Allow fetching personalized snippets from ChromeReader.

components/ntp_snippets/ntp_snippets_fetcher.h

 // Copyright 2016 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_NTP_SNIPPETS_NTP_SNIPPETS_FETCHER_H_
 #define COMPONENTS_NTP_SNIPPETS_NTP_SNIPPETS_FETCHER_H_
 
 #include <memory>
 #include <set>
 #include <string>
 
 #include "base/callback.h"
 #include "base/callback_list.h"
 #include "base/memory/weak_ptr.h"
+#include "google_apis/gaia/oauth2_token_service.h"
 #include "net/url_request/url_fetcher_delegate.h"
 #include "net/url_request/url_request_context_getter.h"
 
+class SigninManagerBase;
+namespace net {
+class HttpRequestHeaders;
+}  // namespace net
+
 namespace ntp_snippets {
 
 // Fetches snippet data for the NTP from the server
-class NTPSnippetsFetcher : public net::URLFetcherDelegate {
+class NTPSnippetsFetcher : public OAuth2TokenService::Consumer,
+                           public OAuth2TokenService::Observer,
+                           public net::URLFetcherDelegate {
  public:
   // If problems occur (explained in |status_message|), |snippets_json| is
   // empty; otherwise, |status_message| is empty.
   using SnippetsAvailableCallback =
       base::Callback<void(const std::string& snippets_json,
                           const std::string& status_message)>;
   using SnippetsAvailableCallbackList =
       base::CallbackList<void(const std::string&, const std::string&)>;
 
   NTPSnippetsFetcher(
+      SigninManagerBase* signin_manager,
+      OAuth2TokenService* oauth2_token_service,
       scoped_refptr<net::URLRequestContextGetter> url_request_context_getter,
       bool is_stable_channel);
   ~NTPSnippetsFetcher() override;
 
   // Adds a callback that is called when a new set of snippets are downloaded.
   std::unique_ptr<SnippetsAvailableCallbackList::Subscription> AddCallback(
       const SnippetsAvailableCallback& callback) WARN_UNUSED_RESULT;
 
   // Fetches snippets from the server. |hosts| can be used to restrict the
   // results to a set of hosts, e.g. "www.google.com". If it is empty, no
   // restrictions are applied.
   //
   // If an ongoing fetch exists, it will be cancelled and a new one started,
   // without triggering additional callbacks (i.e. not noticeable by
   // subscribers).
-  void FetchSnippets(const std::set<std::string>& hosts, int count);
+  void FetchSnippets(const std::set<std::string>& hosts,
+                     const std::string& language_code,
+                     int count);
 
  private:
+  enum Variant {
+    kRestrictedPersonalized,
+    kRestricted,
+    kPersonalized
+  };
+
+  void FetchSnippetsImpl(const GURL& url,
+                         const std::string& auth_header,
+                         const std::string& request);
+  std::string GetHostsRestricts() const;
+  bool UseAuthentication();
+  void FetchSnippetsNonAuthenticated();
+  void FetchSnippetsAuthenticated(const std::string& account_id,
+                                  const std::string& oauth_access_token);
+  void StartTokenRequest();
+
+  // OAuth2TokenService::Consumer overrides:
+  void OnGetTokenSuccess(const OAuth2TokenService::Request* request,
+                         const std::string& access_token,
+                         const base::Time& expiration_time) override;
+  void OnGetTokenFailure(const OAuth2TokenService::Request* request,
+                         const GoogleServiceAuthError& error) override;
+
+  // OAuth2TokenService::Observer overrides:
+  void OnRefreshTokenAvailable(const std::string& account_id) override;
+
   // URLFetcherDelegate implementation.
   void OnURLFetchComplete(const net::URLFetcher* source) override;
 
   // Holds the URL request context.
   scoped_refptr<net::URLRequestContextGetter> url_request_context_getter_;
 
+  // Hosts to restrict the snippets to.
+  std::set<std::string> hosts_;
+
+  // Count of snippets to fetch.
+  int count_;
+
+  // Language code to restrict to for personalized results.
+  std::string locale_;
+
   // The fetcher for downloading the snippets.
   std::unique_ptr<net::URLFetcher> url_fetcher_;
 
   // The callbacks to notify when new snippets get fetched.
   SnippetsAvailableCallbackList callback_list_;
 
+  // Authorization for signed-in users
+  SigninManagerBase* signin_manager_;
+  OAuth2TokenService* token_service_;
+  std::unique_ptr<OAuth2TokenService::Request> oauth_request_;
+  bool waiting_for_refresh_token_;
+
   // Flag for picking the right (stable/non-stable) API key for Chrome Reader
   bool is_stable_channel_;
 
+  // The variant of the fetching to use.
+  Variant variant_;
+
   DISALLOW_COPY_AND_ASSIGN(NTPSnippetsFetcher);
 };
 }  // namespace ntp_snippets
 
 #endif  // COMPONENTS_NTP_SNIPPETS_NTP_SNIPPETS_FETCHER_H_