chromeos/components/phonehub/browser_tabs_metadata_fetcher.h

// Copyright 2020 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 CHROMEOS_COMPONENTS_PHONEHUB_BROWSER_TABS_METADATA_FETCHER_H_
#define CHROMEOS_COMPONENTS_PHONEHUB_BROWSER_TABS_METADATA_FETCHER_H_

#include <vector>
#include "base/callback.h"
#include "chromeos/components/phonehub/browser_tabs_model.h"

namespace sync_sessions {
struct SyncedSession;
}  // namespace sync_sessions

namespace chromeos {
namespace phonehub {

// Used to collect the most recently visited tab metadata from a
// sync_sessions::SyncedSession, fetch their respective favicon images, and
// return a list of BrowserTabMetadata to its caller.
class BrowserTabsMetadataFetcher {
 public:
  virtual ~BrowserTabsMetadataFetcher() = default;

  BrowserTabsMetadataFetcher(const BrowserTabsMetadataFetcher&) = delete;
  BrowserTabsMetadataFetcher& operator=(const BrowserTabsMetadataFetcher&) =
      delete;

  using BrowserTabsMetadataResponse =
      base::Optional<std::vector<BrowserTabsModel::BrowserTabMetadata>>;

  // Fetches the metadata of the most recently visited tabs. Only one fetch is
  // possible at a given time, and if a new fetch is started when another is
  // already in progress, the previous fetch will be passed a base::nullopt.
  virtual void Fetch(
      const sync_sessions::SyncedSession* session,
      base::OnceCallback<void(BrowserTabsMetadataResponse)> callback) = 0;

 protected:
  BrowserTabsMetadataFetcher() = default;
};

}  // namespace phonehub
}  // namespace chromeos

#endif  // CHROMEOS_COMPONENTS_PHONEHUB_BROWSER_TABS_METADATA_FETCHER_H_