Change NTPSnippetsService to implement ContentSuggestionsProvider

components/ntp_snippets/ntp_snippets_service.cc

 // Copyright 2015 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.
 
 #include "components/ntp_snippets/ntp_snippets_service.h"
 
 #include <algorithm>
 #include <iterator>
 #include <utility>
 
@@ skipping 175 matching lines @@
     bool enabled,
     PrefService* pref_service,
     SuggestionsService* suggestions_service,
     const std::string& application_language_code,
     NTPSnippetsScheduler* scheduler,
     std::unique_ptr<NTPSnippetsFetcher> snippets_fetcher,
     std::unique_ptr<ImageFetcher> image_fetcher,
     std::unique_ptr<ImageDecoder> image_decoder,
     std::unique_ptr<NTPSnippetsDatabase> database,
     std::unique_ptr<NTPSnippetsStatusService> status_service)
-    : state_(State::NOT_INITED),
+    : ContentSuggestionsProvider({ContentSuggestionsCategory::ARTICLES}),
+      state_(State::NOT_INITED),
+      category_status_(ContentSuggestionsCategoryStatus::INITIALIZING),
       pref_service_(pref_service),
       suggestions_service_(suggestions_service),
       application_language_code_(application_language_code),
+      observer_(nullptr),
       scheduler_(scheduler),
       snippets_fetcher_(std::move(snippets_fetcher)),
       image_fetcher_(std::move(image_fetcher)),
       image_decoder_(std::move(image_decoder)),
       database_(std::move(database)),
       snippets_status_service_(std::move(status_service)),
       fetch_after_load_(false) {
-  if (!enabled || database_->IsErrorState()) {
-    // Don't even bother loading the database.
-    EnterState(State::SHUT_DOWN);
+  // In some cases, don't even bother loading the database.
+  if (!enabled) {
+    EnterState(State::SHUT_DOWN,
+               ContentSuggestionsCategoryStatus::CATEGORY_EXPLICITLY_DISABLED);
+    return;
+  }
+  if (database_->IsErrorState()) {
+    EnterState(State::SHUT_DOWN,
+               ContentSuggestionsCategoryStatus::LOADING_ERROR);
     return;
   }
 
   database_->SetErrorCallback(base::Bind(&NTPSnippetsService::OnDatabaseError,
                                          base::Unretained(this)));
 
   // We transition to other states while finalizing the initialization, when the
   // database is done loading.
   database_->LoadSnippets(base::Bind(&NTPSnippetsService::OnDatabaseLoaded,
                                      base::Unretained(this)));
 }
 
 NTPSnippetsService::~NTPSnippetsService() {
   DCHECK(state_ == State::SHUT_DOWN);
 }
 
 // static
 void NTPSnippetsService::RegisterProfilePrefs(PrefRegistrySimple* registry) {
   registry->RegisterListPref(prefs::kSnippetHosts);
 }
 
 // Inherited from KeyedService.
 void NTPSnippetsService::Shutdown() {
-  EnterState(State::SHUT_DOWN);
+  EnterState(State::SHUT_DOWN, ContentSuggestionsCategoryStatus::NOT_PROVIDED);
 }
 
 void NTPSnippetsService::FetchSnippets() {
   if (ready())
     FetchSnippetsFromHosts(GetSuggestionsHosts());
   else
     fetch_after_load_ = true;
 }
 
 void NTPSnippetsService::FetchSnippetsFromHosts(
@@ skipping 12 matching lines @@
   if (ready()) {
     base::Time now = base::Time::Now();
     scheduler_->Schedule(
         GetFetchingIntervalWifiCharging(), GetFetchingIntervalWifi(now),
         GetFetchingIntervalFallback(), GetRescheduleTime(now));
   } else {
     scheduler_->Unschedule();
   }
 }
 
-void NTPSnippetsService::FetchSnippetImage(
-    const std::string& snippet_id,
+void NTPSnippetsService::FetchSuggestionImage(
+    const std::string& suggestion_id,
     const ImageFetchedCallback& callback) {
   database_->LoadImage(
-      snippet_id,
+      suggestion_id,
       base::Bind(&NTPSnippetsService::OnSnippetImageFetchedFromDatabase,
-                 base::Unretained(this), snippet_id, callback));
+                 base::Unretained(this), suggestion_id, callback));
 }
 
