keep an AI Chat conversation alive if it has chat messages and its as…

…sociated content is still alive (uplift to 1.74.x) (#26942)

Merge pull request #26502 from brave/ai-chat-keep-conversation-alive

keep an AI Chat conversation alive if it has chat messages and its associated content is still alive

components/ai_chat/core/browser/ai_chat_service.cc

@@ -269,9 +269,26 @@ void AIChatService::OnPremiumStatusReceived(GetPremiumStatusCallback callback,
 
 void AIChatService::MaybeEraseConversation(
     ConversationHandler* conversation_handler) {
-  if (!conversation_handler->IsAnyClientConnected() &&
-      (!features::IsAIChatHistoryEnabled() ||
-       !conversation_handler->HasAnyHistory())) {
+  // Don't unload if there is active UI for the conversation
+  if (conversation_handler->IsAnyClientConnected()) {
+    return;
+  }
+
+  bool has_history = conversation_handler->HasAnyHistory();
+
+  // We can keep a conversation with history in memory until there is no active
+  // content.
+  // TODO(petemill): With the history feature enabled, we should unload (if
+  // there is no request in progress). However, we can only do this when
+  // GetOrCreateConversationHandlerForContent allows a callback so that it
+  // can provide an answer after loading the conversation content from storage.
+  if (conversation_handler->IsAssociatedContentAlive() && has_history) {
+    return;
+  }
+
+  // AIChatHistory feature doesn't yet have persistant storage, so keep
+  // handlers and data around if it's enabled.
+  if (!features::IsAIChatHistoryEnabled() || !has_history) {
     // Can erase because no active UI and no history, so it's
     // not a real / persistable conversation
     auto uuid = conversation_handler->get_conversation_uuid();
@@ -328,6 +345,12 @@ void AIChatService::OnConversationTitleChanged(ConversationHandler* handler,
   OnConversationListChanged();
 }
 
+void AIChatService::OnAssociatedContentDestroyed(ConversationHandler* handler,
+                                                 int content_id) {
+  content_conversations_.erase(content_id);
+  MaybeEraseConversation(handler);
+}
+
 void AIChatService::GetVisibleConversations(
     GetVisibleConversationsCallback callback) {
   std::vector<mojom::ConversationPtr> conversations;

components/ai_chat/core/browser/ai_chat_service.h

@@ -65,6 +65,8 @@ class AIChatService : public KeyedService,
   void OnClientConnectionChanged(ConversationHandler* handler) override;
   void OnConversationTitleChanged(ConversationHandler* handler,
                                   std::string title) override;
+  void OnAssociatedContentDestroyed(ConversationHandler* handler,
+                                    int content_id) override;
 
   // Adds new conversation and returns the handler
   ConversationHandler* CreateConversation();

components/ai_chat/core/browser/ai_chat_service_unittest.cc

@@ -8,6 +8,7 @@
 #include <cstddef>
 #include <memory>
 #include <optional>
+#include <set>
 #include <string>
 #include <string_view>
 #include <utility>
@@ -131,7 +132,6 @@ class MockConversationHandlerClient : public mojom::ConversationUI {
   explicit MockConversationHandlerClient(ConversationHandler* driver) {
     driver->Bind(conversation_handler_remote_.BindNewPipeAndPassReceiver(),
                  conversation_ui_receiver_.BindNewPipeAndPassRemote());
-    conversation_handler_ = driver;
   }
 
   ~MockConversationHandlerClient() override = default;
@@ -141,9 +141,6 @@ class MockConversationHandlerClient : public mojom::ConversationUI {
     conversation_ui_receiver_.reset();
   }
 
-  ConversationHandler* GetConversationHandler() {
-    return conversation_handler_;
-  }
 
   MOCK_METHOD(void, OnConversationHistoryUpdate, (), (override));
 
