import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';
import 'package:media_kit/media_kit.dart';
import 'package:media_kit_video/media_kit_video.dart';
import 'package:share_plus/share_plus.dart';

import '../../core/config/test_stream.dart';
import '../../core/media/download_manager.dart';
import '../../core/media/local_media_server.dart';
import '../../core/network/api_exception.dart';
import '../../core/storage/watch_dedup_store.dart';
import '../../core/theme/app_theme.dart';
import '../../models/video_item.dart';
import '../../providers/auth_provider.dart';
import '../../services/video_service.dart';
import '../feed/widgets/comment_sheet.dart';
import '../feed/widgets/feed_overlays.dart';
import '../feed/widgets/interaction_bar.dart';
import '../feed/widgets/video_info_section.dart';

/// 单视频播放页（搜索/用户主页/作品/收藏/历史/系列共用）：
/// 与 Feed 页体验一致：右侧互动栏、左下信息区、双击点赞、长按倍速/分享、
/// 抖音风格细进度条、系列视频支持上下划切换集数
class SimplePlayerScreen extends ConsumerStatefulWidget {
  const SimplePlayerScreen({super.key, required this.item});

  final VideoItem item;

  @override
  ConsumerState<SimplePlayerScreen> createState() =>
      _SimplePlayerScreenState();
}

class _SimplePlayerScreenState extends ConsumerState<SimplePlayerScreen> {
  late Player _player = Player();
  late VideoController _controller = VideoController(_player);

  Duration _position = Duration.zero;
  Duration _duration = Duration.zero;
  bool _playing = true;
  bool _showPauseIcon = false;
  Timer? _pauseIconTimer;

  bool _seeking = false;
  double _seekValue = 0;

  // 系列
  Map<String, dynamic>? _seriesData;
  List<VideoItem> _episodeItems = [];
  late PageController _pageController;
  int _currentPage = 0;

  // 当前播放的 item（切集后更新，供互动栏/信息区用）
  late VideoItem _currentItem = widget.item;

  // 互动状态（切集后从后端重新拉取）
  bool _isLiked = false;
  bool _isFavorited = false;
  int _likeCount = 0;
  int _favoriteCount = 0;
  int _commentCount = 0;

  StreamSubscription<Duration>? _posSub;
  StreamSubscription<Duration>? _durSub;

  static const _rates = [1.0, 1.5, 2.0, 3.0];
  double _rate = 1.0;

  bool get _hasSeries =>
      _seriesData != null && (_seriesData!['has_series'] as bool? ?? false);

  List<dynamic> get _episodes =>
      (_seriesData?['episodes'] as List?) ?? const [];

  String get _seriesTitle =>
      _seriesData?['series']?['title'] as String? ?? '';

  @override
  void initState() {
    super.initState();
    _open(widget.item);
    _reportWatch();
    _loadSeries();
    _loadInteraction();
    _subscribePlayer();
  }

  // ---------- 播放器 ----------

  void _subscribePlayer() {
    _posSub = _player.stream.position.listen((p) {
      if (!mounted || _seeking) return;
      setState(() => _position = p);
    });
    _durSub = _player.stream.duration.listen((d) {
      if (!mounted) return;
      setState(() => _duration = d);
    });
  }

  void _open(VideoItem item) {
    // 本地已下载地址（127.0.0.1）原样播放；网络 m3u8 经本地代理走 1G 分片缓存
    _player.open(Media(LocalMediaServer.I.wrap(resolvePlayUrl(item))),
        play: true);
  }

  void _toggle() {
    _player.playOrPause();
    setState(() {
      _showPauseIcon = !_playing;
      _playing = !_playing;
    });
    _pauseIconTimer?.cancel();
    _pauseIconTimer = Timer(const Duration(milliseconds: 600), () {
      if (mounted) setState(() => _showPauseIcon = false);
    });
  }

  // ---------- 倍速 ----------

  void _setRate(double r) {
    _player.setRate(r);
    setState(() => _rate = r);
  }

  String get _rateLabel =>
      _rate == _rate.roundToDouble() ? '${_rate.toInt()}X' : '${_rate}X';

