feat: Global search for chat messages in the UI

appinfo/routes.php

@@ -44,6 +44,7 @@
 		['name' => 'chattyLLM#updateSessionTitle', 'url' => '/chat/update_session', 'verb' => 'PATCH'],
 		['name' => 'chattyLLM#deleteSession', 'url' => '/chat/delete_session', 'verb' => 'DELETE'],
 		['name' => 'chattyLLM#getSessions', 'url' => '/chat/sessions', 'verb' => 'GET'],
+		['name' => 'chattyLLM#searchChat', 'url' => '/chat/search', 'verb' => 'GET'],
 		['name' => 'chattyLLM#newMessage', 'url' => '/chat/new_message', 'verb' => 'PUT'],
 		['name' => 'chattyLLM#deleteMessage', 'url' => '/chat/delete_message', 'verb' => 'DELETE'],
 		['name' => 'chattyLLM#getMessages', 'url' => '/chat/messages', 'verb' => 'GET'],

lib/Controller/ChattyLLMController.php

@@ -311,6 +311,39 @@ public function getSessions(): JSONResponse {
 		}
 	}
 
+	/**
+	 * Search chat messages by content
+	 *
+	 * Returns sessions that contain matching messages.
+	 *
+	 * @param string $query Search query (min 2 characters)
+	 * @return JSONResponse<Http::STATUS_OK, array{sessions: list<AssistantChatSession>}, array{}>|JSONResponse<Http::STATUS_UNAUTHORIZED|Http::STATUS_INTERNAL_SERVER_ERROR, array{error: string}, array{}>
+	 *
+	 * 200: Search results
+	 * 401: Not logged in
+	 * 500: Failed to search
+	 */
+	#[NoAdminRequired]
+	#[OpenAPI(scope: OpenAPI::SCOPE_DEFAULT, tags: ['chat_api'])]
+	public function searchChat(string $query = ''): JSONResponse {
+		if ($this->userId === null) {
+			return new JSONResponse(['error' => $this->l10n->t('User not logged in')], Http::STATUS_UNAUTHORIZED);
+		}
+
+		$query = trim($query);
+		if (empty($query) || strlen($query) < 2) {
+			return new JSONResponse(['sessions' => []]);
+		}
+
+		try {
+			$sessions = $this->sessionMapper->searchSessionsByMessageContent($this->userId, $query);
+			return new JSONResponse(['sessions' => $sessions]);
+		} catch (\OCP\DB\Exception $e) {
+			$this->logger->warning('Failed to search chat messages', ['exception' => $e]);
+            return new JSONResponse(['error' => $this->l10n->t('Failed to search chat sessions')], Http::STATUS_INTERNAL_SERVER_ERROR);
+		}
+	}
+
 	/**
 	 * Add a message
 	 *

lib/Db/ChattyLLM/SessionMapper.php

@@ -185,4 +185,24 @@ public function updateSessionIsRemembered(?string $userId, int $sessionId, bool
 		$session->setIsRemembered($is_remembered);
 		$this->update($session);
 	}
+
+	/**
+	 * @return array<Session>
+	 * @throws \OCP\DB\Exception
+	 */
+	public function searchSessionsByMessageContent(string $userId, string $query): array {
+		$qb = $this->db->getQueryBuilder();
+		$qb->select('s.id', 's.user_id', 's.title', 's.timestamp', 's.agency_conversation_token', 's.agency_pending_actions', 's.summary', 's.is_summary_up_to_date', 's.is_remembered')
+			->from($this->getTableName(), 's')
+			->innerJoin('s', 'assistant_chat_msgs', 'm', $qb->expr()->eq('s.id', 'm.session_id'))
+			->where($qb->expr()->eq('s.user_id', $qb->createPositionalParameter($userId, IQueryBuilder::PARAM_STR)))
+			->andWhere($qb->expr()->in('m.role', $qb->createParameter('roles')))
+			->andWhere($qb->expr()->iLike('m.content', $qb->createPositionalParameter('%' . $query . '%', IQueryBuilder::PARAM_STR)))
+			->groupBy('s.id')
+			->orderBy('s.timestamp', 'DESC');
+
+		$qb->setParameter('roles', ['human', 'assistant'], IQueryBuilder::PARAM_STR_ARRAY);
+
+		return $this->findEntities($qb);
+	}
 }