import axios from 'axios';
import * as cheerio from 'cheerio';
import { classifySector } from './classify-sector.js';
import pg from 'pg';
import dotenv from 'dotenv';

dotenv.config();

const pool = new pg.Pool({
  connectionString: process.env.DATABASE_URL || 'postgresql://tenderpilot:tenderpilot123@localhost:5432/tenderpilot'
});

const client = axios.create({
  timeout: 15000,
  maxRedirects: 5,
  headers: {
    'User-Agent': 'TenderRadar/1.0 (UK Public Procurement Aggregator)'
  }
});

function parseDate(dateStr) {
  if (!dateStr || dateStr.trim() === '') return null;
  try {
    const date = new Date(dateStr);
    if (isNaN(date.getTime())) return null;
    return date.toISOString();
  } catch (e) {
    return null;
  }
}

function cleanText(text) {
  if (!text) return '';
  return text
    .replace(/\s+/g, ' ')
    .replace(/^\s+|\s+$/g, '')
    .trim();
}

async function scrapePage(pageNum = 1) {
  try {
    // Fetch list page with pagination
    const listUrl = `https://etendersni.gov.uk/epps/home.do?page=${pageNum}&status=open`;
    
    console.log(`[${new Date().toISOString()}] Fetching page ${pageNum}: ${listUrl}`);
    const listResp = await client.get(listUrl);
    const $ = cheerio.load(listResp.data);
    
    // Extract entryIds and titles from list
    const tenders = [];
    const processedIds = new Set();
    
    $('a[href*="entryId"]').each((i, el) => {
      const href = $(el).attr('href');
      const text = $(el).text().trim();
      
      if (!href || !text) return;
      
      const match = href.match(/entryId=(\d+)/);
      if (match) {
        const id = match[1];
        if (!processedIds.has(id)) {
          processedIds.add(id);
          tenders.push({
            id,
            titleSnippet: text.substring(0, 200),
            detailUrl: href.startsWith('http') ? href : 'https://etendersni.gov.uk' + (href.startsWith('/') ? href : '/epps/' + href)
          });
        }
      }
    });
    
    console.log(`Found ${tenders.length} tenders on page ${pageNum}`);
    
    let insertedCount = 0;
    
    // Fetch detail page for each tender
    for (const tender of tenders) {
      try {
        console.log(`  Fetching tender ${tender.id}...`);
        const detailResp = await client.get(tender.detailUrl);
        const d$ = cheerio.load(detailResp.data);
        
        // Extract tender details from detail page
        let title = tender.titleSnippet;
        let description = '';
        let summary = '';
        let deadline = null;
        let value = null;
        let authority = 'Unknown';
        let location = 'Northern Ireland';
        let documentsUrl = '';
        let cpvCodes = [];
        
        // Try to extract structured data
        const text = d$('body').text();
        
        // Look for common patterns in the page
        d$('div, p, span, td, li').each((i, el) => {
          const content = d$(el).text().trim();
          
          // Try to find deadline
          if (!deadline && content.match(/deadline|closing\s+date|deadline\s+date/i)) {
            const dateMatch = content.match(/(\d{1,2}[\/\-]\d{1,2}[\/\-]\d{2,4})/);
            if (dateMatch) {
              const parsed = parseDate(dateMatch[1]);
              if (parsed) deadline = parsed;
            }
          }
          
          // Try to find value
          if (!value && content.match(/value|budget|estimate|worth|£|GBP/i)) {
            const valueMatch = content.match(/[£\$€]?\s*(\d{1,3}(?:,\d{3})*(?:\.\d{2})?)/);
            if (valueMatch) {
              value = parseFloat(valueMatch[1].replace(/,/g, ''));
            }
          }
          
          // Try to find authority/department
          if (content.match(/department|authority|council|agency|body|organisation/i) && content.length < 200) {
            const cleanContent = cleanText(content);
            if (cleanContent.length > 5 && cleanContent.length < 150) {
              authority = cleanContent;
            }
          }
        });
        
        // Get title from page header
        const pageTitle = d$('h1, h2, .page-title, [class*="title"]').first().text().trim();
        if (pageTitle && pageTitle.length > 0 && pageTitle.length < 500) {
          title = pageTitle;
        }
        
        description = cleanText(text.substring(0, 1000));
        summary = cleanText(title);
        
        // Find documents link if available
        d$('a[href*="download"], a[href*="document"], a[href*="file"]').each((i, el) => {
          const href = d$(el).attr('href');
          if (href && !documentsUrl) {
            documentsUrl = href.startsWith('http') ? href : 'https://etendersni.gov.uk' + (href.startsWith('/') ? href : '/epps/' + href);
            return false;
          }
        });
        
        // Insert into database
        await pool.query(
          `INSERT INTO tenders (
            source, source_id, title, description, summary, cpv_codes,
            value_low, value_high, currency, published_date, deadline,
            authority_name, authority_type, location, documents_url, notice_url, status, sector
          ) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13, $14, $15, $16, $17, $18)
           ON CONFLICT (source_id) DO NOTHING`,
          [
            'etendersni',
            `etendersni_${tender.id}`,
            title.substring(0, 500) || 'Untitled Tender',
            description,
            summary.substring(0, 500),
            cpvCodes,
            value,
            value,
            'GBP',
            new Date().toISOString(),
            deadline,
            authority.substring(0, 255),
            'government',
            location.substring(0, 255),
            documentsUrl,
            tender.detailUrl,
            deadline && new Date(deadline) > new Date() ? 'open' : 'closed',
            classifySector(title, description, authority)
          ]
        );
        
        insertedCount++;
        console.log(`    ✓ Inserted tender ${tender.id}`);
        
        // Rate limiting
        await new Promise(resolve => setTimeout(resolve, 500));
        
      } catch (e) {
        console.error(`  Error processing tender ${tender.id}: ${e.message}`);
      }
    }
    
    return { pageNum, insertedCount, tenderCount: tenders.length };
    
  } catch (error) {
    console.error(`Error scraping page ${pageNum}:`, error.message);
    return { pageNum, insertedCount: 0, tenderCount: 0 };
  }
}

async function scrapeTenders() {
  try {
    console.log(`[${new Date().toISOString()}] Starting eTendersNI scrape...`);
    
    let totalInserted = 0;
    let pageNum = 1;
    let lastPageHadTenders = true;
    
    // Scrape pages until we find one with no tenders (or max 10 pages)
    while (lastPageHadTenders && pageNum <= 10) {
      const result = await scrapePage(pageNum);
      totalInserted += result.insertedCount;
      lastPageHadTenders = result.tenderCount > 0;
      pageNum++;
      
      // Avoid rate limiting
      await new Promise(resolve => setTimeout(resolve, 1000));
    }
    
    console.log(`[${new Date().toISOString()}] eTendersNI scrape complete. Inserted ${totalInserted} tenders`);
    
  } catch (error) {
    console.error('Fatal error:', error.message);
  } finally {
    await pool.end();
  }
}

scrapeTenders();