// Copyright 2019 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CHROME_BROWSER_ANDROID_TAB_FAVICON_H_
#define CHROME_BROWSER_ANDROID_TAB_FAVICON_H_

#include "base/android/scoped_java_ref.h"
#include "base/functional/callback.h"
#include "base/memory/raw_ptr.h"
#include "base/observer_list.h"
#include "components/favicon/core/favicon_driver_observer.h"
#include "third_party/skia/include/core/SkBitmap.h"

class TabAndroid;

namespace content {
class WebContents;
}

namespace favicon {
class FaviconDriver;
}

// Native Favicon provider for Tab. Managed by Java layer.
class TabFavicon : public favicon::FaviconDriverObserver {
 public:
  // Allows observing for when the favicon of the tab changes.
  class Observer : public base::CheckedObserver {
   public:
    virtual void OnFaviconUpdated(const SkBitmap& bitmap) = 0;
  };
  static void AddObserver(TabAndroid* tab_android, Observer* observer);
  static void RemoveObserver(TabAndroid* tab_android, Observer* observer);

  // Returns the bitmap for a tab if `allow_fallback` is true, the fallback
  // favicon from the local favicon DB may be returned if it is loaded.
  static SkBitmap GetBitmapForTab(TabAndroid* tab_android,
                                  bool allow_fallback = false);

  // `callback` will receive the bitmap for the tab immediately if it is
  // available or once the favicon is fetched from the local favicon db
  // asynchronously. In the event the tab loads a favicon before the db entry is
  // available the tab's new favicon will be returned instead.
  static void GetBitmapForTabOrFallback(
      TabAndroid* tab_android,
      base::OnceCallback<void(const SkBitmap&)> callback);

  // TabFavicon JNI
  TabFavicon(JNIEnv* env,
             TabAndroid* tab_android,
             int navigation_transition_favicon_size);
  ~TabFavicon() override;
  void SetWebContents(JNIEnv* env, content::WebContents* web_contents);
  void ResetWebContents(JNIEnv* env);
  void OnDestroyed(JNIEnv* env);
  base::android::ScopedJavaLocalRef<jobject> GetFavicon(JNIEnv* env);

  // favicon::FaviconDriverObserver
  void OnFaviconUpdated(favicon::FaviconDriver* favicon_driver,
                        NotificationIconType notification_icon_type,
                        const GURL& icon_url,
                        bool icon_url_changed,
                        const gfx::Image& image) override;

 private:
  static void GetFaviconOrFallback(
      TabAndroid* tab_android,
      base::OnceCallback<void(const SkBitmap&)> callback);

  static void OnGetFaviconOrFallbackFinished(
      base::OnceCallback<void(const SkBitmap&)> callback,
      const base::android::JavaRef<jobject>& j_bitmap);

  const int navigation_transition_favicon_size_;
  raw_ptr<content::WebContents> active_web_contents_ = nullptr;

  // Rather than a ScopedJavaGlobalRef, we use a raw_ptr to an object we can
  // easily look up the TabFavicon Java object from. This reduces entries in the
  // finite global ref table.
  raw_ptr<TabAndroid> tab_android_;
  raw_ptr<favicon::FaviconDriver> favicon_driver_;

  base::ObserverList<Observer> observers_;
};

#endif  // CHROME_BROWSER_ANDROID_TAB_FAVICON_H_