import { test, expect } from '@playwright/test';
import {
  launchApp,
  resetWorkspace,
  type LaunchedApp,
  openNote,
  scroller,
} from './appFixture';

test.describe('per-tab view state', () => {
  let app: LaunchedApp;
  let window: LaunchedApp['window'];

  test.beforeAll(async () => {
    app = await launchApp();
    window = app.window;
  });
  test.afterAll(async () => {
    await app.close();
  });
  test.beforeEach(async () => {
    await resetWorkspace(app);
  });

  test('restores scroll position when returning to a tab', async () => {
    await openNote(window, 'Target.md');
    await scroller(window).evaluate((el) => {
      el.scrollTop = 600;
    });
    // Let CM record the position before navigating away.
    await window.waitForTimeout(200);
    const before = await scroller(window).evaluate((el) => el.scrollTop);
    expect(before).toBeGreaterThan(0);

    await openNote(window, 'Other.md');
    await openNote(window, 'Target.md');

    // Guards: capturing after React detaches the node reads `scrollTop` 0.
    await expect
      .poll(() => scroller(window).evaluate((el) => el.scrollTop))
      .toBeGreaterThan(before / 2);
  });

  test('restores the cursor position, not just the scroll', async () => {
    await openNote(window, 'Target.md');
    await window.locator('.cm-content').first().click();
    for (let i = 0; i < 12; i++) await window.keyboard.press('ArrowDown');
    const before = await window.evaluate(
      () => document.querySelectorAll('.cm-line').length,
    );
    expect(before).toBeGreaterThan(0);
    const cursorLineBefore = await window.evaluate(() => {
      const active = document.querySelector('.cm-activeLine');
      return active ? active.textContent : null;
    });

    await openNote(window, 'Other.md');
    await openNote(window, 'Target.md');

    await expect
      .poll(() =>
        window.evaluate(() => {
          const active = document.querySelector('.cm-activeLine');
          return active ? active.textContent : null;
        }),
      )
      .toBe(cursorLineBefore);
  });
});