// Optional integration test: requires Playwright + Chromium and the project's test extra.
const assert = require('node:assert/strict');
const { spawn } = require('node:child_process');
const { mkdtemp, rm } = require('node:fs/promises');
const os = require('node:os');
const path = require('node:path');
const { chromium } = require('playwright');

(async () => {
  const temporary = await mkdtemp(path.join(os.tmpdir(), 'nest-browser-'));
  const port = process.env.NEST_BROWSER_TEST_PORT || '18765';
  const origin = `http://127.0.0.1:${port}`;
  const server = spawn(process.env.NEST_TEST_PYTHON || 'python3',
    ['-B', '-m', 'tests.browser_session_server', '--base', temporary, '--port', port],
    { cwd: path.resolve(__dirname, '..'), stdio: ['ignore', 'pipe', 'pipe'] });
  let logs = '';
  server.stdout.on('data', (data) => { logs = (logs + data).slice(-16000); });
  server.stderr.on('data', (data) => { logs = (logs + data).slice(-16000); });
  let browser;
  let page;
  try {
    let ready = false;
    for (let attempt = 0; attempt < 100; attempt++) {
      if (server.exitCode !== null) throw new Error(`Fixture server exited: ${logs}`);
      try {
        const response = await fetch(`${origin}/health`);
        if (response.ok) { ready = true; break; }
      } catch {}
      await new Promise((resolve) => setTimeout(resolve, 100));
    }
    assert.ok(ready, `Fixture server did not start: ${logs}`);
    browser = await chromium.launch({ headless: true });
    const context = await browser.newContext({ viewport: { width: 1440, height: 1100 } });
    page = await context.newPage();
    const errors = [];
    page.on('pageerror', (error) => errors.push(error.message));
    const connected = () => page.waitForFunction(() => document.querySelector('#session-status').textContent === 'Connected');
    const output = (value) => page.waitForFunction((text) => document.querySelector('#session-terminal').textContent.includes(text), value);
    await page.goto(`${origin}/dashboard#vm/vm-test`);
    await page.locator('#token-input').fill('browser-test-token');
    await page.locator('#auth-btn').click();
    await page.locator('#detail-actions [data-action="launch-session"]').click();
    await connected();
    const firstUrl = page.url();
    assert.match(firstUrl, /#vm\/vm-test\/sessions\/session-/);
    await page.keyboard.type('echo alpha');
    await page.keyboard.press('Enter');
    await output('result:echo alpha');

    await page.reload();
    await connected();
    await output('result:echo alpha');
    assert.equal(await page.locator('.session-item').count(), 1);

    // Rename is cancellable, validated, persisted, and preserves the live widget.
    const firstId = new URL(firstUrl).hash.split('/').at(-1);
    const firstRow = () => page.locator(`.session-item[data-session-id="${firstId}"]`);
    await page.locator('#session-rename').click();
    await page.locator('#session-name-input').fill('Discarded name');
    await page.locator('#session-rename-cancel').click();
    assert.equal(await firstRow().locator('strong').textContent(), 'Session 1');
    await page.evaluate(() => { window.originalTerminal = document.querySelector('#session-terminal .xterm'); });
    await page.locator('#session-rename').click();
    await page.locator('#session-name-input').fill('   ');
    await page.locator('#session-rename-save').click();
    assert.ok(await page.locator('#session-rename-dialog').isVisible());
    assert.match(await page.locator('#session-rename-error').textContent(), /Enter a session name/);
    await page.locator('#session-name-input').fill('  Deployment  ');
    await page.locator('#session-rename-save').click();
    await page.locator('#session-rename-dialog').waitFor({ state: 'hidden' });
    await page.waitForFunction(() => document.querySelector('#session-title').textContent.startsWith('Deployment'));
    assert.equal(page.url(), firstUrl);
    assert.ok(await page.evaluate(() => window.originalTerminal === document.querySelector('#session-terminal .xterm')));
    await page.reload();
    await connected();
    await output('result:echo alpha');
    assert.equal(await firstRow().locator('strong').textContent(), 'Deployment');

    await page.locator('#detail-actions [data-action="launch-session"]').click();
    await page.waitForURL((url) => url.href !== firstUrl);
    await connected();
    const secondUrl = page.url();
    assert.equal(await page.locator('.session-item').count(), 2);
    assert.ok(!(await page.locator('#session-terminal').textContent()).includes('result:echo alpha'));
    await page.keyboard.type('echo beta');
    await page.keyboard.press('Enter');
    await output('result:echo beta');
    // History actions also work without selecting the affected session.
    await firstRow().locator('[data-session-action="rename"]').click();
    await page.locator('#session-name-input').fill('Operations <alpha>');
    await page.locator('#session-rename-save').click();
    await page.locator('#session-rename-dialog').waitFor({ state: 'hidden' });
    assert.equal(page.url(), secondUrl);
    assert.equal(await firstRow().locator('strong').textContent(), 'Operations <alpha>');
    assert.equal(await firstRow().locator('alpha').count(), 0);
    await output('result:echo beta');
    await firstRow().locator('.session-link').click();
    await connected();
    await output('result:echo alpha');
    assert.ok(!(await page.locator('#session-terminal').textContent()).includes('result:echo beta'));

