// lib/pages/player_page.dart
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import '../services/audio_service.dart';

class PlayerPage extends StatefulWidget {
  const PlayerPage({super.key});

  @override
  State<PlayerPage> createState() => _PlayerPageState();
}

class _PlayerPageState extends State<PlayerPage> {
  double? _dragProgress; // 拖动时的临时进度

  String _formatDuration(Duration d) {
    if (d.inMilliseconds < 0) return '00:00';
    final minutes = d.inMinutes;
    final seconds = d.inSeconds % 60;
    return '${minutes.toString().padLeft(2, '0')}:${seconds.toString().padLeft(2, '0')}';
  }

  @override
  Widget build(BuildContext context) {
    final service = context.watch<AudioService>();
    final song = service.currentSong;

    if (song == null) {
      return Scaffold(
        backgroundColor: const Color(0xFF0E1211),
        body: const Center(
          child: Text(
            '没有正在播放的歌曲',
            style: TextStyle(color: Colors.grey),
          ),
        ),
      );
    }

    final isPlaying = service.isPlaying;
    final position = service.position;
    final duration = service.duration;
    final bufferedPosition = service.bufferedPosition;

    final progress = duration.inMilliseconds > 0
        ? position.inMilliseconds / duration.inMilliseconds
        : 0.0;

    final bufferProgress = duration.inMilliseconds > 0
        ? (bufferedPosition.inMilliseconds / duration.inMilliseconds)
            .clamp(0.0, 1.0)
        : 0.0;

    // 拖动时显示拖动的进度，否则显示实际播放进度
    final displayProgress = _dragProgress ?? progress;

    return Scaffold(
      backgroundColor: const Color(0xFF0E1211),
      appBar: AppBar(
        backgroundColor: Colors.transparent,
        elevation: 0,
        leading: IconButton(
          icon: const Icon(Icons.arrow_back_ios_new, color: Colors.white),
          onPressed: () => Navigator.pop(context),
        ),
        title: const Text(
          '正在播放',
          style: TextStyle(
            color: Colors.white,
            fontSize: 16,
            fontWeight: FontWeight.w400,
          ),
        ),
        centerTitle: true,
        actions: [
          IconButton(
            icon: const Icon(Icons.more_vert, color: Colors.white54),
            onPressed: () {},
          ),
        ],
      ),
      body: Padding(
        padding: const EdgeInsets.symmetric(horizontal: 24),
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            // ---- 封面占位 ----
            Container(
              width: 240,
              height: 240,
              decoration: BoxDecoration(
                shape: BoxShape.circle,
                color: const Color(0xFF2A3332),
                boxShadow: [
                  BoxShadow(
                    color: const Color(0xFF7C9A9E).withOpacity(0.15),
                    blurRadius: 60,
                    spreadRadius: 10,
                  ),
                ],
              ),
              child: const Icon(
                Icons.music_note,
                size: 64,
                color: Colors.white24,
              ),
            ),
            const SizedBox(height: 48),

            // ---- 歌曲信息 ----
            Column(
              crossAxisAlignment: CrossAxisAlignment.center,
              children: [
                Text(
                  song.title,
                  style: const TextStyle(
                    fontSize: 20,
                    fontWeight: FontWeight.w600,
                    color: Colors.white,
                  ),
                  textAlign: TextAlign.center,
                  maxLines: 2,
                  overflow: TextOverflow.ellipsis,
                ),
                const SizedBox(height: 8),
                Text(
                  song.artist,
                  style: TextStyle(
                    fontSize: 15,
                    color: Colors.grey[400],
                  ),
                  textAlign: TextAlign.center,
                  maxLines: 1,
                  overflow: TextOverflow.ellipsis,
                ),
              ],
            ),
            const SizedBox(height: 40),

