Refactor BrowsingHistoryHandler, create BrowsingHistoryService

chrome/browser/history/browsing_history_service.h

-// Copyright 2015 The Chromium Authors. All rights reserved.
+// 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 CHROME_BROWSER_UI_WEBUI_BROWSING_HISTORY_HANDLER_H_
-#define CHROME_BROWSER_UI_WEBUI_BROWSING_HISTORY_HANDLER_H_
+#ifndef CHROME_BROWSER_HISTORY_BROWSING_HISTORY_SERVICE_H_
+#define CHROME_BROWSER_HISTORY_BROWSING_HISTORY_SERVICE_H_
 
 #include <stdint.h>
 
 #include <memory>
 #include <set>
 #include <string>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/scoped_observer.h"
 #include "base/strings/string16.h"
 #include "base/task/cancelable_task_tracker.h"
 #include "base/time/clock.h"
 #include "base/timer/timer.h"
 #include "base/values.h"
 #include "components/history/core/browser/history_service_observer.h"
 #include "components/history/core/browser/url_row.h"
 #include "components/history/core/browser/web_history_service.h"
 #include "components/history/core/browser/web_history_service_observer.h"
 #include "components/sync/driver/sync_service_observer.h"
-#include "content/public/browser/web_ui_message_handler.h"
 #include "url/gurl.h"
 
-class SupervisedUserService;
-
-namespace bookmarks {
-class BookmarkModel;
-}  // namespace bookmarks
-
 namespace browser_sync {
 class ProfileSyncService;
 }  // namespace browser_sync
 
 namespace history {
 class HistoryService;
 class QueryResults;
 struct QueryOptions;
 }  // namespace history
 
 namespace syncer {
 class SyncServiceObserver;
 }  // namespace syncer
 
-// The handler for Javascript messages related to the "history" view.
-class BrowsingHistoryHandler : public content::WebUIMessageHandler,
-                               public history::HistoryServiceObserver,
+class Profile;
+
+class BrowsingHistoryServiceHandler;
+
+// Interacts with HistoryService, WebHistoryService, and SyncService to query
+// history and provide results to the associated BrowsingHistoryServiceHandler.
+class BrowsingHistoryService : public history::HistoryServiceObserver,
                                public history::WebHistoryServiceObserver,
                                public syncer::SyncServiceObserver {
  public:
   // Represents a history entry to be shown to the user, representing either
   // a local or remote visit. A single entry can represent multiple visits,
   // since only the most recent visit on a particular day is shown.
   struct HistoryEntry {
     // Values indicating whether an entry represents only local visits, only
     // remote visits, or a mixture of both.
     enum EntryType {
       EMPTY_ENTRY = 0,
       LOCAL_ENTRY,
       REMOTE_ENTRY,
       COMBINED_ENTRY
     };
 
     HistoryEntry(EntryType type,
                  const GURL& url,
                  const base::string16& title,
                  base::Time time,
                  const std::string& client_id,
                  bool is_search_result,
                  const base::string16& snippet,
                  bool blocked_visit,
                  base::Clock* clock);
     HistoryEntry();
     HistoryEntry(const HistoryEntry& other);
     virtual ~HistoryEntry();
 
-    // Formats this entry's URL and title and adds them to |result|.
-    void SetUrlAndTitle(base::DictionaryValue* result,
-                        bool limit_title_length) const;
-
-    // Converts the entry to a DictionaryValue to be owned by the caller.
-    std::unique_ptr<base::DictionaryValue> ToValue(
-        bookmarks::BookmarkModel* bookmark_model,
-        SupervisedUserService* supervised_user_service,
-        const browser_sync::ProfileSyncService* sync_service,
-        bool limit_title_length) const;
-
     // Comparison function for sorting HistoryEntries from newest to oldest.
     static bool SortByTimeDescending(
         const HistoryEntry& entry1, const HistoryEntry& entry2);
 
     // The type of visits this entry represents: local, remote, or both.
     EntryType entry_type;
 
     GURL url;
     base::string16 title;  // Title of the entry. May be empty.
 
