import { afterEach, describe, expect, it, vi } from "vitest";
import { combatNow, installCombatClock } from "./combatClock";

describe("combat clock", () => {
  afterEach(() => vi.useRealTimers());

  it("installs a deterministic clock and restores wall time", () => {
    vi.useFakeTimers();
    vi.setSystemTime(42_000);
    const restore = installCombatClock(() => 1_234);

    try {
      expect(combatNow()).toBe(1_234);
    } finally {
      restore();
    }

    expect(combatNow()).toBe(42_000);
  });

  it("restores nested clock installations in last-in-first-out order", () => {
    const restoreOuter = installCombatClock(() => 100);

    try {
      expect(combatNow()).toBe(100);
      const restoreInner = installCombatClock(() => 200);

      try {
        expect(combatNow()).toBe(200);
      } finally {
        restoreInner();
      }

      expect(combatNow()).toBe(100);
    } finally {
      restoreOuter();
    }
  });
});