import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';
import 'package:url_launcher/url_launcher.dart';
import 'package:uuid/uuid.dart';

import '../../core/config/app_config.dart';
import '../../core/network/api_client.dart';
import '../../core/storage/local_store.dart';
import '../../core/theme/app_theme.dart';
import '../../providers/auth_provider.dart';
import '../../services/invite_service.dart';
import '../../services/version_service.dart';

/// 启动页：依次执行 ①设备指纹 ②域名发现+ApiClient 初始化 ③登录态恢复 ④版本/公告检查
class SplashScreen extends ConsumerStatefulWidget {
  const SplashScreen({super.key});

  @override
  ConsumerState<SplashScreen> createState() => _SplashScreenState();
}

class _SplashScreenState extends ConsumerState<SplashScreen> {
  String _step = '正在初始化…';
  String? _notice;

  @override
  void initState() {
    super.initState();
    _bootstrap();
  }

  Future<void> _bootstrap() async {
    try {
      // ① 设备指纹（UUID v4，持久化）
      _setStep('初始化设备…');
      LocalStore.I.ensureDeviceId(() => const Uuid().v4());

      // ② 域名发现（TXT → 兜底）+ 网络客户端初始化
      _setStep('连接服务器…');
      await ApiClient.init();

      // ②.5 推广归因：剪贴板口令（主）→ 无口令则首启模糊匹配上报（辅）
      try {
        await _attributeInvite();
      } catch (_) {
        // 归因失败不阻塞启动
      }

      // ③ 登录态恢复（安全存储 Token → /users/me）
      _setStep('恢复登录态…');
      await ref.read(authProvider.notifier).restore();

      // ④ 版本检查与维护公告（失败不阻塞进入首页）
      try {
        final info = await VersionService.check();
        if (!mounted) return;
        // 强制更新（当前 version_code 低于服务端最低要求）：阻断使用
        if (info.forceUpdate) {
          await _showForceUpdateDialog(info);
          return;
        }
        // 非强制新版本：可跳过的提示弹窗
        if (info.latestVersionCode > AppConfig.appVersionCode) {
          await _showUpdatePrompt(info);
          if (!mounted) return;
        }
        setState(() => _notice = info.notice.isNotEmpty ? info.notice : null);
        if (_notice == null) {
          _goHome();
          return;
        }
        // 有公告：展示 2 秒后进入
        Future.delayed(const Duration(seconds: 2), _goHome);
      } catch (_) {
        _goHome();
      }
    } catch (e) {
      _setStep('网络异常，请检查后重试');
      // 域名发现彻底失败：提供重试入口
    }
  }

  /// 推广归因：
  /// - 剪贴板命中分享口令 → 存 pending 邀请码（注册页预填，准确率 100%）
  /// - 无口令且未上报过 → 模糊匹配上报（每安装仅一次，命中结果服务端缓存）
  Future<void> _attributeInvite() async {
    final clip = await Clipboard.getData(Clipboard.kTextPlain);
    final code = InviteService.parseInviteCommand(clip?.text);
    if (code != null) {
      await LocalStore.I.savePendingInviteCode(code);
      return;
    }
    if (LocalStore.I.inviteMatchReported) return;
    final matched = await InviteService.reportMatch(LocalStore.I.deviceId);
    await LocalStore.I.markInviteMatchReported();
    if (matched != null && matched.isNotEmpty) {
      await LocalStore.I.savePendingInviteCode(matched);
    }
  }

  void _setStep(String s) {
    if (mounted) setState(() => _step = s);
  }

  void _goHome() {
    if (!mounted) return;
    // 游客可直接浏览（计费接口按 device_id 走），登录页由路由守卫按需唤起
    context.go('/home');
  }

  /// 跳转下载页（商店/外部浏览器）
  Future<void> _openUpdateUrl(String url) async {
    if (url.isEmpty) return;
    final uri = Uri.tryParse(url);
    if (uri == null) return;
    try {
      await launchUrl(uri, mode: LaunchMode.externalApplication);
    } catch (_) {
      // 调起失败不阻塞（强制更新场景弹窗仍在，可重试）
    }
  }

  /// 强制更新弹窗：不可关闭、不可返回，仅可跳下载页（《01-开发文档》5.7）
  Future<void> _showForceUpdateDialog(VersionInfo info) {
    return showDialog<void>(
      context: context,
      barrierDismissible: false,
      builder: (ctx) => PopScope(
        canPop: false,
        child: AlertDialog(
          backgroundColor: AppColors.surface,
          title: const Text('版本过低', style: TextStyle(fontSize: 16)),
          content: Text(
            '当前版本已停止服务，请更新到 v${info.latestVersion} 后继续使用。',
          ),
          actions: [
            ElevatedButton(
              onPressed: () => _openUpdateUrl(info.updateUrl),
              child: const Text('立即更新'),
            ),
          ],
        ),
      ),
    );
  }

  /// 非强制更新弹窗：可跳过；点更新跳下载页后继续进入 App
  Future<void> _showUpdatePrompt(VersionInfo info) async {
    final update = await showDialog<bool>(
      context: context,
      builder: (ctx) => AlertDialog(
        backgroundColor: AppColors.surface,
        title: Text('发现新版本 v${info.latestVersion}',
            style: const TextStyle(fontSize: 16)),
        content: const Text('建议更新到最新版本以获得更好的体验。'),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(ctx, false),
            child: const Text('跳过'),
          ),
          ElevatedButton(
            onPressed: () => Navigator.pop(ctx, true),
            child: const Text('立即更新'),
          ),
        ],
      ),
    );
    if (update == true) await _openUpdateUrl(info.updateUrl);
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Container(
              width: 88,
              height: 88,
              decoration: BoxDecoration(
                gradient: const LinearGradient(colors: [AppColors.primary, AppColors.secondary]),
                borderRadius: BorderRadius.circular(20),
              ),
              child: const Icon(Icons.play_arrow_rounded, size: 56, color: Colors.white),
            ),
            const SizedBox(height: 24),
            const Text('短视频', style: TextStyle(fontSize: 22, fontWeight: FontWeight.w700)),
            const SizedBox(height: 40),
            if (_notice != null)
              Padding(
                padding: const EdgeInsets.symmetric(horizontal: 32),
                child: Text(_notice!, textAlign: TextAlign.center,
                    style: const TextStyle(color: AppColors.gold)),
              )
            else
              Text(_step, style: const TextStyle(color: AppColors.textSecondary)),
            if (_step.contains('异常')) ...[
              const SizedBox(height: 16),
              TextButton(onPressed: _bootstrap, child: const Text('点击重试')),
            ],
          ],
        ),
      ),
    );
  }
}