import 'dart:math' as math;

import 'package:flutter/material.dart';
import 'package:lottie/lottie.dart';
import 'package:youtube_player_flutter/youtube_player_flutter.dart';

class VideoItem {
  const VideoItem({required this.title, required this.url});

  final String title;
  final String url;
}

class VideoScreen extends StatelessWidget {
  const VideoScreen({super.key});

  static const Color _teal = Color(0xFF2F9E94);
  static const Color _accentPink = Color(0xFFFF55A7);

  static const List<VideoItem> library = [
    VideoItem(title: 'Como escovar da maneira certa', url: 'https://www.youtube.com/watch?v=uH8dBWkD__0'),
  ];

  @override
  Widget build(BuildContext context) {
    final size = MediaQuery.sizeOf(context);
    return Scaffold(
      appBar: AppBar(
        backgroundColor: _teal,
        foregroundColor: Colors.white,
        elevation: 0,

        title: const Text(
          'Vídeos Educativos',
          style: TextStyle(fontWeight: FontWeight.w900),
        ),
      ),
      body: Stack(
        clipBehavior: Clip.none,
        children: [
          Positioned.fill(
            child: Container(
              decoration: const BoxDecoration(
                gradient: LinearGradient(
                  begin: Alignment.topCenter,
                  end: Alignment.bottomCenter,
                  colors: [
                    Color(0xFFFFE6F1),
                    Color(0xFFFFC9DF),
                  ],
                ),
              ),
            ),
          ),
          Positioned(
            left: -size.width * 0.40,
            bottom: -size.width * 0.45,
            child: IgnorePointer(
              child: SizedBox(
                width: size.width * 1.05,
                height: size.width * 1.05,
                child: Transform.rotate(
                  angle: 35 * math.pi / 180,
                  child: Opacity(
                    opacity: 0.95,
                    child: Lottie.asset(
                      'lottie/Liquid waves.json',
                      fit: BoxFit.cover,
                      repeat: true,
                    ),
                  ),
                ),
              ),
            ),
          ),
          SafeArea(
            child: Align(
              alignment: Alignment.topCenter,
              child: ConstrainedBox(
                constraints: const BoxConstraints(maxWidth: 560),
                child: Padding(
                  padding: const EdgeInsets.fromLTRB(16, 16, 16, 16),
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.stretch,
                    children: [
                      Container(
                        padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 10),
                        decoration: BoxDecoration(
                          color: Colors.white.withValues(alpha: 0.65),
                          borderRadius: BorderRadius.circular(14),
                          border: Border.all(color: Colors.black.withValues(alpha: 0.08)),
                        ),
                        child: const Row(
                          children: [
                            Icon(Icons.play_circle_fill_rounded, color: _accentPink),
                            SizedBox(width: 10),
                            Expanded(
                              child: Text(
                                'Vídeos Educativos',
                                style: TextStyle(
                                  fontWeight: FontWeight.w900,
                                  color: _accentPink,
                                ),
                              ),
                            ),
                          ],
                        ),
                      ),
                      const SizedBox(height: 14),
                      Expanded(
                        child: GridView.count(
                          crossAxisCount: 2,
                          mainAxisSpacing: 12,
                          crossAxisSpacing: 12,
                          childAspectRatio: 0.92,
                          children: library.map((item) {
                            final videoId = YoutubePlayer.convertUrlToId(item.url);
                            final thumb = videoId == null ? null : 'https://img.youtube.com/vi/$videoId/0.jpg';
                            return _VideoCard(
                              title: item.title,
                              thumbnailUrl: thumb,
                              onTap: () {
                                Navigator.of(context).push(
                                  MaterialPageRoute<void>(
                                    builder: (_) => VideoPlayerScreen(url: item.url, title: item.title),
                                  ),
                                );
                              },
                            );
                          }).toList(),
                        ),
                      ),
                    ],
                  ),
                ),
              ),
            ),
          ),
        ],
      ),
    );
  }
}

class _VideoCard extends StatelessWidget {
  const _VideoCard({required this.title, required this.thumbnailUrl, required this.onTap});

  final String title;
  final String? thumbnailUrl;
  final VoidCallback onTap;

