import { act, render } from '@testing-library/react';
import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';

vi.mock('next-intl', () => ({
  useTranslations: () => (key: string, values?: Record<string, string>) =>
    values?.title ? `${key}:${values.title}` : key,
  useLocale: () => 'de',
}));

vi.mock('@/lib/reminders-api', async () => {
  const actual = await vi.importActual<typeof import('@/lib/reminders-api')>('@/lib/reminders-api');
  return {
    REMINDERS_CHANGED_EVENT: actual.REMINDERS_CHANGED_EVENT,
    ReminderRequestError: actual.ReminderRequestError,
    listReminders: vi.fn(),
  };
});

vi.mock('@/lib/reminder-notify', async () => {
  const actual =
    await vi.importActual<typeof import('@/lib/reminder-notify')>('@/lib/reminder-notify');
  return { ...actual, showReminderNotification: vi.fn(async () => undefined) };
});

import { resetNotifiedMemoryForTests, showReminderNotification } from '@/lib/reminder-notify';
import { listReminders, ReminderRequestError } from '@/lib/reminders-api';
import { ReminderNotifier } from './reminder-notifier';

const mockList = listReminders as ReturnType<typeof vi.fn>;
const mockShow = showReminderNotification as ReturnType<typeof vi.fn>;

const NOW = new Date('2026-09-29T12:00:00.000Z');

function reminder(over: Partial<{ id: string; dueAt: string; description: string }> = {}) {
  return {
    id: 'r1',
    title: 'Zahnarzt',
    description: '',
    dueAt: new Date(NOW.getTime() + 30_000).toISOString(),
    emailEnabled: false,
    createdAt: NOW.toISOString(),
    updatedAt: NOW.toISOString(),
    ...over,
  };
}

async function advance(ms: number) {
  await act(async () => {
    await vi.advanceTimersByTimeAsync(ms);
  });
}

beforeEach(() => {
  vi.useFakeTimers();
  vi.setSystemTime(NOW);
  window.localStorage.clear();
  resetNotifiedMemoryForTests();
  mockList.mockReset();
  mockShow.mockClear();
});

afterEach(() => {
  vi.useRealTimers();
});

describe('ReminderNotifier', () => {
  it('meldet eine faellige Erinnerung genau einmal ueber mehrere Takte', async () => {
    mockList.mockResolvedValue([reminder()]);
    render(<ReminderNotifier />);
    await advance(0);
    expect(mockShow).not.toHaveBeenCalled(); // noch nicht faellig (D-02)
    await advance(40_000); // ueber dueAt (+30 s) hinweg
    await advance(30_000);
    expect(mockShow).toHaveBeenCalledTimes(1);
    expect(mockShow.mock.calls[0][0]).toMatchObject({
      title: 'reminder.notificationTitle:Zahnarzt',
      tag: `reminder-r1-${reminder().dueAt}`,
    });
  });

  it('meldet nichts, solange nichts faellig ist', async () => {
    mockList.mockResolvedValue([
      reminder({ dueAt: new Date(NOW.getTime() + 3600_000).toISOString() }),
    ]);
    render(<ReminderNotifier />);
    await advance(30_000);
    expect(mockShow).not.toHaveBeenCalled();
  });

  it('nimmt die Beschreibung als Text, gekuerzt auf 200 Zeichen', async () => {
    mockList.mockResolvedValue([
      reminder({
        dueAt: new Date(NOW.getTime() - 1000).toISOString(),
        description: 'x'.repeat(300),
      }),
    ]);
    render(<ReminderNotifier />);
    await advance(0);
    expect(mockShow.mock.calls[0][0].body).toBe('x'.repeat(200));
  });

  it('meldet nach geaendertem dueAt (Verschieben) erneut', async () => {
    const first = reminder({ dueAt: new Date(NOW.getTime() - 1000).toISOString() });
    mockList.mockResolvedValue([first]);
    render(<ReminderNotifier />);
    await advance(0);
    expect(mockShow).toHaveBeenCalledTimes(1);

    // Verschoben auf +10 s (in der Zukunft), dann faellig
    mockList.mockResolvedValue([{ ...first, dueAt: new Date(Date.now() + 10_000).toISOString() }]);
    await act(async () => {
      window.dispatchEvent(new Event('tessera:reminders-changed'));
      await vi.advanceTimersByTimeAsync(0);
    });
    expect(mockShow).toHaveBeenCalledTimes(1);
    await advance(20_000);
    expect(mockShow).toHaveBeenCalledTimes(2);
  });

  it('das Aenderungsereignis laedt die Liste neu', async () => {
    mockList.mockResolvedValue([]);
    render(<ReminderNotifier />);
    await advance(0);
    const before = mockList.mock.calls.length;
    await act(async () => {
      window.dispatchEvent(new Event('tessera:reminders-changed'));
      await vi.advanceTimersByTimeAsync(0);
    });
    expect(mockList.mock.calls.length).toBe(before + 1);
  });

  it('pausiert bei 401 bis zum naechsten Fokus', async () => {
    mockList.mockRejectedValue(new ReminderRequestError(401));
    render(<ReminderNotifier />);
    await advance(0);
    const after401 = mockList.mock.calls.length;
    await advance(180_000);
    expect(mockList.mock.calls.length).toBe(after401);
    mockList.mockResolvedValue([]);
    await act(async () => {
      window.dispatchEvent(new Event('focus'));
      await vi.advanceTimersByTimeAsync(0);
    });
    expect(mockList.mock.calls.length).toBe(after401 + 1);
  });
});