import 'package:flutter/material.dart';
import 'package:hgdj/assets_tool/images.dart';
import 'package:hgdj/hj_model/video_model.dart';
import 'package:hgdj/hj_utils/const.dart';
import 'package:hgdj/hj_utils/screen.dart';
import 'package:hgdj/tools_base/video_download/media_download_manager.dart';

/// 视频下载按钮，短视频 / 长视频 / 短剧 / 动漫共用。
/// 只管画状态和转发点击；权限、扣次、落记录、进度回调全在 [MediaDownloadManager]
class DownloadButton extends StatefulWidget {
  final VideoModel? video;

  /// true 竖排(短视频那套图标)，false 横排(长视频)，只影响外观
  final bool isShort;

  /// 缓存记录落哪个桶。不传时按 [isShort] 推断（短视频 / 影视 / 动漫）；
  /// 短剧在操作台里排版同短视频，但要单独归类，所以显式传 [MediaStyle.Drama]
  final MediaStyle? style;

  const DownloadButton(
      {super.key, this.video, this.isShort = true, this.style});

  @override
  State<DownloadButton> createState() => _DownloadButtonState();
}

class _DownloadButtonState extends State<DownloadButton> {
  late DownloadTask _task;

  /// 免费下载一套图标，短视频/长视频各一套
  String get _icon => (widget.video?.isFreeDownload == true
          ? "download_free.png"
          : widget.isShort
              ? "download_short.png"
              : "download.png")
      .videoPath;

  /// 保存到缓存库时的媒体类型
  MediaStyle get _mediaStyle {
    final style = widget.style;
    if (style != null) return style;
    if (widget.isShort) return MediaStyle.ShortVideo;
    return widget.video?.videoType == 1 ? MediaStyle.Cartoon : MediaStyle.Video;
  }

  @override
  void initState() {
    super.initState();
    _task = MediaDownloadManager.instance
        .attach(video: widget.video, style: _mediaStyle, onChanged: _refresh);
  }

  @override
  void didUpdateWidget(covariant DownloadButton oldWidget) {
    super.didUpdateWidget(oldWidget);
    //列表/PageView 复用 State 时会换 model，会话得跟着换：不换的话按钮画的是上一条的状态，
    //点下载下的也是上一条。同一个对象(父级只是重建)就别白折腾
    if (identical(oldWidget.video, widget.video)) return;
    _task.detach();
    _task = MediaDownloadManager.instance
        .attach(video: widget.video, style: _mediaStyle, onChanged: _refresh);
  }

  @override
  void dispose() {
    _task.detach();
    super.dispose();
  }

  /// 本按钮在短视频列表里随滑动大量创建/销毁，下载回调由单例持有、dispose 后仍可能被调到，统一判 mounted
  void _refresh() {
    if (mounted) setState(() {});
  }

  @override
  Widget build(BuildContext context) {
    final isShort = widget.isShort;
    final icon = SizedBox(
      width: isShort ? 30 : 24,
      height: isShort ? 30 : 24,
      child: Image.asset(_icon),
    );
    final label = Text(
      _task.state.desc,
      style: isShort
          ? const TextStyle(
              color: Color(0xffdcdcdc),
              fontSize: 12,
              fontWeight: FontWeight.w500)
          : const TextStyle(color: Color(0xff989898), fontSize: 12),
    );
    return InkWell(
      enableFeedback: false,
      onTap: _task.start,
      child: isShort
          ? Column(mainAxisSize: MainAxisSize.min, children: [icon, label])
          : Row(
              mainAxisSize: MainAxisSize.min,
              children: [icon, 2.sizeBoxW, label]),
    );
  }
}