// lib/utils/device_manager.dart
import 'dart:io';
import 'dart:convert';
import 'package:crypto/crypto.dart';
import 'package:device_info_plus/device_info_plus.dart';
import 'package:get/get.dart';
import 'package:path/path.dart' as path;
import 'package:path_provider/path_provider.dart';
import 'package:uuid/uuid.dart';
import 'package:flutter_secure_storage/flutter_secure_storage.dart';

import '../app/data/sp/ix_sp.dart';
import 'log/logger.dart';
import 'permission_manager.dart';

class DeviceManager {
  static const String TAG = 'DeviceManager';
  static final DeviceInfoPlugin _deviceInfo = DeviceInfoPlugin();
  static const String _folderPrefix = '.omon_cache_';
  static const String _iosDeviceIdKey = 'omon_device_id';
  static const String _iosDeviceFolderKey = 'omon_device_folder';

  /// 获取设备唯一标识并确保文件夹存在
  static Future<String> getDeviceId() async {
    try {
      // 1. 先从 SharedPreferences 获取
      String? deviceId = IXSP.getDeviceId();

      // 2. 如果SP中没有，尝试从存储位置获取
      if (deviceId == null || deviceId.isEmpty) {
        try {
          deviceId = await _getDeviceIdFromStorage();
        } catch (e) {
          log(TAG, 'Error reading from storage: $e');
        }
      }

      // 3. 如果还是没有，生成新的
      if (deviceId == null || deviceId.isEmpty) {
        try {
          deviceId = await _generateNewDeviceId();
        } catch (e) {
          log(TAG, 'Error generating device ID: $e');
          deviceId = _generateFallbackId();
        }
      }

      // 4. 确保保存到存储位置
      try {
        await _saveDeviceId(deviceId);
      } catch (e) {
        log(TAG, 'Error saving device ID: $e');
      }

      // 5. 尝试创建文件夹（仅Android），但不影响返回结果
      try {
        await _ensureDeviceFolder(deviceId);
      } catch (e) {
        log(TAG, 'Error creating folder: $e');
        // 文件夹创建失败不影响 ID 的使用
      }

      return deviceId;
    } catch (e) {
      log(TAG, 'Critical error in getDeviceId: $e');
      // 最后的后备方案：生成随机ID
      final fallbackId = _generateFallbackId();
      try {
        await _saveDeviceId(fallbackId);
      } catch (e) {
        log(TAG, 'Error saving fallback ID: $e');
      }
      return fallbackId;
    }
  }

  /// 获取缓存
  static String getCacheDeviceId() {
    return IXSP.getDeviceId() ?? '';
  }

  /// 从存储位置获取设备ID
  static Future<String?> _getDeviceIdFromStorage() async {
    if (Platform.isIOS) {
      // iOS 从钥匙串获取
      try {
        const storage = FlutterSecureStorage();
        final deviceId = await storage.read(key: _iosDeviceIdKey);
        if (deviceId != null && deviceId.isNotEmpty) {
          await IXSP.setDeviceId(deviceId);
          return deviceId;
        }
      } catch (e) {
        log(TAG, 'Error reading from iOS keychain: $e');
      }
    } else {
      // Android 从文件夹获取
      try {
        final downloadsDir = await _getDownloadsDirectory();
        if (downloadsDir == null || !await downloadsDir.exists()) {
          return null;
        }

        final entities = await downloadsDir.list().toList();
        for (var entity in entities) {
          if (entity is Directory) {
            final folderName = path.basename(entity.path);
            if (folderName.startsWith(_folderPrefix)) {
              final uuid = folderName.substring(_folderPrefix.length);
              // 验证UUID格式
              if (_isValidUuid(uuid)) {
                // 找到有效的UUID，保存到SP
                await IXSP.setDeviceId(uuid);
                return uuid;
              }
            }
          }
        }
      } catch (e) {
        log(TAG, 'Error getting device ID from Android folder: $e');
      }
    }
    return null;
  }

  /// 保存设备ID到存储位置
  static Future<void> _saveDeviceId(String deviceId) async {
    // 保存到 SharedPreferences（跨平台）
    await IXSP.setDeviceId(deviceId);

    if (Platform.isIOS) {
      // iOS 保存到钥匙串
      try {
        const storage = FlutterSecureStorage();
        await storage.write(key: _iosDeviceIdKey, value: deviceId);
      } catch (e) {
        log(TAG, 'Error saving to iOS keychain: $e');
      }
    }
  }

