import 'dart:async';

import 'package:flutter/material.dart';

/// 간단한 전면 광고(Interstitial Ad) 모의 서비스
class AdService {
  /// 임시 광고 다이얼로그를 표시하고 사용자가 끝까지 시청했는지 여부를 반환한다.
  Future<bool> showInterstitialAd(BuildContext context) async {
    final result = await showDialog<bool>(
      context: context,
      barrierDismissible: false,
      builder: (_) => const _MockInterstitialAdDialog(),
    );
    return result ?? false;
  }
}

class _MockInterstitialAdDialog extends StatefulWidget {
  const _MockInterstitialAdDialog();

  @override
  State<_MockInterstitialAdDialog> createState() =>
      _MockInterstitialAdDialogState();
}

class _MockInterstitialAdDialogState extends State<_MockInterstitialAdDialog> {
  static const int _adDurationSeconds = 4;

  late Timer _timer;
  int _elapsedSeconds = 0;
  bool _completed = false;

  @override
  void initState() {
    super.initState();
    _timer = Timer.periodic(const Duration(seconds: 1), (timer) {
      if (!mounted) return;
      setState(() {
        _elapsedSeconds++;
      });
      if (_elapsedSeconds >= _adDurationSeconds && !_completed) {
        _completed = true;
        _timer.cancel();
        Navigator.of(context).pop(true);
      }
    });
  }

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

  bool get _canClose => _elapsedSeconds >= _adDurationSeconds;

  double get _progress => (_elapsedSeconds / _adDurationSeconds).clamp(0, 1);

  @override
  Widget build(BuildContext context) {
    final isDark = Theme.of(context).brightness == Brightness.dark;

    return Dialog(
      insetPadding: const EdgeInsets.symmetric(horizontal: 24, vertical: 80),
      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(20)),
      child: Stack(
        children: [
          Padding(
            padding: const EdgeInsets.all(24),
            child: Column(
              mainAxisSize: MainAxisSize.min,
              children: [
                const Icon(
                  Icons.ondemand_video,
                  size: 56,
                  color: Colors.deepPurple,
                ),
                const SizedBox(height: 12),
                Text(
                  '광고 시청 중...',
                  style: TextStyle(
                    fontSize: 20,
                    fontWeight: FontWeight.bold,
                    color: isDark ? Colors.white : Colors.black87,
                  ),
                ),
                const SizedBox(height: 8),
                Text(
                  _canClose ? '광고가 완료되었습니다.' : '잠시만 기다려 주세요.',
                  style: TextStyle(
                    color: isDark ? Colors.white70 : Colors.black54,
                  ),
                ),
                const SizedBox(height: 24),
                LinearProgressIndicator(
                  value: _progress,
                  minHeight: 6,
                  borderRadius: BorderRadius.circular(999),
                  backgroundColor: Colors.grey.withValues(alpha: 0.2),
                  color: Colors.deepPurple,
                ),
                const SizedBox(height: 12),
                Text(
                  _canClose
                      ? '광고가 완료되었어요. 자동으로 계속합니다.'
                      : '남은 시간: ${_adDurationSeconds - _elapsedSeconds}초',
                  style: TextStyle(
                    color: isDark ? Colors.white70 : Colors.black54,
                  ),
                ),
                const SizedBox(height: 12),
                TextButton(
                  onPressed: () {
                    Navigator.of(context).pop(false);
                  },
                  child: const Text('닫기'),
                ),
              ],
            ),
          ),
          Positioned(
            right: 8,
            top: 8,
            child: IconButton(
              onPressed: () => Navigator.of(context).pop(false),
              icon: const Icon(Icons.close),
            ),
          ),
        ],
      ),
    );
  }
}