app-starlock/lib/main/lockDetail/videoLog/widget/video_thumbnail_image.dart

import 'dart:io';

import 'package:flutter/material.dart';
import 'package:flutter/widgets.dart';
import 'package:flutter_screenutil/flutter_screenutil.dart';
import 'package:path_provider/path_provider.dart';
import 'package:video_thumbnail/video_thumbnail.dart';

class VideoThumbnailImage extends StatefulWidget {
  final String videoUrl;

  const VideoThumbnailImage({Key? key, required this.videoUrl})
      : super(key: key);

  @override
  _VideoThumbnailState createState() => _VideoThumbnailState();
}

class _VideoThumbnailState extends State<VideoThumbnailImage> {
  // ✅ 使用 static 缓存：所有实例共享，避免重复请求
  static final Map<String, Future<String?>> _pendingThumbnails = {};

  late Future<String?> _thumbnailFuture;

  @override
  void initState() {
    super.initState();
    // ✅ 如果已存在该 URL 的 Future，复用；否则创建并缓存
    _thumbnailFuture = _pendingThumbnails.putIfAbsent(widget.videoUrl, () {
      return _generateThumbnail(widget.videoUrl);
    });
  }

  // 生成缩略图（只执行一次 per URL）
  Future<String?> _generateThumbnail(String url) async {
    try {
      final tempDir = await getTemporaryDirectory();
      final thumbnail = await VideoThumbnail.thumbnailFile(
        video: url,
        thumbnailPath: tempDir.path,
        imageFormat: ImageFormat.JPEG,
        maxHeight: 200,
        quality: 100,
      );
      return thumbnail;
    } catch (e) {
      print('Failed to generate thumbnail: $e');
      return null;
    }
  }

  @override
  Widget build(BuildContext context) {
    return FutureBuilder<String?>(
      future: _thumbnailFuture,
      builder: (context, snapshot) {
        if (snapshot.connectionState == ConnectionState.waiting) {
          return Center(child: CircularProgressIndicator());
        } else if (snapshot.hasError || !snapshot.hasData) {
          return Center(
            child: Image.asset(
              'images/icon_unHaveData.png',
              fit: BoxFit.cover,
            ),
          );
        } else {
          return Stack(
            alignment: Alignment.center,
            children: <Widget>[
              RotatedBox(
                quarterTurns: -1,
                child: Image.file(
                  File(snapshot.data!),
                  width: 200,
                  height: 200,
                  fit: BoxFit.cover,
                ),
              ),
              Icon(
                Icons.play_arrow_rounded,
                size: 88.sp,
                color: Colors.white.withOpacity(0.8),
              ),
            ],
          );
        }
      },
    );
  }
}