//
//  Copyright 2015 Google, Inc.
//
//  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 <base/macros.h>
#include "abstract_message_loop.h"

namespace ipc {
class IPCManager;
}  // namespace ipc

namespace bluetooth {

class CoreStack;
class Settings;

// The Daemon class is a singleton that represents the root of the ownership
// hierarchy. The single instance sets up and owns the main event loop, the IPC
// handlers, global Settings, and the core Bluetooth stack.
class Daemon {
 public:
  // Initializes the daemon. This must be called to at the start of the
  // application to set up the global daemon instance and everything it manages.
  // Returns false in case of a failure.
  static bool Initialize();

  // Cleans up all the resources associated with the global Daemon object.
  static void ShutDown();

  // Assigns the global Daemon instance for testing. Should only be called from
  // test code.
  static void InitializeForTesting(Daemon* test_daemon);

  // Returns the singleton Daemon instance. All classes can interact with the
  // Daemon, obtain its resources etc using this getter.
  static Daemon* Get();

  // The global Settings object. All classes have direct access to this through
  // the Daemon object.
  virtual Settings* GetSettings() const = 0;

  // The main event loop. This should be used for any events and delayed tasks
  // that should be executed on the daemon's main thread.
  virtual btbase::AbstractMessageLoop* GetMessageLoop() const = 0;

  // Starts the daemon's main loop.
  virtual void StartMainLoop() = 0;

 protected:
  Daemon() = default;
  virtual ~Daemon() = default;

 private:
  // Internal instance helper called by Initialize().
  virtual bool Init() = 0;

  DISALLOW_COPY_AND_ASSIGN(Daemon);
};

}  // namespace bluetooth