import type { FieldRecords, MRZFormat } from '../types.ts';

export function getDocumentNumber(format: MRZFormat, fields: FieldRecords) {
  switch (format) {
    case 'TD1':
    case 'TD2':
    case 'TD3':
    case 'FRENCH_DRIVING_LICENSE':
      return buildDocumentNumber(fields.documentNumber);
    case 'FRENCH_NATIONAL_ID':
      return buildDocumentNumber(
        fields.issueDate,
        fields.administrativeCode2,
        fields.documentNumber,
      );
    case 'SWISS_DRIVING_LICENSE':
      return buildDocumentNumber(fields.pinCode, fields.versionNumber);
    default:
      assertUnreachableFormat(format);
  }
}

function buildDocumentNumber(
  ...parts: Array<string | null | undefined>
): string | null {
  let result = '';
  for (const part of parts) {
    if (!part) {
      return null;
    }
    result += part;
  }
  return result;
}

function assertUnreachableFormat(format: never): never {
  // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
  throw new Error(`unrecognized format: ${format}`);
}