import { afterEach, describe, expect, it, vi } from "vitest";
import { applyTheme, effectiveDark, readTheme, saveTheme } from "./theme.ts";

describe("тема", () => {
  afterEach(() => document.documentElement.removeAttribute("data-theme"));
  it("читает graph-theme, неизвестное значение — системная", () => {
    localStorage.setItem("graph-theme", "dark");
    expect(readTheme()).toBe("dark");
    localStorage.setItem("graph-theme", "purple");
    expect(readTheme()).toBe("");
  });
  it("без сохранённого значения readTheme возвращает пустую строку, а не null", () => {
    expect(readTheme()).toBe("");
  });
  it("applyTheme ставит и снимает data-theme, saveTheme пишет ключ", () => {
    applyTheme("light");
    expect(document.documentElement.getAttribute("data-theme")).toBe("light");
    applyTheme("");
    expect(document.documentElement.hasAttribute("data-theme")).toBe(false);
    saveTheme("dark");
    expect(localStorage.getItem("graph-theme")).toBe("dark");
  });
  it("effectiveDark: системная следует matchMedia, light — всегда светлая, dark — тёмная", () => {
    vi.stubGlobal("matchMedia", (q: string) => ({ matches: q.includes("dark"), media: q }));
    expect(effectiveDark("")).toBe(true);
    expect(effectiveDark("light")).toBe(false);
    expect(effectiveDark("dark")).toBe(true);
    vi.stubGlobal("matchMedia", undefined);
    expect(effectiveDark("")).toBe(false);
  });
});