Initial commit

lib/data/database/daos/chat_dao.dart

@@ -0,0 +1,43 @@
+import 'package:drift/drift.dart';
+import 'package:trainhub_flutter/data/database/app_database.dart';
+
+part 'chat_dao.g.dart';
+
+@DriftAccessor(tables: [ChatSessions, ChatMessages])
+class ChatDao extends DatabaseAccessor<AppDatabase> with _$ChatDaoMixin {
+  ChatDao(super.db);
+
+  Future<List<ChatSession>> getAllSessions() =>
+      (select(chatSessions)
+            ..orderBy([
+              (t) => OrderingTerm(
+                  expression: t.createdAt, mode: OrderingMode.desc)
+            ]))
+          .get();
+
+  Future<ChatSession?> getSession(String id) =>
+      (select(chatSessions)..where((t) => t.id.equals(id)))
+          .getSingleOrNull();
+
+  Future<void> insertSession(ChatSessionsCompanion entry) =>
+      into(chatSessions).insert(entry);
+
+  Future<void> deleteSession(String id) =>
+      (delete(chatSessions)..where((t) => t.id.equals(id))).go();
+
+  Future<void> updateSessionTitle(String id, String title) =>
+      (update(chatSessions)..where((t) => t.id.equals(id)))
+          .write(ChatSessionsCompanion(title: Value(title)));
+
+  Future<List<ChatMessage>> getMessages(String sessionId) =>
+      (select(chatMessages)
+            ..where((t) => t.sessionId.equals(sessionId))
+            ..orderBy([
+              (t) =>
+                  OrderingTerm(expression: t.createdAt, mode: OrderingMode.asc)
+            ]))
+          .get();
+
+  Future<void> insertMessage(ChatMessagesCompanion entry) =>
+      into(chatMessages).insert(entry);
+}