Next refactors

lib/presentation/chat/chat_controller.dart

@@ -1,30 +1,32 @@
+import 'dart:convert';
 import 'package:dio/dio.dart';
 import 'package:riverpod_annotation/riverpod_annotation.dart';
+import 'package:trainhub_flutter/core/constants/ai_constants.dart';
 import 'package:trainhub_flutter/domain/repositories/chat_repository.dart';
 import 'package:trainhub_flutter/domain/repositories/note_repository.dart';
+import 'package:trainhub_flutter/data/services/ai_process_manager.dart';
 import 'package:trainhub_flutter/injection.dart';
 import 'package:trainhub_flutter/presentation/chat/chat_state.dart';
+import 'package:uuid/uuid.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
+AiProcessManager aiProcessManager(AiProcessManagerRef ref) {
+  final manager = getIt<AiProcessManager>();
+  manager.addListener(() => ref.notifyListeners());
+  return manager;
+}
 
 @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),
+      connectTimeout: AiConstants.serverConnectTimeout,
+      receiveTimeout: AiConstants.serverReceiveTimeout,
     ),
   );
 
@@ -32,14 +34,14 @@ class ChatController extends _$ChatController {
   Future<ChatState> build() async {
     _repo = getIt<ChatRepository>();
     _noteRepo = getIt<NoteRepository>();
+    final aiManager = ref.read(aiProcessManagerProvider);
+    if (aiManager.status == AiServerStatus.offline) {
+      aiManager.startServers();
+    }
     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();
@@ -72,28 +74,29 @@ class ChatController extends _$ChatController {
     );
   }
 
-  // -------------------------------------------------------------------------
-  // Send message  (RAG + Step D)
-  // -------------------------------------------------------------------------
-
   Future<void> sendMessage(String content) async {
     final current = state.valueOrNull;
     if (current == null) return;
+    final sessionId = await _resolveSession(current, content);
+    await _persistUserMessage(sessionId, content);
+    final contextChunks = await _searchKnowledgeBase(content);
+    final systemPrompt = _buildSystemPrompt(contextChunks);
+    final history = _buildHistory();
+    final fullAiResponse = await _streamResponse(systemPrompt, history);
+    await _persistAssistantResponse(sessionId, content, fullAiResponse);
+  }
 
-    // ── 1. Resolve / create a session ─────────────────────────────────────
-    String sessionId;
-    if (current.activeSession == null) {
-      final session = await _repo.createSession();
-      sessionId = session.id;
-      final sessions = await _repo.getAllSessions();
-      state = AsyncValue.data(
-        current.copyWith(sessions: sessions, activeSession: session),
-      );
-    } else {
-      sessionId = current.activeSession!.id;
-    }
+  Future<String> _resolveSession(ChatState current, String content) async {
+    if (current.activeSession != null) return current.activeSession!.id;
+    final session = await _repo.createSession();
+    final sessions = await _repo.getAllSessions();
+    state = AsyncValue.data(
+      current.copyWith(sessions: sessions, activeSession: session),
+    );
+    return session.id;
+  }
 
-    // ── 2. Persist user message & show typing indicator ───────────────────
+  Future<void> _persistUserMessage(String sessionId, String content) async {
     await _repo.addMessage(
       sessionId: sessionId,
       role: 'user',
@@ -104,95 +107,196 @@ class ChatController extends _$ChatController {
       state.valueOrNull!.copyWith(
         messages: messagesAfterUser,
         isTyping: true,
+        thinkingSteps: [],
+        streamingContent: '',
       ),
     );
+  }
 
-    // ── 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.
+  Future<List<String>> _searchKnowledgeBase(String query) async {
+    final searchStep = _createStep('Searching knowledge base...');
     List<String> contextChunks = [];
     try {
-      contextChunks = await _noteRepo.searchSimilar(content, topK: 3);
-    } catch (_) {
-      // Nomic server not running or no chunks stored — continue without RAG.
+      contextChunks = await _noteRepo.searchSimilar(query, topK: 3);
+      if (contextChunks.isNotEmpty) {
+        _updateStep(
+          searchStep.id,
+          status: ThinkingStepStatus.completed,
+          title: 'Found ${contextChunks.length} documents',
+          details: 'Context added for assistant.',
+        );
+      } else {
+        _updateStep(
+          searchStep.id,
+          status: ThinkingStepStatus.completed,
+          title: 'No matching documents in knowledge base',
+          details: 'Responding based on general knowledge.',
+        );
+      }
+    } catch (e) {
+      _updateStep(
+        searchStep.id,
+        status: ThinkingStepStatus.error,
+        title: 'Knowledge base search error',
+        details: e.toString(),
+      );
     }
+    return contextChunks;
+  }
 
