fix(chat): fix ChatBloc event callback and test reliability

- Fix onEvent callback initialization in ChatBloc constructor
- Add MockAgUiService to isolate test from mock API behavior
- Remove unnecessary non-null assertions in tests

apps/lib/features/chat/data/ai/ai_decision_engine.dart

@@ -2,17 +2,23 @@ import 'dart:convert';
 
 enum Intent { createEvent, searchEvent, unknown }
 
-class AiDecisionEngine {
 /// 意图匹配规则（顺序敏感：searchEvent 优先级高于 createEvent）
-  static final List<(RegExp, Intent)> _orderedPatterns = [
+final _orderedPatterns = <(RegExp, Intent)>[
   (RegExp(r'^查看|^有什么|^今天.*日程|^明天.*安排|^查询'), Intent.searchEvent),
   (RegExp(r'提醒|开会|预约|安排.*时间|创建.*日程'), Intent.createEvent),
-    (
+  (RegExp(r'明天.*\d|今天.*\d|后天.*\d|\d{1,2}点|\d{1,2}:\d{2}'), Intent.createEvent),
-      RegExp(r'明天.*\d|今天.*\d|后天.*\d|\d{1,2}点|\d{1,2}:\d{2}'),
-      Intent.createEvent,
-    ),
 ];
 
+/// 时区常量
+const _defaultTimezone = 'Asia/Shanghai';
+const _dayToday = '今天';
+const _dayTomorrow = '明天';
+const _dayAfterTomorrow = '后天';
+const _tomorrowOffset = 1;
+const _dayAfterTomorrowOffset = 2;
+const _defaultMinute = 0;
+
+class AiDecisionEngine {
   Intent matchIntent(String text) {
     for (final (pattern, intent) in _orderedPatterns) {
       if (pattern.hasMatch(text)) return intent;
@@ -34,31 +40,33 @@ class AiDecisionEngine {
           .trim();
     }
 
-    if (args['title'] == null || (args['title'] as String).isEmpty) return null;
+    final title = args['title'];
+    if (title == null || (title as String).isEmpty) return null;
 
     final timeMatch = RegExp(
       r'(明天|今天|后天)?\s*(\d{1,2})[:点](\d{2})?',
     ).firstMatch(text);
     if (timeMatch != null) {
-      final dayStr = timeMatch.group(1) ?? '今天';
+      final dayStr = timeMatch.group(1) ?? _dayToday;
       final hour = int.parse(timeMatch.group(2)!);
-      final minute = int.parse(timeMatch.group(3) ?? '0');
+      final minute = int.parse(timeMatch.group(3) ?? '$_defaultMinute');
 
       final now = DateTime.now();
-      DateTime startAt;
+      final dayOffset = switch (dayStr) {
-      switch (dayStr) {
+        _dayTomorrow => _tomorrowOffset,
-        case '明天':
+        _dayAfterTomorrow => _dayAfterTomorrowOffset,
-          startAt = DateTime(now.year, now.month, now.day + 1, hour, minute);
+        _ => 0,
-          break;
+      };
-        case '后天':
+      final startAt = DateTime(
-          startAt = DateTime(now.year, now.month, now.day + 2, hour, minute);
+        now.year,
-          break;
+        now.month,
-        default:
+        now.day + dayOffset,
-          startAt = DateTime(now.year, now.month, now.day, hour, minute);
+        hour,
-      }
+        minute,
+      );
 
       args['startAt'] = startAt.toIso8601String();
-      args['timezone'] = 'Asia/Shanghai';
+      args['timezone'] = _defaultTimezone;
     }
 
     if (!args.containsKey('startAt')) return null;