-void NTPSnippetsService::ClearSnippets() {
+void NTPSnippetsService::ClearCachedSuggestionsForDebugging() {
   if (!initialized())
     return;
 
   if (snippets_.empty())
     return;
 
   database_->DeleteSnippets(snippets_);
   snippets_.clear();
 
-  FOR_EACH_OBSERVER(NTPSnippetsServiceObserver, observers_,
-                    NTPSnippetsServiceLoaded());
+  NotifyNewSuggestions();
 }
 
 std::set<std::string> NTPSnippetsService::GetSuggestionsHosts() const {
   // |suggestions_service_| can be null in tests.
   if (!suggestions_service_)
     return std::set<std::string>();
 
   // TODO(treib): This should just call GetSnippetHostsFromPrefs.
   return GetSuggestionsHostsImpl(
       suggestions_service_->GetSuggestionsDataFromCache());
 }
 
-bool NTPSnippetsService::DiscardSnippet(const std::string& snippet_id) {
+void NTPSnippetsService::DiscardSuggestion(const std::string& suggestion_id) {
   if (!ready())
-    return false;
+    return;
 
-  auto it =
-      std::find_if(snippets_.begin(), snippets_.end(),
-                   [&snippet_id](const std::unique_ptr<NTPSnippet>& snippet) {
-                     return snippet->id() == snippet_id;
-                   });
+  auto it = std::find_if(
+      snippets_.begin(), snippets_.end(),
+      [&suggestion_id](const std::unique_ptr<NTPSnippet>& snippet) {
+        return snippet->id() == suggestion_id;
+      });
   if (it == snippets_.end())
-    return false;
+    return;
 
   (*it)->set_discarded(true);
 
   database_->SaveSnippet(**it);
   database_->DeleteImage((*it)->id());
 
   discarded_snippets_.push_back(std::move(*it));
   snippets_.erase(it);
 
-  FOR_EACH_OBSERVER(NTPSnippetsServiceObserver, observers_,
-                    NTPSnippetsServiceLoaded());
-  return true;
+  NotifyNewSuggestions();
 }
 
-void NTPSnippetsService::ClearDiscardedSnippets() {
+void NTPSnippetsService::ClearDiscardedSuggestionsForDebugging() {
   if (!initialized())
     return;
 
   if (discarded_snippets_.empty())
     return;
 
   database_->DeleteSnippets(discarded_snippets_);
   discarded_snippets_.clear();
 }
 
+void NTPSnippetsService::SetObserver(Observer* observer) {
+  observer_ = observer;
+}
+
+ContentSuggestionsCategoryStatus NTPSnippetsService::GetCategoryStatus(
+    ContentSuggestionsCategory category) {
+  DCHECK_EQ(ContentSuggestionsCategory::ARTICLES, category);
+  return category_status_;
+}
+
 void NTPSnippetsService::AddObserver(NTPSnippetsServiceObserver* observer) {
   observers_.AddObserver(observer);
 }
 
 void NTPSnippetsService::RemoveObserver(NTPSnippetsServiceObserver* observer) {
   observers_.RemoveObserver(observer);
 }
 
 // static
 int NTPSnippetsService::GetMaxSnippetCountForTesting() {
@@ skipping 38 matching lines @@
             [](const std::unique_ptr<NTPSnippet>& lhs,
                const std::unique_ptr<NTPSnippet>& rhs) {
               return lhs->score() > rhs->score();
             });
 
   ClearExpiredSnippets();
   FinishInitialization();
 }
 
 void NTPSnippetsService::OnDatabaseError() {
-  EnterState(State::SHUT_DOWN);
+  EnterState(State::SHUT_DOWN, ContentSuggestionsCategoryStatus::LOADING_ERROR);
 }
 
 void NTPSnippetsService::OnSuggestionsChanged(
     const SuggestionsProfile& suggestions) {
   DCHECK(initialized());
 
   std::set<std::string> hosts = GetSuggestionsHostsImpl(suggestions);
   if (hosts == GetSnippetHostsFromPrefs())
     return;
 
