import { content } from "@deadhead/content";
import { realToGame } from "@deadhead/sim";
import { act, render } from "@testing-library/react";
import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
import type { ApiClient } from "../src/api/client";
import { serverNow, startClockTicker, syncClock, useClock } from "../src/clock/clock";
import { formatGameTime, GameClock } from "../src/clock/GameClock";

const DEVICE_NOW = Date.parse("2100-01-01T00:00:00Z");
const TEN_MINUTES = 10 * 60_000;

/** An API whose server clock runs `aheadMs` ahead of the device. */
function serverAhead(aheadMs: number): ApiClient {
  return {
    call: vi.fn(async () => ({ realTime: Date.now() + aheadMs, gameTime: 0 })),
  } as unknown as ApiClient;
}

describe("server-synced clock", () => {
  beforeEach(() => {
    vi.useFakeTimers();
    vi.setSystemTime(DEVICE_NOW);
    useClock.setState({ offsetMs: 0, synced: false, now: DEVICE_NOW });
  });
  afterEach(() => vi.useRealTimers());

  it("returns a time 10 minutes ahead when the server is 10 minutes ahead", async () => {
    await syncClock(serverAhead(TEN_MINUTES));
    expect(useClock.getState().synced).toBe(true);
    expect(serverNow()).toBe(DEVICE_NOW + TEN_MINUTES);

    vi.advanceTimersByTime(5000);
    expect(serverNow()).toBe(DEVICE_NOW + TEN_MINUTES + 5000);
  });

  it("works when the server is behind the device", async () => {
    await syncClock(serverAhead(-30_000));
    expect(serverNow()).toBe(DEVICE_NOW - 30_000);
  });

  it("ticks the store every second", async () => {
    await syncClock(serverAhead(TEN_MINUTES));
    const stop = startClockTicker();
    vi.advanceTimersByTime(3000);
    expect(useClock.getState().now).toBe(DEVICE_NOW + TEN_MINUTES + 3000);
    stop();
    vi.advanceTimersByTime(3000);
    expect(useClock.getState().now).toBe(DEVICE_NOW + TEN_MINUTES + 3000);
  });

  it("shows the in-game time in the game clock and keeps it ticking", async () => {
    await syncClock(serverAhead(0));
    const stop = startClockTicker();
    const { container } = render(<GameClock />);
    // Date and time are separate spans (the date hides on phones).
    const clock = () => container.querySelector("time")!;
    // The default clock follows the device locale (CR-011).
    const at = (real: number) => formatGameTime(realToGame(real, content.config), "locale");
    expect(clock()).toHaveTextContent(at(DEVICE_NOW));

    // One real minute is one game hour.
    act(() => vi.advanceTimersByTime(60_000));
    expect(clock()).toHaveTextContent(at(DEVICE_NOW + 60_000));
    stop();
  });
});