import 'dart:convert';

import 'text_message_format.dart';

/// Writes ASP.NET Core SignalR JSON hub messages.
class SignalrProtocol {
  static String handshakeRequest() =>
      TextMessageFormat.write(jsonEncode(<String, dynamic>{
        'protocol': 'json',
        'version': 1,
      }));

  static String handshakeResponse({String? error}) =>
      TextMessageFormat.write(jsonEncode(<String, dynamic>{
        if (error != null) 'error': error,
      }));

  static String invocation({
    required String target,
    required List<Object?> arguments,
    String? invocationId,
  }) {
    return TextMessageFormat.write(jsonEncode(<String, dynamic>{
      'type': 1,
      'target': target,
      'arguments': arguments,
      if (invocationId != null) 'invocationId': invocationId,
    }));
  }

  static String ping() => TextMessageFormat.write(jsonEncode(<String, dynamic>{
        'type': 6,
      }));

  static String close({String? error}) =>
      TextMessageFormat.write(jsonEncode(<String, dynamic>{
        'type': 7,
        if (error != null) 'error': error,
      }));
}