chrome/browser/ui/web_applications/web_app_metrics.h

// Copyright 2018 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 CHROME_BROWSER_UI_WEB_APPLICATIONS_WEB_APP_METRICS_H_
#define CHROME_BROWSER_UI_WEB_APPLICATIONS_WEB_APP_METRICS_H_

#include "base/macros.h"
#include "base/memory/weak_ptr.h"
#include "base/power_monitor/power_observer.h"
#include "base/scoped_observer.h"
#include "chrome/browser/banners/app_banner_manager.h"
#include "chrome/browser/engagement/site_engagement_observer.h"
#include "chrome/browser/ui/browser_tab_strip_tracker.h"
#include "chrome/browser/ui/tabs/tab_strip_model_observer.h"
#include "chrome/browser/web_applications/components/web_app_id.h"
#include "components/keyed_service/core/keyed_service.h"

class Profile;
class Browser;
class TabStripModel;

namespace content {
class WebContents;
}  // namespace content

namespace web_app {

// A per-profile keyed service, responsible for all Web Applications-related
// metrics recording (UMA histograms and UKM keyed by web-apps).
class WebAppMetrics : public KeyedService,
                      public SiteEngagementObserver,
                      public BrowserListObserver,
                      public TabStripModelObserver,
                      public banners::AppBannerManager::Observer,
                      public base::PowerObserver {
 public:
  static WebAppMetrics* Get(Profile* profile);

  explicit WebAppMetrics(Profile* profile);
  ~WebAppMetrics() override;

  // SiteEngagementObserver:
  void OnEngagementEvent(
      content::WebContents* web_contents,
      const GURL& url,
      double score,
      SiteEngagementService::EngagementType engagement_type) override;

  // BrowserListObserver:
  void OnBrowserNoLongerActive(Browser* browser) override;
  void OnBrowserSetLastActive(Browser* browser) override;

  // TabStripModelObserver for all Browsers:
  void OnTabStripModelChanged(
      TabStripModel* tab_strip_model,
      const TabStripModelChange& change,
      const TabStripSelectionChange& selection) override;

  // base::PowerObserver:
  void OnSuspend() override;

  // Called when a web contents changes associated AppId (may be empty).
  void NotifyOnAssociatedAppChanged(content::WebContents* web_contents,
                                    const AppId& previous_app_id,
                                    const AppId& new_app_id);

  // banners::AppBannerManager::Observer:
  void OnInstallableWebAppStatusUpdated() override;

  // Browser activation causes flaky tests. Call observer methods directly.
  void RemoveBrowserListObserverForTesting();
  void CountUserInstalledAppsForTesting();

 private:
  void CountUserInstalledApps();
  enum class TabSwitching { kFrom, kTo, kBackgroundClosing };
  void UpdateUkmData(content::WebContents* web_contents, TabSwitching mode);
  void UpdateForegroundWebContents(content::WebContents* web_contents);

  // Calculate number of user installed apps once on start to avoid cpu costs
  // in OnEngagementEvent: sacrifice histograms accuracy for speed.
  static constexpr int kNumUserInstalledAppsNotCounted = -1;
  int num_user_installed_apps_ = kNumUserInstalledAppsNotCounted;

  base::flat_map<web_app::AppId, base::Time> app_last_interacted_time_{};
  content::WebContents* foreground_web_contents_ = nullptr;
  GURL last_recorded_web_app_start_url_;

  Profile* const profile_;

  BrowserTabStripTracker browser_tab_strip_tracker_;
  ScopedObserver<banners::AppBannerManager, banners::AppBannerManager::Observer>
      app_banner_manager_observer_{this};

  base::WeakPtrFactory<WebAppMetrics> weak_ptr_factory_{this};

  DISALLOW_COPY_AND_ASSIGN(WebAppMetrics);
};

}  // namespace web_app

#endif  // CHROME_BROWSER_UI_WEB_APPLICATIONS_WEB_APP_METRICS_H_