// update_provider.dart — 应用更新检查(轻量版,无后台轮询)。
//
// 手动触发(设置页「检查更新」)向控制面 GET $kApiBaseUrl/version 拉取最新版本信息,
// 与本地版本(package_info_plus)做语义比较;有更新则由调用方(settings_page)弹窗
// 展示(见 widgets/update_dialog.dart)。检查失败静默返回 null,不影响主流程。
//
// 对照 jiu client/lib/providers/update_provider.dart,去掉了定时轮询 Timer 与
// dismiss 状态——按需求这里只做「手动检查」,启动期自动检查留作后续 TODO。
import 'dart:convert';
import 'dart:io';

import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:http/http.dart' as http;
import 'package:package_info_plus/package_info_plus.dart';

import '../services/api_config.dart';

/// 一次更新检查的结果。
class AppUpdateInfo {
  const AppUpdateInfo({
    required this.latestVersion,
    required this.buildNumber,
    required this.forceUpdate,
    required this.releaseNotes,
    required this.downloadUrls,
    required this.hasUpdate,
  });

  final String latestVersion;
  final int buildNumber;
  final bool forceUpdate;
  final String releaseNotes;
  final Map<String, String> downloadUrls;
  final bool hasUpdate;
}

/// 无状态更新检查服务,供设置页「检查更新」按钮直接调用。
final updateCheckerProvider = Provider<UpdateChecker>((ref) => const UpdateChecker());

class UpdateChecker {
  const UpdateChecker();

  /// 拉取 `$kApiBaseUrl/version` 并与本地版本比较。网络/解析失败返回 null(静默)。
  Future<AppUpdateInfo?> check() async {
    try {
      final resp = await http
          .get(Uri.parse('$kApiBaseUrl/version'))
          .timeout(const Duration(seconds: 8));
      if (resp.statusCode != 200) return null;
      final data = jsonDecode(resp.body) as Map<String, dynamic>;

      final latestVersion = data['version'] as String? ?? '0.0.0';
      final buildNumber = (data['build_number'] as num?)?.toInt() ?? 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>? ?? const {};
      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;
    }
  }

  /// 语义化版本比较:latest > current → true。容忍 1.1.4-dev / 1.1.4+7 等后缀。
  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) {
      final m = RegExp(r'^\d+').firstMatch(s);
      return m == null ? 0 : int.parse(m.group(0)!);
    }).toList();
    while (parts.length < 3) {
      parts.add(0);
    }
    return parts;
  }
}

/// 按当前平台从服务端 download_urls 里取对应下载直链。
String? platformDownloadUrl(Map<String, String> downloadUrls) {
  if (Platform.isMacOS) return downloadUrls['macos'];
  if (Platform.isWindows) return downloadUrls['windows'];
  if (Platform.isIOS) return downloadUrls['ios'];
  if (Platform.isAndroid) return downloadUrls['android'];
  return downloadUrls['web'];
}