import { config } from '@config/index.js';
import axios from 'axios';
import * as cheerio from 'cheerio';

interface ScrapedChannelData {
  name: string;
  description: string;
  iconUrl: string;
  followerCount: number;
  inviteLink: string;
}

export class WhatsAppChannelScraper {
  private readonly userAgent = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36';
  private readonly delay = config.SCRAPER_INTERVAL_MS;

  async scrape(channelUrl: string): Promise<ScrapedChannelData> {
    // Add delay to respect rate limit
    await this.sleep(this.delay);

    const response = await axios.get(channelUrl, {
      headers: {
        'User-Agent': this.userAgent,
        'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8',
        'Accept-Language': 'en-US,en;q=0.5',
        'Accept-Encoding': 'gzip, deflate, br',
        'Connection': 'keep-alive',
        'Upgrade-Insecure-Requests': '1',
      },
      timeout: 15000,
      maxRedirects: 5,
    });

    const $ = cheerio.load(response.data);

    // Extract channel data from WhatsApp web page
    const name = this.extractName($);
    const description = this.extractDescription($);
    const iconUrl = this.extractIcon($);
    const followerCount = this.extractFollowers($);

    return {
      name,
      description,
      iconUrl,
      followerCount,
      inviteLink: channelUrl,
    };
  }

  private extractName($: cheerio.CheerioAPI): string {
    // Try multiple selectors for channel name
    const selectors = [
      'h1[data-testid="channel-name"]',
      'h1._amgw',
      'header h1',
      'div[role="heading"] h1',
      'h1',
    ];

    for (const selector of selectors) {
      const element = $(selector).first();
      if (element.length && element.text().trim()) {
        return element.text().trim();
      }
    }

    // Fallback: try to get from meta tags
    const ogTitle = $('meta[property="og:title"]').attr('content');
    if (ogTitle) return ogTitle;

    const twitterTitle = $('meta[name="twitter:title"]').attr('content');
    if (twitterTitle) return twitterTitle;

    return 'Canal WhatsApp';
  }

  private extractDescription($: cheerio.CheerioAPI): string {
    const selectors = [
      'div[data-testid="channel-description"]',
      'div._amgx',
      'header + div',
      'meta[property="og:description"]',
      'meta[name="twitter:description"]',
    ];

    for (const selector of selectors) {
      const element = $(selector).first();
      if (element.length) {
        if (element.is('meta')) {
          const content = element.attr('content');
          if (content) return content.trim();
        } else {
          const text = element.text().trim();
          if (text) return text;
        }
      }
    }

    return '';
  }

  private extractIcon($: cheerio.CheerioAPI): string {
    const selectors = [
      'img[data-testid="channel-avatar"]',
      'header img[alt]',
      'img._amgy',
      'meta[property="og:image"]',
      'meta[name="twitter:image"]',
    ];

    for (const selector of selectors) {
      const element = $(selector).first();
      if (element.length) {
        if (element.is('meta')) {
          const content = element.attr('content');
          if (content) return content;
        } else {
          const src = element.attr('src') || element.attr('data-src');
          if (src) return src;
        }
      }
    }

    return '';
  }

  private extractFollowers($: cheerio.CheerioAPI): number {
    const selectors = [
      'span[data-testid="channel-followers"]',
      'span._amgz',
      'header span:contains("abonnés")',
      'header span:contains("followers")',
      'header span:contains("follower")',
    ];

    for (const selector of selectors) {
      const element = $(selector).first();
      if (element.length) {
        const text = element.text().trim();
        const parsed = this.parseNumber(text);
        if (parsed > 0) return parsed;
      }
    }

    // Try to find in page text
    const bodyText = $('body').text();
    const patterns = [
      /(\d[\d\s,.]*)\s*abonnés?/i,
      /(\d[\d\s,.]*)\s*followers?/i,
      /"follower_count":\s*(\d+)/,
    ];

    for (const pattern of patterns) {
      const match = bodyText.match(pattern);
      if (match) {
        return this.parseNumber(match[1]);
      }
    }

    return 0;
  }

  private parseNumber(text: string): number {
    const cleaned = text.replace(/[^\d.,KkMm]/g, '').replace(',', '.').trim();
    if (!cleaned) return 0;

    const multiplier = cleaned.toLowerCase().includes('k') ? 1000 : 
                       cleaned.toLowerCase().includes('m') ? 1000000 : 1;
    const num = parseFloat(cleaned.replace(/[KkMm]/g, ''));
    return Math.round(num * multiplier);
  }

  private sleep(ms: number): Promise<void> {
    return new Promise(resolve => setTimeout(resolve, ms));
  }
}

export const channelScraper = new WhatsAppChannelScraper();