const mysql = require('mysql2/promise');
require('dotenv').config({ override: true });

function formatToYYYYMMDD(val) {
  if (!val) return null;
  const s = String(val).trim().replace(/[^0-9]/g, '');
  if (s.length === 8) {
    // YYYYMMDD
    return `${s.substring(0, 4)}-${s.substring(4, 6)}-${s.substring(6, 8)}`;
  } else if (s.length === 6) {
    // YYMMDD -> Assume 20XX
    const year = parseInt(s.substring(0, 2)) > 50 ? '19' + s.substring(0, 2) : '20' + s.substring(0, 2);
    return `${year}-${s.substring(2, 4)}-${s.substring(4, 6)}`;
  }
  
  // Try to split by dots or slashes if original had them
  const parts = String(val).trim().split(/[\.\-\/]/);
  if (parts.length === 3) {
    let y = parts[0];
    let m = parts[1].padStart(2, '0');
    let d = parts[2].padStart(2, '0');
    if (y.length === 2) y = '20' + y;
    if (y.length === 4 && m.length <= 2 && d.length <= 2) {
        return `${y}-${m}-${d}`;
    }
  }

  return val; // Return as is if format is unknown
}

(async () => {
  const pool = mysql.createPool({
    host: process.env.DB_HOST,
    user: process.env.DB_USER,
    password: process.env.DB_PASS,
    database: process.env.DB_NAME,
    port: parseInt(process.env.DB_PORT || '3306')
  });

  const connection = await pool.getConnection();
  try {
    const [rows] = await connection.query('SELECT id, purchase_date FROM asset_core WHERE purchase_date IS NOT NULL AND purchase_date != \'\'');
    console.log(`Found ${rows.length} rows to check.`);

    let updatedCount = 0;
    for (const row of rows) {
      const original = row.purchase_date;
      const formatted = formatToYYYYMMDD(original);

      if (formatted !== original && /^\d{4}-\d{2}-\d{2}$/.test(formatted)) {
        await connection.query('UPDATE asset_core SET purchase_date = ? WHERE id = ?', [formatted, row.id]);
        updatedCount++;
      }
    }

    console.log(`✅ Successfully updated ${updatedCount} rows to YYYY-MM-DD format.`);
  } catch (err) {
    console.error('❌ Error during date migration:', err);
  } finally {
    connection.release();
    await pool.end();
  }
})();