@@ skipping 12 matching lines @@
 
     // The entry's search snippet, if this entry is a search result.
     base::string16 snippet;
 
     // Whether this entry was blocked when it was attempted.
     bool blocked_visit;
 
     base::Clock* clock;  // Weak reference.
   };
 
-  BrowsingHistoryHandler();
-  ~BrowsingHistoryHandler() override;
+  // Contains information about a completed history query.
+  struct QueryResultsInfo {
+    QueryResultsInfo();
+    ~QueryResultsInfo();
 
-  // WebUIMessageHandler implementation.
-  void RegisterMessages() override;
+    // The query search text.
+    base::string16 search_text;
+
+    // Whether the query reached the beginning of the database.
+    bool reached_beginning;
+
+    // Whether the last call to Web History returned synced results.
+    bool has_synced_results;
+
+    // The localized query start time.
+    base::Time start_time;
+
+    // The localized query end time.
+    base::Time end_time;
+  };
+
+  BrowsingHistoryService(
+      Profile* profile,
+      BrowsingHistoryServiceHandler* handler);
+  ~BrowsingHistoryService() override;
+
+  // Core implementation of history querying.
+  void QueryHistory(const base::string16& search_text,
+                    const history::QueryOptions& options);
+
+  // Removes |items| from history.
+  void RemoveVisits(
+      std::vector<std::unique_ptr<BrowsingHistoryService::HistoryEntry>>*
+          items);
 
   // SyncServiceObserver implementation.
   void OnStateChanged() override;
 
-  // Handler for the "queryHistory" message.
-  void HandleQueryHistory(const base::ListValue* args);
-
-  // Handler for the "removeVisits" message.
-  void HandleRemoveVisits(const base::ListValue* args);
-
-  // Handler for "clearBrowsingData" message.
-  void HandleClearBrowsingData(const base::ListValue* args);
-
-  // Handler for "removeBookmark" message.
-  void HandleRemoveBookmark(const base::ListValue* args);
-
   // Merges duplicate entries from the query results, only retaining the most
   // recent visit to a URL on a particular day. That visit contains the
   // timestamps of the other visits.
   static void MergeDuplicateResults(
-      std::vector<BrowsingHistoryHandler::HistoryEntry>* results);
+      std::vector<BrowsingHistoryService::HistoryEntry>* results);
 
- protected:
   // Callback from the history system when a history query has completed.
   // Exposed for testing.
   void QueryComplete(const base::string16& search_text,
                      const history::QueryOptions& options,
                      history::QueryResults* results);
 
-  // For tests.
-  void set_clock(std::unique_ptr<base::Clock> clock) {
-    clock_ = std::move(clock);
-  }
-
  private:
   FRIEND_TEST_ALL_PREFIXES(BrowsingHistoryHandlerTest,
                            ObservingWebHistoryDeletions);
-  FRIEND_TEST_ALL_PREFIXES(BrowsingHistoryHandlerTest, SetQueryTimeInWeeks);
-  FRIEND_TEST_ALL_PREFIXES(BrowsingHistoryHandlerTest, SetQueryTimeInMonths);
-
-  // The range for which to return results:
-  // - ALLTIME: allows access to all the results in a paginated way.
-  // - WEEK: the last 7 days.
-  // - MONTH: the last calendar month.
-  enum Range {
-    ALL_TIME = 0,
-    WEEK = 1,
-    MONTH = 2
-  };
-
-  // Core implementation of history querying.
-  void QueryHistory(const base::string16& search_text,
-                    const history::QueryOptions& options);
 
   // Combines the query results from the local history database and the history
-  // server, and sends the combined results to the front end.
-  void ReturnResultsToFrontEnd();
+  // server, and sends the combined results to the
+  // BrowsingHistoryServiceHandler.
+  void ReturnResultsToHandler();
 
   // Callback from |web_history_timer_| when a response from web history has
   // not been received in time.
   void WebHistoryTimeout();
 
