SAF测试阶段，验证中

lib/services/saf_storage_service.dart

@@ -1,4 +1,3 @@
-import 'dart:io';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/services.dart';
 import 'package:shared_preferences/shared_preferences.dart';
@@ -12,55 +11,49 @@ class SafStorageService {
   static const MethodChannel _channel = MethodChannel(
     'com.lxh.battery_health/saf',
   );
-  static const String _prefKeySafPath = 'saf_storage_path';
-  String? _cachedPath;
+  static const String _prefKeySafUri = 'saf_storage_uri';
+  String? _cachedUri;
 
+  // 🟢 初始化时从 SharedPreferences 恢复 URI
   Future<void> init() async {
-    final prefs = await SharedPreferences.getInstance();
-    _cachedPath = prefs.getString(_prefKeySafPath);
-    if (kDebugMode) {
-      print('[SAF] 初始化，缓存路径: $_cachedPath');
+    try {
+      final prefs = await SharedPreferences.getInstance();
+      _cachedUri = prefs.getString(_prefKeySafUri);
+      if (kDebugMode) {
+        print('[SAF] 初始化，缓存 URI: $_cachedUri');
+      }
+    } catch (e) {
+      if (kDebugMode) {
+        print('[SAF] 初始化失败: $e');
+      }
+      _cachedUri = null;
     }
   }
 
   Future<SafPermissionState> getPermissionState() async {
-    if (_cachedPath == null || _cachedPath!.isEmpty) {
+    if (_cachedUri == null || _cachedUri!.isEmpty) {
       return SafPermissionState.unauthorized;
     }
-    try {
-      final dir = Directory(_cachedPath!);
-      if (!await dir.exists()) {
-        _clearCache();
-        return SafPermissionState.expired;
-      }
-      return SafPermissionState.authorized;
-    } catch (e) {
-      _clearCache();
-      return SafPermissionState.expired;
-    }
+    // 🟢 简化：直接返回 authorized，相信本地缓存的 URI
+    return SafPermissionState.authorized;
   }
 
   Future<SafAuthorizationResult> requestPermission() async {
     try {
-      final String? selectedPath = await _channel.invokeMethod('selectFolder');
+      final String? uriString = await _channel.invokeMethod('selectFolder');
 
-      if (selectedPath == null || selectedPath.isEmpty) {
+      if (uriString == null || uriString.isEmpty) {
         return SafAuthorizationResult.denied();
       }
 
-      // 验证路径是否包含 mbattery_charger
-      if (!selectedPath.contains('mbattery_charger')) {
-        return SafAuthorizationResult.error('请选择 mbattery_charger 文件夹');
-      }
-
-      _cachedPath = selectedPath;
-      await _savePath(selectedPath);
+      _cachedUri = uriString;
+      await _saveUri(uriString);
 
       if (kDebugMode) {
-        print('[SAF] 授权成功，路径: $selectedPath');
+        print('[SAF] 授权成功，URI: $uriString');
       }
 
-      return SafAuthorizationResult.success(selectedPath);
+      return SafAuthorizationResult.success(uriString);
     } catch (e) {
       if (kDebugMode) {
         print('[SAF] 授权失败: $e');
@@ -73,8 +66,11 @@ class SafStorageService {
     final state = await getPermissionState();
     if (state != SafPermissionState.authorized) return false;
     try {
-      final file = File('${_cachedPath!}/$fileName');
-      return await file.exists();
+      final files = await _channel.invokeMethod('listFiles');
+      if (files is List) {
+        return files.contains(fileName);
+      }
+      return false;
     } catch (e) {
       return false;
     }
@@ -84,9 +80,11 @@ class SafStorageService {
     final state = await getPermissionState();
     if (state != SafPermissionState.authorized) return [];
     try {
-      final file = File('${_cachedPath!}/$fileName');
-      if (!await file.exists()) return [];
-      return await file.readAsLines();
+      final String? content = await _channel.invokeMethod('readLogFile', {
+        'fileName': fileName,
+      });
+      if (content == null || content.isEmpty) return [];
+      return content.split('\n');
     } catch (e) {
       if (kDebugMode) {
         print('[SAF] 读取文件失败: $e');
@@ -99,13 +97,11 @@ class SafStorageService {
     final state = await getPermissionState();
     if (state != SafPermissionState.authorized) return [];
     try {
-      final dir = Directory(_cachedPath!);
-      if (!await dir.exists()) return [];
-      final entities = await dir.list().toList();
-      return entities
-          .where((e) => e is File)
-          .map((e) => e.path.split(Platform.pathSeparator).last)
-          .toList();
+      final result = await _channel.invokeMethod('listFiles');
+      if (result is List) {
+        return result.cast<String>();
+      }
+      return [];
     } catch (e) {
       if (kDebugMode) {
         print('[SAF] 列出文件失败: $e');
@@ -120,18 +116,30 @@ class SafStorageService {
   }
 
   void _clearCache() {
-    _cachedPath = null;
-    _savePath(null);
+    _cachedUri = null;
+    _saveUri(null);
   }
 
-  Future<void> _savePath(String? path) async {
-    final prefs = await SharedPreferences.getInstance();
-    if (path != null && path.isNotEmpty) {
-      await prefs.setString(_prefKeySafPath, path);
-    } else {
-      await prefs.remove(_prefKeySafPath);
+  Future<void> _saveUri(String? uri) async {
+    try {
+      final prefs = await SharedPreferences.getInstance();
+      if (uri != null && uri.isNotEmpty) {
+        await prefs.setString(_prefKeySafUri, uri);
+        if (kDebugMode) {
+          print('[SAF] 保存 URI 成功: $uri');
+        }
+      } else {
+        await prefs.remove(_prefKeySafUri);
+        if (kDebugMode) {
+          print('[SAF] 清除 URI');
+        }
+      }
+    } catch (e) {
+      if (kDebugMode) {
+        print('[SAF] 保存 URI 失败: $e');
+      }
     }
   }
 
-  String? get cachedPath => _cachedPath;
+  String? get cachedUri => _cachedUri;
 }