  // ---------- 互动 ----------

  Future<void> _loadInteraction() async {
    // 从后端拉当前视频的点赞/收藏状态
    try {
      final data = await VideoService.fetchDetail(_currentItem.videoId);
      if (!mounted) return;
      setState(() {
        _isLiked = (data['is_liked'] as bool?) ?? false;
        _isFavorited = (data['is_favorited'] as bool?) ?? false;
        _likeCount = (data['like_count'] as num?)?.toInt() ?? 0;
        _favoriteCount = (data['favorite_count'] as num?)?.toInt() ?? 0;
        _commentCount = (data['comment_count'] as num?)?.toInt() ?? 0;
      });
    } catch (_) {
      // 游客或未登录时忽略，用默认值
    }
  }

  void _onLike() {
    if (!ref.read(authProvider).isLoggedIn) {
      context.go('/login');
      return;
    }
    setState(() {
      _isLiked = !_isLiked;
      _likeCount = _isLiked ? _likeCount + 1 : _likeCount - 1;
    });
    VideoService.toggleLike(_currentItem.videoId).catchError((_) {
      setState(() {
        _isLiked = !_isLiked;
        _likeCount = _isLiked ? _likeCount + 1 : _likeCount - 1;
      });
      return <String, dynamic>{};
    });
  }

  void _onFavorite() {
    if (!ref.read(authProvider).isLoggedIn) {
      context.go('/login');
      return;
    }
    setState(() {
      _isFavorited = !_isFavorited;
      _favoriteCount = _isFavorited ? _favoriteCount + 1 : _favoriteCount - 1;
    });
    VideoService.toggleFavorite(_currentItem.videoId).catchError((_) {
      setState(() {
        _isFavorited = !_isFavorited;
        _favoriteCount =
            _isFavorited ? _favoriteCount + 1 : _favoriteCount - 1;
      });
      return <String, dynamic>{};
    });
  }

  Future<void> _openComments() async {
    _player.pause();
    await showCommentSheet(
      context,
      videoId: _currentItem.videoId,
      onCountChanged: (delta) =>
          setState(() => _commentCount = (_commentCount + delta).clamp(0, 1 << 31)),
    );
    if (mounted) _player.play();
  }

  void _share() {
    Share.share(
      '${_currentItem.title}\n${_currentItem.videoUrl}',
      subject: _currentItem.title,
    );
  }

  // ---------- 系列 ----------

  Future<void> _loadSeries() async {
    final data = await VideoService.fetchVideoSeries(_currentItem.videoId);
    if (!mounted) return;
    setState(() => _seriesData = data);
    _initEpisodePage();
  }

  void _initEpisodePage() {
    if (!_hasSeries) return;
    final episodes = _episodes;
    if (episodes.isEmpty) return;

    _episodeItems = episodes.map((ep) {
      final m = ep as Map<String, dynamic>;
      return VideoItem(
        videoId: m['video_id'],
        title: m['title'] ?? '',
        coverUrl: m['cover_url'] ?? '',
        videoUrl: m['video_url'] ?? '',
        duration: (m['duration'] as num?)?.toInt() ?? 0,
        author: widget.item.author,
      );
    }).toList();

    _currentPage = _episodeItems.indexWhere(
      (e) => e.videoId == _currentItem.videoId,
    );
    if (_currentPage < 0) _currentPage = 0;
    _pageController = PageController(initialPage: _currentPage);
  }

  void _onPageChanged(int index) {
    if (index < 0 || index >= _episodeItems.length) return;
    _switchToEpisodeById(_episodeItems[index].videoId);
  }

  void _switchToEpisodeById(int videoId) {
    if (videoId == _currentItem.videoId) return;

    // 从 episodes 原始数据构造新 VideoItem
    final epData = _episodes.firstWhere(
      (e) => (e as Map)['video_id'] == videoId,
      orElse: () => null,
    ) as Map<String, dynamic>?;
    if (epData == null) return;

    final newItem = VideoItem(
      videoId: videoId,
      title: epData['title'] ?? '',
      coverUrl: epData['cover_url'] ?? '',
      videoUrl: epData['video_url'] ?? '',
      duration: (epData['duration'] as num?)?.toInt() ?? 0,
      author: widget.item.author,
    );

