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

export interface RemoveItemFromTaxonomyInput {
  itemId: string;
  taxonomyNodeId: string;
}

/**
 * Function: removeItemFromTaxonomy
 *
 * Removes the link between an item and a taxonomy node.
 */
export async function run(db: Transaction, input: RemoveItemFromTaxonomyInput) {
  const { itemId, taxonomyNodeId } = input;

  // 1. Check assignment exists (read-then-delete — lock)
  const assignment = await db
    .selectFrom("ItemTaxonomyAssignment")
    .selectAll()
    .where("itemId", "=", itemId)
    .where("taxonomyNodeId", "=", taxonomyNodeId)
    .forUpdate()
    .executeTakeFirst();

  if (!assignment) {
    return err(new AssignmentNotFoundError(`${itemId} in ${taxonomyNodeId}`));
  }

  // 2. Delete assignment
  await db.deleteFrom("ItemTaxonomyAssignment").where("id", "=", assignment.id).execute();

  return ok({ success: true as const });
}