apps/lib/features/chat/data/models/ag_ui_event.dart

@@ -32,63 +32,39 @@ enum AgUiEventType {
   unknown,
 }
 
-AgUiEventType agUiEventTypeFromWire(String wire) {
+const _wireToTypeMap = {
-  switch (wire) {
+  AgUiEventTypeWire.runStarted: AgUiEventType.runStarted,
-    case AgUiEventTypeWire.runStarted:
+  AgUiEventTypeWire.runFinished: AgUiEventType.runFinished,
-      return AgUiEventType.runStarted;
+  AgUiEventTypeWire.runError: AgUiEventType.runError,
-    case AgUiEventTypeWire.runFinished:
+  AgUiEventTypeWire.textMessageStart: AgUiEventType.textMessageStart,
-      return AgUiEventType.runFinished;
+  AgUiEventTypeWire.textMessageContent: AgUiEventType.textMessageContent,
-    case AgUiEventTypeWire.runError:
+  AgUiEventTypeWire.textMessageEnd: AgUiEventType.textMessageEnd,
-      return AgUiEventType.runError;
+  AgUiEventTypeWire.toolCallStart: AgUiEventType.toolCallStart,
-    case AgUiEventTypeWire.textMessageStart:
+  AgUiEventTypeWire.toolCallArgs: AgUiEventType.toolCallArgs,
-      return AgUiEventType.textMessageStart;
+  AgUiEventTypeWire.toolCallEnd: AgUiEventType.toolCallEnd,
-    case AgUiEventTypeWire.textMessageContent:
+  AgUiEventTypeWire.toolCallResult: AgUiEventType.toolCallResult,
-      return AgUiEventType.textMessageContent;
+  AgUiEventTypeWire.toolCallError: AgUiEventType.toolCallError,
-    case AgUiEventTypeWire.textMessageEnd:
+};
-      return AgUiEventType.textMessageEnd;
-    case AgUiEventTypeWire.toolCallStart:
-      return AgUiEventType.toolCallStart;
-    case AgUiEventTypeWire.toolCallArgs:
-      return AgUiEventType.toolCallArgs;
-    case AgUiEventTypeWire.toolCallEnd:
-      return AgUiEventType.toolCallEnd;
-    case AgUiEventTypeWire.toolCallResult:
-      return AgUiEventType.toolCallResult;
-    case AgUiEventTypeWire.toolCallError:
-      return AgUiEventType.toolCallError;
-    default:
-      return AgUiEventType.unknown;
-  }
-}
 
-String agUiEventTypeToWire(AgUiEventType type) {
+const _typeToWireMap = {
-  switch (type) {
+  AgUiEventType.runStarted: AgUiEventTypeWire.runStarted,
-    case AgUiEventType.runStarted:
+  AgUiEventType.runFinished: AgUiEventTypeWire.runFinished,
-      return AgUiEventTypeWire.runStarted;
+  AgUiEventType.runError: AgUiEventTypeWire.runError,
-    case AgUiEventType.runFinished:
+  AgUiEventType.textMessageStart: AgUiEventTypeWire.textMessageStart,
-      return AgUiEventTypeWire.runFinished;
+  AgUiEventType.textMessageContent: AgUiEventTypeWire.textMessageContent,
-    case AgUiEventType.runError:
+  AgUiEventType.textMessageEnd: AgUiEventTypeWire.textMessageEnd,
-      return AgUiEventTypeWire.runError;
+  AgUiEventType.toolCallStart: AgUiEventTypeWire.toolCallStart,
-    case AgUiEventType.textMessageStart:
+  AgUiEventType.toolCallArgs: AgUiEventTypeWire.toolCallArgs,
-      return AgUiEventTypeWire.textMessageStart;
+  AgUiEventType.toolCallEnd: AgUiEventTypeWire.toolCallEnd,
-    case AgUiEventType.textMessageContent:
+  AgUiEventType.toolCallResult: AgUiEventTypeWire.toolCallResult,
-      return AgUiEventTypeWire.textMessageContent;
+  AgUiEventType.toolCallError: AgUiEventTypeWire.toolCallError,
-    case AgUiEventType.textMessageEnd:
+  AgUiEventType.unknown: '',
-      return AgUiEventTypeWire.textMessageEnd;
+};
-    case AgUiEventType.toolCallStart:
+
-      return AgUiEventTypeWire.toolCallStart;
+AgUiEventType agUiEventTypeFromWire(String wire) =>
-    case AgUiEventType.toolCallArgs:
+    _wireToTypeMap[wire] ?? AgUiEventType.unknown;
-      return AgUiEventTypeWire.toolCallArgs;
+
-    case AgUiEventType.toolCallEnd:
+String agUiEventTypeToWire(AgUiEventType type) => _typeToWireMap[type] ?? '';
-      return AgUiEventTypeWire.toolCallEnd;
-    case AgUiEventType.toolCallResult:
-      return AgUiEventTypeWire.toolCallResult;
-    case AgUiEventType.toolCallError:
-      return AgUiEventTypeWire.toolCallError;
-    case AgUiEventType.unknown:
-      return '';
-  }
-}
 
