// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COMPONENTS_ARC_METRICS_ARC_METRICS_SERVICE_H_
#define COMPONENTS_ARC_METRICS_ARC_METRICS_SERVICE_H_

#include <vector>

#include "base/macros.h"
#include "base/memory/weak_ptr.h"
#include "base/threading/thread_checker.h"
#include "base/timer/timer.h"
#include "components/arc/arc_service.h"
#include "components/arc/common/metrics.mojom.h"
#include "components/arc/common/process.mojom.h"
#include "components/arc/instance_holder.h"
#include "components/arc/metrics/oom_kills_monitor.h"
#include "mojo/public/cpp/bindings/binding.h"

namespace arc {

class ArcBridgeService;

// Collects information from other ArcServices and send UMA metrics.
class ArcMetricsService
    : public ArcService,
      public InstanceHolder<mojom::MetricsInstance>::Observer,
      public mojom::MetricsHost {
 public:
  explicit ArcMetricsService(ArcBridgeService* bridge_service);
  ~ArcMetricsService() override;

  // InstanceHolder<mojom::MetricsInstance>::Observer overrides.
  void OnInstanceReady() override;
  void OnInstanceClosed() override;

  // Implementations for InstanceHolder<mojom::ProcessInstance>::Observer.
  void OnProcessInstanceReady();
  void OnProcessInstanceClosed();

  // MetricsHost overrides.
  void ReportBootProgress(
      std::vector<mojom::BootProgressEventPtr> events) override;

 private:
  bool CalledOnValidThread();
  void RequestProcessList();
  void ParseProcessList(std::vector<mojom::RunningAppProcessInfoPtr> processes);

  // DBus callbacks.
  void OnArcStartTimeRetrieved(bool success, base::TimeTicks arc_start_time);

 private:
  // Adapter to be able to also observe ProcessInstance events.
  class ProcessObserver
      : public InstanceHolder<mojom::ProcessInstance>::Observer {
   public:
    explicit ProcessObserver(ArcMetricsService* arc_metrics_service);
    ~ProcessObserver() override;

   private:
    // InstanceHolder<mojom::ProcessInstance>::Observer overrides.
    void OnInstanceReady() override;
    void OnInstanceClosed() override;

    ArcMetricsService* arc_metrics_service_;
  };

  mojo::Binding<mojom::MetricsHost> binding_;

  ProcessObserver process_observer_;
  base::ThreadChecker thread_checker_;
  base::RepeatingTimer timer_;

  OomKillsMonitor::Handle oom_kills_monitor_handle_;

  base::TimeTicks arc_start_time_;

  // Always keep this the last member of this class to make sure it's the
  // first thing to be destructed.
  base::WeakPtrFactory<ArcMetricsService> weak_ptr_factory_;

  DISALLOW_COPY_AND_ASSIGN(ArcMetricsService);
};

}  // namespace arc

#endif  // COMPONENTS_ARC_METRICS_ARC_METRICS_SERVICE_H_