import 'package:flutter/services.dart';
import 'package:mime/mime.dart';

import '../track_event_manager/device_service.dart';
import 'file_util.dart';

class MediaInfo {
  int? size;
  String? resolution;
  int? videoHeight;
  double? ratio;
  int? playTime;
  String? bitrate;
  String? mimeType;
}

const _channel = MethodChannel(DeviceInfoService.naticeChannel);

/// 获取本地视频的元信息（高度/分辨率/比例/时长/比特率/大小/MIME）
Future<MediaInfo?> getMediaInfo(String localPath) async {
  if (!FileUtil.isFileExist(localPath)) return null;
  final info = MediaInfo();
  info.videoHeight = int.tryParse(await _invokeChannel("getVideoHeight", localPath, "")) ?? 0;
  info.resolution = await _invokeChannel("getVideoResolution", localPath, "");
  info.ratio = double.tryParse(await _invokeChannel("getVideoRatio", localPath, "")) ?? 0;
  info.playTime = await _invokeChannel("getVideoDuration", localPath, 0);
  info.bitrate = await _invokeChannel("getVideoBitrate", localPath, "");
  info.size = FileUtil.getFileSize(localPath);
  info.mimeType = _getMimeType(localPath);
  return info;
}

/// 统一调用原生方法，异常或类型不符时返回 fallback
/// 注：不能只 catch PlatformException——原生 notImplemented / 没实现该 channel(iOS 就没实现这几个)
/// 抛的是 MissingPluginException，不是 PlatformException，只兜前者等于没兜
Future<T> _invokeChannel<T>(String method, String localPath, T fallback) async {
  try {
    final result = await _channel.invokeMethod(method, {'filePath': localPath});
    return result is T ? result : fallback;
  } catch (_) {
    return fallback;
  }
}

/// 获取 MIME 类型，识别不到返回空串
String _getMimeType(String localPath) => lookupMimeType(localPath) ?? '';