 @JsonSerializable()
 class AgUiEvent {

apps/lib/features/chat/data/models/tool_result.dart

@@ -2,6 +2,9 @@ import 'package:json_annotation/json_annotation.dart';
 
 part 'tool_result.g.dart';
 
+/// Schema 版本常量
+const _defaultSchemaVersion = 'v1';
+
 /// 工具执行结果（给 AI 的原始数据）
 @JsonSerializable()
 class ToolResult {
@@ -31,7 +34,7 @@ class UiCard {
 
   UiCard({
     required this.cardType,
-    this.schemaVersion = 'v1',
+    this.schemaVersion = _defaultSchemaVersion,
     required this.data,
     this.actions,
   });

apps/lib/features/chat/data/services/ag_ui_service.dart

@@ -8,6 +8,18 @@ import '../models/ag_ui_event.dart';
 import '../models/tool_result.dart';
 import '../tools/tool_registry.dart';
 
+/// Mock ID 前缀常量
+const _threadIdPrefix = 'thread_';
+const _runIdPrefix = 'run_';
+const _toolCallIdPrefix = 'tc_';
+const _messageIdPrefix = 'msg_';
+
+/// 流式输出延迟 (毫秒)
+const _streamChunkDelayMs = 50;
+
+/// 文本块大小
+const _textChunkSize = 10;
+
 typedef EventCallback = void Function(AgUiEvent event);
 
 class AgUiService {
@@ -27,8 +39,8 @@ class AgUiService {
   }
 
   Future<void> _mockEventStream(String content) async {
-    final threadId = 'thread_${DateTime.now().millisecondsSinceEpoch}';
+    final threadId = '$_threadIdPrefix${DateTime.now().millisecondsSinceEpoch}';
-    final runId = 'run_${DateTime.now().millisecondsSinceEpoch}';
+    final runId = '$_runIdPrefix${DateTime.now().millisecondsSinceEpoch}';
 
     onEvent(RunStartedEvent(threadId: threadId, runId: runId));
 
@@ -58,7 +70,8 @@ class AgUiService {
     String toolName,
     Map<String, dynamic> args,
   ) async {
-    final toolCallId = 'tc_${DateTime.now().millisecondsSinceEpoch}';
+    final toolCallId =
+        '$_toolCallIdPrefix${DateTime.now().millisecondsSinceEpoch}';
 
     onEvent(ToolCallStartEvent(toolCallId: toolCallId, toolCallName: toolName));
 
@@ -82,7 +95,8 @@ class AgUiService {
       ToolRegistry.initialize();
       final result = await ToolRegistry.execute(toolName, args);
       final ui = _buildUiCard(toolName, result);
-      final messageId = 'msg_${DateTime.now().millisecondsSinceEpoch}';
+      final messageId =
+          '$_messageIdPrefix${DateTime.now().millisecondsSinceEpoch}';
 
       onEvent(
         ToolCallResultEvent(
@@ -145,20 +159,20 @@ class AgUiService {
 
   Future<void> _mockTextMessageStream(List<String> replies) async {
     for (final reply in replies) {
-      final messageId = 'msg_${DateTime.now().millisecondsSinceEpoch}';
+      final messageId =
+          '$_messageIdPrefix${DateTime.now().millisecondsSinceEpoch}';
 
       onEvent(TextMessageStartEvent(messageId: messageId, role: 'assistant'));
 
-      const chunkSize = 10;
+      for (var i = 0; i < reply.length; i += _textChunkSize) {
-      for (var i = 0; i < reply.length; i += chunkSize) {
+        final end = (i + _textChunkSize < reply.length)
-        final end = (i + chunkSize < reply.length)
+            ? i + _textChunkSize
-            ? i + chunkSize
             : reply.length;
         final chunk = reply.substring(i, end);
 
         onEvent(TextMessageContentEvent(messageId: messageId, delta: chunk));
 
