// Copyright (c) 2012 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_GOOGLE_APIS_AUTH_SERVICE_H_
#define CHROME_BROWSER_GOOGLE_APIS_AUTH_SERVICE_H_

#include <string>
#include <vector>

#include "base/memory/weak_ptr.h"
#include "base/observer_list.h"
#include "chrome/browser/google_apis/auth_service_interface.h"
#include "chrome/browser/google_apis/base_operations.h"
#include "chrome/browser/google_apis/gdata_errorcode.h"
#include "content/public/browser/notification_observer.h"
#include "content/public/browser/notification_registrar.h"

class Profile;

namespace net {
class URLRequestContextGetter;
}

namespace google_apis {

class OperationRegistry;
class AuthServiceObserver;

// This class provides authentication for Google services.
// It integrates specific service integration with OAuth2 stack
// (TokenService) and provides OAuth2 token refresh infrastructure.
// All public functions must be called on UI thread.
class AuthService : public AuthServiceInterface,
                    public content::NotificationObserver {
 public:
  // |url_request_context_getter| is used to perform authentication with
  // URLFetcher.
  //
  // |scopes| specifies OAuth2 scopes.
  AuthService(net::URLRequestContextGetter* url_request_context_getter,
              const std::vector<std::string>& scopes);
  virtual ~AuthService();

  // Overriden from AuthServiceInterface:
  virtual void AddObserver(AuthServiceObserver* observer) OVERRIDE;
  virtual void RemoveObserver(AuthServiceObserver* observer) OVERRIDE;
  virtual void Initialize(Profile* profile) OVERRIDE;
  virtual void StartAuthentication(OperationRegistry* registry,
                           const AuthStatusCallback& callback) OVERRIDE;
  virtual bool HasAccessToken() const OVERRIDE;
  virtual bool HasRefreshToken() const OVERRIDE;
  virtual const std::string& access_token() const OVERRIDE;
  virtual void ClearAccessToken() OVERRIDE;

  // Overridden from content::NotificationObserver:
  virtual void Observe(int type,
                       const content::NotificationSource& source,
                       const content::NotificationDetails& details) OVERRIDE;

  // Sets the access_token as specified.  This should be used only for testing.
  void set_access_token_for_testing(const std::string& token) {
    access_token_ = token;
  }

  // Returns true if authentication can be done using the class for the given
  // profile. For instance, this function returns false if the profile is
  // used for the incognito mode.
  static bool CanAuthenticate(Profile* profile);

 private:
  // Callback for AuthOperation (InternalAuthStatusCallback).
  void OnAuthCompleted(const AuthStatusCallback& callback,
                       GDataErrorCode error,
                       const std::string& access_token);

  Profile* profile_;
  net::URLRequestContextGetter* url_request_context_getter_;  // Not owned.
  std::string refresh_token_;
  std::string access_token_;
  std::vector<std::string> scopes_;
  ObserverList<AuthServiceObserver> observers_;

  content::NotificationRegistrar registrar_;

  // Note: This should remain the last member so it'll be destroyed and
  // invalidate its weak pointers before any other members are destroyed.
  base::WeakPtrFactory<AuthService> weak_ptr_factory_;

  DISALLOW_COPY_AND_ASSIGN(AuthService);
};

}  // namespace google_apis

#endif  // CHROME_BROWSER_GOOGLE_APIS_AUTH_SERVICE_H_