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

export interface DeleteTimeEntryCodeInput {
  id: string;
}

/**
 * Function: deleteTimeEntryCode
 * Description: Removes a TimeEntryCode only when it is referenced by no
 * WorkRule premium-category pin, preserving historical calculated results whose
 * traceability depends on the code's key. (EligibilityRule no longer grants
 * TimeEntryCodes — the TIME_ENTRY_CODE grant kind was dropped in #39 — so
 * there is no eligibility reference to check.)
 */
export async function run(db: Transaction, input: DeleteTimeEntryCodeInput, _ctx: CommandContext) {
  const timeEntryCode = await db
    .selectFrom("TimeEntryCode")
    .selectAll()
    .where("id", "=", input.id)
    .forUpdate()
    .executeTakeFirst();
  if (!timeEntryCode) {
    return err(new TimeEntryCodeNotFoundError(input.id));
  }

  const workRules = await db.selectFrom("WorkRule").selectAll().execute();
  const referencedByWorkRule = workRules.some((workRule) =>
    (workRule.premiumRatePercent ?? []).some((rate) => rate.key === timeEntryCode.key),
  );
  if (referencedByWorkRule) {
    return err(new TimeEntryCodeInUseError(input.id));
  }

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

  return ok({});
}