-        await Future.delayed(const Duration(milliseconds: 50));
+        await Future.delayed(const Duration(milliseconds: _streamChunkDelayMs));
       }
 
       onEvent(TextMessageEndEvent(messageId: messageId));

apps/lib/features/chat/data/tools/tool_registry.dart

@@ -1,6 +1,14 @@
 typedef ToolHandler =
     Future<Map<String, dynamic>> Function(Map<String, dynamic> args);
 
+/// 工具常量
+const _toolNameCreateCalendar = 'create_calendar_event';
+const _defaultTimezone = 'Asia/Shanghai';
+const _defaultEventColor = '#4F46E5';
+const _defaultSourceType = 'agentGenerated';
+const _titleMinLength = 1;
+const _titleMaxLength = 100;
+
 class ToolDefinition {
   final String name;
   final String description;
@@ -22,8 +30,8 @@ class ToolRegistry {
   static void initialize() {
     if (_initialized) return;
 
-    _tools['create_calendar_event'] = ToolDefinition(
+    _tools[_toolNameCreateCalendar] = ToolDefinition(
-      name: 'create_calendar_event',
+      name: _toolNameCreateCalendar,
       description: '创建一个日历事件或待办事项',
       parameters: {
         'type': 'object',
@@ -31,8 +39,8 @@ class ToolRegistry {
           'title': {
             'type': 'string',
             'description': '事件标题',
-            'minLength': 1,
+            'minLength': _titleMinLength,
-            'maxLength': 100,
+            'maxLength': _titleMaxLength,
           },
           'description': {'type': 'string', 'description': '事件描述'},
           'startAt': {
@@ -45,7 +53,7 @@ class ToolRegistry {
             'format': 'date-time',
             'description': '结束时间 (ISO8601)',
           },
-          'timezone': {'type': 'string', 'default': 'Asia/Shanghai'},
+          'timezone': {'type': 'string', 'default': _defaultTimezone},
           'location': {'type': 'string'},
           'notes': {'type': 'string'},
         },
@@ -69,10 +77,10 @@ class ToolRegistry {
       'description': args['description'],
       'startAt': args['startAt'],
       'endAt': args['endAt'],
-      'timezone': args['timezone'] ?? 'Asia/Shanghai',
+      'timezone': args['timezone'] ?? _defaultTimezone,
       'location': args['location'],
-      'color': '#4F46E5',
+      'color': _defaultEventColor,
-      'sourceType': 'agentGenerated',
+      'sourceType': _defaultSourceType,
     };
   }
 
@@ -93,18 +101,20 @@ class ToolRegistry {
     Map<String, dynamic> args,
   ) {
     final tool = _tools[toolName];
-    if (tool == null)
+    if (tool == null) {
       return ToolValidationResult(
         ok: false,
         error: 'Tool not found: $toolName',
       );
+    }
 
     final required = tool.parameters['required'] as List<dynamic>? ?? [];
     final missing = <String>[];
     for (final field in required) {
-      if (!args.containsKey(field) || args[field] == null)
+      if (!args.containsKey(field) || args[field] == null) {
         missing.add(field as String);
       }
+    }
 
     if (missing.isNotEmpty) {
       return ToolValidationResult(

apps/lib/features/chat/presentation/bloc/chat_bloc.dart

@@ -5,6 +5,7 @@ import 'package:flutter_bloc/flutter_bloc.dart';
 import '../../data/models/ag_ui_event.dart';
 import '../../data/models/chat_list_item.dart';
 import '../../data/models/tool_result.dart';
+import '../../data/services/ag_ui_service.dart';
 
 class ChatState {
   final List<ChatListItem> items;
@@ -38,20 +39,12 @@ class ChatState {
   }
 }
 
-class AgUiService {
-  void Function(AgUiEvent)? onEvent;
-
-  AgUiService({this.onEvent});
-
-  Future<void> sendMessage(String content) async {}
-}
-
 class ChatBloc extends Cubit<ChatState> {
   final AgUiService _service;
   final Map<String, String> _toolCallArgsBuffer = {};
 