@@ -174,7 +171,6 @@ class MockConversationHandlerClient : public mojom::ConversationUI {
  private:
   mojo::Receiver<mojom::ConversationUI> conversation_ui_receiver_{this};
   mojo::Remote<mojom::ConversationHandler> conversation_handler_remote_;
-  raw_ptr<ConversationHandler, DanglingUntriaged> conversation_handler_;
 };
 
 class MockAssociatedContent
@@ -203,6 +199,30 @@ class MockAssociatedContent
               (override));
   MOCK_METHOD(bool, HasOpenAIChatPermission, (), (const, override));
 
+  void AddRelatedConversation(ConversationHandler* conversation) override {
+    related_conversations_.insert(conversation);
+  }
+
+  void OnRelatedConversationDisassociated(
+      ConversationHandler* conversation) override {
+    related_conversations_.erase(conversation);
+  }
+
+  void DisassociateWithConversations(std::string archived_text_content,
+                                     bool archived_is_video) {
+    std::vector<base::WeakPtr<ConversationHandler>> related_conversations;
+    for (auto& conversation : related_conversations_) {
+      related_conversations.push_back(conversation->GetWeakPtr());
+    }
+
+    for (auto& conversation : related_conversations) {
+      if (conversation) {
+        conversation->OnAssociatedContentDestroyed(archived_text_content,
+                                                   archived_is_video);
+      }
+    }
+  }
+
   base::WeakPtr<ConversationHandler::AssociatedContentDelegate> GetWeakPtr() {
     return weak_ptr_factory_.GetWeakPtr();
   }
@@ -211,6 +231,7 @@ class MockAssociatedContent
   base::WeakPtrFactory<ConversationHandler::AssociatedContentDelegate>
       weak_ptr_factory_{this};
   int content_id_ = 0;
+  std::set<raw_ptr<ConversationHandler>> related_conversations_;
 };
 
 }  // namespace
@@ -404,6 +425,55 @@ TEST_P(AIChatServiceUnitTest, ConversationLifecycle_WithMessages) {
   task_environment_.RunUntilIdle();
 }
 
+TEST_P(AIChatServiceUnitTest, ConversationLifecycle_WithContent) {
+  NiceMock<MockAssociatedContent> associated_content{};
+  ON_CALL(associated_content, GetURL())
+      .WillByDefault(testing::Return(GURL("https://example.com")));
+  associated_content.SetContentId(1);
+  ConversationHandler* conversation_with_content_no_messages =
+      ai_chat_service_->GetOrCreateConversationHandlerForContent(
+          associated_content.GetContentId(), associated_content.GetWeakPtr());
+  EXPECT_TRUE(conversation_with_content_no_messages);
+  // Asking again for same content ID gets same conversation
+  EXPECT_EQ(
+      conversation_with_content_no_messages,
+      ai_chat_service_->GetOrCreateConversationHandlerForContent(
+          associated_content.GetContentId(), associated_content.GetWeakPtr()));
+  // Shouldn't be visible without messages
+  ExpectVisibleConversationsSize(FROM_HERE, 0u);
+  EXPECT_EQ(ai_chat_service_->GetInMemoryConversationCountForTesting(), 1u);
+  // Disconnecting the client should unload the handler and delete the
+  // conversation.
+  auto client1 =
+      CreateConversationClient(conversation_with_content_no_messages);
+  DisconnectConversationClient(client1.get());
+  EXPECT_EQ(ai_chat_service_->GetInMemoryConversationCountForTesting(), 0u);
+  ExpectVisibleConversationsSize(FROM_HERE, 0u);
+
+  // Create a new conversation for same content, with messages this time
+  ConversationHandler* conversation_with_content =
+      ai_chat_service_->GetOrCreateConversationHandlerForContent(
+          associated_content.GetContentId(), associated_content.GetWeakPtr());
+  conversation_with_content->SetChatHistoryForTesting(CreateSampleHistory());
+  ExpectVisibleConversationsSize(FROM_HERE, 1u);
+  EXPECT_EQ(ai_chat_service_->GetInMemoryConversationCountForTesting(), 1u);
+  auto client2 = CreateConversationClient(conversation_with_content);
+  DisconnectConversationClient(client2.get());
+  // Disconnecting all clients should keep the handler in memory until
+  // the content is destroyed.
+  EXPECT_EQ(ai_chat_service_->GetInMemoryConversationCountForTesting(), 1u);
+  ExpectVisibleConversationsSize(FROM_HERE, 1u);
+  associated_content.DisassociateWithConversations("", false);
+
+  if (IsAIChatHistoryEnabled()) {
+    EXPECT_EQ(ai_chat_service_->GetInMemoryConversationCountForTesting(), 1u);
+    ExpectVisibleConversationsSize(FROM_HERE, 1u);
+  } else {
+    EXPECT_EQ(ai_chat_service_->GetInMemoryConversationCountForTesting(), 0u);
+    ExpectVisibleConversationsSize(FROM_HERE, 0u);
+  }
+}
+
 TEST_P(AIChatServiceUnitTest, GetOrCreateConversationHandlerForContent) {
   ConversationHandler* conversation_without_content = CreateConversation();
 
