// Copyright 2015 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_FAVICON_CORE_LARGE_ICON_SERVICE_H_
#define COMPONENTS_FAVICON_CORE_LARGE_ICON_SERVICE_H_

#include <vector>

#include "base/task/cancelable_task_tracker.h"
#include "components/favicon_base/favicon_callback.h"
#include "components/keyed_service/core/keyed_service.h"

class GURL;

namespace base {
class TaskRunner;
}

namespace favicon {

class FaviconService;

// The large icon service provides methods to access large icons. It relies on
// the favicon service.
class LargeIconService : public KeyedService {
 public:
  LargeIconService(
      FaviconService* favicon_service,
      const scoped_refptr<base::TaskRunner>& background_task_runner);
  ~LargeIconService() override;

  // Requests the best large icon for the page at |page_url|.
  // Case 1. An icon exists whose size is >= |min_source_size_in_pixel|:
  // - If |desired_size_in_pixel| == 0: returns icon as is.
  // - Else: returns the icon resized to |desired_size_in_pixel|.
  // Case 2. An icon exists whose size is < |min_source_size_in_pixel|:
  // - Extracts dominant color of smaller image, returns a fallback icon style
  //   that has a matching background.
  // Case 3. No icon exists.
  // - Returns the default fallback icon style.
  // For cases 2 and 3, this function returns the style of the fallback icon
  // instead of rendering an icon so clients can render the icon themselves.
  base::CancelableTaskTracker::TaskId GetLargeIconOrFallbackStyle(
    const GURL& page_url,
    int min_source_size_in_pixel,
    int desired_size_in_pixel,
    const favicon_base::LargeIconCallback& callback,
    base::CancelableTaskTracker* tracker);

 private:
  // For testing.
  friend class TestLargeIconService;

  FaviconService* favicon_service_;
  scoped_refptr<base::TaskRunner> background_task_runner_;

  // A pre-populated list of icon types to consider when looking for large
  // icons. This is an optimization over populating an icon type vector on each
  // request.
  std::vector<int> large_icon_types_;

  DISALLOW_COPY_AND_ASSIGN(LargeIconService);
};

}  // namespace favicon

#endif  // COMPONENTS_FAVICON_CORE_LARGE_ICON_SERVICE_H_