-    // ── 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,
-          },
-        )
+  List<Map<String, String>> _buildHistory() {
+    final messages = state.valueOrNull?.messages ?? [];
+    return messages
+        .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;
+  Future<String> _streamResponse(
+    String systemPrompt,
+    List<Map<String, String>> history,
+  ) async {
+    final generateStep = _createStep('Generating response...');
+    String fullAiResponse = '';
     try {
-      final response = await _dio.post<Map<String, dynamic>>(
-        _chatApiUrl,
+      final response = await _dio.post<ResponseBody>(
+        AiConstants.chatApiUrl,
+        options: Options(responseType: ResponseType.stream),
         data: {
           'messages': [
             {'role': 'system', 'content': systemPrompt},
             ...history,
           ],
-          'temperature': 0.7,
+          'temperature': AiConstants.chatTemperature,
+          'stream': true,
         },
       );
-      aiResponse =
-          response.data!['choices'][0]['message']['content'] as String;
+      _updateStep(
+        generateStep.id,
+        status: ThinkingStepStatus.running,
+        title: 'Writing...',
+      );
+      final stream = response.data!.stream;
+      await for (final chunk in stream) {
+        final textChunk = utf8.decode(chunk);
+        for (final line in textChunk.split('\n')) {
+          if (!line.startsWith('data: ')) continue;
+          final dataStr = line.substring(6).trim();
+          if (dataStr == '[DONE]') break;
+          if (dataStr.isEmpty) continue;
+          try {
+            final data = jsonDecode(dataStr);
+            final delta = data['choices']?[0]?['delta']?['content'] ?? '';
+            if (delta.isNotEmpty) {
+              fullAiResponse += delta;
+              final updatedState = state.valueOrNull;
+              if (updatedState != null) {
+                state = AsyncValue.data(
+                  updatedState.copyWith(streamingContent: fullAiResponse),
+                );
+              }
+            }
+          } catch (_) {}
+        }
+      }
+      _updateStep(
+        generateStep.id,
+        status: ThinkingStepStatus.completed,
+        title: 'Response generated',
+      );
     } on DioException catch (e) {
-      aiResponse =
-          'Could not reach the AI server (${e.message}). '
-          'Make sure AI models are downloaded and the inference servers have '
-          'had time to start.';
+      fullAiResponse += '\n\n[AI model communication error]';
+      _updateStep(
+        generateStep.id,
+        status: ThinkingStepStatus.error,
+        title: 'Generation failed',
+        details: '${e.message}',
+      );
     } catch (e) {
-      aiResponse = 'An unexpected error occurred: $e';
+      fullAiResponse += '\n\n[Unexpected error]';
+      _updateStep(
+        generateStep.id,
+        status: ThinkingStepStatus.error,
+        title: 'Generation failed',
+        details: e.toString(),
+      );
     }
+    return fullAiResponse;
+  }
 
-    // ── 6. Persist response & update session title on first exchange ───────
+  Future<void> _persistAssistantResponse(
+    String sessionId,
+    String userContent,
+    String aiResponse,
+  ) async {
     await _repo.addMessage(
       sessionId: sessionId,
       role: 'assistant',
       content: aiResponse,
     );
-
     final messagesAfterAi = await _repo.getMessages(sessionId);
     if (messagesAfterAi.length <= 2) {
-      final title =
-          content.length > 30 ? '${content.substring(0, 30)}…' : content;
+      final title = userContent.length > 30
+          ? '${userContent.substring(0, 30)}…'
+          : userContent;
       await _repo.updateSessionTitle(sessionId, title);
     }
-
     final sessions = await _repo.getAllSessions();
     state = AsyncValue.data(
       state.valueOrNull!.copyWith(
         messages: messagesAfterAi,
         isTyping: false,
+        streamingContent: null,
+        thinkingSteps: [],
         sessions: sessions,
       ),
     );
   }
 
-  // -------------------------------------------------------------------------
-  // Helpers
-  // -------------------------------------------------------------------------
+  ThinkingStep _createStep(String title) {
+    final step = ThinkingStep(
+      id: const Uuid().v4(),
+      title: title,
+      status: ThinkingStepStatus.pending,
+    );
+    final current = state.valueOrNull;
+    if (current != null) {
+      state = AsyncValue.data(
+        current.copyWith(thinkingSteps: [...current.thinkingSteps, step]),
+      );
+    }
+    return step;
+  }
+
+  void _updateStep(
+    String id, {
+    ThinkingStepStatus? status,
+    String? title,
+    String? details,
+  }) {
+    final current = state.valueOrNull;
+    if (current == null) return;
+    final updatedSteps = current.thinkingSteps.map((s) {
+      if (s.id != id) return s;
+      return s.copyWith(
+        status: status ?? s.status,
+        title: title ?? s.title,
+        details: details ?? s.details,
+      );
+    }).toList();
+    state = AsyncValue.data(current.copyWith(thinkingSteps: updatedSteps));
+  }
 
-  /// Builds the system prompt, injecting RAG context when available.
   static String _buildSystemPrompt(List<String> chunks) {
-    if (chunks.isEmpty) return _baseSystemPrompt;
-
+    if (chunks.isEmpty) return AiConstants.baseSystemPrompt;
     final contextBlock = chunks
         .asMap()
         .entries
         .map((e) => '[${e.key + 1}] ${e.value}')
         .join('\n\n');
-
-    return '$_baseSystemPrompt\n\n'
+    return '${AiConstants.baseSystemPrompt}\n\n'
         '### Relevant notes from the trainer\'s knowledge base:\n'
         '$contextBlock\n\n'
         'Use the above context to inform your response when relevant. '