Integrate Riverpod-based navigation state management

lib/providers/navigation/models/home_tab.dart

@@ -0,0 +1,15 @@
+/// Primary destinations for [HomeScreen] bottom navigation.
+enum HomeTab {
+  dashboard,
+  calendar,
+  workspace,
+  chat,
+  profile;
+
+  static HomeTab fromIndex(int index) {
+    if (index < 0 || index >= HomeTab.values.length) {
+      return HomeTab.dashboard;
+    }
+    return HomeTab.values[index];
+  }
+}

lib/providers/navigation_provider.dart

@@ -1,8 +1,8 @@
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 
-/// Bottom navigation index for the home shell ([HomeScreen]).
-///
-/// 0: Dashboard, 1: Calendar, 2: Workspace, 3: Chat, 4: Profile.
-///
-/// Not wired to [HomeScreen] yet — foundation for future migration.
-final homeTabIndexProvider = StateProvider<int>((ref) => 0);
+import 'navigation/models/home_tab.dart';
+
+/// Selected tab for [HomeScreen] bottom navigation.
+final homeTabProvider = StateProvider<HomeTab>(
+  (ref) => HomeTab.dashboard,
+);

lib/screens/home/home_screen.dart

@@ -1,73 +1,32 @@
 import 'package:flutter/material.dart';
-import 'package:flutter/services.dart';
-import '../../widgets/custom_widgets.dart';
-import '../../services/navigation_service.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import '../../providers/navigation/models/home_tab.dart';
+import '../../providers/navigation_provider.dart';
 import '../workspace/workspace_screen.dart';
 import '../calendar/calendar_screen.dart';
 import '../profile/profile_screen.dart';
 import '../chat/chat_screen.dart';
 import 'dashboard_screen.dart';
 
-class HomeScreen extends StatefulWidget {
+class HomeScreen extends ConsumerStatefulWidget {
   final Map<String, dynamic>? arguments;
 
   const HomeScreen({super.key, this.arguments});
 
   @override
-  State<HomeScreen> createState() => _HomeScreenState();
+  ConsumerState<HomeScreen> createState() => _HomeScreenState();
 }
 
-class _HomeScreenState extends State<HomeScreen>
-    with SingleTickerProviderStateMixin {
-  final TextEditingController _messageController = TextEditingController();
-  final ScrollController _scrollController = ScrollController();
-  final List<ChatMessage> _messages = [];
-  bool _isListening = false;
-  int _selectedIndex = 0;
-  bool _isFabExpanded = false;
-  late AnimationController _fabController;
-  late Animation<double> _fabAnimation;
-
+class _HomeScreenState extends ConsumerState<HomeScreen> {
   List<Widget> _screens = [];
 
   @override
   void initState() {
     super.initState();
-    _fabController = AnimationController(
-      duration: const Duration(milliseconds: 300),
-      vsync: this,
-    );
-    _fabAnimation = CurvedAnimation(
-      parent: _fabController,
-      curve: Curves.easeOut,
-      reverseCurve: Curves.easeIn,
-    );
-
-    // Initialize screens
     _initializeScreens();
 
-    // Handle initial arguments if provided
     WidgetsBinding.instance.addPostFrameCallback((_) {
-      if (widget.arguments != null) {
-        if (widget.arguments!.containsKey('screen') &&
-            widget.arguments!['screen'] is int) {
-          setState(() {
-            _selectedIndex = widget.arguments!['screen'];
-          });
-        }
-
-        // Handle initial message for chat screen
-        if (widget.arguments!.containsKey('initial_message') &&
-            widget.arguments!['initial_message'] is String &&
-            _selectedIndex == 3) {
-          // Update the chat screen with the initial message
-          setState(() {
-            _screens[3] = ChatScreen(arguments: {
-              'initial_message': widget.arguments!['initial_message']
-            });
-          });
-        }
-      }
+      _applyRouteArguments();
     });
   }
 
@@ -81,70 +40,43 @@ class _HomeScreenState extends State<HomeScreen>
     ];
   }
 
