import type { Browser } from 'puppeteer';
import type { Store } from '../models/store.js';
import type { ScrapedItem } from './result-parser.js';

let browser: Browser | null = null;

const SELECTOR_TIMEOUT = 15_000;
const NAVIGATION_TIMEOUT = 15_000;

function log(msg: string) {
  console.log(`[browser-scraper] ${msg}`);
}

async function getBrowser(): Promise<Browser> {
  if (browser && browser.connected) return browser;

  log('Launching Chromium...');
  const puppeteer = await import('puppeteer');
  browser = await puppeteer.default.launch({
    headless: true,
    args: [
      '--no-sandbox',
      '--disable-setuid-sandbox',
      '--disable-dev-shm-usage',
      '--disable-gpu',
      '--disable-extensions',
      '--no-first-run',
    ],
  });
  log('Chromium launched');

  return browser;
}

export interface BrowserScrapeResult {
  items: ScrapedItem[];
  html: string;
  statusCode: number;
}

export async function scrapeStoreWithBrowser(store: Store, searchUrl: string): Promise<BrowserScrapeResult> {
  log(`Scraping ${store.name}: ${searchUrl}`);
  const b = await getBrowser();
  const page = await b.newPage();

  try {
    if (store.user_agent) {
      await page.setUserAgent(store.user_agent);
    }

    if (store.headers_json) {
      try {
        const headers = JSON.parse(store.headers_json);
        await page.setExtraHTTPHeaders(headers);
      } catch { /* ignore */ }
    }

    log(`${store.name}: navigating...`);
    const response = await page.goto(searchUrl, {
      waitUntil: 'domcontentloaded',
      timeout: NAVIGATION_TIMEOUT,
    });

    const statusCode = response?.status() ?? 200;
    log(`${store.name}: DOM loaded (status ${statusCode})`);

    log(`${store.name}: waiting for selector "${store.sel_container}"...`);
    try {
      await page.waitForSelector(store.sel_container, { timeout: SELECTOR_TIMEOUT });
    } catch {
      log(`${store.name}: selector not found, returning empty`);
      return { items: [], html: '', statusCode };
    }
    log(`${store.name}: selector found`);

    // Brief wait for remaining renders
    await new Promise((r) => setTimeout(r, 300));

    log(`${store.name}: extracting products...`);
    const items = await page.evaluate((selectors) => {
      const containers = document.querySelectorAll(selectors.container);
      const results: Array<{ name: string; priceText: string; link: string; image: string | null }> = [];

      containers.forEach((el) => {
        const nameEl = el.querySelector(selectors.name);
        const priceEl = el.querySelector(selectors.price);
        const linkEl = el.querySelector(selectors.link) as HTMLAnchorElement | null;
        const imageEl = selectors.image ? el.querySelector(selectors.image) as HTMLImageElement | null : null;

        const name = nameEl?.textContent?.trim() || '';
        const priceText = priceEl?.textContent?.trim() || '';
        const link = linkEl?.getAttribute('href') || '';
        const image = imageEl?.getAttribute('src') || imageEl?.getAttribute('data-src') || null;

        if (name && priceText) {
          results.push({ name, priceText, link, image });
        }
      });

      return results;
    }, {
      container: store.sel_container,
      name: store.sel_name,
      price: store.sel_price,
      link: store.sel_link,
      image: store.sel_image || null,
    });

    log(`${store.name}: found ${items.length} products`);

    return { items, html: '', statusCode };
  } finally {
    log(`${store.name}: closing page`);
    await page.close();
    log(`${store.name}: done`);
  }
}

export async function warmupBrowser(): Promise<void> {
  log('Warming up browser...');
  await getBrowser();
  log('Browser ready');
}

export async function closeBrowser(): Promise<void> {
  if (browser) {
    await browser.close();
    browser = null;
  }
}