    // 彻底销毁旧 Player，创建新 Player
    _posSub?.cancel();
    _durSub?.cancel();
    _player.dispose();

    setState(() {
      _player = Player();
      _controller = VideoController(_player);
      _currentItem = newItem;
      _position = Duration.zero;
      _duration = Duration.zero;
      _playing = true;
      _rate = 1.0;
      _open(newItem);
    });

    _subscribePlayer();
    _reportWatch();
    _loadSeries();
    _loadInteraction();
  }

  // ---------- Watch ----------

  Future<void> _reportWatch() async {
    final dedup = WatchDedupStore.I;
    if (dedup.hasWatched(_currentItem.videoId)) return;
    await dedup.markWatched(_currentItem.videoId);
    try {
      final result = await VideoService.reportWatch(_currentItem.videoId);
      if (!mounted) return;
      if (result.isPointsCost) {
        showTopToast(context, '本次消耗 ${result.costPoints} 积分');
      }
    } on ApiException catch (e) {
      if (!mounted) return;
      _player.pause();
      if (e.isGuestLimit) {
        showGuestLimitDialog(context);
      } else if (e.isPointsInsufficient) {
        showPointsInsufficientDialog(
          context,
          (e.data?['points'] as num?)?.toInt() ?? 0,
        );
      } else {
        showTopToast(context, e.message);
      }
    } catch (_) {}
  }

  // ---------- 长按 ----------

  void _onLongPress() {
    showModalBottomSheet<void>(
      context: context,
      backgroundColor: Colors.white,
      isScrollControlled: true,
      useSafeArea: true,
      shape: const RoundedRectangleBorder(
        borderRadius: BorderRadius.vertical(top: Radius.circular(16)),
      ),
      builder: (sheetContext) => Theme(
        // 弹窗是白底，APP 主题为暗色（默认白字），需显式套用亮色主题
        data: ThemeData.light(),
        child: Padding(
        padding: const EdgeInsets.fromLTRB(20, 20, 20, 12),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            // 标题 + 当前倍速
            Row(
              children: [
                const Icon(Icons.speed, color: AppColors.primary, size: 20),
                const SizedBox(width: 6),
                const Text('倍速播放',
                    style: TextStyle(
                        fontSize: 15, fontWeight: FontWeight.w600)),
                const Spacer(),
                Text('当前 $_rateLabel',
                    style: TextStyle(fontSize: 12, color: Colors.grey[600])),
              ],
            ),
            const SizedBox(height: 14),

            // 四档倍速：1X / 1.5X / 2X / 3X
            Row(
              children: [
                for (final r in _rates) ...[
                  Expanded(
                    child: GestureDetector(
                      onTap: () {
                        _setRate(r);
                        Navigator.of(sheetContext).pop();
                      },
                      child: Container(
                        height: 46,
                        alignment: Alignment.center,
                        decoration: BoxDecoration(
                          color: (_rate - r).abs() < 0.01
                              ? AppColors.primary.withValues(alpha: 0.15)
                              : Colors.grey[100],
                          border: Border.all(
                            color: (_rate - r).abs() < 0.01
                                ? AppColors.primary
                                : Colors.transparent,
                          ),
                          borderRadius: BorderRadius.circular(8),
                        ),
                        child: Text(
                          r == r.roundToDouble()
                              ? '${r.toInt()}X'
                              : '${r}X',
                          style: TextStyle(
                            fontSize: 16,
                            fontWeight: FontWeight.w600,
                            color: (_rate - r).abs() < 0.01
                                ? AppColors.primary
                                : Colors.black87,
                          ),
                        ),
                      ),
                    ),
                  ),
                  if (r != _rates.last) const SizedBox(width: 10),
                ],
              ],
            ),

            const SizedBox(height: 16),
            const Divider(height: 1),

            // 分享
            ListTile(
              contentPadding: EdgeInsets.zero,
              leading: const Icon(Icons.share_outlined),
              title: const Text('分享'),
              onTap: () {
                Navigator.of(sheetContext).pop();
                _share();
              },
            ),

