
  void addConductor(Conductor* const exec, uint64_t executionNumber);
  std::shared_ptr<Conductor> conductor(uint64_t executionNumber);

  void addWorker(IWorker* const worker, uint64_t executionNumber);
  std::shared_ptr<IWorker> worker(uint64_t executionNumber);

  void cleanupConductor(uint64_t executionNumber);
  void cleanupWorker(uint64_t executionNumber);
  void cleanupAll();

  // ThreadPool* threadPool() { return _threadPool.get(); }
  RecoveryManager* recoveryManager() {
    if (_recoveryManager) {
      return _recoveryManager.get();
    }
    return nullptr;
  }

  static void handleConductorRequest(std::string const& path,
                                     VPackSlice const& body,
                                     VPackBuilder& outResponse);
  static void handleWorkerRequest(TRI_vocbase_t* vocbase,
                                  std::string const& path,
                                  VPackSlice const& body,
                                  VPackBuilder& outBuilder);

 private:
  Mutex _mutex;
  std::unique_ptr<RecoveryManager> _recoveryManager;
  std::unordered_map<uint64_t, std::shared_ptr<Conductor>> _conductors;
  std::unordered_map<uint64_t, std::shared_ptr<IWorker>> _workers;
};
}
}

#endif