import "server-only";
import type PocketBase from "pocketbase";
import { supplierKey, type Terms } from "./supplier";

/**
 * The supplier a purchase order or slip belongs to — found, or created.
 *
 * Match order: the supplier's CODE from the PO ("09YTS001") when there is one, then the folded
 * NAME. A new supplier takes `terms` (a till slip is "cash"; a PO supplier nobody has classified
 * yet is left "" so the list shows it as needing terms). An existing supplier's terms are never
 * overwritten here — only a person changes those.
 */
export async function resolveSupplier(
  pb: PocketBase,
  input: { name: string; code?: string; terms?: Terms; source: string },
): Promise<string> {
  const name = (input.name || "").trim();
  const key = supplierKey(name);
  if (!name || !key) return "";
  const code = (input.code || "").trim().toUpperCase();

  const all = await pb.collection("suppliers").getFullList({ fields: "id,key,code" });
  const hit = (code && all.find((s) => (s.code || "").toUpperCase() === code)) || all.find((s) => s.key === key);
  if (hit) {
    // Learn a code we did not have, without disturbing anything a person set.
    if (code && !(hit.code || "").trim()) await pb.collection("suppliers").update(hit.id, { code }).catch(() => {});
    return hit.id;
  }
  try {
    const created = await pb.collection("suppliers").create({ name, key, code, terms: input.terms ?? "", source: input.source });
    return created.id;
  } catch {
    // Lost a race to the unique key: someone created it a moment ago.
    const again = (await pb.collection("suppliers").getFullList({ fields: "id,key" })).find((s) => s.key === key);
    return again?.id ?? "";
  }
}