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

export interface GetShiftInput {
  shiftId: string;
}

/**
 * Function: getShift
 * Retrieves a single Shift by id, regardless of status, with its planned
 * segments included from the embedded `segments` array (ADR-022), ordered
 * by sequence.
 */
export async function run(db: ReadonlyDB<DB>, input: GetShiftInput) {
  const shift = await db
    .selectFrom("Shift")
    .selectAll()
    .where("id", "=", input.shiftId)
    .executeTakeFirst();

  if (!shift) {
    return err(new ShiftNotFoundError(input.shiftId));
  }

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

  return ok({ shift, segments });
}