import type { Identifier, Patient } from "fhir/r4";

const MR_TYPE_CODE = "MR";
const IMPORT_SOURCE_ID_SYSTEM = /\/fhir\/import\/[^/]+\/source-id$/;

// Only an identifier typed MR is a medical record number; any other one (an SSN, an import's
// old-system id) shown under that label would misname it, and an SSN would be exposed in full.
export const getMedicalRecordNumber = (patient: Patient): string =>
  (patient.identifier ?? []).find((identifier: Identifier) =>
    identifier.type?.coding?.some((coding) => coding.code === MR_TYPE_CODE),
  )?.value ?? "";

export const getImportSourceId = (patient: Patient): string =>
  (patient.identifier ?? []).find((identifier: Identifier) =>
    IMPORT_SOURCE_ID_SYSTEM.test(identifier.system ?? ""),
  )?.value ?? "";