feat: AI 对话附件上下文解析 + 历史会话归档 + 多页面 UI 重构

- 后端: 新增 AttachmentContextBuilder 解析图片/PDF 摘要并拼入 LLM 上下文; ai_chat_endpoints 扩展附件接口; 新增 ReportAnalysisService
- 前端: 新增历史会话页与 conversation_history_provider; chat 链路支持附件展示与回放
- UI: 重构 medication_checkin / notification_center / profile / health_drawer 等多页面
- 配置: api_client baseUrl 适配当前 WiFi IP

health_app/lib/providers/chat_provider.dart

@@ -1,7 +1,9 @@
 import 'dart:async';
+import 'dart:convert';
 import 'dart:io';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'auth_provider.dart';
+import 'conversation_history_provider.dart';
 import 'data_providers.dart';
 import '../utils/sse_handler.dart';
 
@@ -86,6 +88,15 @@ class ChatNotifier extends Notifier<ChatState> {
 
   void markNeedsRebuild() => state = state.copyWith();
 
+  /// 重置整个会话：取消正在进行的 SSE，清空消息和会话 ID。
+  /// 历史记录页一键清空 / 删除当前会话时调用。
+  Future<void> resetSession() async {
+    await _cancelActiveStream();
+    _lastTriggeredAgent = null;
+    state = const ChatState();
+    ref.read(selectedAgentProvider.notifier).select(null);
+  }
+
   /// 不可变消息操作方法（供 chat_messages_view 新版代码调用）
   Future<String?> confirmMessage(String id) async {
     final msgs = state.messages.toList();
@@ -103,7 +114,9 @@ class ChatNotifier extends Notifier<ChatState> {
     try {
       final api = ref.read(apiClientProvider);
       for (final confirmationId in confirmationIds.toList()) {
-        final response = await api.post('/api/ai/confirm-write/$confirmationId');
+        final response = await api.post(
+          '/api/ai/confirm-write/$confirmationId',
+        );
         final body = response.data;
         if (body is! Map || body['code'] != 0) {
           return body is Map ? body['message']?.toString() ?? '录入失败' : '录入失败';
@@ -203,14 +216,19 @@ class ChatNotifier extends Notifier<ChatState> {
       final rawMessages = (res.data['data'] as List?) ?? [];
       final messages = rawMessages.map((m) {
         final map = m as Map<String, dynamic>;
+        final role = map['role']?.toString().toLowerCase() == 'user'
+            ? 'user'
+            : 'assistant';
+        final metadata = _parseMetadata(map['metadataJson']);
         return ChatMessage(
           id: map['id']?.toString() ?? '',
-          role: map['role']?.toString() ?? 'user',
+          role: role,
           content: map['content']?.toString() ?? '',
           createdAt:
               DateTime.tryParse(map['createdAt']?.toString() ?? '') ??
               DateTime.now(),
-          type: MessageType.text,
+          type: _messageTypeFromMetadata(metadata),
+          metadata: metadata,
         );
       }).toList();
 
@@ -259,6 +277,7 @@ class ChatNotifier extends Notifier<ChatState> {
   }
 
   Future<void> sendImage(String imagePath, String text) async {
+    if (state.isStreaming) return;
     final file = File(imagePath);
     if (!await file.exists()) return;
     _lastTriggeredAgent = null;
@@ -303,16 +322,70 @@ class ChatNotifier extends Notifier<ChatState> {
       final errorMsg = ChatMessage(
         id: '${DateTime.now().millisecondsSinceEpoch}_upload_error',
         role: 'assistant',
-        content: uploadError == null ? '图片上传失败，请稍后重试。' : '图片上传失败，请检查文件大小或网络后重试。',
+        content: uploadError == null
+            ? '图片上传失败，请稍后重试。'
+            : '图片上传失败，请检查文件大小或网络后重试。',
         createdAt: DateTime.now(),
       );
       state = state.copyWith(messages: [...state.messages, errorMsg]);
       return;
     }
 