   ChatBloc({AgUiService? service})
-    : _service = service ?? AgUiService(onEvent: (_) {}),
+    : _service = service ?? AgUiService(),
       super(const ChatState()) {
     _service.onEvent = _handleEvent;
   }

apps/lib/features/chat/ui/widgets/ui_schema_renderer.dart

@@ -2,16 +2,19 @@ import 'package:flutter/material.dart';
 import 'package:social_app/core/theme/design_tokens.dart';
 import '../../data/models/tool_result.dart';
 
+/// 卡片类型常量
+const _calendarCardType = 'calendar_card.v1';
+const _errorCardType = 'error_card.v1';
+const _aiGeneratedSource = 'ai_generated';
+const _primaryActionType = 'primary';
+
 class UiSchemaRenderer {
   static Widget render(UiCard card) {
-    switch (card.cardType) {
+    return switch (card.cardType) {
-      case 'calendar_card.v1':
+      _calendarCardType => _renderCalendarCard(card),
-        return _renderCalendarCard(card);
+      _errorCardType => _renderErrorCard(card),
-      case 'error_card.v1':
+      _ => _renderUnknownCard(card),
-        return _renderErrorCard(card);
+    };
-      default:
-        return _renderUnknownCard(card);
-    }
   }
 
   static Widget _renderCalendarCard(UiCard card) {
@@ -19,6 +22,7 @@ class UiSchemaRenderer {
     final color = data.color != null
         ? Color(int.parse(data.color!.replaceFirst('#', '0xFF')))
         : AppColors.blue500;
+    final isAiGenerated = data.sourceType == _aiGeneratedSource;
 
     return Container(
       decoration: BoxDecoration(
@@ -44,23 +48,10 @@ class UiSchemaRenderer {
             child: Column(
               crossAxisAlignment: CrossAxisAlignment.start,
               children: [
-                if (data.sourceType == 'ai_generated')
+                if (isAiGenerated) ...[
-                  Container(
+                  _buildAiTag(),
-                    padding: EdgeInsets.symmetric(
-                      horizontal: AppSpacing.sm,
-                      vertical: AppSpacing.xs,
-                    ),
-                    decoration: BoxDecoration(
-                      color: AppColors.messageTagBg,
-                      borderRadius: BorderRadius.circular(AppRadius.sm),
-                    ),
-                    child: Text(
-                      'AI生成',
-                      style: TextStyle(fontSize: 10, color: AppColors.blue600),
-                    ),
-                  ),
-                if (data.sourceType == 'ai_generated')
                   SizedBox(height: AppSpacing.sm),
+                ],
                 Text(
                   _formatTime(data.startAt, data.endAt),
                   style: TextStyle(fontSize: 12, color: AppColors.slate500),
@@ -83,32 +74,11 @@ class UiSchemaRenderer {
                 ],
                 if (data.location != null) ...[
                   SizedBox(height: AppSpacing.sm),
-                  Row(
+                  _buildLocation(data.location!),
-                    children: [
-                      Icon(
-                        Icons.location_on_outlined,
-                        size: 16,
-                        color: AppColors.slate500,
-                      ),
-                      SizedBox(width: AppSpacing.xs),
-                      Text(
-                        data.location!,
-                        style: TextStyle(
-                          fontSize: 12,
-                          color: AppColors.slate500,
-                        ),
-                      ),
-                    ],
-                  ),
                 ],
                 if (card.actions != null && card.actions!.isNotEmpty) ...[
                   SizedBox(height: AppSpacing.md),
-                  Wrap(
+                  _buildActions(card.actions!),
-                    spacing: AppSpacing.sm,
-                    children: card.actions!
-                        .map((action) => _buildActionButton(action))
-                        .toList(),
-                  ),
                 ],
               ],
             ),
@@ -118,8 +88,45 @@ class UiSchemaRenderer {
     );
   }
 
