import {
  ok,
  type ReadonlyDB,
  type PaginationInput,
  buildPaginatedResult,
  DEFAULT_PAGE_SIZE,
} from "@tailor-platform/erp-kit/core";
import type { DB } from "../generated/kysely-tailordb";

type ShiftPatternOrderByField = "code" | "name" | "kind" | "createdAt";

export type ListShiftPatternsInput = PaginationInput<ShiftPatternOrderByField>;

/**
 * Function: listShiftPatterns
 * Returns a paginated, unfiltered list of all reusable ShiftPatterns, for
 * pattern-picker UIs and administrative pattern management screens.
 */
export async function run(db: ReadonlyDB<DB>, input: ListShiftPatternsInput) {
  const limit = input.limit ?? DEFAULT_PAGE_SIZE;
  const offset = input.offset ?? 0;
  const orderBy = input.orderBy ?? "id";
  const orderDirection = input.orderDirection ?? "asc";

  const shiftPatterns = await db
    .selectFrom("ShiftPattern")
    .selectAll()
    .orderBy(orderBy, orderDirection)
    // Total order: a non-unique sort column alone lets same-value rows shift between pages.
    .orderBy("id", "asc")
    .limit(limit + 1)
    .offset(offset)
    .execute();

  return ok(buildPaginatedResult(shiftPatterns, limit));
}