import mysql from 'mysql2/promise';
import XLSX from 'xlsx';
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('📡 Fetching data from DB...');
  const [pcs] = await pool.query('SELECT * FROM asset_pc');
  const [servers] = await pool.query('SELECT * FROM asset_server');

  const getPrefix = (type) => {
    const t = type || '';
    if (t.includes('서버 렉') || t.includes('워크스테이션')) return 'SVR';
    if (t.includes('스토리지 렉')) return 'STO';
    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 processList = (list) => {
    // 1. Prepare data with sorting keys and groups
    const mapped = list.map(item => {
      const prefix = getPrefix(item.asset_type);
      const yyyymm = parseYYYYMM(item.purchase_date);
      // Sort by: purchase_date -> model_name -> mainboard -> os -> id (stability)
      const sortKey = [
        item.purchase_date || '9999-99-99',
        item.model_name || '',
        item.mainboard || '',
        item.os || '',
        item.id
      ].join('|');

      return { ...item, prefix, yyyymm, sortKey };
    });

    // 2. Sort the list
    mapped.sort((a, b) => a.sortKey.localeCompare(b.sortKey));

    // 3. Assign new codes
    const counters = {};
    return mapped.map(item => {
      const groupKey = `${item.prefix}-${item.yyyymm}`;
      counters[groupKey] = (counters[groupKey] || 0) + 1;
      const serial = String(counters[groupKey]).padStart(4, '0');
      const newCode = `${groupKey}-${serial}`;

      return {
        asset_code: newCode,
        category: item.category,
        asset_type: item.asset_type,
        asset_purpose: item.asset_purpose || '',
        memo: `[Legacy: ${item.asset_code || 'N/A'}] ${item.memo || ''}`.trim()
      };
    });
  };

  console.log('🔄 Processing codes...');
  const finalServers = processList(servers);
  const finalPcs = processList(pcs);

  console.log('📊 Generating Excel...');
  const wb = XLSX.utils.book_new();
  const wsServers = XLSX.utils.json_to_sheet(finalServers);
  const wsPcs = XLSX.utils.json_to_sheet(finalPcs);

  XLSX.utils.book_append_sheet(wb, wsServers, 'asset_server');
  XLSX.utils.book_append_sheet(wb, wsPcs, 'asset_pc');

  const fileName = 'Asset_Code_Preview_20260602.xlsx';
  XLSX.writeFile(wb, fileName);

  console.log(`✅ Completed! File saved as: ${fileName}`);
  await pool.end();
}

run().catch(console.error);