encode method

Uint8List encode(dynamic registry)

Implementation

Uint8List encode(dynamic registry) {
  if (customSignedExtensions.isNotEmpty && registry is! Registry) {
    throw Exception(
        'Custom signed extensions are not supported on this registry. Please use registry from `runtimeMetadata.chainInfo.scaleCodec.registry`.');
  }
  final ByteOutput tempOutput = ByteOutput();

  tempOutput.write(method);

  final ByteOutput output = ByteOutput();

  late final SignedExtensions signedExtensions;
  if (usesChargeAssetTxPayment(registry)) {
    signedExtensions = SignedExtensions.assetHubSignedExtensions;
  } else {
    signedExtensions = SignedExtensions.substrateSignedExtensions;
  }

  final encodedMap = toEncodedMap(registry);

  late List<String> signedExtensionKeys;

  //
  //
  // Do the keys preparation of signedExtensions
  {
    if (registry.getSignedExtensionTypes() is Map) {
      // Usage here for the Registry from the polkadart_scale_codec
      signedExtensionKeys =
          (registry.getSignedExtensionTypes() as Map<String, Codec<dynamic>>)
              .keys
              .toList();
    } else {
      // Usage here for the generated lib from the polkadart_cli
      signedExtensionKeys =
          (registry.getSignedExtensionTypes() as List<dynamic>)
              .cast<String>();
    }
  }

  //
  // Traverse through the signedExtension keys and encode the payload
  for (final extension in signedExtensionKeys) {
    final (payload, found) =
        signedExtensions.signedExtension(extension, encodedMap);
    if (found) {
      if (payload.isNotEmpty) {
        tempOutput.write(hex.decode(payload));
      }
    } else {
      if (registry.getSignedExtensionTypes() is List) {
        // This method call is from polkadot cli and not from the Reigstry of the polkadart_scale_codec.
        continue;
      }
      // Most probably, it is a custom signed extension.
      // check if this signed extension is NullCodec or not!
      final signedExtensionMap = registry.getSignedExtensionTypes();
      if (signedExtensionMap[extension] != null &&
          signedExtensionMap[extension] is! NullCodec &&
          signedExtensionMap[extension].hashCode !=
              NullCodec.codec.hashCode) {
        if (customSignedExtensions.containsKey(extension) == false) {
          // throw exception as this is encodable key and we need this key to be present in customSignedExtensions
          throw Exception(
              'Key `$extension` is missing in customSignedExtensions.');
        }
        signedExtensionMap[extension]
            .encodeTo(customSignedExtensions[extension], tempOutput);
      }
    }
  }

  late List<String> additionalSignedExtensionKeys;
  {
    //
    // Do the keys preparation of signedExtensions
    if (registry.getSignedExtensionTypes() is Map) {
      // Usage here for the Registry from the polkadart_scale_codec
      additionalSignedExtensionKeys =
          (registry.getAdditionalSignedExtensionTypes()
                  as Map<String, Codec<dynamic>>)
              .keys
              .toList();
    } else {
      // Usage here for the generated lib from the polkadart_cli
      additionalSignedExtensionKeys =
          (registry.getSignedExtensionExtra() as List<dynamic>)
              .cast<String>();
    }
  }

  //
  // Traverse through the additionalSignedExtension keys and encode the payload
  for (final extension in additionalSignedExtensionKeys) {
    final (payload, found) =
        signedExtensions.additionalSignedExtension(extension, encodedMap);
    if (found) {
      if (payload.isNotEmpty) {
        tempOutput.write(hex.decode(payload));
      }
    } else {
      // Most probably, it is a custom signed extension.
      // check if this signed extension is NullCodec or not!
      if (registry.getSignedExtensionTypes() is List) {
        // This method call is from polkadot cli and not from the Reigstry of the polkadart_scale_codec.
        continue;
      }
      final additionalSignedExtensionMap =
          registry.getAdditionalSignedExtensionTypes();
      if (additionalSignedExtensionMap[extension] != null &&
          additionalSignedExtensionMap[extension] is! NullCodec &&
          additionalSignedExtensionMap[extension].hashCode !=
              NullCodec.codec.hashCode) {
        if (customSignedExtensions.containsKey(extension) == false) {
          // throw exception as this is encodable key and we need this key to be present in customSignedExtensions
          throw Exception(
              'Key `$extension` is missing in customSignedExtensions.');
        }
        additionalSignedExtensionMap[extension]
            .encodeTo(customSignedExtensions[extension], tempOutput);
      }
    }
  }

  output.write(tempOutput.toBytes());
  final payloadEncoded = output.toBytes();

  // See rust code: https://github.com/paritytech/polkadot-sdk/blob/e349fc9ef8354eea1bafc1040c20d6fe3189e1ec/substrate/primitives/runtime/src/generic/unchecked_extrinsic.rs#L253
  return payloadEncoded.length > 256
      ? Blake2bHasher(32).hash(payloadEncoded)
      : payloadEncoded;
}