-  @override
-  void dispose() {
-    _messageController.dispose();
-    _scrollController.dispose();
-    _fabController.dispose();
-    super.dispose();
+  void _applyRouteArguments() {
+    final args = widget.arguments;
+    if (args == null) return;
+
+    if (args.containsKey('screen') && args['screen'] is int) {
+      ref.read(homeTabProvider.notifier).state =
+          HomeTab.fromIndex(args['screen'] as int);
+    }
+
+    if (args.containsKey('initial_message') &&
+        args['initial_message'] is String &&
+        ref.read(homeTabProvider) == HomeTab.chat) {
+      setState(() {
+        _screens[HomeTab.chat.index] = ChatScreen(arguments: {
+          'initial_message': args['initial_message'],
+        });
+      });
+    }
   }
 
-  void _sendMessage() {
-    if (_messageController.text.trim().isEmpty) return;
-
-    setState(() {
-      _messages.add(
-        ChatMessage(
-          text: _messageController.text,
-          isUser: true,
-          timestamp: DateTime.now(),
-        ),
-      );
-      _messageController.clear();
-    });
-
-    _scrollToBottom();
-    // TODO: Implement AI response
-  }
-
-  void _scrollToBottom() {
-    WidgetsBinding.instance.addPostFrameCallback((_) {
-      if (_scrollController.hasClients) {
-        _scrollController.animateTo(
-          _scrollController.position.maxScrollExtent,
-          duration: const Duration(milliseconds: 300),
-          curve: Curves.easeOut,
-        );
-      }
-    });
-  }
-
-  void _toggleListening() {
-    setState(() {
-      _isListening = !_isListening;
-    });
-    // TODO: Implement voice recognition
-  }
-
-  void _toggleFab() {
-    setState(() {
-      _isFabExpanded = !_isFabExpanded;
-      if (_isFabExpanded) {
-        _fabController.forward();
-      } else {
-        _fabController.reverse();
-      }
-    });
+  void _selectTab(int index) {
+    ref.read(homeTabProvider.notifier).state = HomeTab.fromIndex(index);
   }
 
   @override
   Widget build(BuildContext context) {
     final theme = Theme.of(context);
+    final selectedTab = ref.watch(homeTabProvider);
+
     return Scaffold(
-      body: IndexedStack(index: _selectedIndex, children: _screens),
+      body: IndexedStack(
+        index: selectedTab.index,
+        children: _screens,
+      ),
       bottomNavigationBar: BottomNavigationBar(
-        currentIndex: _selectedIndex,
-        onTap: (index) => setState(() => _selectedIndex = index),
+        currentIndex: selectedTab.index,
+        onTap: _selectTab,
         type: BottomNavigationBarType.fixed,
         selectedItemColor: theme.colorScheme.primary,
         unselectedItemColor: theme.colorScheme.onSurfaceVariant,
@@ -157,57 +89,20 @@ class _HomeScreenState extends State<HomeScreen>
             icon: Icon(Icons.calendar_today),
             label: 'Calendar',
           ),
-          BottomNavigationBarItem(icon: Icon(Icons.work), label: 'Workspace'),
+          BottomNavigationBarItem(
+            icon: Icon(Icons.work),
+            label: 'Workspace',
+          ),
           BottomNavigationBarItem(
             icon: Icon(Icons.chat_bubble_outline),
             label: 'Chat',
           ),
-          BottomNavigationBarItem(icon: Icon(Icons.person), label: 'Profile'),
-        ],
-      ),
-    );
-  }
-}
-
-class _ChatBubble extends StatelessWidget {
-  final ChatMessage message;
-
-  const _ChatBubble({required this.message});
-
-  @override
-  Widget build(BuildContext context) {
-    return Align(
-      alignment: message.isUser ? Alignment.centerRight : Alignment.centerLeft,
-      child: Container(
-        margin: const EdgeInsets.symmetric(vertical: 4),
-        padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 10),
-        decoration: BoxDecoration(
-          color: message.isUser
-              ? Colors.green.shade400
-              : Theme.of(context).colorScheme.surfaceContainerHighest,
-          borderRadius: BorderRadius.circular(20),
-        ),
-        child: Text(
-          message.text,
-          style: TextStyle(
-            color: message.isUser
-                ? Colors.white
-                : Theme.of(context).colorScheme.onSurface,
+          BottomNavigationBarItem(
+            icon: Icon(Icons.person),
+            label: 'Profile',
           ),
-        ),
+        ],
       ),
     );
   }
 }
-
-class ChatMessage {
-  final String text;
-  final bool isUser;
-  final DateTime timestamp;
-
-  ChatMessage({
-    required this.text,
-    required this.isUser,
-    required this.timestamp,
-  });
-}