-    // 将图片 URL 作为消息内容发送给 AI
-    final msgWithImage = text.isNotEmpty ? '$text\n[图片已上传]' : '[图片已上传]';
-    await _sendToAI(msgWithImage);
+    // 把图片 URL 透传给后端，后端会调 VLM 识图并把描述拼到 LLM 上下文
+    final userText = text.isNotEmpty ? text : '请帮我看看这张图片';
+    await _sendToAI(userText, imageUrl: uploadedUrl);
+  }
+
+  /// 发送 PDF 附件 + 文字（PDF 解析在后端做）。
+  Future<void> sendPdf(String pdfPath, String fileName, String text) async {
+    if (state.isStreaming) return;
+    final file = File(pdfPath);
+    if (!await file.exists()) return;
+    _lastTriggeredAgent = null;
+
+    final userMsg = ChatMessage(
+      id: '${DateTime.now().millisecondsSinceEpoch}',
+      role: 'user',
+      content: text.isNotEmpty ? text : '请帮我看看这份 PDF',
+      createdAt: DateTime.now(),
+      metadata: {'pdfFileName': fileName},
+    );
+    state = state.copyWith(messages: [...state.messages, userMsg]);
+
+    String? uploadedUrl;
+    try {
+      final api = ref.read(apiClientProvider);
+      uploadedUrl = await api.uploadFile('/api/files/upload', file);
+    } catch (_) {
+      // ignore，下方统一处理
+    }
+
+    // 更新消息附带的远程 URL
+    if (uploadedUrl != null) {
+      final updatedMsgs = state.messages.toList();
+      final idx = updatedMsgs.indexWhere((m) => m.id == userMsg.id);
+      if (idx >= 0) {
+        updatedMsgs[idx] = ChatMessage(
+          id: userMsg.id,
+          role: 'user',
+          content: userMsg.content,
+          createdAt: userMsg.createdAt,
+          metadata: {'pdfFileName': fileName, 'pdfUrl': uploadedUrl},
+        );
+        state = state.copyWith(messages: updatedMsgs);
+      }
+    } else {
+      final errorMsg = ChatMessage(
+        id: '${DateTime.now().millisecondsSinceEpoch}_upload_error',
+        role: 'assistant',
+        content: 'PDF 上传失败，请检查文件大小或网络后重试。',
+        createdAt: DateTime.now(),
+      );
+      state = state.copyWith(messages: [...state.messages, errorMsg]);
+      return;
+    }
+
+    await _sendToAI(userMsg.content, pdfUrl: uploadedUrl);
   }
 
   Future<void> sendMessage(String text) async {
@@ -333,7 +406,11 @@ class ChatNotifier extends Notifier<ChatState> {
     await _sendToAI(text);
   }
 
-  Future<void> _sendToAI(String text) async {
+  Future<void> _sendToAI(
+    String text, {
+    String? imageUrl,
+    String? pdfUrl,
+  }) async {
     final aiMsg = ChatMessage(
       id: '${DateTime.now().millisecondsSinceEpoch}_ai',
       role: 'assistant',
@@ -359,6 +436,8 @@ class ChatNotifier extends Notifier<ChatState> {
         agentType: 'unified',
         message: text,
         conversationId: state.conversationId,
+        imageUrl: imageUrl,
+        pdfUrl: pdfUrl,
         token: token,
       );
 
@@ -454,6 +533,26 @@ class ChatNotifier extends Notifier<ChatState> {
     }
   }
 
+  Map<String, dynamic>? _parseMetadata(dynamic raw) {
+    if (raw == null) return null;
+    if (raw is Map) return Map<String, dynamic>.from(raw);
+    if (raw is! String || raw.trim().isEmpty) return null;
+    try {
+      final decoded = jsonDecode(raw);
+      return decoded is Map ? Map<String, dynamic>.from(decoded) : null;
+    } catch (_) {
+      return null;
+    }
+  }
+
+  MessageType _messageTypeFromMetadata(Map<String, dynamic>? metadata) {
+    if (metadata == null) return MessageType.text;
+    final type = metadata['messageType']?.toString();
+    if (type != null && type.isNotEmpty) return _parseMessageType(type);
+    if (metadata['confirmationIds'] is List) return MessageType.dataConfirm;
+    return MessageType.text;
+  }
+
   void _update(ChatMessage m) {
     final u = state.messages.toList();
     final i = u.indexWhere((x) => x.id == m.id);
@@ -478,5 +577,6 @@ class ChatNotifier extends Notifier<ChatState> {
       u.add(m);
     }
     state = state.copyWith(messages: u, isStreaming: false, thinkingText: null);
+    ref.invalidate(conversationHistoryProvider);
   }
 }