import type { Reference } from 'fhir/r4';
import type { IValueSet } from '../../services';

/**
 * Immunization.manufacturer is a Reference in R4, not a CodeableConcept, so a maker chosen from
 * CDC's MVX list cannot be stored the way every other picker on the form stores its choice. The
 * code rides in manufacturer.identifier with the MVX system, and the display beside it.
 *
 * A reference that arrived from elsewhere - an Organization resource, say - carries no MVX
 * identifier and is passed through untouched in both directions, so editing a record never
 * discards a maker this form did not choose.
 */
export const MVX_SYSTEM = 'http://hl7.org/fhir/sid/mvx';

export const toManufacturerReference = (value: IValueSet | Reference | null | undefined): Reference | undefined => {
    if (!value) return undefined;
    if ('code' in value && value.code) {
        return {
            identifier: { system: value.system || MVX_SYSTEM, value: value.code },
            ...(value.display ? { display: value.display } : {}),
        };
    }
    if ('reference' in value && value.reference) return value as Reference;
    return undefined;
};

export const fromManufacturerReference = (reference: Reference | undefined): IValueSet | Reference | null => {
    if (!reference) return null;
    const code = reference.identifier?.value;
    if (code) {
        return {
            system: reference.identifier?.system || MVX_SYSTEM,
            code,
            display: reference.display || code,
        };
    }
    return reference;
};