+  static Widget _buildAiTag() {
+    return Container(
+      padding: EdgeInsets.symmetric(
+        horizontal: AppSpacing.sm,
+        vertical: AppSpacing.xs,
+      ),
+      decoration: BoxDecoration(
+        color: AppColors.messageTagBg,
+        borderRadius: BorderRadius.circular(AppRadius.sm),
+      ),
+      child: Text(
+        'AI生成',
+        style: TextStyle(fontSize: 10, color: AppColors.blue600),
+      ),
+    );
+  }
+
+  static Widget _buildLocation(String location) {
+    return Row(
+      children: [
+        Icon(Icons.location_on_outlined, size: 16, color: AppColors.slate500),
+        SizedBox(width: AppSpacing.xs),
+        Text(
+          location,
+          style: TextStyle(fontSize: 12, color: AppColors.slate500),
+        ),
+      ],
+    );
+  }
+
+  static Widget _buildActions(List<CardAction> actions) {
+    return Wrap(
+      spacing: AppSpacing.sm,
+      children: actions.map((action) => _buildActionButton(action)).toList(),
+    );
+  }
+
   static Widget _buildActionButton(CardAction action) {
-    final isPrimary = action.type == 'primary';
+    final isPrimary = action.type == _primaryActionType;
     return GestureDetector(
       onTap: () => _handleAction(action),
       child: Container(

apps/lib/features/home/ui/screens/home_screen.dart

@@ -10,6 +10,25 @@ import '../../../../shared/widgets/toast/toast.dart';
 import '../../../../shared/widgets/toast/toast_type.dart';
 import 'home_sheet.dart';
 
+/// 布局常量
+const _headerHeight = 60.0;
+const _defaultPadding = 20.0;
+const _itemSpacing = 16.0;
+const _inputPadding = 16.0;
+const _iconSize = 24.0;
+const _avatarSize = 32.0;
+const _botIconSize = 18.0;
+const _messagePaddingH = 13.0;
+const _messagePaddingV = 9.0;
+const _cornerRadius = 12.0;
+const _inputMinHeight = 48.0;
+const _inputRadius = 24.0;
+const _scrollDurationMs = 300;
+
+/// 颜色常量
+const _chatBgColor = Color(0xFFF8FAFC);
+const _userBubbleColor = Color(0xFFEAF1FB);
+
 class HomeScreen extends StatefulWidget {
   const HomeScreen({super.key});
 
@@ -53,7 +72,7 @@ class _HomeScreenState extends State<HomeScreen> {
         },
         builder: (context, state) {
           return Scaffold(
-            backgroundColor: const Color(0xFFF8FAFC),
+            backgroundColor: _chatBgColor,
             body: SafeArea(
               child: Column(
                 children: [
@@ -71,16 +90,16 @@ class _HomeScreenState extends State<HomeScreen> {
 
   Widget _buildHeader(BuildContext context) {
     return SizedBox(
-      height: 60,
+      height: _headerHeight,
       child: Padding(
-        padding: const EdgeInsets.symmetric(horizontal: 20),
+        padding: const EdgeInsets.symmetric(horizontal: _defaultPadding),
         child: Row(
           mainAxisAlignment: MainAxisAlignment.spaceBetween,
           children: [
             IconButton(
               icon: const Icon(
                 LucideIcons.settings,
-                size: 24,
+                size: _iconSize,
                 color: AppColors.slate900,
               ),
               onPressed: () => context.push('/settings'),
@@ -90,16 +109,16 @@ class _HomeScreenState extends State<HomeScreen> {
                 IconButton(
                   icon: const Icon(
                     LucideIcons.calendar,
-                    size: 24,
+                    size: _iconSize,
                     color: AppColors.slate900,
                   ),
                   onPressed: () => context.push('/calendar/dayweek?from=home'),
                 ),
-                const SizedBox(width: 16),
+                const SizedBox(width: _itemSpacing),
                 IconButton(
                   icon: const Icon(
                     LucideIcons.messageSquare,
-                    size: 24,
+                    size: _iconSize,
                     color: AppColors.slate900,
                   ),
                   onPressed: () => context.push('/messages/invites'),
@@ -126,7 +145,7 @@ class _HomeScreenState extends State<HomeScreen> {
       if (_scrollController.hasClients) {
         _scrollController.animateTo(
           _scrollController.position.maxScrollExtent,
-          duration: const Duration(milliseconds: 300),
+          duration: const Duration(milliseconds: _scrollDurationMs),
           curve: Curves.easeOut,
         );
       }
@@ -134,12 +153,12 @@ class _HomeScreenState extends State<HomeScreen> {
 
