// Copyright 2013 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_EXTENSIONS_FAVICON_DOWNLOADER_H_
#define CHROME_BROWSER_EXTENSIONS_FAVICON_DOWNLOADER_H_

#include <map>
#include <set>
#include <vector>

#include "base/callback.h"
#include "base/memory/weak_ptr.h"
#include "content/public/browser/web_contents_observer.h"

class SkBitmap;

namespace content {
struct FaviconURL;
}

namespace gfx {
class Size;
}

// Class to help download all favicons for a tab.
class FaviconDownloader : public content::WebContentsObserver {
 public:
  typedef std::map<GURL, std::vector<SkBitmap> > FaviconMap;
  typedef base::Callback<void(
          bool,  /* success */
          /* A map of icon urls to the bitmaps provided by that url. */
          const FaviconMap&)>
      FaviconDownloaderCallback;
  // |extra_favicon_urls| allows callers to provide icon urls that aren't
  // |provided by the renderer (e.g touch icons on non-android environments).
  FaviconDownloader(content::WebContents* web_contents,
                    const std::vector<GURL>& extra_favicon_urls,
                    FaviconDownloaderCallback callback);
  virtual ~FaviconDownloader();

  void Start();

 private:
  friend class TestFaviconDownloader;

  // Initiates a download of the image at |url| and returns the download id.
  // This is overridden in testing.
  virtual int DownloadImage(const GURL& url);

  // Queries FaviconTabHelper for the page's current favicon URLs.
  // This is overridden in testing.
  virtual std::vector<content::FaviconURL> GetFaviconURLsFromWebContents();

  // Fetches icons for the given urls.
  // |callback_| is run when all downloads complete.
  void FetchIcons(const std::vector<content::FaviconURL>& favicon_urls);
  void FetchIcons(const std::vector<GURL>& urls);

  // Icon download callback.
  void DidDownloadFavicon(int id,
                          int http_status_code,
                          const GURL& image_url,
                          const std::vector<SkBitmap>& bitmaps,
                          const std::vector<gfx::Size>& original_bitmap_sizes);

  // content::WebContentsObserver overrides:
  virtual void DidNavigateMainFrame(
      const content::LoadCommittedDetails& details,
      const content::FrameNavigateParams& params) OVERRIDE;
  virtual void DidUpdateFaviconURL(
      const std::vector<content::FaviconURL>& candidates) OVERRIDE;

  // Whether we have received favicons from the renderer.
  bool got_favicon_urls_;

  // URLs that aren't given by WebContentsObserver::DidUpdateFaviconURL() that
  // should be used for this favicon. This is necessary in order to get touch
  // icons on non-android environments.
  std::vector<GURL> extra_favicon_urls_;

  // The icons which were downloaded. Populated by FetchIcons().
  FaviconMap favicon_map_;

  // Request ids of in-progress requests.
  std::set<int> in_progress_requests_;

  // Urls for which a download has already been initiated. Used to prevent
  // duplicate downloads of the same url.
  std::set<GURL> processed_urls_;

  // Callback to run on favicon download completion.
  FaviconDownloaderCallback callback_;

  base::WeakPtrFactory<FaviconDownloader> weak_ptr_factory_;

  DISALLOW_COPY_AND_ASSIGN(FaviconDownloader);
};

#endif  // CHROME_BROWSER_EXTENSIONS_FAVICON_DOWNLOADER_H_