@@ -439,27 +509,24 @@ TEST_P(AIChatServiceUnitTest, GetOrCreateConversationHandlerForContent) {
   // Creating a second conversation with the same associated content should
   // make the second conversation the default for that content, but leave
   // the first still associated with the content.
-  ConversationHandler* conversation_with_content2 =
+  ConversationHandler* conversation2 =
       ai_chat_service_->CreateConversationHandlerForContent(
           associated_content.GetContentId(), associated_content.GetWeakPtr());
-  EXPECT_NE(conversation_with_content, conversation_with_content2);
+  EXPECT_NE(conversation_with_content, conversation2);
   EXPECT_NE(conversation_with_content->get_conversation_uuid(),
-            conversation_with_content2->get_conversation_uuid());
-  EXPECT_EQ(
-      conversation_with_content2->GetAssociatedContentDelegateForTesting(),
-      &associated_content);
-  EXPECT_EQ(
-      conversation_with_content->GetAssociatedContentDelegateForTesting(),
-      conversation_with_content2->GetAssociatedContentDelegateForTesting());
+            conversation2->get_conversation_uuid());
+  EXPECT_EQ(conversation2->GetAssociatedContentDelegateForTesting(),
+            &associated_content);
+  EXPECT_EQ(conversation_with_content->GetAssociatedContentDelegateForTesting(),
+            conversation2->GetAssociatedContentDelegateForTesting());
   // Check the second conversation is the default for that content ID
   EXPECT_EQ(
       ai_chat_service_->GetOrCreateConversationHandlerForContent(
           associated_content.GetContentId(), associated_content.GetWeakPtr()),
-      conversation_with_content2);
+      conversation2);
   // Let the conversation be deleted
-  std::string conversation2_uuid =
-      conversation_with_content2->get_conversation_uuid();
-  auto client1 = CreateConversationClient(conversation_with_content2);
+  std::string conversation2_uuid = conversation2->get_conversation_uuid();
+  auto client1 = CreateConversationClient(conversation2);
   DisconnectConversationClient(client1.get());
   ConversationHandler* conversation_with_content3 =
       ai_chat_service_->GetOrCreateConversationHandlerForContent(

components/ai_chat/core/browser/associated_content_driver.cc

@@ -61,12 +61,7 @@ AssociatedContentDriver::AssociatedContentDriver(
     : url_loader_factory_(url_loader_factory) {}
 
 AssociatedContentDriver::~AssociatedContentDriver() {
-  for (auto& conversation : associated_conversations_) {
-    if (conversation) {
-      conversation->OnAssociatedContentDestroyed(cached_text_content_,
-                                                 is_video_);
-    }
-  }
+  DisassociateWithConversations();
 }
 
 void AssociatedContentDriver::AddRelatedConversation(
@@ -273,10 +268,10 @@ void AssociatedContentDriver::OnFaviconImageDataChanged() {
 }
 
 void AssociatedContentDriver::OnNewPage(int64_t navigation_id) {
-  // Tell the associated_conversations_ that we're breaking up
-  for (auto& conversation : associated_conversations_) {
-    conversation->OnAssociatedContentDestroyed(cached_text_content_, is_video_);
-  }
+  // This instance will now be used for different content so existing
+  // conversations need to be disassociated.
+  DisassociateWithConversations();
+
   // Tell the observer how to find the next conversation
   for (auto& observer : observers_) {
     observer.OnAssociatedContentNavigated(navigation_id);
@@ -292,4 +287,16 @@ void AssociatedContentDriver::OnNewPage(int64_t navigation_id) {
   ConversationHandler::AssociatedContentDelegate::OnNewPage(navigation_id);
 }
 
