import 'package:dio/dio.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter_patcher/flutter_patcher.dart';
import 'package:logger/logger.dart';
import 'package:path_provider/path_provider.dart';
import 'dart:io';

/// 应用版本信息模型
class AppVersionInfo {
  final String version;
  final int versionCode;
  final String updateType;
  final bool forceUpdate;
  final String updateDesc;
  final String? patchUrl;
  final String? patchMd5;
  final String? apkUrl;
  final String? apkMd5;

  AppVersionInfo({
    required this.version,
    required this.versionCode,
    required this.updateType,
    required this.forceUpdate,
    required this.updateDesc,
    this.patchUrl,
    this.patchMd5,
    this.apkUrl,
    this.apkMd5,
  });

  factory AppVersionInfo.fromJson(Map<String, dynamic> json) {
    final patchData = json['patch'] as Map<String, dynamic>?;
    final fullApkData = json['fullApk'] as Map<String, dynamic>?;

    return AppVersionInfo(
      version: json['version'] ?? '',
      versionCode: json['versionCode'] ?? 0,
      updateType: json['updateType'] ?? 'full',
      forceUpdate: json['forceUpdate'] ?? false,
      updateDesc: json['updateDesc'] ?? '',
      patchUrl: patchData?['patchUrl'] as String?,
      patchMd5: patchData?['md5'] as String?,
      apkUrl: fullApkData?['apkUrl'] as String?,
      apkMd5: fullApkData?['md5'] as String?,
    );
  }
}

/// 版本检查服务
class VersionCheckService {
  static final VersionCheckService _instance = VersionCheckService._internal();
  factory VersionCheckService() => _instance;
  VersionCheckService._internal();

  final Logger _logger = Logger();
  final Dio _dio = Dio(BaseOptions(
    connectTimeout: const Duration(seconds: 10),
    receiveTimeout: const Duration(seconds: 10),
    validateStatus: (status) => true,
  ));

  static const String apiUrl = 'http://8.159.134.0:8012/api/update/check';
  static const String _patchVersionFileName = '.patch_version';

  /// 检查版本更新
  Future<AppVersionInfo?> checkUpdate({
    required String currentVersion,
    required int currentVersionCode,
  }) async {
    try {
      debugPrint('');
      debugPrint('========================================');
      debugPrint('  UPDATE CHECK START');
      debugPrint('========================================');
      debugPrint('[1] APK version: $currentVersion ($currentVersionCode)');
  
      // 从文件读取已应用的补丁版本
      final patchInfo = await _loadPatchVersionInfo();
      final appliedPatchVersion = patchInfo['version'] as String?;
      final appliedPatchVersionCode = patchInfo['versionCode'] as int?;
      
      debugPrint('[2] Patch file version: $appliedPatchVersion ($appliedPatchVersionCode)');
        
      // 始终用 APK 基础版本请求服务端，让服务端返回最新版本
      // 客户端自己判断本地是否已经是最新
      final requestVersion = currentVersion;
      final requestVersionCode = currentVersionCode;
        
      debugPrint('[3] Request to server: version=$requestVersion, versionCode=$requestVersionCode');
      debugPrint('[4] URL: $apiUrl?version=$requestVersion&versionCode=$requestVersionCode');
  
      final response = await _dio.get(
        apiUrl,
        queryParameters: {
          'version': requestVersion,
          'versionCode': requestVersionCode,
        },
      );
  
      debugPrint('[5] HTTP status: ${response.statusCode}');
      debugPrint('[6] Response body: ${response.data}');
  
      final respCode = response.data['code'];
      final data = response.data['data'];
      final message = response.data['message'] ?? '';
  
      debugPrint('[7] respCode=$respCode, data=$data, message=$message');

      if (respCode != 200 || data == null) {
        debugPrint('[RESULT] No update - server returned code=$respCode, data=${data == null ? "NULL" : "NOT_NULL"}, message=$message');
        debugPrint('========================================');
        debugPrint('');
        return null;
      }

      debugPrint('[7.1] data type: ${data.runtimeType}');
      debugPrint('[7.2] data keys: ${data is Map ? data.keys.toList() : "NOT A MAP"}');
      debugPrint('[7.3] hasUpdate = ${data['hasUpdate']} (type: ${data['hasUpdate']?.runtimeType})');
      debugPrint('[7.4] version = ${data['version']}');
      debugPrint('[7.5] versionCode = ${data['versionCode']}');
      debugPrint('[7.6] updateType = ${data['updateType']}');
      debugPrint('[7.7] patch = ${data['patch']}');
      debugPrint('[7.8] fullApk = ${data['fullApk']}');

      if (data['hasUpdate'] == false) {
        debugPrint('[RESULT] No update - hasUpdate=false');
        debugPrint('========================================');
        debugPrint('');
        return null;
      }

      final versionInfo = AppVersionInfo.fromJson(data);
      debugPrint('[8] Server version: ${versionInfo.version} (${versionInfo.versionCode})');
      debugPrint('[9] Update type: ${versionInfo.updateType}, force: ${versionInfo.forceUpdate}');
      debugPrint('[10] patchUrl: ${versionInfo.patchUrl}');
      debugPrint('[11] patchMd5: ${versionInfo.patchMd5}');
      debugPrint('[12] apkUrl: ${versionInfo.apkUrl}');
  
