import { act, cleanup, renderHook } from "@testing-library/react";
import { afterEach, beforeEach, expect, it, vi } from "vitest";
import type { ScadaReplay } from "../api/scada-replay-client";
import { useScadaPlayback } from "./use-scada-playback";

const start = Date.parse("2026-07-16T07:30:00+08:00");
const end = start + 3600_000;
function receipt(time: number, status = "paused") {
  return { virtual_now: new Date(time).toISOString(), status, step_pending: false } as ScadaReplay;
}
function setup(advance = vi.fn<() => Promise<ScadaReplay | null>>()) {
  const options = { active: true, enabled: true, busy: false, start, end, now: start,
    intervalSeconds: 900, restart: false, advance };
  return { ...renderHook((props) => useScadaPlayback(props), { initialProps: options }), options, advance };
}
beforeEach(() => vi.useFakeTimers());
afterEach(() => { cleanup(); vi.useRealTimers(); });

it("advances the display first and monitors once at each project boundary until the end", async () => {
  let count = 0;
  const advance = vi.fn(async () => {
    count += 1;
    return receipt(start + count * 900_000, count === 4 ? "completed" : "paused");
  });
  const { result } = setup(advance);
  act(() => result.current.play());
  await act(() => vi.advanceTimersByTimeAsync(2500));
  expect(result.current.time).toBe(start + 450_000);
  expect(advance).not.toHaveBeenCalled();
  await act(() => vi.advanceTimersByTimeAsync(17500));
  expect(advance).toHaveBeenCalledTimes(4);
  expect(result.current.time).toBe(end);
  expect(result.current.playing).toBe(false);
  await act(() => vi.advanceTimersByTimeAsync(10000));
  expect(advance).toHaveBeenCalledTimes(4);
});

it("waits for a slow diagnosis without overlapping requests or jumping ahead", async () => {
  let resolve!: (value: ScadaReplay) => void;
  const advance = vi.fn(() => new Promise<ScadaReplay>((done) => { resolve = done; }));
  const { result } = setup(advance);
  act(() => result.current.play());
  await act(() => vi.advanceTimersByTimeAsync(20000));
  expect(advance).toHaveBeenCalledTimes(1);
  expect(result.current.time).toBe(start + 900_000);
  act(() => result.current.pause());
  await act(async () => resolve(receipt(start + 900_000)));
  await act(() => vi.advanceTimersByTimeAsync(10000));
  expect(advance).toHaveBeenCalledTimes(1);
  expect(result.current.playing).toBe(false);
});

it("pauses when the panel becomes inactive and resumes from the same display time", async () => {
  const { result, rerender, options, advance } = setup();
  act(() => result.current.play());
  await act(() => vi.advanceTimersByTimeAsync(2000));
  expect(result.current.newRound).toBe(false);
  const pausedAt = result.current.time;
  rerender({ ...options, active: false });
  await act(() => vi.advanceTimersByTimeAsync(10000));
  expect(result.current.time).toBe(pausedAt);
  expect(result.current.playing).toBe(false);
  expect(advance).not.toHaveBeenCalled();
  rerender(options);
  act(() => result.current.play());
  await act(() => vi.advanceTimersByTimeAsync(1000));
  expect(result.current.time).toBe(pausedAt + 180_000);
});

it("pauses on a failed command and does not retry automatically", async () => {
  const { result, advance } = setup(vi.fn(async () => null));
  act(() => result.current.play());
  await act(() => vi.advanceTimersByTimeAsync(15000));
  expect(advance).toHaveBeenCalledTimes(1);
  expect(result.current.playing).toBe(false);
});

it("uses the configured monitoring interval independently of the dial's five-minute ticks", async () => {
  const { result, rerender, options, advance } = setup(vi.fn(async () => receipt(start + 300_000)));
  rerender({ ...options, intervalSeconds: 300 });
  act(() => result.current.play());
  await act(() => vi.advanceTimersByTimeAsync(1700));
  expect(advance).toHaveBeenCalledTimes(1);
  expect(result.current.time).toBe(start + 300_000);
});

it("pauses for a hidden page and cleans up its automatic monitor on unmount", async () => {
  const { result, unmount, advance } = setup();
  act(() => result.current.play());
  const visibility = vi.spyOn(document, "visibilityState", "get").mockReturnValue("hidden");
  act(() => document.dispatchEvent(new Event("visibilitychange")));
  await act(() => vi.advanceTimersByTimeAsync(10000));
  expect(result.current.playing).toBe(false);
  visibility.mockRestore();
  act(() => result.current.play());
  unmount();
  await vi.advanceTimersByTimeAsync(10000);
  expect(advance).not.toHaveBeenCalled();
});

it("resumes a restarted round before its first request without resetting the clock again", async () => {
  const { result, rerender, options, advance } = setup();
  rerender({ ...options, now: end, restart: true });
  act(() => result.current.play());
  await act(() => vi.advanceTimersByTimeAsync(2000));
  expect(result.current.newRound).toBe(true);
  const pausedAt = result.current.time;
  act(() => result.current.pause());
  act(() => result.current.play());
  expect(result.current.time).toBe(pausedAt);
  await act(() => vi.advanceTimersByTimeAsync(1000));
  expect(result.current.time).toBe(pausedAt + 180_000);
  expect(advance).not.toHaveBeenCalled();
});

it("keeps playing when the refreshed snapshot arrives before the command promise resolves", async () => {
  let resolve!: (value: ScadaReplay) => void;
  const { result, rerender, options } = setup(vi.fn(() => new Promise<ScadaReplay>((done) => { resolve = done; })));
  act(() => result.current.play());
  await act(() => vi.advanceTimersByTimeAsync(5000));
  rerender({ ...options, now: start + 900_000 });
  await act(async () => resolve(receipt(start + 900_000)));
  expect(result.current.playing).toBe(true);
  await act(() => vi.advanceTimersByTimeAsync(1000));
  expect(result.current.time).toBe(start + 1080_000);
});

it("resets to a paused beginning without processing until play is pressed again", async () => {
  const { result, rerender, options, advance } = setup(vi.fn(async () => receipt(start + 900_000)));
  act(() => result.current.play());
  await act(() => vi.advanceTimersByTimeAsync(2000));
  expect(result.current.time).toBe(start + 360_000);
  act(() => result.current.reset());
  expect(result.current.time).toBe(start);
  expect(result.current.playing).toBe(false);
  expect(result.current.started).toBe(false);
  expect(result.current.newRound).toBe(false);
  rerender(options);
  await act(() => vi.advanceTimersByTimeAsync(10000));
  expect(advance).not.toHaveBeenCalled();
  act(() => result.current.play());
  await act(() => vi.advanceTimersByTimeAsync(5000));
  expect(advance).toHaveBeenCalledTimes(1);
});