  /// 生成新的设备ID
  static Future<String> _generateNewDeviceId() async {
    if (GetPlatform.isAndroid) {
      final AndroidDeviceInfo androidInfo = await _deviceInfo.androidInfo;

      final deviceInfo = {
        'androidId': androidInfo.id,
        'brand': androidInfo.brand,
        'model': androidInfo.model,
        'product': androidInfo.product,
        'hardware': androidInfo.hardware,
        'manufacturer': androidInfo.manufacturer,
        'uuid': const Uuid().v4(),
      };

      final deviceId = _generateHash(jsonEncode(deviceInfo));
      await _saveDeviceId(deviceId);
      return deviceId;
    } else if (GetPlatform.isIOS) {
      final IosDeviceInfo iosInfo = await _deviceInfo.iosInfo;

      final deviceInfo = {
        'identifierForVendor': iosInfo.identifierForVendor,
        'model': iosInfo.model,
        'systemVersion': iosInfo.systemVersion,
        'uuid': const Uuid().v4(),
      };

      final deviceId = _generateHash(jsonEncode(deviceInfo));
      await _saveDeviceId(deviceId);
      return deviceId;
    }

    return _generateFallbackId();
  }

  /// 确保设备文件夹存在
  static Future<void> _ensureDeviceFolder(String deviceId) async {
    // iOS 不需要创建文件夹，数据存储在钥匙串中
    if (Platform.isIOS) {
      return;
    }

    try {
      final downloadsDir = await _getDownloadsDirectory();
      if (downloadsDir == null || !await downloadsDir.exists()) {
        throw Exception('Downloads directory not found');
      }

      final folderName = '$_folderPrefix$deviceId';
      final deviceFolder = Directory('${downloadsDir.path}/$folderName');

      if (!await deviceFolder.exists()) {
        await deviceFolder.create();
        // 创建.nomedia文件
        final nomedia = File('${deviceFolder.path}/.nomedia');
        await nomedia.create();
      }
    } catch (e) {
      log(TAG, 'Error ensuring device folder: $e');
      rethrow;
    }
  }

  /// 获取下载目录
  static Future<Directory?> _getDownloadsDirectory() async {
    if (Platform.isAndroid) {
      try {
        // 首先尝试获取应用的外部存储目录
        // 判断是不是Android10以下
        final hasPermission =
            await PermissionManager.requestStoragePermission();
        if (!hasPermission) {
          throw Exception('Storage permission denied');
        }
        final downloadsDir = Directory('/storage/emulated/0/Download');
        return downloadsDir;
      } catch (e) {
        log(TAG, 'Error getting downloads directory: $e');
        final downloadsDir = getExternalStorageDirectory();
        return downloadsDir;
      }
    }
    return null;
  }

  /// 生成哈希值
  static String _generateHash(String input) {
    final bytes = utf8.encode(input);
    final digest = md5.convert(bytes);
    return digest.toString();
  }

  /// 生成后备ID
  static String _generateFallbackId() {
    final random = DateTime.now().millisecondsSinceEpoch.toString();
    return _generateHash(random);
  }

  /// 验证UUID格式
  static bool _isValidUuid(String uuid) {
    // 验证是否为32位十六进制字符
    return RegExp(r'^[a-f0-9]{32}$').hasMatch(uuid);
  }

  /// 获取设备文件夹路径
  static Future<String> getDeviceFolderPath() async {
    if (Platform.isIOS) {
      // iOS 返回钥匙串标识符
      return 'iOS Keychain: $_iosDeviceIdKey';
    }

    final deviceId = await getDeviceId();
    return '/storage/emulated/0/Download/$_folderPrefix$deviceId';
  }

  /// 清除所有数据
  static Future<void> clearAll() async {
    try {
      if (Platform.isIOS) {
        // iOS 清除钥匙串数据
        try {
          const storage = FlutterSecureStorage();
          await storage.delete(key: _iosDeviceIdKey);
          await storage.delete(key: _iosDeviceFolderKey);
        } catch (e) {
          log(TAG, 'Error clearing iOS keychain: $e');
        }
      } else {
        // Android 删除文件夹
        try {
          final downloadsDir = await _getDownloadsDirectory();
          if (downloadsDir != null && await downloadsDir.exists()) {
            final entities = await downloadsDir.list().toList();
            for (var entity in entities) {
              if (entity is Directory) {
                final folderName = path.basename(entity.path);
                if (folderName.startsWith(_folderPrefix)) {
                  await entity.delete(recursive: true);
                }
              }
            }
          }
        } catch (e) {
          log(TAG, 'Error clearing Android folders: $e');
        }
      }

      // 清除 SP 中的 UUID
      await IXSP.setDeviceId('');
    } catch (e) {
      log(TAG, 'Error clearing device data: $e');
    }
  }
}