[FEATURE] - Implement `no_peer_id` parameter support;

Description

The no_peer_id parameter is mentioned in comments but not implemented. According to BEP 0003, this parameter is used with non-compact peer format to omit peer IDs from the response, reducing response size.

Location

File: lib/src/tracker/http_tracker.dart
Line: 90

Current Code

if (currentTrackerId != null) params['trackerid'] = currentTrackerId!;
// params['no_peer_id']
// params['ip'] ; optional
// params['key'] ; optional
return params;

The parameter is commented out and not implemented.

Expected Behavior

According to BEP 0003:

• no_peer_id: If compact=0, clients can set no_peer_id=1 to omit peer IDs from the response
• When compact=1, this parameter is ignored (peer list is always compact format)
• Used to reduce response size when peer IDs are not needed

Use Cases

• Clients that don't need peer IDs for initial connection
• Reducing bandwidth usage
• Improving response parsing speed

Proposed Implementation

@override
Map<String, String> generateQueryParameters(Map<String, dynamic> options) {
  // ... existing code ...
  
  var compact = options['compact'] as int? ?? 1;
  params['compact'] = compact.toString();
  
  // no_peer_id only makes sense when compact=0
  if (compact == 0) {
    var noPeerId = options['no_peer_id'] as bool? ?? false;
    if (noPeerId) {
      params['no_peer_id'] = '1';
    }
  }
  // If compact=1, no_peer_id is ignored (per BEP 0003)
  
  // ... rest of parameters ...
  return params;
}

Update AnnounceOptionsProvider interface documentation:

abstract class AnnounceOptionsProvider {
  /// Get options for tracker announce request
  /// 
  /// Options map can include:
  /// - 'downloaded', 'uploaded', 'left': int (bytes)
  /// - 'compact': int (0 or 1, default 1)
  /// - 'numwant': int (0-50, default 50)
  /// - 'peerId': String or Uint8List (20 bytes)
  /// - 'port': int (1-65535)
  /// - 'no_peer_id': bool (only used when compact=0, default false)
  /// - 'ip': String or InternetAddress (optional)
  /// - 'key': int or Uint8List (4 bytes, optional)
  Future<Map<String, dynamic>> getOptions(Uri uri, String infoHash);
}

Example usage:

class MyProvider implements AnnounceOptionsProvider {
  @override
  Future<Map<String, dynamic>> getOptions(Uri uri, String infoHash) {
    return Future.value({
      'downloaded': 0,
      'uploaded': 0,
      'left': torrent.length,
      'compact': 0,  // Non-compact format
      'no_peer_id': true,  // ✅ Don't include peer IDs
      'numwant': 50,
      'peerId': peerId,
      'port': port,
    });
  }
}

Impact

• Severity: Low (Feature Enhancement)
• Affected: HTTP tracker requests with compact=0
• Benefits:
  • Full BEP 0003 compliance
  • Reduced response size
  • Optional peer ID omission when not needed
  • Bandwidth optimization

Additional Context

• no_peer_id only applies when compact=0
• Many clients always use compact=1, making this less commonly used
• Still important for full BEP 0003 compliance
• Some trackers may require or prefer this parameter

Related Standards

• BEP 0003: HTTP/HTTPS Tracker Protocol