//
// Copyright (C) 2015 The Android Open Source Project
//
// 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.
//

#ifndef SHILL_DAEMON_TASK_H_
#define SHILL_DAEMON_TASK_H_

#include <memory>
#include <string>
#include <vector>

#include <base/callback.h>
#include <base/macros.h>

#include "shill/event_dispatcher.h"
#if !defined(DISABLE_WIFI)
#include "shill/wifi/callback80211_metrics.h"
#endif  // DISABLE_WIFI

namespace shill {

class Config;
class ControlInterface;
class DHCPProvider;
class Error;
class Manager;
class Metrics;
class ProcessManager;
class RoutingTable;
class RTNLHandler;

#if !defined(DISABLE_WIFI)
class NetlinkManager;
#endif  // DISABLE_WIFI

// DaemonTask contains most of the logic used in ShillDaemon (e.g.
// init/shutdown, start/stop). This class is kept separate from ShillDaemon to
// ensure that it does not inherit brillo::Daemon. This is necessary for
// DaemonTask unit tests to run, since the base::ExitManager inherited from
// brillo::Daemon cannot coexist with the base::ExitManager used by shill's
// test_runner.cc.
class DaemonTask {
 public:
  // Run-time settings retrieved from command line.
  struct Settings {
    Settings()
        : ignore_unknown_ethernet(false),
          minimum_mtu(0),
          passive_mode(false),
          use_portal_list(false) {}
    std::string accept_hostname_from;
    std::string default_technology_order;
    std::vector<std::string> device_blacklist;
    std::vector<std::string> device_whitelist;
    std::vector<std::string> dhcpv6_enabled_devices;
    bool ignore_unknown_ethernet;
    int minimum_mtu;
    bool passive_mode;
    std::string portal_list;
    std::string prepend_dns_servers;
    bool use_portal_list;
  };

  DaemonTask(const Settings& settings, Config* config);
  virtual ~DaemonTask();

  void Init();

  // Starts the termination actions in the manager. Returns true if
  // termination actions have completed synchronously, and false
  // otherwise. Arranges for |completion_callback| to be invoked after
  // all asynchronous work completes, but ignores
  // |completion_callback| if no asynchronous work is required.
  virtual bool Quit(const base::Closure& completion_callback);

  // Break the termination loop started in DaemonTask::OnShutdown. Invoked
  // after shill completes its termination tasks during shutdown.
  void BreakTerminationLoop();

 private:
  friend class DaemonTaskTest;
  friend class DaemonTaskForTest;

  void Start();

  // Apply run-time settings to the manager.
  void ApplySettings();

  // Called when the termination actions are completed.
  void TerminationActionsCompleted(const Error& error);

  // Calls Stop() and then causes the dispatcher message loop to terminate and
  // return to the main function which started the daemon.
  void StopAndReturnToMain();

  void Stop();

  Settings settings_;
  Config* config_;
  std::unique_ptr<EventDispatcher> dispatcher_;
  // IMPORTANT: |control_| must declared before |manager_|, since the adaptors
  // that Manager and some of its members (e.g. Device) own might hold raw
  // pointers to |control_|. This is currently the case when Binder adaptors are
  // used.
  std::unique_ptr<ControlInterface> control_;
  std::unique_ptr<Metrics> metrics_;
  RTNLHandler* rtnl_handler_;
  RoutingTable* routing_table_;
  DHCPProvider* dhcp_provider_;
  ProcessManager* process_manager_;
#if !defined(DISABLE_WIFI)
  NetlinkManager* netlink_manager_;
  std::unique_ptr<Callback80211Metrics> callback80211_metrics_;
#endif  // DISABLE_WIFI
  std::unique_ptr<Manager> manager_;
  base::Closure termination_completed_callback_;

  DISALLOW_COPY_AND_ASSIGN(DaemonTask);
};

}  // namespace shill

#endif  // SHILL_DAEMON_TASK_H_