Refactoring

lib/presentation/chat/chat_controller.dart

@@ -1,21 +1,45 @@
+import 'package:dio/dio.dart';
 import 'package:riverpod_annotation/riverpod_annotation.dart';
-import 'package:trainhub_flutter/injection.dart';
 import 'package:trainhub_flutter/domain/repositories/chat_repository.dart';
+import 'package:trainhub_flutter/domain/repositories/note_repository.dart';
+import 'package:trainhub_flutter/injection.dart';
 import 'package:trainhub_flutter/presentation/chat/chat_state.dart';
 
 part 'chat_controller.g.dart';
 
+const _chatApiUrl = 'http://localhost:8080/v1/chat/completions';
+
+/// Base system prompt that is always included.
+const _baseSystemPrompt =
+    'You are a helpful AI fitness assistant for personal trainers. '
+    'Help users design training plans, analyse exercise technique, '
+    'and answer questions about sports science and nutrition.';
+
 @riverpod
 class ChatController extends _$ChatController {
   late ChatRepository _repo;
+  late NoteRepository _noteRepo;
+
+  // Shared Dio client — generous timeout for 7B models running on CPU.
+  final _dio = Dio(
+    BaseOptions(
+      connectTimeout: const Duration(seconds: 30),
+      receiveTimeout: const Duration(minutes: 5),
+    ),
+  );
 
   @override
   Future<ChatState> build() async {
     _repo = getIt<ChatRepository>();
+    _noteRepo = getIt<NoteRepository>();
     final sessions = await _repo.getAllSessions();
     return ChatState(sessions: sessions);
   }
 
+  // -------------------------------------------------------------------------
+  // Session management (unchanged)
+  // -------------------------------------------------------------------------
+
   Future<void> createSession() async {
     final session = await _repo.createSession();
     final sessions = await _repo.getAllSessions();
@@ -48,9 +72,15 @@ class ChatController extends _$ChatController {
     );
   }
 
+  // -------------------------------------------------------------------------
+  // Send message  (RAG + Step D)
+  // -------------------------------------------------------------------------
+
   Future<void> sendMessage(String content) async {
     final current = state.valueOrNull;
     if (current == null) return;
+
+    // ── 1. Resolve / create a session ─────────────────────────────────────
     String sessionId;
     if (current.activeSession == null) {
       final session = await _repo.createSession();
@@ -62,6 +92,8 @@ class ChatController extends _$ChatController {
     } else {
       sessionId = current.activeSession!.id;
     }
+
+    // ── 2. Persist user message & show typing indicator ───────────────────
     await _repo.addMessage(
       sessionId: sessionId,
       role: 'user',
@@ -69,22 +101,73 @@ class ChatController extends _$ChatController {
     );
     final messagesAfterUser = await _repo.getMessages(sessionId);
     state = AsyncValue.data(
-      state.valueOrNull!.copyWith(messages: messagesAfterUser, isTyping: true),
+      state.valueOrNull!.copyWith(
+        messages: messagesAfterUser,
+        isTyping: true,
+      ),
     );
-    await Future<void>.delayed(const Duration(seconds: 1));
-    final String response = _getMockResponse(content);
+
+    // ── 3. RAG: retrieve relevant chunks from the knowledge base ──────────
+    // Gracefully degrades — if Nomic server is unavailable or no chunks
+    // exist, the chat still works with the base system prompt alone.
+    List<String> contextChunks = [];
+    try {
+      contextChunks = await _noteRepo.searchSimilar(content, topK: 3);
+    } catch (_) {
+      // Nomic server not running or no chunks stored — continue without RAG.
+    }
+
+    // ── 4. Build enriched system prompt (Step D) ──────────────────────────
+    final systemPrompt = _buildSystemPrompt(contextChunks);
+
+    // Build the full conversation history so the model maintains context.
+    final history = messagesAfterUser
+        .map(
+          (m) => <String, String>{
+            'role': m.isUser ? 'user' : 'assistant',
+            'content': m.content,
+          },
+        )
+        .toList();
+
+    // ── 5. POST to Qwen (http://localhost:8080/v1/chat/completions) ────────
+    String aiResponse;
+    try {
+      final response = await _dio.post<Map<String, dynamic>>(
+        _chatApiUrl,
+        data: {
+          'messages': [
+            {'role': 'system', 'content': systemPrompt},
+            ...history,
+          ],
+          'temperature': 0.7,
+        },
+      );
+      aiResponse =
+          response.data!['choices'][0]['message']['content'] as String;
+    } on DioException catch (e) {
+      aiResponse =
+          'Could not reach the AI server (${e.message}). '
+          'Make sure AI models are downloaded and the inference servers have '
+          'had time to start.';
+    } catch (e) {
+      aiResponse = 'An unexpected error occurred: $e';
+    }
+
+    // ── 6. Persist response & update session title on first exchange ───────
     await _repo.addMessage(
       sessionId: sessionId,
       role: 'assistant',
-      content: response,
+      content: aiResponse,
     );
+
     final messagesAfterAi = await _repo.getMessages(sessionId);
     if (messagesAfterAi.length <= 2) {
-      final title = content.length > 30
-          ? '${content.substring(0, 30)}...'
-          : content;
+      final title =
+          content.length > 30 ? '${content.substring(0, 30)}…' : content;
       await _repo.updateSessionTitle(sessionId, title);
     }
+
     final sessions = await _repo.getAllSessions();
     state = AsyncValue.data(
       state.valueOrNull!.copyWith(
@@ -95,15 +178,25 @@ class ChatController extends _$ChatController {
     );
   }
 
-  String _getMockResponse(String input) {
-    final String lower = input.toLowerCase();
-    if (lower.contains('plan') || lower.contains('program')) {
-      return "I can help you design a training plan! What are your goals? Strength, hypertrophy, or endurance?";
-    } else if (lower.contains('squat') || lower.contains('bench')) {
-      return "Compound movements are great. Remember to maintain proper form. For squats, keep your chest up and knees tracking over toes.";
-    } else if (lower.contains('nutrition') || lower.contains('eat')) {
-      return "Nutrition is key. Aim for 1.6-2.2g of protein per kg of bodyweight if you're training hard.";
-    }
-    return "I'm your AI training assistant. How can I help you today?";
+  // -------------------------------------------------------------------------
+  // Helpers
+  // -------------------------------------------------------------------------
+
+  /// Builds the system prompt, injecting RAG context when available.
+  static String _buildSystemPrompt(List<String> chunks) {
+    if (chunks.isEmpty) return _baseSystemPrompt;
+
+    final contextBlock = chunks
+        .asMap()
+        .entries
+        .map((e) => '[${e.key + 1}] ${e.value}')
+        .join('\n\n');
+
+    return '$_baseSystemPrompt\n\n'
+        '### Relevant notes from the trainer\'s knowledge base:\n'
+        '$contextBlock\n\n'
+        'Use the above context to inform your response when relevant. '
+        'If the context is not directly applicable, rely on your general '
+        'fitness knowledge.';
   }
 }