type Echo10XmlBaseGranule = {
  Granule: {
    GranuleUR?: string;
    DataGranule?: {
      ProducerGranuleId?: string;
    }
    [key: string]: unknown;
  };
};

function isEcho10XmlBaseGranule(obj: any): obj is Echo10XmlBaseGranule {
  return typeof obj === 'object' && obj !== null
    && obj.Granule?.GranuleUR !== undefined;
}

/**
 * Updates an ECHO10 metadata XML object with a new GranuleUR and ProducerGranuleId.
 *
 * This function:
 * - Validates that the input is a minimally valid ECHO10 metadata object.
 * - Performs a deep clone to avoid mutating the original input.
 * - Sets the new `GranuleUR` and `ProducerGranuleId` values accordingly.
 *
 * @param params
 * @param params.xml - The parsed XML object (e.g., from xml2js) representing ECHO10 metadata.
 * @param params.granuleUr - The new GranuleUR value to apply to the metadata.
 * @param params.producerGranuleId - The original identifier value to be set as ProducerGranuleId.
 * @param params.excludeDataGranule - Whether to add or update the DataGranule node in the metadata
 * @returns A deep-cloned and updated copy of the original ECHO10 metadata object.
 * @throws If the input object does not conform to the expected ECHO10 structure.
 */
export function updateEcho10XMLGranuleUrAndGranuleIdentifier({
  xml, // The parsed XML object (e.g., from xml2js)
  granuleUr, // The new GranuleUR value
  producerGranuleId, // The original identifier to store
  excludeDataGranule = false, // Whether to add/update the DataGranule node in the metadata
}: {
  xml: unknown;
  granuleUr: string;
  producerGranuleId: string;
  excludeDataGranule?: boolean;
}): any {
  if (!isEcho10XmlBaseGranule(xml)) {
    throw new Error('Invalid XML input - expected an object with GranuleUR');
  }

  const moddedXml = structuredClone(xml);

  moddedXml.Granule ??= {};
  moddedXml.Granule.GranuleUR = granuleUr;

  if (excludeDataGranule === false) {
    moddedXml.Granule.DataGranule ??= {};

    const dataGranule = moddedXml.Granule.DataGranule as any;
    const orderedDataGranule = new Map<string, any>();

    // ECHO10 DataGranule element order as defined in the XSD schema
    // https://git.earthdata.nasa.gov/projects/EMFD/repos/echo-schemas/browse/schemas/10.0/Granule.xsd
    const echo10DataGranuleOrder = [
      'DataGranuleSizeInBytes',
      'SizeMBDataGranule',
      'Checksum',
      'ReprocessingPlanned',
      'ReprocessingActual',
      'ProducerGranuleId',
      'DayNightFlag',
      'ProductionDateTime',
      'LocalVersionId',
      'AdditionalFile',
    ];

    const existingKeys = Object.keys(dataGranule);
    const unexpectedKeys = existingKeys.filter((key) => !echo10DataGranuleOrder.includes(key));

    if (unexpectedKeys.length > 0) {
      throw new Error(
        `Unexpected DataGranule key(s) found: ${unexpectedKeys.join(', ')}. `
        + `Valid keys are: ${echo10DataGranuleOrder.join(', ')}. `
        + `GranuleUR: ${moddedXml.Granule.GranuleUR}`
      );
    }

    echo10DataGranuleOrder.forEach((key) => {
      if (key === 'ProducerGranuleId') {
        orderedDataGranule.set(key, producerGranuleId);
      } else if (dataGranule[key] !== undefined) {
        orderedDataGranule.set(key, dataGranule[key]);
      }
    });

    moddedXml.Granule.DataGranule = orderedDataGranule as any;
  }

  return moddedXml;
}