import useSWR from "swr";
import { Medication, MedicationFormulationsResponse } from "../types";
import { fhirBaseUrl, openmrsFetch } from "@openmrs/esm-framework";
import {
  getConceptCodingUuid,
  getMedicationsByConceptEndpoint,
} from "../utils";

/**
 * Given a Medication Reference, fetches that Medication and returns the codeable concept associated with it
 * Note: returns null if existingMedicationCodeableConcept already defined
 *
 * @param existingMedicationCodeableConceptUuid
 * @param medicationReference
 */
export function useMedicationCodeableConcept(
  existingMedicationCodeableConceptUuid: string,
  medicationReference: string
) {
  const { data } = useSWR<{ data: Medication }, Error>(
    existingMedicationCodeableConceptUuid || !medicationReference
      ? null
      : `${fhirBaseUrl}/${medicationReference}`,
    openmrsFetch
  );

  return {
    medicationCodeableConceptUuid: data
      ? getConceptCodingUuid(data.data.code.coding)
      : null,
  };
}

/**
 * Given a concept uuid, returns all Medications associated with that concept
 *
 * @param medicationCodeableConcept
 */
export function useMedicationFormulations(medicationCodeableConcept: string) {
  const { data } = useSWR<{ data: MedicationFormulationsResponse }, Error>(
    medicationCodeableConcept
      ? getMedicationsByConceptEndpoint(medicationCodeableConcept)
      : null, // note that we don't start the search until we've confirmed we have a uuid to search for
    openmrsFetch
  );

  if (data) {
    return {
      medicationFormulations: data.data.entry.map((e) => e.resource),
    };
  } else {
    return {};
  }
}