     return ListView.builder(
       controller: _scrollController,
-      padding: const EdgeInsets.all(20),
+      padding: const EdgeInsets.all(_defaultPadding),
       itemCount: state.items.length,
       itemBuilder: (context, index) {
         final item = state.items[index];
         return Padding(
-          padding: const EdgeInsets.only(bottom: 16),
+          padding: const EdgeInsets.only(bottom: _itemSpacing),
           child: _buildChatItem(item),
         );
       },
@@ -167,15 +186,15 @@ class _HomeScreenState extends State<HomeScreen> {
       children: [
         if (!isUser) ...[
           Container(
-            width: 32,
+            width: _avatarSize,
-            height: 32,
+            height: _avatarSize,
             decoration: BoxDecoration(
               color: AppColors.blue100,
               shape: BoxShape.circle,
             ),
             child: const Icon(
               LucideIcons.bot,
-              size: 18,
+              size: _botIconSize,
               color: AppColors.blue600,
             ),
           ),
@@ -183,14 +202,17 @@ class _HomeScreenState extends State<HomeScreen> {
         ],
         Flexible(
           child: Container(
-            padding: const EdgeInsets.symmetric(horizontal: 13, vertical: 9),
+            padding: const EdgeInsets.symmetric(
+              horizontal: _messagePaddingH,
+              vertical: _messagePaddingV,
+            ),
             decoration: BoxDecoration(
-              color: isUser ? const Color(0xFFEAF1FB) : AppColors.white,
+              color: isUser ? _userBubbleColor : AppColors.white,
               borderRadius: BorderRadius.only(
-                topLeft: const Radius.circular(12),
+                topLeft: const Radius.circular(_cornerRadius),
-                topRight: const Radius.circular(12),
+                topRight: const Radius.circular(_cornerRadius),
-                bottomLeft: Radius.circular(isUser ? 12 : 0),
+                bottomLeft: Radius.circular(isUser ? _cornerRadius : 0),
-                bottomRight: Radius.circular(isUser ? 0 : 12),
+                bottomRight: Radius.circular(isUser ? 0 : _cornerRadius),
               ),
               border: isUser ? null : Border.all(color: AppColors.slate300),
             ),
@@ -207,32 +229,28 @@ class _HomeScreenState extends State<HomeScreen> {
   }
 
   Widget _buildToolCallItem(ToolCallItem item) {
-    String statusText;
+    final (statusText, statusColor, statusIcon) = switch (item.status) {
-    Color statusColor;
+      ToolCallStatus.pending => (
-    IconData statusIcon;
+        '准备中...',
-
+        AppColors.slate500,
-    switch (item.status) {
+        LucideIcons.clock,
-      case ToolCallStatus.pending:
+      ),
-        statusText = '准备中...';
+      ToolCallStatus.executing => (
-        statusColor = AppColors.slate500;
+        '执行中...',
-        statusIcon = LucideIcons.clock;
+        AppColors.blue600,
-        break;
+        LucideIcons.loader,
-      case ToolCallStatus.executing:
+      ),
-        statusText = '执行中...';
+      ToolCallStatus.error => (
-        statusColor = AppColors.blue600;
+        item.errorMessage ?? '执行失败',
-        statusIcon = LucideIcons.loader;
+        AppColors.red600,
-        break;
+        LucideIcons.alertCircle,
-      case ToolCallStatus.error:
+      ),
-        statusText = item.errorMessage ?? '执行失败';
+      ToolCallStatus.completed => (
-        statusColor = AppColors.red600;
+        '已完成',
-        statusIcon = LucideIcons.alertCircle;
+        AppColors.emerald600,
-        break;
+        LucideIcons.checkCircle,
-      case ToolCallStatus.completed:
+      ),
-        statusText = '已完成';
+    };
-        statusColor = AppColors.emerald600;
-        statusIcon = LucideIcons.checkCircle;
-        break;
-    }
 
     return Container(
       padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
@@ -267,8 +285,8 @@ class _HomeScreenState extends State<HomeScreen> {
 