// ---- 双层进度条（视觉与交互分离） ----
            Column(
              children: [
                SizedBox(
                  height: 20,
                  child: LayoutBuilder(
                    builder: (context, constraints) {
                      final width = constraints.maxWidth;

                      final bufferWidth =
                          width * bufferProgress.clamp(0.0, 1.0);
                      final progressWidth = width * progress.clamp(0.0, 1.0);

                      return Stack(
                        alignment: Alignment.centerLeft,
                        children: [
                          // ① 底层：整首歌曲（暗灰色）
                          Container(
                            width: width,
                            height: 4,
                            decoration: BoxDecoration(
                              color: Colors.grey[800],
                              borderRadius: BorderRadius.circular(2),
                            ),
                          ),

                          // ② 缓冲层（深青色）
                          Container(
                            width: bufferWidth,
                            height: 4,
                            decoration: BoxDecoration(
                              color: const Color(0xFF4A7A7A),
                              borderRadius: BorderRadius.circular(2),
                            ),
                          ),

                          // ③ 播放进度层（亮青色）
                          Container(
                            width: progressWidth,
                            height: 4,
                            decoration: BoxDecoration(
                              color: const Color(0xFFB8D4D0),
                              borderRadius: BorderRadius.circular(2),
                            ),
                          ),

                          // ④ 交互层（只负责手势，不显示任何轨道）
                          Positioned.fill(
                            child: SliderTheme(
                              data: SliderTheme.of(context).copyWith(
                                trackHeight: 0,
                                activeTrackColor: Colors.transparent,
                                inactiveTrackColor: Colors.transparent,
                                thumbColor: Colors.transparent, // ✅ 完全隐藏小球
                                overlayColor: Colors.transparent,
                                thumbShape: const RoundSliderThumbShape(
                                  enabledThumbRadius: 0,
                                ),
                              ),
                              child: Slider(
                                value: progress.clamp(0.0, 1.0),
                                min: 0.0,
                                max: 1.0,
                                onChanged: (value) {
                                  // 拖动时只更新本地状态，不触发 seek
                                  setState(() {
                                    _dragProgress = value;
                                  });
                                },
                                onChangeEnd: (value) {
                                  final newPosition = Duration(
                                    milliseconds:
                                        (value * duration.inMilliseconds)
                                            .round(),
                                  );
                                  service.seekTo(newPosition);
                                  setState(() {
                                    _dragProgress = null;
                                  });
                                },
                              ),
                            ),
                          ),
                        ],
                      );
                    },
                  ),
                ),
                // 时间显示
                Row(
                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
                  children: [
                    Text(
                      _formatDuration(position),
                      style: TextStyle(
                        fontSize: 12,
                        color: Colors.grey[500],
                      ),
                    ),
                    Text(
                      _formatDuration(duration),
                      style: TextStyle(
                        fontSize: 12,
                        color: Colors.grey[500],
                      ),
                    ),
                  ],
                ),
              ],
            ),
            const SizedBox(height: 32),

            // ---- 播放控制 ----
            Row(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                IconButton(
                  onPressed: () {},
                  icon: const Icon(Icons.skip_previous, size: 28),
                  color: Colors.white60,
                  padding: const EdgeInsets.all(12),
                ),
                const SizedBox(width: 20),
                Container(
                  width: 56,
                  height: 56,
                  decoration: BoxDecoration(
                    color: const Color(0xFFB8D4D0),
                    shape: BoxShape.circle,
                  ),
                  child: IconButton(
                    icon: Icon(
                      isPlaying ? Icons.pause : Icons.play_arrow,
                      color: Colors.black87,
                      size: 28,
                    ),
                    padding: EdgeInsets.zero,
                    onPressed: () {
                      service.togglePlay();
                    },
                  ),
                ),
                const SizedBox(width: 20),
                IconButton(
                  onPressed: () {},
                  icon: const Icon(Icons.skip_next, size: 28),
                  color: Colors.white60,
                  padding: const EdgeInsets.all(12),
                ),
              ],
            ),
            const SizedBox(height: 16),
          ],
        ),
      ),
    );
  }
}