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

export interface CreateHolidayCalendarInput {
  key: string;
  name: string;
}

/**
 * Function: createHolidayCalendar
 * Description: Registers a new HolidayCalendar — a stable key and a display
 * name — that CompanyHoliday entries and WorkRules bind to. The key is unique
 * across calendars; registering a second calendar with an existing key is
 * rejected.
 */
export async function run(
  db: Transaction,
  input: CreateHolidayCalendarInput,
  _ctx: CommandContext,
) {
  const existing = await db
    .selectFrom("HolidayCalendar")
    .selectAll()
    .where("key", "=", input.key)
    .forUpdate()
    .executeTakeFirst();
  if (existing) {
    return err(new DuplicateCalendarKeyError(input.key));
  }

  const holidayCalendar = await db
    .insertInto("HolidayCalendar")
    .values({ key: input.key, name: input.name })
    .returningAll()
    .executeTakeFirstOrThrow();

  return ok({ holidayCalendar });
}