import 'package:flutter_inappwebview/flutter_inappwebview.dart';

abstract class ILinkExtractionService {
  Future<String?> extractVideoUrl(String pageUrl);
}

class LinkExtractionService implements ILinkExtractionService {
  HeadlessInAppWebView? _headlessWebView;

  @override
  Future<String?> extractVideoUrl(String pageUrl) async {
    // 1. Check if it's already a video link
    if (_isVideoUrl(pageUrl)) return pageUrl;

    // 2. Use Headless WebView to find the video
    String? foundUrl;
    
    _headlessWebView = HeadlessInAppWebView(
      initialUrlRequest: URLRequest(url: WebUri(pageUrl)),
      onLoadResource: (controller, resource) {
        final url = resource.url.toString();
        if (_isVideoUrl(url)) {
          foundUrl = url;
          _headlessWebView?.dispose();
        }
      },
    );

    await _headlessWebView?.run();
    
    // Wait for some time to catch resources
    await Future.delayed(const Duration(seconds: 5));
    
    return foundUrl;
  }

  bool _isVideoUrl(String url) {
    final lower = url.toLowerCase();
    return lower.contains('.m3u8') || 
           lower.contains('.mp4') || 
           lower.contains('.mkv');
  }
}