import * as puppeteer from 'puppeteer';
import { Logger } from '@nestjs/common';
import { ChdtpResult } from './chdtp_target';

export const ChngCrawler = {
  name: '华能集团电子商务平台',
  url: 'https://ec.chng.com.cn/ecmall/index.html#/purchase/home?top=0',
  baseUrl: 'https://ec.chng.com.cn/ecmall/index.html',

  async crawl(browser: puppeteer.Browser): Promise<ChdtpResult[]> {
    const logger = new Logger('ChngCrawler');
    let page = await browser.newPage();

    const username = process.env.PROXY_USERNAME;
    const password = process.env.PROXY_PASSWORD;
    if (username && password) {
      await page.authenticate({ username, password });
    }
    
    await page.evaluateOnNewDocument(() => {
      Object.defineProperty(navigator, 'webdriver', { get: () => false });
    });

    await page.setUserAgent('Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/143.0.0.0 Safari/537.36');
    await page.setViewport({ width: 1920, height: 1080 });

    const allResults: ChdtpResult[] = [];
    let currentPage = 1;
    const maxPages = 5; 

    try {
      logger.log('Navigating to Bing...');
      await page.goto('https://cn.bing.com', { waitUntil: 'networkidle2' });

      logger.log('Searching for target site...');
      const searchBoxSelector = 'input[name="q"]'; 
      await page.waitForSelector(searchBoxSelector);
      await page.type(searchBoxSelector, 'https://ec.chng.com.cn/');
      await page.keyboard.press('Enter');
      await page.waitForNavigation({ waitUntil: 'networkidle2' });
      
      logger.log('Clicking search result...');
      const firstResultSelector = '#b_results .b_algo h2 a';
      await page.waitForSelector(firstResultSelector);
      
      const newTargetPromise = browser.waitForTarget(target => target.opener() === page.target());
      await page.click(firstResultSelector);
      
      const newTarget = await newTargetPromise;
      const newPage = await newTarget.page();
      
      if (newPage) {
        await page.close();
        page = newPage;
        if (username && password) {
          await page.authenticate({ username, password });
        }
      }
      
      await page.waitForNavigation({ waitUntil: 'domcontentloaded' }).catch(() => {});
      
      // PAUSE 15 SECONDS as requested
      logger.log('Pausing 15 seconds before looking for "采购专栏"...');
      await new Promise(r => setTimeout(r, 15000));

      logger.log('Looking for "采购专栏" link...');
      await page.waitForFunction(() => {
        const divs = Array.from(document.querySelectorAll('div.text'));
        return divs.some(div => div.textContent && div.textContent.includes('采购专栏'));
      }, { timeout: 60000 });

      const purchaseTargetPromise = browser.waitForTarget(target => target.opener() === page.target(), { timeout: 15000 }).catch(() => null);
         
      await page.evaluate(() => {
        const divs = Array.from(document.querySelectorAll('div.text'));
        const target = divs.find(div => div.textContent && div.textContent.includes('采购专栏')) as HTMLElement;
        if (target) target.click();
      });
      
      const purchaseTarget = await purchaseTargetPromise;
      if (purchaseTarget) {
          const pPage = await purchaseTarget.page();
          if (pPage) {
              logger.log('Switched to Purchase Page tab.');
              page = pPage;
              if (username && password) {
                await page.authenticate({ username, password });
              }
              await new Promise(r => setTimeout(r, 5000));
          }
      }
      
      logger.log(`Active URL: ${page.url()}`);
      
      while (currentPage <= maxPages) {
        logger.log(`Processing page ${currentPage}...`);
        
        // Wait for table rows to load
        await page.waitForFunction(() => {
            return document.querySelectorAll('tr.ant-table-row').length > 0;
        }, { timeout: 60000 }).catch(() => logger.warn('Content not found. Site might be slow.'));

        const pageResults = await page.evaluate((baseUrl) => {
          // Extract from table rows
          const items = Array.from(document.querySelectorAll('tr.ant-table-row'));
          return items.map(item => {
            const titleSpan = item.querySelector('span.list-text');
            const dateCell = item.querySelector('td.ant-table-row-cell-break-word p');
            
            if (titleSpan && dateCell) {
              const title = titleSpan.textContent?.trim() || '';
              const dateStr = dateCell.textContent?.trim() || '';
              
              if (title.length < 5) return null; // Filter noise
              
              // URL is not directly available in the table, need to construct from data-row-key
              const rowKey = item.getAttribute('data-row-key');
              const url = rowKey ? `${baseUrl}#/purchase/detail?id=${rowKey}` : '';
              
              return {
                title,
                dateStr,
                url
              };
            }
            return null;
          }).filter(i => i !== null);
        }, this.baseUrl);

        if (pageResults.length === 0) {
           logger.warn(`No results found on page ${currentPage}. Extraction failed.`);
           break;
        }

        allResults.push(...pageResults.map(r => ({
            title: r!.title,
            publishDate: new Date(r!.dateStr),
            url: r!.url
        })));
        
        logger.log(`Extracted ${pageResults.length} items.`);

        // Pagination: look for the "right" icon SVG
        const nextButton = await page.$('svg[data-icon="right"]');
        if (!nextButton) break;

        await nextButton.click();
        await new Promise(r => setTimeout(r, 5000));
        currentPage++;
      }

      return allResults;

    } catch (error) {
      logger.error(`Crawl failed: ${error.message}`);
      return allResults;
    } finally {
      if (page) await page.close();
    }
  },

  extract() { return []; }
};