            // 下载（已下载/下载中置灰；本地已下载视频不再重复下载）
            Builder(builder: (_) {
              final dm = ref.read(downloadManagerProvider);
              final downloaded =
                  dm.items.any((e) => e.videoId == _currentItem.videoId);
              final downloading =
                  dm.progress.containsKey(_currentItem.videoId);
              final isLocal = _currentItem.videoUrl.contains('127.0.0.1');
              return ListTile(
                contentPadding: EdgeInsets.zero,
                leading: Icon(downloaded || isLocal
                    ? Icons.check_circle_outline
                    : Icons.download_outlined),
                title: Text(downloaded || isLocal
                    ? '已下载'
                    : (downloading ? '下载中…' : '下载')),
                enabled: !downloaded && !downloading && !isLocal,
                onTap: () {
                  Navigator.of(sheetContext).pop();
                  showTopToast(context, '开始下载，可在「我的 → 已下载」查看');
                  ref
                      .read(downloadManagerProvider.notifier)
                      .start(_currentItem)
                      .catchError((_) {
                    if (mounted) showTopToast(context, '下载失败，请重试');
                  });
                },
              );
            }),
          ],
        ),
        ),
      ),
    );
  }

  // ---------- 进度条 ----------

  /// 有效时长：流上报优先，异常（如被当直播 duration=0）回退到 DB 时长
  Duration get _effectiveDuration => _duration.inMilliseconds > 0
      ? _duration
      : Duration(seconds: _currentItem.duration);

  double get _sliderValue {
    if (_seeking) return _seekValue;
    if (_effectiveDuration.inMilliseconds <= 0) return 0;
    return (_position.inMilliseconds / _effectiveDuration.inMilliseconds)
        .clamp(0.0, 1.0);
  }

  static String _fmtDuration(Duration d) {
    final h = d.inHours;
    final m = d.inMinutes.remainder(60).toString().padLeft(2, '0');
    final s = d.inSeconds.remainder(60).toString().padLeft(2, '0');
    return h > 0 ? '$h:$m:$s' : '$m:$s';
  }

  void _onSeekStart(double v) {
    setState(() {
      _seeking = true;
      _seekValue = v;
    });
  }

  void _onSeek(double v) {
    setState(() => _seekValue = v);
  }

  void _onSeekEnd(double v) {
    setState(() => _seeking = false);
    if (_effectiveDuration.inMilliseconds > 0) {
      final target = Duration(
        milliseconds: (v * _effectiveDuration.inMilliseconds).round(),
      );
      _player.seek(target);
    }
  }

  // ---------- 生命周期 ----------

  @override
  void dispose() {
    _pauseIconTimer?.cancel();
    _posSub?.cancel();
    _durSub?.cancel();
    _player.dispose();
    if (_hasSeries && _episodeItems.isNotEmpty) {
      _pageController.dispose();
    }
    super.dispose();
  }

  // ---------- 构建 ----------

  @override
  Widget build(BuildContext context) {
    // 互动栏 item（用当前播放的 item + 本地互动状态）
    final interactionItem = _currentItem.copyWith(
      isLiked: _isLiked,
      isFavorited: _isFavorited,
      likeCount: _likeCount,
      favoriteCount: _favoriteCount,
      commentCount: _commentCount,
    );

    final content = GestureDetector(
      behavior: HitTestBehavior.opaque,
      onTap: _toggle,
      onDoubleTap: _onLike,
      onLongPress: _onLongPress,
      child: Stack(
        fit: StackFit.expand,
        children: [
          // 视频画面
          Center(
            child: Video(
              controller: _controller,
              controls: NoVideoControls,
              fit: BoxFit.contain,
            ),
          ),

          // 中央播放/暂停图标（短暂显示）
          if (_showPauseIcon)
            const IgnorePointer(
              child: Center(
                child: Icon(
                  Icons.play_circle_outline,
                  size: 72,
                  color: Colors.white70,
                ),
              ),
            ),

          // 底部渐变（提升文字可读性）
          const Positioned(
            left: 0, right: 0, bottom: 0, height: 200,
            child: IgnorePointer(
              child: DecoratedBox(
                decoration: BoxDecoration(
                  gradient: LinearGradient(
                    begin: Alignment.topCenter,
                    end: Alignment.bottomCenter,
                    colors: [Colors.transparent, Colors.black54],
                  ),
                ),
              ),
            ),
          ),

