Feature/chat message search

appinfo/routes.php

@@ -48,6 +48,7 @@
 		['name' => 'chattyLLM#deleteMessage', 'url' => '/chat/delete_message', 'verb' => 'DELETE'],
 		['name' => 'chattyLLM#getMessages', 'url' => '/chat/messages', 'verb' => 'GET'],
 		['name' => 'chattyLLM#getMessage', 'url' => '/chat/sessions/{sessionId}/messages/{messageId}', 'verb' => 'GET'],
+		['name' => 'chattyLLM#searchMessages', 'url' => '/chat/search', 'verb' => 'GET'],
 		['name' => 'chattyLLM#generateForSession', 'url' => '/chat/generate', 'verb' => 'GET'],
 		['name' => 'chattyLLM#regenerateForSession', 'url' => '/chat/regenerate', 'verb' => 'GET'],
 		['name' => 'chattyLLM#checkSession', 'url' => '/chat/check_session', 'verb' => 'GET'],

lib/Controller/ChattyLLMController.php

@@ -466,6 +466,33 @@ public function deleteMessage(int $messageId, int $sessionId): JSONResponse {
 		}
 	}
 
+	/**
+	 * Search chat messages
+	 *
+	 * Search through all chat messages for the current user
+	 *
+	 * @param string $query The search query
+	 * @return JSONResponse<Http::STATUS_OK, array{messages: list<AssistantChatMessage>, sessionIds: list<int>}, array{}>|JSONResponse<Http::STATUS_INTERNAL_SERVER_ERROR|Http::STATUS_UNAUTHORIZED, array{error: string}, array{}>
+	 *
+	 * 200: Search results returned successfully
+	 * 401: Not logged in
+	 */
+	#[NoAdminRequired]
+	#[OpenAPI(scope: OpenAPI::SCOPE_DEFAULT, tags: ['chat_api'])]
+	public function searchMessages(string $query): JSONResponse {
+
+		try {
+			$result = $this->chatService->searchMessages($this->userId, $query);
+			return new JSONResponse($result);
+		} catch (InternalException $e) {
+			$this->logger->warning('Failed to search chat messages', ['exception' => $e]);
+			return new JSONResponse(['error' => $this->l10n->t('Failed to search chat messages')], Http::STATUS_INTERNAL_SERVER_ERROR);
+		} catch (\OCA\Assistant\Service\UnauthorizedException $e) {
+			return new JSONResponse(['error' => $this->l10n->t('User not logged in')], Http::STATUS_UNAUTHORIZED);
+		}
+	}
+
+
 	/**
 	 * Generate a new assistant message
 	 *

lib/Db/ChattyLLM/MessageMapper.php

@@ -181,4 +181,24 @@ public function deleteMessageById(int $sessionId, int $messageId): void {
 
 		$qb->executeStatement();
 	}
+
+	/**
+	 * @param string $userId
+	 * @param string $query
+	 * @param int $limit
+	 * @return list<Message>
+	 * @throws \OCP\DB\Exception
+	 */
+	public function searchMessages(string $userId, string $query, int $limit = 100): array {
+		$qb = $this->db->getQueryBuilder();
+		$qb->select(Message::$columns)
+			->from($this->getTableName(), 'm')
+			->join('m', 'assistant_chat_sns', 's', $qb->expr()->eq('m.session_id', 's.id'))
+			->where($qb->expr()->eq('s.user_id', $qb->createPositionalParameter($userId, IQueryBuilder::PARAM_STR)))
+			->andWhere($qb->expr()->iLike('m.content', $qb->createPositionalParameter('%' . $this->db->escapeLikeParameter($query) . '%', IQueryBuilder::PARAM_STR)))
+			->orderBy('m.timestamp', 'DESC')
+			->setMaxResults($limit);
+
+		return $this->findEntities($qb);
+	}
 }

lib/Service/ChatService.php

@@ -168,6 +168,32 @@ public function getSessionsForUser(?string $userId): array {
 		}
 	}
 
+	/**
+	 * @return array{messages: list<array<string,mixed>>, sessionIds: list<int>}
+	 * @throws UnauthorizedException
+	 * @throws InternalException
+	 */
+	public function searchMessages(?string $userId, string $query): array {
+		if ($userId === null) {
+			throw new UnauthorizedException($this->l10n->t('Unauthorized'));
+		}
+		// For empty queries return two empty lists right away
+		if (trim($query) === '') {
+			return ['messages' => [], 'sessionIds' => []];
+		}
+		try {
+			$messages = $this->messageMapper->searchMessages($userId, $query);
+		} catch (Exception $e) {
+			throw new InternalException(previous: $e);
+		}
+		$sessionIds = array_values(array_unique(
+			array_map(fn(Message $m) => $m->getSessionId(), $messages)
+		));
+		return [
+			'messages' => array_map(fn(Message $m) => $m->jsonSerialize(), $messages), // convert Message objects into plain arrays
+			'sessionIds' => $sessionIds,
+		];
+	}
 	/**
 	 * @throws BadRequestException
 	 * @throws InternalException

