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

export interface DeleteHolidayCalendarInput {
  id: string;
}

/**
 * Function: deleteHolidayCalendar
 * Description: Deletes a HolidayCalendar. Rejected when the calendar is still
 * referenced by any CompanyHoliday entry or WorkRule, so a calendar in use is
 * never orphaned.
 */
export async function run(
  db: Transaction,
  input: DeleteHolidayCalendarInput,
  _ctx: CommandContext,
) {
  const holidayCalendar = await db
    .selectFrom("HolidayCalendar")
    .selectAll()
    .where("id", "=", input.id)
    .forUpdate()
    .executeTakeFirst();
  if (!holidayCalendar) {
    return err(new HolidayCalendarNotFoundError(input.id));
  }

  const referencingHoliday = await db
    .selectFrom("CompanyHoliday")
    .select("id")
    .where("calendarId", "=", input.id)
    .executeTakeFirst();
  const referencingWorkRule = await db
    .selectFrom("WorkRule")
    .select("id")
    .where("holidayCalendarId", "=", input.id)
    .executeTakeFirst();
  if (referencingHoliday || referencingWorkRule) {
    return err(new CalendarInUseError(input.id));
  }

  await db.deleteFrom("HolidayCalendar").where("id", "=", input.id).execute();

  return ok({ id: input.id });
}