          // ---------- 顶部：返回 + 倍速 ----------
          SafeArea(
            child: Row(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: [
                const BackButton(color: Colors.white),
                // 倍速按钮
                GestureDetector(
                  onTap: _onLongPress,
                  child: Container(
                    margin: const EdgeInsets.only(right: 16),
                    padding: const EdgeInsets.symmetric(
                        horizontal: 10, vertical: 4),
                    decoration: BoxDecoration(
                      color: Colors.black45,
                      borderRadius: BorderRadius.circular(8),
                    ),
                    child: Text(
                      _rateLabel,
                      style: const TextStyle(
                        color: Colors.white,
                        fontSize: 13,
                        fontWeight: FontWeight.w600,
                      ),
                    ),
                  ),
                ),
              ],
            ),
          ),

          // ---------- 右侧互动栏 ----------
          Positioned(
            right: 8, bottom: 96,
            child: InteractionBar(
              item: interactionItem,
              onLike: (_) => _onLike(),
              onFavorite: (_) => _onFavorite(),
              onComment: (_) => _openComments(),
            ),
          ),

          // ---------- 左下信息区 ----------
          Positioned(
            left: 12, right: 88, bottom: 24,
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              mainAxisSize: MainAxisSize.min,
              children: [
                // 系列标题（当前视频属于系列时显示，点击弹出系列列表）
                if (_hasSeries)
                  GestureDetector(
                    onTap: _showSeriesSheet,
                    child: Container(
                      margin: const EdgeInsets.only(bottom: 8),
                      padding: const EdgeInsets.symmetric(
                          horizontal: 10, vertical: 6),
                      decoration: BoxDecoration(
                        color: Colors.black54,
                        borderRadius: BorderRadius.circular(8),
                      ),
                      child: Row(
                        mainAxisSize: MainAxisSize.min,
                        children: [
                          const Icon(Icons.playlist_play,
                              color: Colors.white, size: 16),
                          const SizedBox(width: 4),
                          Text(
                            _seriesTitle,
                            style: const TextStyle(
                              color: Colors.white,
                              fontSize: 13,
                              fontWeight: FontWeight.w600,
                            ),
                          ),
                          const SizedBox(width: 2),
                          const Icon(Icons.chevron_right,
                              color: Colors.white, size: 14),
                        ],
                      ),
                    ),
                  ),
                // 视频信息（昵称/标题/描述/标签）
                VideoInfoSection(item: _currentItem),
              ],
            ),
          ),

          // ---------- 进度条：抖音风格一条细线 + 时间刻度 ----------
          Positioned(
            left: 0, right: 0, bottom: 0,
            child: Column(
              mainAxisSize: MainAxisSize.min,
              children: [
                // 时间刻度：左当前（拖动时为目标位置），右总时长
                Padding(
                  padding:
                      const EdgeInsets.symmetric(horizontal: 14, vertical: 2),
                  child: Row(
                    mainAxisAlignment: MainAxisAlignment.spaceBetween,
                    children: [
                      Text(
                        _fmtDuration(_seeking
                            ? Duration(
                                milliseconds: (_seekValue *
                                        _effectiveDuration.inMilliseconds)
                                    .round())
                            : _position),
                        style: const TextStyle(
                            color: Colors.white70, fontSize: 11),
                      ),
                      Text(
                        _fmtDuration(_effectiveDuration),
                        style: const TextStyle(
                            color: Colors.white70, fontSize: 11),
                      ),
                    ],
                  ),
                ),
                _ThinProgressBar(
                  value: _sliderValue,
                  onChanged: _onSeek,
                  onChangeStart: _onSeekStart,
                  onChangeEnd: _onSeekEnd,
                  totalMs: _effectiveDuration.inMilliseconds,
                ),
              ],
            ),
          ),
        ],
      ),
    );

    // 系列视频：用 PageView 支持上下划切换集数
    if (_hasSeries && _episodeItems.isNotEmpty) {
      return Scaffold(
        backgroundColor: Colors.black,
        body: PageView.builder(
          controller: _pageController,
          scrollDirection: Axis.vertical,
          itemCount: _episodeItems.length,
          onPageChanged: _onPageChanged,
          itemBuilder: (_, index) {
            if (index == _currentPage) return content;
            return Container(
              color: Colors.black,
              child: Center(
                child: Text(
                  _episodeItems[index].title,
                  style: const TextStyle(color: Colors.white38),
                ),
              ),
            );
          },
        ),
      );
    }