   // Remove existing snippets that aren't in the suggestions anymore.
   // TODO(treib,maybelle): If there is another source with an allowed host,
   // then we should fall back to that.
   // First, move them over into |to_delete|.
   NTPSnippet::PtrVector to_delete;
   for (std::unique_ptr<NTPSnippet>& snippet : snippets_) {
     if (!hosts.count(snippet->best_source().url.host()))
       to_delete.emplace_back(std::move(snippet));
   }
   Compact(&snippets_);
   // Then delete the removed snippets from the database.
   database_->DeleteSnippets(to_delete);
 
   StoreSnippetHostsToPrefs(hosts);
 
-  FOR_EACH_OBSERVER(NTPSnippetsServiceObserver, observers_,
-                    NTPSnippetsServiceLoaded());
+  NotifyNewSuggestions();
 
   FetchSnippetsFromHosts(hosts);
 }
 
 void NTPSnippetsService::OnFetchFinished(
     NTPSnippetsFetcher::OptionalSnippets snippets) {
   if (!ready())
     return;
 
   if (snippets) {
@@ skipping 16 matching lines @@
     database_->DeleteSnippets(to_delete);
   }
 
   UMA_HISTOGRAM_SPARSE_SLOWLY("NewTabPage.Snippets.NumArticles",
                               snippets_.size());
   if (snippets_.empty() && !discarded_snippets_.empty()) {
     UMA_HISTOGRAM_COUNTS("NewTabPage.Snippets.NumArticlesZeroDueToDiscarded",
                          discarded_snippets_.size());
   }
 
-  FOR_EACH_OBSERVER(NTPSnippetsServiceObserver, observers_,
-                    NTPSnippetsServiceLoaded());
+  NotifyNewSuggestions();
 }
 
 void NTPSnippetsService::MergeSnippets(NTPSnippet::PtrVector new_snippets) {
   DCHECK(ready());
 
   // Remove new snippets that we already have, or that have been discarded.
   std::set<std::string> old_snippet_ids;
   InsertAllIDs(discarded_snippets_, &old_snippet_ids);
   InsertAllIDs(snippets_, &old_snippet_ids);
   new_snippets.erase(
@@ skipping 171 matching lines @@
   if (snippets_fetcher_->UsesHostRestrictions() && suggestions_service_) {
     suggestions_service_subscription_ =
         suggestions_service_->AddCallback(base::Bind(
             &NTPSnippetsService::OnSuggestionsChanged, base::Unretained(this)));
   }
 
   RescheduleFetching();
 }
 
 void NTPSnippetsService::EnterStateDisabled() {
-  ClearSnippets();
-  ClearDiscardedSnippets();
+  ClearCachedSuggestionsForDebugging();
+  ClearDiscardedSuggestionsForDebugging();
 
   expiry_timer_.Stop();
   suggestions_service_subscription_.reset();
   RescheduleFetching();
 }
 
 void NTPSnippetsService::EnterStateShutdown() {
   FOR_EACH_OBSERVER(NTPSnippetsServiceObserver, observers_,
                     NTPSnippetsServiceShutdown());
 
@@ skipping 10 matching lines @@
 
   // |image_fetcher_| can be null in tests.
   if (image_fetcher_)
     image_fetcher_->SetImageFetcherDelegate(this);
 
   // Note: Initializing the status service will run the callback right away with
   // the current state.
   snippets_status_service_->Init(base::Bind(
       &NTPSnippetsService::UpdateStateForStatus, base::Unretained(this)));
 
-  FOR_EACH_OBSERVER(NTPSnippetsServiceObserver, observers_,
-                    NTPSnippetsServiceLoaded());
+  NotifyNewSuggestions();
 }
 
 void NTPSnippetsService::UpdateStateForStatus(DisabledReason disabled_reason) {
   FOR_EACH_OBSERVER(NTPSnippetsServiceObserver, observers_,
                     NTPSnippetsServiceDisabledReasonChanged(disabled_reason));
 
