// Copyright 2017 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_SEARCH_ONE_GOOGLE_BAR_ONE_GOOGLE_BAR_SERVICE_H_
#define CHROME_BROWSER_SEARCH_ONE_GOOGLE_BAR_ONE_GOOGLE_BAR_SERVICE_H_

#include <memory>

#include "base/observer_list.h"
#include "base/optional.h"
#include "chrome/browser/search/one_google_bar/one_google_bar_data.h"
#include "chrome/browser/search/one_google_bar/one_google_bar_service_observer.h"
#include "components/keyed_service/core/keyed_service.h"

class OneGoogleBarFetcher;
class SigninManagerBase;

// A service that downloads, caches, and hands out OneGoogleBarData. It never
// initiates a download automatically, only when Refresh is called. When the
// user signs in or out, the cached value is cleared.
class OneGoogleBarService : public KeyedService {
 public:
  OneGoogleBarService(SigninManagerBase* signin_manager,
                      std::unique_ptr<OneGoogleBarFetcher> fetcher);
  ~OneGoogleBarService() override;

  // KeyedService implementation.
  void Shutdown() override;

  // Returns the currently cached OneGoogleBarData, if any.
  const base::Optional<OneGoogleBarData>& one_google_bar_data() const {
    return one_google_bar_data_;
  }

  // Requests an asynchronous refresh from the network. After the update
  // completes, the observers will be notified only if something changed.
  void Refresh();

  // Add/remove observers. All observers must unregister themselves before the
  // OneGoogleBarService is destroyed.
  void AddObserver(OneGoogleBarServiceObserver* observer);
  void RemoveObserver(OneGoogleBarServiceObserver* observer);

  OneGoogleBarFetcher* fetcher_for_testing() { return fetcher_.get(); }

 private:
  class SigninObserver;

  void SigninStatusChanged();

  void OneGoogleBarDataFetched(const base::Optional<OneGoogleBarData>& data);

  void SetOneGoogleBarData(const base::Optional<OneGoogleBarData>& data);

  std::unique_ptr<OneGoogleBarFetcher> fetcher_;

  std::unique_ptr<SigninObserver> signin_observer_;

  base::ObserverList<OneGoogleBarServiceObserver, true> observers_;

  base::Optional<OneGoogleBarData> one_google_bar_data_;
};

#endif  // CHROME_BROWSER_SEARCH_ONE_GOOGLE_BAR_ONE_GOOGLE_BAR_SERVICE_H_