  @override
  Widget build(BuildContext context) {
    return Material(
      color: Colors.white.withValues(alpha: 0.80),
      borderRadius: BorderRadius.circular(16),
      child: InkWell(
        borderRadius: BorderRadius.circular(16),
        onTap: onTap,
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            Expanded(
              child: ClipRRect(
                borderRadius: const BorderRadius.vertical(top: Radius.circular(16)),
                child: Stack(
                  fit: StackFit.expand,
                  children: [
                    if (thumbnailUrl != null)
                      Image.network(
                        thumbnailUrl!,
                        fit: BoxFit.cover,
                      )
                    else
                      Container(color: Colors.black.withValues(alpha: 0.06)),
                    Container(
                      decoration: BoxDecoration(
                        gradient: LinearGradient(
                          begin: Alignment.topCenter,
                          end: Alignment.bottomCenter,
                          colors: [
                            Colors.black.withValues(alpha: 0.10),
                            Colors.black.withValues(alpha: 0.42),
                          ],
                        ),
                      ),
                    ),
                    const Align(
                      alignment: Alignment.center,
                      child: Icon(Icons.play_circle_fill_rounded, size: 54, color: Colors.white),
                    ),
                  ],
                ),
              ),
            ),
            Padding(
              padding: const EdgeInsets.fromLTRB(12, 10, 12, 12),
              child: Text(
                title,
                maxLines: 2,
                overflow: TextOverflow.ellipsis,
                style: const TextStyle(
                  fontWeight: FontWeight.w900,
                  color: Color(0xFF2F9E94),
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }
}

class VideoPlayerScreen extends StatefulWidget {
  const VideoPlayerScreen({super.key, required this.url, required this.title});

  final String url;
  final String title;

  @override
  State<VideoPlayerScreen> createState() => _VideoPlayerScreenState();
}

class _VideoPlayerScreenState extends State<VideoPlayerScreen> {
  static const Color _teal = Color(0xFF2F9E94);
  static const Color _bg = Color(0xFFFFE6F1);

  late final YoutubePlayerController _controller;

  @override
  void initState() {
    super.initState();
    final id = YoutubePlayer.convertUrlToId(widget.url);
    _controller = YoutubePlayerController(
      initialVideoId: id ?? '',
      flags: const YoutubePlayerFlags(
        autoPlay: true,
        mute: false,
        enableCaption: true,
      ),
    );
  }

  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    final hasVideo = _controller.initialVideoId.isNotEmpty;

    return Scaffold(
      appBar: AppBar(
        backgroundColor: _teal,
        foregroundColor: Colors.white,
        elevation: 0,
        title: Text(
          widget.title,
          style: const TextStyle(fontWeight: FontWeight.w900),
        ),
      ),
      body: Container(
        color: _bg,
        child: SafeArea(
          child: ListView(
            padding: const EdgeInsets.fromLTRB(16, 16, 16, 16),
            children: [
              ClipRRect(
                borderRadius: BorderRadius.circular(16),
                child: AspectRatio(
                  aspectRatio: 16 / 9,
                  child: hasVideo
                      ? YoutubePlayer(
                          controller: _controller,
                          showVideoProgressIndicator: true,
                          progressIndicatorColor: Colors.white,
                        )
                      : Container(
                          color: Colors.black.withValues(alpha: 0.10),
                          child: const Center(
                            child: Text(
                              'Link de vídeo inválido',
                              style: TextStyle(fontWeight: FontWeight.w800),
                            ),
                          ),
                        ),
                ),
              ),
              const SizedBox(height: 14),
              Text(
                widget.title,
                style: const TextStyle(
                  fontSize: 18,
                  fontWeight: FontWeight.w900,
                  color: Color(0xFFFF55A7),
                ),
              ),
              const SizedBox(height: 6),
              Text(
                'Assista ao vídeo e aprenda mais sobre saúde bucal.',
                style: TextStyle(
                  color: Colors.black.withValues(alpha: 0.70),
                  fontWeight: FontWeight.w600,
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }
}