   // Callback from the WebHistoryService when a query has completed.
   void WebHistoryQueryComplete(const base::string16& search_text,
                                const history::QueryOptions& options,
                                base::TimeTicks start_time,
                                history::WebHistoryService::Request* request,
                                const base::DictionaryValue* results_value);
 
   // Callback telling us whether other forms of browsing history were found
   // on the history server.
   void OtherFormsOfBrowsingHistoryQueryComplete(
       bool found_other_forms_of_browsing_history);
 
   // Callback from the history system when visits were deleted.
   void RemoveComplete();
 
   // Callback from history server when visits were deleted.
   void RemoveWebHistoryComplete(bool success);
 
-  bool ExtractIntegerValueAtIndex(
-      const base::ListValue* value, int index, int* out_int);
-
-  // Sets the query options for a week-wide query, |offset| weeks ago.
-  void SetQueryTimeInWeeks(int offset, history::QueryOptions* options);
-
-  // Sets the query options for a monthly query, |offset| months ago.
-  void SetQueryTimeInMonths(int offset, history::QueryOptions* options);
-
-  // kAcceptLanguages pref value.
-  std::string GetAcceptLanguages() const;
-
   // history::HistoryServiceObserver:
   void OnURLsDeleted(history::HistoryService* history_service,
                      bool all_history,
                      bool expired,
                      const history::URLRows& deleted_rows,
                      const std::set<GURL>& favicon_urls) override;
 
   // history::WebHistoryServiceObserver:
   void OnWebHistoryDeleted() override;
 
   // Tracker for search requests to the history service.
   base::CancelableTaskTracker query_task_tracker_;
 
   // The currently-executing request for synced history results.
   // Deleting the request will cancel it.
   std::unique_ptr<history::WebHistoryService::Request> web_history_request_;
 
   // True if there is a pending delete requests to the history service.
   bool has_pending_delete_request_;
 
   // Tracker for delete requests to the history service.
   base::CancelableTaskTracker delete_task_tracker_;
 
   // The list of URLs that are in the process of being deleted.
   std::set<GURL> urls_to_be_deleted_;
 
-  // The info value that is returned to the front end with the query results.
-  base::DictionaryValue results_info_value_;
+  // The info value that is returned to the handler with the query results.
+  BrowsingHistoryService::QueryResultsInfo query_results_info_;
 
   // The list of query results received from the history service.
   std::vector<HistoryEntry> query_results_;
 
   // The list of query results received from the history server.
   std::vector<HistoryEntry> web_history_query_results_;
 
   // Timer used to implement a timeout on a Web History response.
   base::OneShotTimer web_history_timer_;
 
   // HistoryService (local history) observer.
   ScopedObserver<history::HistoryService, history::HistoryServiceObserver>
       history_service_observer_;
 
   // WebHistoryService (synced history) observer.
   ScopedObserver<history::WebHistoryService, history::WebHistoryServiceObserver>
       web_history_service_observer_;
 
   // ProfileSyncService observer listens to late initialization of history sync.
   ScopedObserver<browser_sync::ProfileSyncService, syncer::SyncServiceObserver>
       sync_service_observer_;
 
   // Whether the last call to Web History returned synced results.
   bool has_synced_results_;
 
   // Whether there are other forms of browsing history on the history server.
   bool has_other_forms_of_browsing_history_;
 
+  Profile* profile_;
+
+  BrowsingHistoryServiceHandler* handler_;
+
   // The clock used to vend times.
   std::unique_ptr<base::Clock> clock_;
 
-  base::WeakPtrFactory<BrowsingHistoryHandler> weak_factory_;
+  base::WeakPtrFactory<BrowsingHistoryService> weak_factory_;
 
-  DISALLOW_COPY_AND_ASSIGN(BrowsingHistoryHandler);
+  DISALLOW_COPY_AND_ASSIGN(BrowsingHistoryService);
 };
 
-#endif  // CHROME_BROWSER_UI_WEBUI_BROWSING_HISTORY_HANDLER_H_
+#endif  // CHROME_BROWSER_HISTORY_BROWSING_HISTORY_SERVICE_H_