import type { Extension, Questionnaire } from 'fhir/r4';

// The old two-state builder wrote initial false for both an untouched yes/no and an authored No, so
// only a Questionnaire saved by the Not set / Yes / No editor (stamped here) can carry an authored No.
export const QUESTIONNAIRE_COMPATIBILITY_URL =
    'https://akashichealthrecords.com/fhir/StructureDefinition/questionnaire-compatibility-version';

export const QUESTIONNAIRE_COMPATIBILITY_VERSION = 1;

export const questionnaireCompatibilityStamp = (): Extension => ({
    url: QUESTIONNAIRE_COMPATIBILITY_URL,
    valueInteger: QUESTIONNAIRE_COMPATIBILITY_VERSION
});

export const isCompatibilityVersioned = (questionnaire?: Pick<Questionnaire, 'extension'> | null): boolean =>
    (questionnaire?.extension ?? []).some((extension: Extension) =>
        extension.url === QUESTIONNAIRE_COMPATIBILITY_URL &&
        typeof extension.valueInteger === 'number' &&
        extension.valueInteger >= QUESTIONNAIRE_COMPATIBILITY_VERSION);

/** A stored boolean initial as Yes (true), No (false) or unset (null); legacy false is unset. */
export const readBooleanInitial = (value: unknown, versioned: boolean): boolean | null => {
    if (value === true) return true;
    if (value === false && versioned) return false;
    return null;
};