import 'dart:async';
import 'dart:io';

import 'package:dio/dio.dart';
import 'package:flutter/foundation.dart' show kIsWeb;
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:package_info_plus/package_info_plus.dart';
import 'package:url_launcher/url_launcher.dart';
import '../core/config/app_config.dart';

// ── 数据模型 ────────────────────────────────────────────────
class AppUpdateInfo {
  final String latestVersion;
  final int buildNumber;
  final bool forceUpdate;
  final String releaseNotes;
  final Map<String, String> downloadUrls;
  final bool hasUpdate;

  const AppUpdateInfo({
    required this.latestVersion,
    required this.buildNumber,
    required this.forceUpdate,
    required this.releaseNotes,
    required this.downloadUrls,
    required this.hasUpdate,
  });
}

// ── Provider ────────────────────────────────────────────────
/// null = 检查失败或无更新数据（不影响主流程）
/// AppUpdateInfo with hasUpdate=false = 已是最新版
/// AppUpdateInfo with hasUpdate=true  = 有新版本
final updateProvider =
    AsyncNotifierProvider<UpdateNotifier, AppUpdateInfo?>(UpdateNotifier.new);

class UpdateNotifier extends AsyncNotifier<AppUpdateInfo?> {
  String get _checkUrl => AppConfig.versionUrl;
  Timer? _timer;
  bool _dismissed = false; // 用户已手动关闭非强制更新提示

  final _dio = Dio(BaseOptions(
    connectTimeout: const Duration(seconds: 5),
    receiveTimeout: const Duration(seconds: 5),
  ));

  @override
  Future<AppUpdateInfo?> build() async {
    ref.onDispose(() {
      _timer?.cancel();
      _dio.close(force: true);
    });

    // 启动后 3 秒延迟首次检查（避免与登录请求竞争）
    await Future.delayed(const Duration(seconds: 3));
    final result = await _check();

    // 每小时检查一次
    _timer = Timer.periodic(const Duration(hours: 1), (_) async {
      _dismissed = false;
      final r = await _check();
      state = AsyncValue.data(r);
    });

    return result;
  }

  /// 手动触发一次检查（供设置页"检查更新"按钮调用）
  Future<void> forceCheck() async {
    _dismissed = false;
    state = const AsyncValue.loading();
    state = AsyncValue.data(await _check());
  }

  /// 用户点击"稍后再说"后调用，隐藏 banner（直到下次定时刷新）
  void dismiss() {
    _dismissed = true;
    // 保留数据但 UI 通过 dismissed 状态判断是否显示
    state = AsyncValue.data(state.valueOrNull);
  }

  bool get isDismissed => _dismissed;

  Future<AppUpdateInfo?> _check() async {
    try {
      final resp = await _dio.get(_checkUrl);
      final data = resp.data as Map<String, dynamic>;

      final latestVersion = data['version'] as String? ?? '0.0.0';
      final buildNumber = data['build_number'] as int? ?? 0;
      final forceUpdate = data['force_update'] as bool? ?? false;
      final releaseNotes = data['release_notes'] as String? ?? '';
      final rawUrls = data['download_urls'] as Map<String, dynamic>? ?? {};
      final downloadUrls =
          rawUrls.map((k, v) => MapEntry(k, v?.toString() ?? ''));

      final info = await PackageInfo.fromPlatform();
      final hasUpdate = _isNewer(latestVersion, info.version);

      return AppUpdateInfo(
        latestVersion: latestVersion,
        buildNumber: buildNumber,
        forceUpdate: forceUpdate,
        releaseNotes: releaseNotes,
        downloadUrls: downloadUrls,
        hasUpdate: hasUpdate,
      );
    } catch (_) {
      return null; // 检查失败静默处理，不影响主业务
    }
  }

  /// 语义化版本比较：latest > current → true
  bool _isNewer(String latest, String current) {
    final l = _parse(latest);
    final c = _parse(current);
    for (var i = 0; i < 3; i++) {
      if (l[i] > c[i]) return true;
      if (l[i] < c[i]) return false;
    }
    return false;
  }

  List<int> _parse(String v) {
    final parts = v.split('.').map((s) => int.tryParse(s) ?? 0).toList();
    while (parts.length < 3) parts.add(0);
    return parts;
  }
}

// ── 版本号 Provider（供状态栏 / 门店信息面板使用）──────────
final appVersionProvider = FutureProvider<String>((ref) async {
  final info = await PackageInfo.fromPlatform();
  return 'v${info.version}';
});

// ── 打开下载链接工具函数 ────────────────────────────────────
Future<void> launchUpdateUrl(Map<String, String> downloadUrls) async {
  String? urlStr;

  if (kIsWeb) {
    urlStr = downloadUrls['web'];
  } else if (Platform.isMacOS) {
    urlStr = downloadUrls['macos'];
  } else if (Platform.isWindows) {
    urlStr = downloadUrls['windows'];
  } else if (Platform.isIOS) {
    urlStr = downloadUrls['ios'];
  } else if (Platform.isAndroid) {
    urlStr = downloadUrls['android'];
  } else {
    // Linux 等
    urlStr = downloadUrls['web'];
  }

  if (urlStr == null || urlStr.isEmpty) return;

  final uri = Uri.parse(urlStr);
  if (await canLaunchUrl(uri)) {
    await launchUrl(uri, mode: LaunchMode.externalApplication);
  }
}