import mysql from 'mysql2/promise';
import dotenv from 'dotenv';

dotenv.config();

const { DB_HOST, DB_USER, DB_PASS, DB_NAME, DB_PORT } = process.env;

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

  console.log('🔄 Step 1: Updating purchase_date for PC-000000 assets to 2015-12-01...');
  const [updateResult] = await pool.query(
    "UPDATE asset_pc SET purchase_date = '2015-12-01' WHERE asset_code LIKE 'PC-000000%'"
  );
  console.log(`✅ Updated ${updateResult.affectedRows} records.`);

  console.log('🔄 Step 2: Re-sequencing all PC asset codes by Year...');
  const [pcs] = await pool.query('SELECT * FROM asset_pc');

  const getPrefix = (type) => {
    const t = type || '';
    if (t.includes('공용PC') || t.includes('개인PC') || t.includes('서버PC') || t === 'PC') return 'PC';
    return 'ETC';
  };

  const parseYYYYMM = (dateStr) => {
    if (!dateStr) return '000000';
    const clean = dateStr.replace(/[^0-9]/g, '');
    if (clean.length >= 6) return clean.substring(0, 6);
    return '000000';
  };

  const parseYYYY = (dateStr) => {
    const yyyymm = parseYYYYMM(dateStr);
    return yyyymm.substring(0, 4);
  };

  // Group and sort
  const mapped = pcs.map(item => {
    const prefix = getPrefix(item.asset_type);
    const yyyymm = parseYYYYMM(item.purchase_date);
    const yyyy = yyyymm.substring(0, 4);
    const sortKey = [
      item.purchase_date || '9999-99-99',
      item.model_name || '',
      item.mainboard || '',
      item.os || '',
      item.id
    ].join('|');
    return { ...item, prefix, yyyymm, yyyy, sortKey };
  });

  mapped.sort((a, b) => a.sortKey.localeCompare(b.sortKey));

  const counters = {};
  const updates = mapped.map(item => {
    const groupKey = `${item.prefix}-${item.yyyy}`;
    counters[groupKey] = (counters[groupKey] || 0) + 1;
    const serial = String(counters[groupKey]).padStart(4, '0');
    const newCode = `${item.prefix}-${item.yyyymm}-${serial}`;
    return { id: item.id, asset_code: newCode };
  });

  console.log('💾 Reflecting changes to DB...');
  const connection = await pool.getConnection();
  try {
    await connection.beginTransaction();
    // Clear codes to avoid unique constraint issues
    await connection.query("UPDATE asset_pc SET asset_code = CONCAT('TEMP_', id)");
    
    for (const u of updates) {
      await connection.query("UPDATE asset_pc SET asset_code = ? WHERE id = ?", [u.asset_code, u.id]);
    }
    await connection.commit();
    console.log(`✅ Re-sequencing completed for ${updates.length} PCs.`);
  } catch (err) {
    await connection.rollback();
    console.error('❌ Failed to re-sequence:', err);
  } finally {
    connection.release();
  }

  await pool.end();
}

run().catch(console.error);