+void AssociatedContentDriver::DisassociateWithConversations() {
+  // Iterator might be invalidated by destruction, so copy the items
+  std::vector<ConversationHandler*> conversations{
+      associated_conversations_.begin(), associated_conversations_.end()};
+  for (auto& conversation : conversations) {
+    if (conversation) {
+      conversation->OnAssociatedContentDestroyed(cached_text_content_,
+                                                 is_video_);
+    }
+  }
+}
+
 }  // namespace ai_chat

components/ai_chat/core/browser/associated_content_driver.h

@@ -122,6 +122,12 @@ class AssociatedContentDriver
       ConversationHandler::GetStagedEntriesCallback callback,
       int64_t navigation_id,
       api_request_helper::APIRequestResult result);
+
+  // Let all conversations using this content know that the content
+  // has been destroyed or changed to represent different content (e.g. a
+  // navigation).
+  void DisassociateWithConversations();
+
   static std::optional<std::vector<SearchQuerySummary>>
   ParseSearchQuerySummaryResponse(const base::Value& value);
 

components/ai_chat/core/browser/conversation_handler.cc

@@ -199,6 +199,10 @@ bool ConversationHandler::HasAnyHistory() {
                               });
 }
 
+bool ConversationHandler::IsAssociatedContentAlive() {
+  return associated_content_delegate_ && !archive_content_;
+}
+
 void ConversationHandler::OnConversationDeleted() {
   for (auto& client : conversation_ui_handlers_) {
     client->OnConversationDeleted();
@@ -256,11 +260,11 @@ void ConversationHandler::InitEngine() {
 void ConversationHandler::OnAssociatedContentDestroyed(
     std::string last_text_content,
     bool is_video) {
-  // The associated content delegate is destroyed, so we should not try to
-  // fetch. It may be populated later, e.g. through back navigation.
-  // If this conversation is allowed to be associated with content, we can keep
-  // using our current cached content.
-  associated_content_delegate_ = nullptr;
+  // The associated content delegate is already or about to be destroyed.
+  auto content_id = associated_content_delegate_
+                        ? associated_content_delegate_->GetContentId()
+                        : -1;
+  DisassociateContentDelegate();
   if (!chat_history_.empty() && should_send_page_contents_ &&
       associated_content_info_ && associated_content_info_->url.has_value()) {
     // Get the latest version of article text and
@@ -276,6 +280,10 @@ void ConversationHandler::OnAssociatedContentDestroyed(
     archive_content_ = std::move(archive_content);
   }
   OnAssociatedContentInfoChanged();
+  // Notify observers
+  for (auto& observer : observers_) {
+    observer.OnAssociatedContentDestroyed(this, content_id);
+  }
 }
 
 void ConversationHandler::SetAssociatedContentDelegate(

components/ai_chat/core/browser/conversation_handler.h

@@ -142,6 +142,8 @@ class ConversationHandler : public mojom::ConversationHandler,
     virtual void OnSelectedLanguageChanged(
         ConversationHandler* handler,
         const std::string& selected_language) {}
+    virtual void OnAssociatedContentDestroyed(ConversationHandler* handler,
+                                              int content_id) {}
   };
 
   ConversationHandler(
@@ -167,6 +169,9 @@ class ConversationHandler : public mojom::ConversationHandler,
   bool HasAnyHistory();
   void OnConversationDeleted();
 
+  // Returns true if the conversation has associated content that is non-archive
+  bool IsAssociatedContentAlive();
+
   // Called when the associated content is destroyed or navigated away. If
   // it's a navigation, the AssociatedContentDelegate will set itself to a new
   // ConversationHandler.