// @vitest-environment jsdom
//
// E30 review: the server orders some lists by the reader's STORED language (their keys carry none), so a
// switch must re-ask for them — after the save lands, not before (the server would sort in the old one).
import { afterEach, describe, expect, it, vi } from "vitest";
import { QueryClient } from "@tanstack/react-query";
import { api } from "./api";
import { LANGUAGE_ORDERED, qk } from "./queryKeys";
import { saveLanguage, serverOrderLang } from "./saveLanguage";

afterEach(() => vi.restoreAllMocks());

describe("saveLanguage", () => {
  it("asks again for the server-ordered lists once the save has landed", async () => {
    let land!: () => void;
    vi.spyOn(api, "savePrefs").mockReturnValue(
      new Promise<never>((r) => (land = r as () => void)) as never,
    );
    const qc = new QueryClient();
    const asked = vi.spyOn(qc, "invalidateQueries");
    const done = saveLanguage(qc, "hu");
    await Promise.resolve();
    expect(asked).not.toHaveBeenCalled(); // the server still sorts in the old language
    land();
    await done;
    const keys = asked.mock.calls.map((c) => c[0]?.queryKey);
    expect(keys).toEqual([...LANGUAGE_ORDERED]);
    expect(keys).toContainEqual(qk.feed());
    expect(keys).toContainEqual(qk.channels());
  });

  it("leaves the lists alone when the save fails", async () => {
    vi.spyOn(api, "savePrefs").mockRejectedValue(new Error("offline"));
    const qc = new QueryClient();
    const asked = vi.spyOn(qc, "invalidateQueries");
    await expect(saveLanguage(qc, "hu")).rejects.toThrow("offline");
    expect(asked).not.toHaveBeenCalled();
  });
});

describe("serverOrderLang", () => {
  it("is the stored language, else English — never the UI's guess", () => {
    expect(serverOrderLang({ language: "hu" })).toBe("hu");
    expect(serverOrderLang({})).toBe("en"); // nothing stored: the server sorts in English
    expect(serverOrderLang({ language: "de" })).toBe("en");
    expect(serverOrderLang(undefined)).toBe("en");
  });
});