   Widget _buildInputContainer(BuildContext context) {
     return Container(
-      padding: const EdgeInsets.all(16),
+      padding: const EdgeInsets.all(_inputPadding),
-      color: const Color(0xFFF8FAFC),
+      color: _chatBgColor,
       child: Row(
         crossAxisAlignment: CrossAxisAlignment.center,
         children: [
@@ -292,11 +310,11 @@ class _HomeScreenState extends State<HomeScreen> {
           const SizedBox(width: 8),
           Expanded(
             child: Container(
-              constraints: const BoxConstraints(minHeight: 48),
+              constraints: const BoxConstraints(minHeight: _inputMinHeight),
               padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
               decoration: BoxDecoration(
                 color: Colors.transparent,
-                borderRadius: BorderRadius.circular(24),
+                borderRadius: BorderRadius.circular(_inputRadius),
                 border: Border.all(color: AppColors.slate300),
               ),
               child: Row(
@@ -327,7 +345,7 @@ class _HomeScreenState extends State<HomeScreen> {
                     onTap: _hasMessage ? () => _sendMessage(context) : null,
                     child: Icon(
                       _hasMessage ? LucideIcons.send : LucideIcons.mic,
-                      size: 24,
+                      size: _iconSize,
                       color: _hasMessage
                           ? AppColors.blue600
                           : AppColors.slate500,

apps/test/features/chat/chat_bloc_test.dart

@@ -2,14 +2,22 @@ import 'package:bloc_test/bloc_test.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:social_app/features/chat/data/models/ag_ui_event.dart';
 import 'package:social_app/features/chat/data/models/chat_list_item.dart';
+import 'package:social_app/features/chat/data/services/ag_ui_service.dart';
 import 'package:social_app/features/chat/presentation/bloc/chat_bloc.dart';
 
+class MockAgUiService extends AgUiService {
+  MockAgUiService() : super(onEvent: (_) {});
+
+  @override
+  Future<void> sendMessage(String content) async {}
+}
+
 void main() {
   late ChatBloc chatBloc;
   late AgUiService service;
 
   setUp(() {
-    service = AgUiService();
+    service = MockAgUiService();
     chatBloc = ChatBloc(service: service);
   });
 
@@ -49,7 +57,7 @@ void main() {
       build: () => chatBloc,
       act: (bloc) {
         bloc.emit(chatBloc.state.copyWith(isLoading: true));
-        service.onEvent!(
+        service.onEvent(
           TextMessageStartEvent(messageId: 'msg_1', role: 'assistant'),
         );
       },
@@ -86,7 +94,7 @@ void main() {
         currentMessageId: 'msg_1',
       ),
       act: (bloc) {
-        service.onEvent!(
+        service.onEvent(
           TextMessageContentEvent(messageId: 'msg_1', delta: 'Hello'),
         );
       },
@@ -115,7 +123,7 @@ void main() {
         currentMessageId: 'msg_1',
       ),
       act: (bloc) {
-        service.onEvent!(TextMessageEndEvent(messageId: 'msg_1'));
+        service.onEvent(TextMessageEndEvent(messageId: 'msg_1'));
       },
       expect: () => [
         isA<ChatState>()
@@ -132,7 +140,7 @@ void main() {
       'runStarted sets isLoading to true',
       build: () => chatBloc,
       act: (bloc) {
-        service.onEvent!(RunStartedEvent(threadId: 't1', runId: 'r1'));
+        service.onEvent(RunStartedEvent(threadId: 't1', runId: 'r1'));
       },
       expect: () => [
         isA<ChatState>()
@@ -146,7 +154,7 @@ void main() {
       build: () => chatBloc,
       seed: () => const ChatState(isLoading: true),
       act: (bloc) {
-        service.onEvent!(RunFinishedEvent(threadId: 't1', runId: 'r1'));
+        service.onEvent(RunFinishedEvent(threadId: 't1', runId: 'r1'));
       },
       expect: () => [
         isA<ChatState>()
@@ -160,7 +168,7 @@ void main() {
       build: () => chatBloc,
       seed: () => const ChatState(isLoading: true),
       act: (bloc) {
-        service.onEvent!(
+        service.onEvent(
           RunErrorEvent(message: 'Something went wrong', code: 'ERR'),
         );
       },
@@ -183,7 +191,7 @@ void main() {
       'toolCallStart adds ToolCallItem',
       build: () => chatBloc,
       act: (bloc) {
-        service.onEvent!(
+        service.onEvent(
           ToolCallStartEvent(
             toolCallId: 'tc_1',
             toolCallName: 'create_calendar_event',