/**
 * Shared browser launch configuration and navigation helpers.
 *
 * Fixes:
 * - DNS resolution inside Docker (--dns-resolution-order=hostname-first)
 * - Slow sites: uses waitUntil: 'commit' + waitForLoadState instead of 'networkidle'
 * - UA fingerprinting: realistic Chrome user agent
 *
 * Usage:
 *   const { launchBrowser, navigateTo } = require('./lib/browser-launcher');
 *   const browser = await launchBrowser();
 *   const page = ...;
 *   await navigateTo(page, 'https://example.com');
 */

const { chromium } = require('playwright');

const USE_DNS_FIX = process.env.DNS_RESOLUTION_ORDER === 'hostname-first';

const BASE_ARGS = [
  '--no-sandbox',
  '--disable-setuid-sandbox',
  '--disable-gpu',
  '--disable-dev-shm-usage',
  '--disable-blink-features=AutomationControlled',
  ...(USE_DNS_FIX ? ['--dns-resolution-order=hostname-first'] : []),
];

const DEFAULT_UA = 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/121.0.0.0 Safari/537.36';

async function launchBrowser(options = {}) {
  const args = [...BASE_ARGS, ...(options.extraArgs || [])];
  return chromium.launch({
    headless: options.headless !== undefined ? options.headless : true,
    args,
  });
}

async function newContext(browser, options = {}) {
  return browser.newContext({
    viewport: { width: 1280, height: 720 },
    deviceScaleFactor: 1,
    userAgent: DEFAULT_UA,
    ...options,
  });
}

async function navigateTo(page, url, options = {}) {
  const waitUntil = options.waitUntil || 'commit';
  const timeout = options.timeout || 60000;

  const response = await page.goto(url, { waitUntil, timeout });

  if (options.waitForDom !== false) {
    await page.waitForLoadState('domcontentloaded', { timeout: options.domTimeout || 15000 }).catch(() => {});
  }

  const delay = options.delay || 2000;
  if (delay > 0) await page.waitForTimeout(delay);

  return response;
}

module.exports = { launchBrowser, newContext, navigateTo, BASE_ARGS, DEFAULT_UA };