      // 只用版本字符串判断是否已更新：服务端 hasUpdate=true 说了算
      if (appliedPatchVersion != null && appliedPatchVersion == versionInfo.version) {
        debugPrint('[RESULT] No update - already at version ${versionInfo.version}');
        debugPrint('========================================');
        debugPrint('');
        return null;
      }
      
      debugPrint('[8.1] Local patch version: ${appliedPatchVersion ?? "none"}');
      debugPrint('[8.2] Server version: ${versionInfo.version}');
      debugPrint('[8.3] Version different: ${appliedPatchVersion != versionInfo.version}');
  
      debugPrint('[RESULT] NEW VERSION FOUND: ${versionInfo.version} (${versionInfo.versionCode})');
      debugPrint('========================================');
      debugPrint('');
  
      return versionInfo;
    } catch (e) {
      debugPrint('[RESULT] ERROR: $e');
      debugPrint('========================================');
      debugPrint('');
      return null;
    }
  }

  /// 下载并应用差量补丁
  Future<bool> applyPatch({
    required String patchUrl,
    required String version,
    required int targetVersionCode,
    String? md5,
    Function(double)? onProgress,
  }) async {
    try {
      _logger.i('⬇️ 开始下载补丁: $patchUrl');
      _logger.i('🎯 目标版本: $version ($targetVersionCode)');

      final tempDir = await getTemporaryDirectory();
      final patchPath = '${tempDir.path}/update_patch.so';

      await _dio.download(
        patchUrl,
        patchPath,
        onReceiveProgress: (received, total) {
          if (total != -1 && onProgress != null) {
            onProgress(received / total);
          }
        },
      );

      _logger.i('✅ 补丁下载完成，开始应用...');

      final result = await FlutterPatcher.applyPatch(
        PatchInfo(
          version: version,
          patchUrl: 'file://$patchPath',
          targetVersionCode: targetVersionCode,
          md5: md5 ?? '',
        ),
      );

      if (result.ok) {
        _logger.i('✅ 补丁应用成功');
        // 保存补丁版本号到文件
        await _savePatchVersionInfo(version, targetVersionCode);
        
        // 验证保存
        final verifyInfo = await _loadPatchVersionInfo();
        _logger.i('💾 已保存并验证: ${verifyInfo['version']} (${verifyInfo['versionCode']})');
      } else {
        _logger.e('❌ 补丁应用失败: ${result.error}');
      }

      return result.ok;
    } catch (e) {
      _logger.e('❌ 应用补丁异常: $e');
      return false;
    }
  }

  /// 下载完整 APK
  Future<String?> downloadApk(String apkUrl, Function(double) onProgress) async {
    try {
      _logger.i('⬇️ 开始下载 APK: $apkUrl');

      final cacheDir = await getApplicationCacheDirectory();
      final apkPath = '${cacheDir.path}/app-update.apk';
      
      _logger.i('📁 APK 下载路径: $apkPath');

      await _dio.download(
        apkUrl,
        apkPath,
        onReceiveProgress: (received, total) {
          if (total != -1) {
            onProgress(received / total);
          }
        },
      );

      _logger.i('✅ APK 下载完成: $apkPath');
      return apkPath;
    } catch (e) {
      _logger.e('❌ 下载 APK 失败: $e');
      return null;
    }
  }

  /// 回滚到内置版本
  Future<void> rollback() async {
    try {
      _logger.i('🔄 执行回滚操作');
      await FlutterPatcher.rollback();
      _logger.i('✅ 回滚成功');
    } catch (e) {
      _logger.e('❌ 回滚失败: $e');
    }
  }
  
  /// 清除补丁版本信息（整包更新后调用）
  Future<void> clearPatchVersionInfo() async {
    try {
      final directory = await getApplicationSupportDirectory();
      final file = File('${directory.path}/$_patchVersionFileName');
      if (await file.exists()) {
        await file.delete();
        _logger.i('🗑️ 已清除补丁版本记录');
      }
    } catch (e) {
      _logger.e('❌ 清除补丁版本信息失败: $e');
    }
  }
  
  /// 保存补丁版本信息到文件
  Future<void> _savePatchVersionInfo(String version, int versionCode) async {
    try {
      final directory = await getApplicationSupportDirectory();
      final file = File('${directory.path}/$_patchVersionFileName');
      final content = '$version|$versionCode';
      await file.writeAsString(content);
      
      // 🔥 立即验证写入
      final verifyContent = await file.readAsString();
      _logger.i('💾 补丁版本已保存到: ${file.path}');
      _logger.i('💾 写入内容: $content');
      _logger.i('💾 验证读取: $verifyContent');
      _logger.i('💾 文件存在: ${await file.exists()}');
    } catch (e) {
      _logger.e('❌ 保存补丁版本信息失败: $e');
    }
  }
  
  /// 从文件加载补丁版本信息
  Future<Map<String, dynamic>> _loadPatchVersionInfo() async {
    try {
      final directory = await getApplicationSupportDirectory();
      final file = File('${directory.path}/$_patchVersionFileName');
      
      _logger.i('📂 尝试加载补丁版本文件: ${file.path}');
      _logger.i('📂 文件存在: ${await file.exists()}');
      
      if (await file.exists()) {
        final content = await file.readAsString();
        _logger.i('📂 文件内容: $content');
        
        final parts = content.split('|');
        if (parts.length == 2) {
          final version = parts[0];
          final versionCode = int.tryParse(parts[1]);
          if (versionCode != null) {
            _logger.i('📂 解析成功: version=$version, versionCode=$versionCode');
            return {'version': version, 'versionCode': versionCode};
          } else {
            _logger.e('📂 versionCode 解析失败: ${parts[1]}');
          }
        } else {
          _logger.e('📂 文件格式错误，parts.length=${parts.length}');
        }
      }
      
      _logger.i('📂 未找到有效的补丁版本信息');
      return {'version': null, 'versionCode': null};
    } catch (e) {
      _logger.e('❌ 加载补丁版本信息失败: $e');
      return {'version': null, 'versionCode': null};
    }
  }
}