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

// 模拟人类鼠标移动
async function simulateHumanMouseMovement(page: puppeteer.Page) {
  const viewport = page.viewport();
  if (!viewport) return;

  const movements = 5 + Math.floor(Math.random() * 5); // 5-10次随机移动

  for (let i = 0; i < movements; i++) {
    const x = Math.floor(Math.random() * viewport.width);
    const y = Math.floor(Math.random() * viewport.height);
    
    await page.mouse.move(x, y, {
      steps: 10 + Math.floor(Math.random() * 20) // 10-30步，使移动更平滑
    });
    
    // 随机停顿 100-500ms
    await new Promise(r => setTimeout(r, 100 + Math.random() * 400));
  }
}

// 模拟人类滚动
async function simulateHumanScrolling(page: puppeteer.Page) {
  const scrollCount = 3 + Math.floor(Math.random() * 5); // 3-7次滚动

  for (let i = 0; i < scrollCount; i++) {
    const scrollDistance = 100 + Math.floor(Math.random() * 400); // 100-500px
    
    await page.evaluate((distance) => {
      window.scrollBy({
        top: distance,
        behavior: 'smooth'
      });
    }, scrollDistance);

    // 随机停顿 500-1500ms
    await new Promise(r => setTimeout(r, 500 + Math.random() * 1000));
  }

  // 滚动回顶部
  await page.evaluate(() => {
    window.scrollTo({ top: 0, behavior: 'smooth' });
  });
  await new Promise(r => setTimeout(r, 1000));
}

export interface EpsResult {
  title: string;
  publishDate: Date;
  url: string;
}

export const EpsCrawler = {
  name: '中国三峡集团电子商务平台',
  url: 'https://eps.ctg.com.cn/cms/channel/1ywgg1/index.htm',
  baseUrl: 'https://eps.ctg.com.cn/',

  async crawl(browser: puppeteer.Browser): Promise<EpsResult[]> {
    const logger = new Logger('EpsCrawler');
    const 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 });
      Object.defineProperty(navigator, 'language', {	get: () => "zh-CN"});
      Object.defineProperty(navigator, 'plugins', {	get: () => [1,2,3,4,5]});
    });

    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: EpsResult[] = [];
    let currentPage = 1;
    const maxPages = 5;

    try {
      logger.log(`Navigating to ${this.url}...`);
      await page.goto(this.url, { waitUntil: 'networkidle2', timeout: 60000 });

      // 模拟人类行为
      logger.log('Simulating human mouse movements...');
      await simulateHumanMouseMovement(page);
      
      logger.log('Simulating human scrolling...');
      await simulateHumanScrolling(page);

      while (currentPage <= maxPages) {
        logger.log(`Processing page ${currentPage}...`);

        const content = await page.content();
        const pageResults = this.extract(content);

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

        allResults.push(...pageResults);
        logger.log(`Extracted ${pageResults.length} items from page ${currentPage}`);

        // 模拟人类行为 - 翻页前
        logger.log('Simulating human mouse movements before pagination...');
        await simulateHumanMouseMovement(page);
        
        logger.log('Simulating human scrolling before pagination...');
        await simulateHumanScrolling(page);

        // 查找下一页按钮 - 根据网站实际结构调整选择器
        // 分页结构: <a href="javascript:;" aria-label="Next" class="pageItem" page="2">下页</a>
        const nextButtonSelector = 'a.pageItem[aria-label="Next"]';
        const nextButton = await page.$(nextButtonSelector);

        if (!nextButton) {
          logger.log('Next page button not found. Reached end of list.');
          break;
        }

        logger.log(`Navigating to page ${currentPage + 1}...`);

        try {
          // 点击下一页按钮，等待页面更新
          await nextButton.click();
          await new Promise(r => setTimeout(r, 3000)); // 等待页面加载
        } catch (navError) {
          logger.error(`Navigation to page ${currentPage + 1} failed: ${navError.message}`);
          break;
        }

        currentPage++;

        // 模拟人类行为 - 翻页后
        logger.log('Simulating human mouse movements after pagination...');
        await simulateHumanMouseMovement(page);
        
        logger.log('Simulating human scrolling after pagination...');
        await simulateHumanScrolling(page);

        // Random delay between pages
        const delay = Math.floor(Math.random() * (3000 - 1000 + 1)) + 1000;
        await new Promise(resolve => setTimeout(resolve, delay));
      }

      return allResults;

    } catch (error) {
      logger.error(`Failed to crawl ${this.name}: ${error.message}`);
      return allResults;
    } finally {
      await page.close();
    }
  },

  extract(html: string): EpsResult[] {
    const results: EpsResult[] = [];
    /**
     * Regex groups for eps.ctg.com.cn:
     * 1: URL (href属性)
     * 2: Title (title属性)
     * 3: Date (发布时间，格式：2026-01-09)
     *
     * HTML结构示例:
     * <li name="li_name">
     *   <a id="0" href="https://eps.ctg.com.cn/cms/channel/1ywgg1/240630340.htm"
     *      title="三峡福清兴化湾海上风电场一期项目金风Y6风机发电机更换施工招标公告"
     *      target="_blank" style="">
     *     <span style="max-width: 700px;">
     *       <i class="iconfont"></i>
     *       <em style="width:6.5em; color: #1e52a8;font-weight: 700;float: none;"></em>
     *       三峡福清兴化湾海上风电场一期项目金风Y6风机发电机更换施工招标公告
     *     </span>
     *     <em>2026-01-09</em>
     *   </a>
     * </li>
     */
    const regex = /<li[^>]*name="li_name"[^>]*>[\s\S]*?<a[^>]*href="([^"]*)"[^>]*title="([^"]*)"[^>]*>[\s\S]*?<em>\s*(\d{4}-\d{2}-\d{2})\s*<\/em>[\s\S]*?<\/a>[\s\S]*?<\/li>/gs;

    let match;
    while ((match = regex.exec(html)) !== null) {
      const url = match[1]?.trim();
      const title = match[2]?.trim();
      const dateStr = match[3]?.trim();

      if (title && url) {
        results.push({
          title,
          publishDate: dateStr ? new Date(dateStr) : new Date(),
          url: url.startsWith('http') ? url : this.baseUrl + url
        });
      }
    }

    return results;
  }
};