import { afterEach, describe, expect, it, vi } from "vitest";
import {
  buttonKeys,
  defaultPreferences,
  keyMap,
  keyName,
  loadPreferences,
  rebind,
  savePreferences,
} from "../src/ui/preferences";

function storage(initial: Record<string, string> = {}) {
  const values = new Map(Object.entries(initial));
  return {
    getItem: (key: string) => values.get(key) ?? null,
    setItem: (key: string, value: string) => void values.set(key, value),
    values,
  };
}

describe("interface preferences", () => {
  afterEach(() => vi.unstubAllGlobals());

  it("defaults to the original keys and standard text", () => {
    const preferences = defaultPreferences();
    expect(preferences.textScale).toBe(1);
    const map = keyMap(preferences);
    expect(map.get("KeyX")).toBe("a");
    expect(map.get("KeyZ")).toBe("b");
    expect(map.get("Enter")).toBe("start");
    expect(map.get("ShiftRight")).toBe("select");
    expect(buttonKeys(preferences, "select")).toBe("Shift");
    expect(buttonKeys(preferences, "up")).toBe("↑");
  });

  it("names keys readably", () => {
    expect(keyName("KeyQ")).toBe("Q");
    expect(keyName("Digit4")).toBe("4");
    expect(keyName("ArrowLeft")).toBe("←");
    expect(keyName("Semicolon")).toBe("Semicolon");
  });

  it("moves a key to its new button and refuses reserved keys", () => {
    let preferences = rebind(defaultPreferences(), "a", "KeyZ");
    expect(preferences.keys.a).toEqual(["KeyZ"]);
    expect(preferences.keys.b).toEqual([]);
    expect(buttonKeys(preferences, "b")).toBe("None");
    preferences = rebind(preferences, "start", "Tab");
    expect(preferences.keys.start).toEqual(["Enter"]);
  });

  it("round-trips through storage and rejects invalid entries", () => {
    const store = storage();
    vi.stubGlobal("localStorage", store);
    const saved = { ...rebind(defaultPreferences(), "start", "KeyQ"), textScale: 1.5 as const };
    savePreferences(saved);
    expect(loadPreferences()).toEqual(saved);
    // A duplicated key or an unknown scale falls back to the defaults.
    store.values.set(
      "crystal-preferences-v1",
      JSON.stringify({ textScale: 3, keys: { ...saved.keys, b: ["KeyQ"] } }),
    );
    expect(loadPreferences()).toEqual(defaultPreferences());
    store.values.set("crystal-preferences-v1", "{not json");
    expect(loadPreferences()).toEqual(defaultPreferences());
  });

  it("falls back to the defaults without storage", () => {
    vi.stubGlobal("localStorage", {
      getItem: () => {
        throw new Error("blocked");
      },
      setItem: () => {
        throw new Error("blocked");
      },
    });
    expect(loadPreferences()).toEqual(defaultPreferences());
    expect(() => savePreferences(defaultPreferences())).not.toThrow();
  });
});