    await page.goto(`${origin}/dashboard#vm/vm-other/sessions`);
    await page.locator('#vm-sessions-panel').waitFor({ state: 'visible' });
    await page.waitForFunction(() => document.querySelector('#vm-session-count').textContent === '0');
    assert.equal(await page.locator('.session-item').count(), 0);
    assert.ok(await page.locator('#detail-actions [data-action="launch-session"]').isDisabled());
    assert.ok(!(await page.locator('#session-terminal').textContent()).includes('alpha'));

    await page.goto(firstUrl);
    await connected();
    await output('result:echo alpha');
    await page.locator('#session-end').click();
    await page.locator('#confirm-ok').click();
    await page.waitForFunction(() => document.querySelector('#session-status').textContent.startsWith('closed'));
    await page.reload();
    await output('result:echo alpha');
    assert.ok(await page.locator('#session-end').isDisabled());
    await page.locator('#session-rename').click();
    await page.locator('#session-name-input').fill('Archived run');
    await page.locator('#session-rename-save').click();
    await page.locator('#session-rename-dialog').waitFor({ state: 'hidden' });
    await page.reload();
    await output('result:echo alpha');
    assert.equal(await firstRow().locator('strong').textContent(), 'Archived run');

    await page.setViewportSize({ width: 390, height: 844 });
    await page.waitForTimeout(300);
    const fits = await page.evaluate(() => document.documentElement.scrollWidth <= window.innerWidth);
    assert.ok(fits, 'mobile layout overflows the viewport');
    if (process.env.NEST_BROWSER_SCREENSHOT) await page.screenshot({ path: process.env.NEST_BROWSER_SCREENSHOT, fullPage: true });

    // Cancel preserves history; confirmation removes an ended session and clears selection.
    await page.locator('#session-delete').click();
    await page.locator('#confirm-dialog button[value="cancel"]').click();
    assert.equal(await page.locator('.session-item').count(), 2);
    await firstRow().locator('[data-session-action="delete"]').click();
    await page.locator('#confirm-ok').click();
    await page.waitForURL((url) => url.hash === '#vm/vm-test/sessions');
    await page.waitForFunction(() => document.querySelector('#vm-session-count').textContent === '1');
    assert.ok(await page.locator('#session-terminal').isHidden());
    await page.reload();
    await page.waitForFunction(() => document.querySelector('#vm-session-count').textContent === '1');
    assert.equal(await firstRow().count(), 0);

    // Deleting an active session clears other attached browser views as well.
    await page.goto(secondUrl);
    await connected();
    await output('result:echo beta');
    const observer = await page.context().newPage();
    observer.on('pageerror', (error) => errors.push(error.message));
    await observer.goto(secondUrl);
    await observer.locator('#token-input').fill('browser-test-token');
    await observer.locator('#auth-btn').click();
    await observer.waitForFunction(() => document.querySelector('#session-status').textContent === 'Connected');
    await page.locator('#session-rename').click();
    await page.locator('#session-name-input').fill('Second workspace');
    await page.locator('#session-rename-save').click();
    await page.locator('#session-rename-dialog').waitFor({ state: 'hidden' });
    await observer.waitForFunction(() => document.querySelector('#session-title').textContent.startsWith('Second workspace'));
    await page.locator('#session-delete').click();
    await page.locator('#confirm-ok').click();
    await page.waitForFunction(() => document.querySelector('#vm-session-count').textContent === '0');
    await observer.waitForURL((url) => url.hash === '#vm/vm-test/sessions');
    assert.ok(await observer.locator('#session-terminal').isHidden());
    await page.reload();
    await page.waitForFunction(() => document.querySelector('#vm-session-count').textContent === '0');
    assert.equal(await page.locator('.session-item').count(), 0);
    assert.deepEqual(errors, []);
    await observer.close();
    console.log('Browser sessions passed: terminal/reconnect, VM isolation, persistent rename, active/ended deletion, cancellation, live browser updates, and mobile layout.');
  } catch (error) {
    if (page) console.error('Browser state:', await page.locator('#sessions-error').textContent(), await page.locator('#session-status').textContent());
    console.error(logs);
    throw error;
  } finally {
    await browser?.close();
    server.kill('SIGTERM');
    if (server.exitCode === null) await new Promise((resolve) => server.once('exit', resolve));
    await rm(temporary, { recursive: true, force: true });
  }
})().catch((error) => { console.error(error); process.exitCode = 1; });