import { describe, expect, it } from "vitest";
import { filterPickupLocationIds } from "../../app/services/pickup-locations.server";

const candidates = [{ id: "a" }, { id: "b" }, { id: "c" }, { id: "d" }];

describe("filterPickupLocationIds", () => {
  it("keeps only candidates that both offer PICKUP slots and stock the cart, in candidate order", () => {
    const result = filterPickupLocationIds({
      candidates,
      pickupTemplateLocationIds: new Set(["a", "b", "c"]),
      stockedLocationIds: new Set(["b", "c", "d"]),
    });
    expect(result).toEqual(["b", "c"]);
  });

  it("drops a location with no PICKUP slot template even if it's in stock", () => {
    const result = filterPickupLocationIds({
      candidates,
      pickupTemplateLocationIds: new Set(["a"]),
      stockedLocationIds: new Set(["a", "b", "c", "d"]),
    });
    expect(result).toEqual(["a"]);
  });

  it("drops a pickup-capable location that stocks none of the cart", () => {
    const result = filterPickupLocationIds({
      candidates,
      pickupTemplateLocationIds: new Set(["a", "b"]),
      stockedLocationIds: new Set(["b"]),
    });
    expect(result).toEqual(["b"]);
  });

  it("returns [] when nothing qualifies", () => {
    expect(
      filterPickupLocationIds({
        candidates,
        pickupTemplateLocationIds: new Set(["a"]),
        stockedLocationIds: new Set(["b"]),
      }),
    ).toEqual([]);
  });

  it("preserves the candidate ordering (oldest-first) rather than set iteration order", () => {
    const result = filterPickupLocationIds({
      candidates: [{ id: "d" }, { id: "c" }, { id: "b" }, { id: "a" }],
      pickupTemplateLocationIds: new Set(["a", "b", "c", "d"]),
      stockedLocationIds: new Set(["a", "b", "c", "d"]),
    });
    expect(result).toEqual(["d", "c", "b", "a"]);
  });
});