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

export interface GetShiftPatternByCodeInput {
  code: string;
}

/**
 * Function: getShiftPatternByCode
 * Resolves a ShiftPattern by its stable `code` rather than its id, with
 * segments included from the embedded `segments` array (ADR-022). Lookups
 * match only against `code`, never against the display `name`.
 */
export async function run(db: ReadonlyDB<DB>, input: GetShiftPatternByCodeInput) {
  const shiftPattern = await db
    .selectFrom("ShiftPattern")
    .selectAll()
    .where("code", "=", input.code)
    .executeTakeFirst();

  if (!shiftPattern) {
    return err(new ShiftPatternNotFoundError(input.code));
  }

  const segments = [...(shiftPattern.segments ?? [])].sort((a, b) => a.sequence - b.sequence);

  return ok({ shiftPattern, segments });
}