   State new_state;
+  ContentSuggestionsCategoryStatus new_status;
   switch (disabled_reason) {
     case DisabledReason::NONE:
       new_state = State::READY;
+      new_status = ContentSuggestionsCategoryStatus::AVAILABLE;
       break;
 
     case DisabledReason::HISTORY_SYNC_STATE_UNKNOWN:
       // HistorySync is not initialized yet, so we don't know what the actual
       // state is and we just return the current one. If things change,
       // |OnStateChanged| will call this function again to update the state.
       DVLOG(1) << "Sync configuration incomplete, continuing based on the "
                   "current state.";
       new_state = state_;
+      new_status = ContentSuggestionsCategoryStatus::INITIALIZING;
       break;
 
     case DisabledReason::EXPLICITLY_DISABLED:
+      new_state = State::DISABLED;
+      new_status =
+          ContentSuggestionsCategoryStatus::CATEGORY_EXPLICITLY_DISABLED;
+      break;
+
     case DisabledReason::SIGNED_OUT:
+      new_state = State::DISABLED;
+      new_status = ContentSuggestionsCategoryStatus::SIGNED_OUT;
+      break;
+
     case DisabledReason::SYNC_DISABLED:
+      new_state = State::DISABLED;
+      new_status = ContentSuggestionsCategoryStatus::SYNC_DISABLED;
+      break;
+
     case DisabledReason::PASSPHRASE_ENCRYPTION_ENABLED:
+      new_state = State::DISABLED;
+      new_status =
+          ContentSuggestionsCategoryStatus::PASSPHRASE_ENCRYPTION_ENABLED;
+      break;
+
     case DisabledReason::HISTORY_SYNC_DISABLED:
       new_state = State::DISABLED;
+      new_status = ContentSuggestionsCategoryStatus::HISTORY_SYNC_DISABLED;
       break;
 
     default:
       // All cases should be handled by the above switch
       NOTREACHED();
       new_state = State::DISABLED;
+      new_status = ContentSuggestionsCategoryStatus::LOADING_ERROR;
       break;
   }
 
-  EnterState(new_state);
+  EnterState(new_state, new_status);
 }
 
-void NTPSnippetsService::EnterState(State state) {
+void NTPSnippetsService::EnterState(State state,
+                                    ContentSuggestionsCategoryStatus status) {
+  if (status != category_status_) {
+    category_status_ = status;
+    NotifyCategoryStatusChanged();
+  }
+
   if (state == state_)
     return;
 
   switch (state) {
     case State::NOT_INITED:
       // Initial state, it should not be possible to get back there.
       NOTREACHED();
       return;
 
     case State::READY: {
@@ skipping 16 matching lines @@
       return;
 
     case State::SHUT_DOWN:
       DVLOG(1) << "Entering state: SHUT_DOWN";
       state_ = State::SHUT_DOWN;
       EnterStateShutdown();
       return;
   }
 }
 
+void NTPSnippetsService::NotifyNewSuggestions() {
+  // TODO(pke): Remove this as soon as this becomes a pure provider.
+  FOR_EACH_OBSERVER(NTPSnippetsServiceObserver, observers_,
+                    NTPSnippetsServiceLoaded());
+
+  if (!observer_)
+    return;
+
+  std::vector<ContentSuggestion> result;
+  for (const std::unique_ptr<NTPSnippet>& snippet : snippets_) {
+    if (!snippet->is_complete())
+      continue;
+    ContentSuggestion suggestion(
+        MakeUniqueID(ContentSuggestionsCategory::ARTICLES, snippet->id()),
+        snippet->best_source().url);
+    suggestion.set_amp_url(snippet->best_source().amp_url);
+    suggestion.set_title(snippet->title());
+    suggestion.set_snippet_text(snippet->snippet());
+    suggestion.set_publish_date(snippet->publish_date());
+    suggestion.set_publisher_name(snippet->best_source().publisher_name);
+    suggestion.set_score(snippet->score());
+    result.emplace_back(std::move(suggestion));
+  }
+  observer_->OnNewSuggestions(ContentSuggestionsCategory::ARTICLES,
+                              std::move(result));
+}
+
+void NTPSnippetsService::NotifyCategoryStatusChanged() {
+  if (observer_) {
+    observer_->OnCategoryStatusChanged(ContentSuggestionsCategory::ARTICLES,
+                                       category_status_);
+  }
+}
+
 }  // namespace ntp_snippets