parse method

Implementation

@override
Future<bool> parse(
  Socket socket,
  Uri uri,
  Map<String, String> headers,
) async {
  try {
    DownloadTask task = DownloadTask(
      uri: uri,
      hlsKey: uri.generateMd5,
      headers: headers,
    );
    HlsSegment? hlsSegment = findSegmentByUri(uri);
    if (hlsSegment != null) task.hlsKey = hlsSegment.key;
    Uint8List? data = await cache(task);
    // if the task has been added, wait for the download to complete
    bool exitUri = VideoProxy.downloadManager.isUrlExit(task.url);
    if (exitUri) {
      while (data == null) {
        await Future.delayed(const Duration(milliseconds: 100));
        data = await cache(task);
      }
    }
    if (data == null) {
      concurrentLoop(hlsSegment, headers);
      task.priority += 10;
      data = await download(task);
    }
    if (data == null) return false;
    String contentType = 'application/octet-stream';
    if (VideoProxy.urlMatcherImpl.matchM3u8(task.uri)) {
      // Parse and rewrite M3U8 playlist lines for local proxying
      List<String> lines = readLineFromUint8List(data);
      String lastLine = '';
      StringBuffer buffer = StringBuffer();
      for (String line in lines) {
        String hlsLine = line.trim();
        String? parseUri;
        if (hlsLine.startsWith("#EXT-X-KEY") ||
            hlsLine.startsWith("#EXT-X-MEDIA")) {
          Match? match = RegExp(r'URI="([^"]+)"').firstMatch(hlsLine);
          if (match != null && match.groupCount >= 1) {
            parseUri = match.group(1);
            if (parseUri != null) {
              String newUri = parseUri.startsWith('http')
                  ? parseUri.toLocalUrl()
                  : '$parseUri${parseUri.contains('?') ? '&' : '?'}'
                      'origin=${base64Url.encode(utf8.encode(uri.origin))}';
              line = hlsLine.replaceAll(parseUri, newUri);
            }
          }
        }
        if (lastLine.startsWith("#EXTINF") ||
            lastLine.startsWith("#EXT-X-BYTERANGE") ||
            lastLine.startsWith("#EXT-X-STREAM-INF")) {
          if (!line.startsWith("#EXT")) {
            line = line.toSafeUrl();
            line = line.startsWith('http')
                ? line.toLocalUrl()
                : '$line${line.contains('?') ? '&' : '?'}'
                    'origin=${base64Url.encode(utf8.encode(uri.origin))}';
          }
        }
        // Add HLS segment to download list
        if (hlsLine.startsWith("#EXT-X-KEY") ||
            hlsLine.startsWith("#EXT-X-MEDIA")) {
          if (parseUri != null) {
            if (!parseUri.startsWith('http')) {
              int relativePath = 0;
              while (hlsLine.startsWith("../")) {
                hlsLine = hlsLine.substring(3);
                relativePath++;
              }
              parseUri = '${uri.pathPrefix(relativePath)}/' + parseUri;
            }
            concurrentAdd(
              HlsSegment(url: parseUri, key: task.hlsKey!),
              headers,
            );
          }
        }
        if (lastLine.startsWith("#EXTINF") ||
            lastLine.startsWith("#EXT-X-BYTERANGE") ||
            lastLine.startsWith("#EXT-X-STREAM-INF")) {
          if (!line.startsWith("#EXT")) {
            if (!hlsLine.startsWith('http')) {
              int relativePath = 0;
              // when hlsLine is relative path
              while (hlsLine.startsWith("../")) {
                hlsLine = hlsLine.substring(3);
                relativePath++;
              }
              // when hlsLine start with /, and prefix contain hlsLine
              String prefix = '${uri.pathPrefix(relativePath)}/';
              if (hlsLine.startsWith("/")) {
                List<String> split = hlsLine.split("/");
                List<String> result = [];
                for (var item in split) {
                  if (prefix.contains(item)) continue;
                  result.add(item);
                }
                hlsLine = result.join("/");
              }
              hlsLine = prefix + hlsLine;
            }
            concurrentAdd(
              HlsSegment(url: hlsLine, key: task.hlsKey!),
              headers,
            );
          }
        }
        buffer.write('$line\r\n');
        lastLine = line;
      }
      data = Uint8List.fromList(buffer.toString().codeUnits);
      contentType = 'application/vnd.apple.mpegurl';
    } else if (VideoProxy.urlMatcherImpl.matchM3u8Key(task.uri)) {
      contentType = 'application/octet-stream';
    } else if (VideoProxy.urlMatcherImpl.matchM3u8Segment(task.uri)) {
      contentType = 'video/MP2T';
    }
    String responseHeaders = <String>[
      'HTTP/1.1 200 OK',
      'Content-Type: $contentType',
      'Connection: keep-alive',
      if (contentType == 'video/MP2T') 'Accept-Ranges: bytes',
    ].join('\r\n');
    await socket.append(responseHeaders);
    await socket.append(data);
    await socket.flush();
    logD('Return request data: $uri');
    return true;
  } catch (e) {
    logW('[UrlParserM3U8] ⚠ ⚠ ⚠ parse socket close: $e');
    return false;
  } finally {
    await socket.close();
    logD('Connection closed\n');
  }
}