import '../protocol/runtime_protocol.dart';

class RuntimeCommand {
  const RuntimeCommand({
    required this.type,
    this.target,
    this.payload = const {},
  });

  final String type;
  final String? target;
  final Map<String, Object?> payload;

  static RuntimeCommand fromMap(Map<String, Object?> map) {
    final type = map[RuntimeProtocolField.type];
    if (type is! String || type.isEmpty) {
      throw const FormatException('RuntimeCommand.type must be a string');
    }

    if (!RuntimeCommandType.isSupported(type)) {
      throw FormatException('RuntimeCommand.type is unsupported: $type');
    }
    RuntimeProtocolSchema.ensureKnownKeys(
      map,
      allowed: RuntimeProtocolSchema.allowedCommandFields(type),
      context: 'RuntimeCommand.$type',
    );

    final targetValue = map[RuntimeProtocolField.target];
    if (targetValue != null && targetValue is! String) {
      throw const FormatException('RuntimeCommand.target must be a string');
    }

    final payload = Map<String, Object?>.from(map)
      ..remove(RuntimeProtocolField.type)
      ..remove(RuntimeProtocolField.target);
    return RuntimeCommand(
      type: type,
      target: targetValue as String?,
      payload: payload,
    );
  }
}