#!/usr/bin/env node

/**
 * Script to verify broken links by pinging localhost:3001
 * Reads broken-links CSV, tests each URL, updates "Fixed?" column
 */

const fs = require('fs');
const http = require('http');
const path = require('path');

const CSV_FILE = 'broken-links.csv';
const BASE_URL = 'http://localhost:3001';

/**
 * Parse CSV file
 */
function parseCSV(content) {
  const lines = content.split('\n');
  const headers = lines[0].split(',');
  const rows = lines.slice(1).map(line => {
    // Handle CSV with quoted fields
    const fields = [];
    let current = '';
    let inQuotes = false;

    for (let i = 0; i < line.length; i++) {
      const char = line[i];

      if (char === '"') {
        inQuotes = !inQuotes;
      } else if (char === ',' && !inQuotes) {
        fields.push(current);
        current = '';
      } else {
        current += char;
      }
    }
    fields.push(current); // Add last field

    return fields;
  });

  return { headers, rows };
}

/**
 * Convert parsed data back to CSV
 */
function toCSV(headers, rows) {
  const headerLine = headers.join(',');
  const dataLines = rows.map(row => row.join(','));
  return [headerLine, ...dataLines].join('\n');
}

/**
 * Check if a URL returns 404 or shows Next.js 404 page
 */
function checkURL(url) {
  return new Promise((resolve) => {
    const fullUrl = `${BASE_URL}${url}`;

    http.get(fullUrl, (res) => {
      // If actual HTTP 404, definitely broken
      if (res.statusCode === 404) {
        resolve(true);
        return;
      }

      // Next.js often returns 200 for custom 404 pages
      // So we need to check the content
      let data = '';

      res.on('data', (chunk) => {
        data += chunk;
      });

      res.on('end', () => {
        // Check for common 404 page indicators
        const is404Page =
          data.includes('Page Not Found') ||
          data.includes('404') && data.includes('couldn\'t find the page') ||
          data.includes('"statusCode":404') ||
          data.includes('class="error-404"') ||
          data.includes('id="__next-error__"') ||
          data.includes('name="next-error" content="not-found"') ||
          data.includes('NEXT_HTTP_ERROR_FALLBACK;404');

        resolve(is404Page);
      });
    }).on('error', (err) => {
      console.error(`Error checking ${url}:`, err.message);
      resolve(null); // null means error occurred
    });
  });
}

/**
 * Main function
 */
async function main() {
  console.log('🔍 Verifying broken links...\n');

  // Read CSV file
  const csvPath = path.join(process.cwd(), CSV_FILE);
  if (!fs.existsSync(csvPath)) {
    console.error(`❌ Error: ${CSV_FILE} not found`);
    process.exit(1);
  }

  const content = fs.readFileSync(csvPath, 'utf8');
  const { headers, rows } = parseCSV(content);

  console.log(`📄 Found ${rows.length} broken link entries\n`);

  // Check each URL
  let checked = 0;
  let stillBroken = 0;
  let fixed = 0;
  let errors = 0;

  for (let i = 0; i < rows.length; i++) {
    const row = rows[i];
    if (row.length < 4) continue; // Skip invalid rows

    const brokenUrl = row[3]; // Column 4 (0-indexed = 3)
    if (!brokenUrl || brokenUrl === 'broken_url') continue; // Skip header or empty

    process.stdout.write(`[${i + 1}/${rows.length}] Checking ${brokenUrl}... `);

    const is404 = await checkURL(brokenUrl);

    if (is404 === null) {
      console.log('❌ ERROR');
      errors++;
      // Don't update the "Fixed?" column on error
    } else if (is404) {
      console.log('❌ Still broken (404)');
      row[0] = 'no'; // Update "Fixed?" column
      stillBroken++;
    } else {
      console.log('✅ Fixed (not 404)');
      row[0] = 'yes'; // Update "Fixed?" column
      fixed++;
    }

    checked++;
  }

  // Write updated CSV
  const updatedCSV = toCSV(headers, rows);
  fs.writeFileSync(csvPath, updatedCSV, 'utf8');

  console.log('\n📊 Summary:');
  console.log(`  Total checked: ${checked}`);
  console.log(`  Still broken (404): ${stillBroken}`);
  console.log(`  Fixed (not 404): ${fixed}`);
  console.log(`  Errors: ${errors}`);
  console.log(`\n✅ Updated ${CSV_FILE}`);
}

// Run the script
if (require.main === module) {
  main()
    .catch(error => {
      console.error('❌ Error:', error);
      process.exit(1);
    });
}

module.exports = { checkURL, parseCSV, toCSV };