tests/unit/Service/ChatServiceSearchTest.php

@@ -0,0 +1,130 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\Assistant\Tests;
+
+use OCA\Assistant\Db\ChattyLLM\Message;
+use OCA\Assistant\Db\ChattyLLM\MessageMapper;
+use OCA\Assistant\Db\ChattyLLM\SessionMapper;
+use OCA\Assistant\Service\ChatService;
+use OCA\Assistant\Service\SessionSummaryService;
+use OCA\Assistant\Service\UnauthorizedException;
+use OCP\AppFramework\Utility\ITimeFactory;
+use OCP\IAppConfig;
+use OCP\IL10N;
+use OCP\IUserManager;
+use OCP\TaskProcessing\IManager;
+use PHPUnit\Framework\TestCase;
+use Psr\Log\LoggerInterface;
+
+class ChatServiceSearchTest extends TestCase {
+
+    private ChatService $service;
+    private MessageMapper $messageMapper;
+
+    protected function setUp(): void {
+        parent::setUp();
+
+        // Mock all ChatService dependencies
+        $this->messageMapper = $this->createMock(MessageMapper::class);
+
+        $l10n = $this->createMock(IL10N::class);
+        $l10n->method('t')->willReturnArgument(0);
+
+        $this->service = new ChatService(
+            $this->createMock(IUserManager::class),
+            $this->createMock(IAppConfig::class),
+            $l10n,
+            $this->createMock(SessionMapper::class),
+            $this->messageMapper,
+            $this->createMock(SessionSummaryService::class),
+            $this->createMock(IManager::class),
+            $this->createMock(LoggerInterface::class),
+            $this->createMock(ITimeFactory::class),
+        );
+    }
+
+    public function testSearchMessagesUserIdNull(): void {
+        // UserId = null should throw an error
+        $this->expectException(UnauthorizedException::class);
+        $this->service->searchMessages(null, 'hello');
+    }
+
+    public function testSearchMessagesBlankQuery(): void {
+        // A blank query should not hit the database but return empty
+        $this->messageMapper->expects($this->never())
+            ->method('searchMessages');
+
+        $result = $this->service->searchMessages('user1', '   ');
+
+        $this->assertSame([], $result['messages']);
+        $this->assertSame([], $result['sessionIds']);
+    }
+
+    public function testSearchMessagesSameSession(): void {
+        // Two messages from the same session
+        $msg1 = new Message();
+        $msg1->setSessionId(1);
+        $msg1->setRole(Message::ROLE_HUMAN);
+        $msg1->setContent('hello assistant');
+        $msg1->setTimestamp(1000);
+        $msg1->setSources('[]');
+        $msg1->setAttachments('[]');
+
+        $msg2 = new Message();
+        $msg2->setSessionId(1);
+        $msg2->setRole(Message::ROLE_ASSISTANT);
+        $msg2->setContent('hello human');
+        $msg2->setTimestamp(1001);
+        $msg2->setSources('[]');
+        $msg2->setAttachments('[]');
+
+        $this->messageMapper->expects($this->once())
+            ->method('searchMessages')
+            ->with('user1', 'hello')
+            ->willReturn([$msg1, $msg2]);
+
+        $result = $this->service->searchMessages('user1', 'hello');
+
+        // Two messages returned
+        $this->assertCount(2, $result['messages']);
+        // Check that the messages have the same session ID
+        $this->assertSame([1], $result['sessionIds']);
+    }
+
+    public function testSearchMessagesDifferentSession(): void {
+        $msg1 = new Message();
+        $msg1->setSessionId(2);
+        $msg1->setRole(Message::ROLE_HUMAN);
+        $msg1->setContent('hello from session 2');
+        $msg1->setTimestamp(1000);
+        $msg1->setSources('[]');
+        $msg1->setAttachments('[]');
+
+        $msg2 = new Message();
+        $msg2->setSessionId(3);
+        $msg2->setRole(Message::ROLE_HUMAN);
+        $msg2->setContent('hello from session 3');
+        $msg2->setTimestamp(1001);
+        $msg2->setSources('[]');
+        $msg2->setAttachments('[]');
+
+        $this->messageMapper->expects($this->once())
+            ->method('searchMessages')
+            ->with('user1', 'hello')
+            ->willReturn([$msg1, $msg2]);
+
+        $result = $this->service->searchMessages('user1', 'hello');
+
+        $this->assertCount(2, $result['messages']);
+
+        // Check that the messages have different session IDs
+        $this->assertSame([2, 3], $result['sessionIds']);
+    }
+}