    // 非系列视频：直接渲染
    return Scaffold(
      backgroundColor: Colors.black,
      body: content,
    );
  }

  // ---------- 系列列表弹窗 ----------

  void _showSeriesSheet() {
    showModalBottomSheet<void>(
      context: context,
      backgroundColor: Colors.white,
      isScrollControlled: true,
      useSafeArea: true,
      shape: const RoundedRectangleBorder(
        borderRadius: BorderRadius.vertical(top: Radius.circular(16)),
      ),
      builder: (_) => Theme(
        data: ThemeData.light(),
        child: DraggableScrollableSheet(
        initialChildSize: 0.6,
        minChildSize: 0.4,
        maxChildSize: 0.9,
        expand: false,
        builder: (_, controller) => Column(
          children: [
            Container(
              margin: const EdgeInsets.only(top: 12),
              width: 40, height: 4,
              decoration: BoxDecoration(
                color: Colors.grey[300],
                borderRadius: BorderRadius.circular(2),
              ),
            ),
            Padding(
              padding: const EdgeInsets.all(16),
              child: Row(
                children: [
                  Expanded(
                    child: Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        Text(
                          _seriesTitle,
                          style: const TextStyle(
                              fontSize: 16, fontWeight: FontWeight.w600),
                          maxLines: 1, overflow: TextOverflow.ellipsis,
                        ),
                        const SizedBox(height: 2),
                        Text(
                          '共 ${_episodes.length} 集',
                          style: TextStyle(
                              fontSize: 12, color: Colors.grey[600]),
                        ),
                      ],
                    ),
                  ),
                ],
              ),
            ),
            const Divider(height: 1),
            Expanded(
              child: ListView.builder(
                controller: controller,
                itemCount: _episodes.length,
                itemBuilder: (_, i) {
                  final ep = _episodes[i] as Map<String, dynamic>;
                  final isCurrent = ep['video_id'] == _currentItem.videoId;
                  return ListTile(
                    leading: Container(
                      width: 40, height: 40,
                      alignment: Alignment.center,
                      decoration: BoxDecoration(
                        color: isCurrent
                            ? AppColors.primary.withValues(alpha: 0.15)
                            : Colors.grey[100],
                        borderRadius: BorderRadius.circular(8),
                      ),
                      child: Text(
                        '${ep['episode_no'] ?? i + 1}',
                        style: TextStyle(
                          fontWeight: FontWeight.w700,
                          color: isCurrent
                              ? AppColors.primary
                              : Colors.black87,
                        ),
                      ),
                    ),
                    title: Text(
                      ep['title'] as String? ?? '',
                      maxLines: 1, overflow: TextOverflow.ellipsis,
                      style: TextStyle(
                        fontSize: 14,
                        fontWeight: isCurrent
                            ? FontWeight.w600
                            : FontWeight.normal,
                        color: isCurrent
                            ? AppColors.primary
                            : Colors.black87,
                      ),
                    ),
                    trailing: isCurrent
                        ? const Icon(Icons.play_circle_filled,
                            color: AppColors.primary, size: 20)
                        : null,
                    onTap: () {
                      Navigator.of(context).pop();
                      _switchToEpisodeById(ep['video_id'] as int);
                    },
                  );
                },
              ),
            ),
          ],
        ),
        ),
      ),
    );
  }
}

/// 抖音风格进度条：默认一条 2px 细线（已播放部分白色、未播放部分 20% 透明白），
/// 拖动时自动变厚显示 thumb，松开后恢复细线。
class _ThinProgressBar extends StatefulWidget {
  const _ThinProgressBar({
    required this.value,
    required this.onChanged,
    required this.onChangeStart,
    required this.onChangeEnd,
    this.totalMs = 0,
  });

  final double value;
  final ValueChanged<double> onChanged;
  final ValueChanged<double> onChangeStart;
  final ValueChanged<double> onChangeEnd;

  /// 视频总时长（毫秒）：拖动时气泡显示目标位置用时/分/秒
  final int totalMs;

