import 'dart:async';

import 'package:flutter/material.dart';
import 'package:google_fonts/google_fonts.dart';

import 'core/auth/auth_service.dart';
import 'core/theme/app_colors.dart';
import 'core/theme/app_theme.dart';
import 'features/shell/main_screen.dart';

class App extends StatelessWidget {
  const App({super.key, required this.title});

  final String title;

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: title,
      debugShowCheckedModeBanner: false,
      theme: buildFunyMeeTheme(),
      home: const MainScreen(),
      builder: (context, child) {
        return Stack(
          fit: StackFit.expand,
          children: [
            SafeArea(
              top: false,
              left: false,
              right: false,
              bottom: false,
              child: child ?? const SizedBox.shrink(),
            ),
            ValueListenableBuilder<bool>(
              valueListenable: AuthService.isLoginComplete,
              builder: (context, done, _) {
                if (done) return const SizedBox.shrink();
                return const _StartupLoginOverlay();
              },
            ),
          ],
        );
      },
    );
  }
}

/// 对齐 app_client：首帧即进入壳层，登录完成前遮罩 + 久等网络提示。
class _StartupLoginOverlay extends StatefulWidget {
  const _StartupLoginOverlay();

  @override
  State<_StartupLoginOverlay> createState() => _StartupLoginOverlayState();
}

class _StartupLoginOverlayState extends State<_StartupLoginOverlay> {
  static const _longWaitAfter = Duration(seconds: 22);
  Timer? _longWaitTimer;
  bool _showNetworkHint = false;

  @override
  void initState() {
    super.initState();
    _longWaitTimer = Timer(_longWaitAfter, () {
      if (mounted) setState(() => _showNetworkHint = true);
    });
  }

  @override
  void dispose() {
    _longWaitTimer?.cancel();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Positioned.fill(
      child: AbsorbPointer(
        child: Container(
          color: Colors.black.withValues(alpha: 0.22),
          child: Center(
            child: Padding(
              padding: const EdgeInsets.symmetric(horizontal: 28),
              child: Column(
                mainAxisSize: MainAxisSize.min,
                children: [
                  const CircularProgressIndicator(color: AppColors.primary),
                  const SizedBox(height: 16),
                  Text(
                    'Signing in…',
                    style: GoogleFonts.inter(
                      color: Colors.white.withValues(alpha: 0.92),
                      fontSize: 15,
                      fontWeight: FontWeight.w600,
                    ),
                  ),
                  if (_showNetworkHint) ...[
                    const SizedBox(height: 22),
                    Text(
                      'Network is slow or unavailable',
                      textAlign: TextAlign.center,
                      style: GoogleFonts.inter(
                        color: Colors.white.withValues(alpha: 0.96),
                        fontSize: 16,
                        fontWeight: FontWeight.w600,
                      ),
                    ),
                    const SizedBox(height: 10),
                    Text(
                      'Check Wi‑Fi or mobile data. If the connection is fine, the server may be busy—try again shortly.',
                      textAlign: TextAlign.center,
                      style: GoogleFonts.inter(
                        color: Colors.white.withValues(alpha: 0.78),
                        fontSize: 14,
                        height: 1.4,
                      ),
                    ),
                  ],
                ],
              ),
            ),
          ),
        ),
      ),
    );
  }
}