import { err, ok, type ReadonlyDB } from "@tailor-platform/erp-kit/core";
import type { DB } from "../generated/kysely-tailordb";
import { HolidayCalendarNotFoundError } from "../lib/errors.generated";

export interface GetHolidayCalendarInput {
  id: string;
}

/**
 * Function: getHolidayCalendar
 * Description: Retrieves a single HolidayCalendar by its surrogate id,
 * returning its stable key and display name.
 */
export async function run(db: ReadonlyDB<DB>, input: GetHolidayCalendarInput) {
  const holidayCalendar = await db
    .selectFrom("HolidayCalendar")
    .selectAll()
    .where("id", "=", input.id)
    .executeTakeFirst();

  if (!holidayCalendar) {
    return err(new HolidayCalendarNotFoundError(input.id));
  }

  return ok({ holidayCalendar });
}