  @override
  State<_ThinProgressBar> createState() => _ThinProgressBarState();
}

/// 拖动气泡时间：>1 小时显示 x时xx分xx秒，否则 xx分xx秒
String _seekBubbleText(double value, int totalMs) {
  final d = Duration(milliseconds: (value * totalMs).round());
  final h = d.inHours;
  final m = d.inMinutes.remainder(60).toString().padLeft(2, '0');
  final s = d.inSeconds.remainder(60).toString().padLeft(2, '0');
  return h > 0 ? '$h时$m分$s秒' : '$m分$s秒';
}

class _ThinProgressBarState extends State<_ThinProgressBar> {
  bool _dragging = false;
  double _dragValue = 0;

  void _start(Offset local, double width) {
    setState(() => _dragging = true);
    widget.onChangeStart(widget.value);
    _update(local, width);
  }

  void _update(Offset local, double width) {
    final v = (local.dx / width).clamp(0.0, 1.0);
    _dragValue = v;
    widget.onChanged(v);
  }

  void _end(double width) {
    setState(() => _dragging = false);
    final v = _dragValue.clamp(0.0, 1.0);
    widget.onChangeEnd(v);
  }

  @override
  Widget build(BuildContext context) {
    return LayoutBuilder(
      builder: (_, constraints) {
        final w = constraints.maxWidth;
        return GestureDetector(
          behavior: HitTestBehavior.opaque,
          onHorizontalDragStart: (d) => _start(d.localPosition, w),
          onHorizontalDragUpdate: (d) => _update(d.localPosition, w),
          onHorizontalDragEnd: (_) => _end(w),
          onTapDown: (d) {
            setState(() => _dragging = true);
            _start(d.localPosition, w);
          },
          onTapUp: (_) => _end(w),
          child: SizedBox(
            height: 32, // 触摸热区 32px（比视觉线条大，提升交互）
            child: Stack(
              clipBehavior: Clip.none,
              alignment: Alignment.bottomCenter,
              children: [
                Align(
                  alignment: Alignment.bottomCenter,
                  child: AnimatedContainer(
                    duration: const Duration(milliseconds: 150),
                    height: _dragging ? 4 : 2,
                    width: double.infinity,
                    child: CustomPaint(
                      painter: _ProgressPainter(
                        value: _dragging ? _dragValue : widget.value,
                        dragging: _dragging,
                      ),
                    ),
                  ),
                ),
                // 拖动中的时间气泡（跟随 thumb，两端自动夹在屏内）
                if (_dragging && widget.totalMs > 0)
                  Positioned(
                    bottom: 14,
                    left: (_dragValue * w - 38)
                        .clamp(0.0, (w - 76).clamp(0.0, w)),
                    child: Container(
                      width: 76,
                      height: 24,
                      alignment: Alignment.center,
                      decoration: BoxDecoration(
                        color: Colors.black.withValues(alpha: 0.82),
                        borderRadius: BorderRadius.circular(6),
                      ),
                      child: Text(
                        _seekBubbleText(_dragValue, widget.totalMs),
                        style: const TextStyle(
                            color: Colors.white, fontSize: 11.5),
                      ),
                    ),
                  ),
              ],
            ),
          ),
        );
      },
    );
  }
}

class _ProgressPainter extends CustomPainter {
  _ProgressPainter({required this.value, required this.dragging});

  final double value;
  final bool dragging;

  @override
  void paint(Canvas canvas, Size size) {
    final w = size.width;
    final h = size.height;
    final y = h / 2;

    // 背景（未播放）
    final bgPaint = Paint()
      ..color = Colors.white.withValues(alpha: 0.2)
      ..strokeWidth = h
      ..strokeCap = StrokeCap.round;
    canvas.drawLine(Offset(0, y), Offset(w, y), bgPaint);

    // 已播放
    final fgPaint = Paint()
      ..color = Colors.white
      ..strokeWidth = h
      ..strokeCap = StrokeCap.round;
    final playedX = (w * value).clamp(0.0, w);
    canvas.drawLine(Offset(0, y), Offset(playedX, y), fgPaint);

    // 拖动时显示 thumb
    if (dragging) {
      final thumbPaint = Paint()
        ..color = Colors.white
        ..style = PaintingStyle.fill;
      canvas.drawCircle(Offset(playedX, y), 6, thumbPaint);
    }
  }

  @override
  bool shouldRepaint(covariant _ProgressPainter oldDelegate) =>
      oldDelegate.value != value || oldDelegate.dragging != dragging;
}