import express from 'express';
import cors from 'cors';
import mysql from 'mysql2/promise';
import dotenv from 'dotenv';
import path from 'path';
import { fileURLToPath } from 'url';

dotenv.config();

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

const app = express();
app.use(cors());
app.use(express.json({ limit: '50mb' }));

// MySQL Connection Pool
const pool = mysql.createPool({
  host: process.env.DB_HOST || 'localhost',
  user: process.env.DB_USER || 'itam_user',
  password: process.env.DB_PASSWORD || 'itam_pw',
  database: process.env.DB_NAME || 'itam_db',
  waitForConnections: true,
  connectionLimit: 10,
  queueLimit: 0
});

// Helper for DB updates
async function ensureTables() {
  try {
    // Cloud_Assets Table
    await pool.query(`
      CREATE TABLE IF NOT EXISTS cloud_assets (
        id VARCHAR(50) PRIMARY KEY,
        platform_name VARCHAR(100),
        corp VARCHAR(50),
        dept VARCHAR(100),
        purpose VARCHAR(255),
        account_name VARCHAR(100),
        payment_method VARCHAR(50),
        payment_date VARCHAR(50),
        card_number VARCHAR(50),
        monthly_fee VARCHAR(50),
        note TEXT
      )
    `);
    
    // Logs Table
    await pool.query(`
      CREATE TABLE IF NOT EXISTS asset_logs (
        id VARCHAR(50) PRIMARY KEY,
        asset_id VARCHAR(50),
        date VARCHAR(20),
        details TEXT,
        user VARCHAR(50),
        INDEX(asset_id)
      )
    `);
    console.log('✅ Cloud & Logs tables ensured.');
  } catch (err) {
    console.error('❌ Error ensuring tables:', err);
  }
}

ensureTables();

// --- API Endpoints ---

// Get Master Data (Multi-tab)
app.get('/api/master-data', async (req, res) => {
  try {
    const [pc] = await pool.query('SELECT * FROM pc_assets');
    const [server] = await pool.query('SELECT * FROM server_assets');
    const [storage] = await pool.query('SELECT * FROM storage_assets');
    const [equip] = await pool.query('SELECT * FROM equip_assets');
    const [mobile] = await pool.query('SELECT * FROM mobile_assets');
    const [subSw] = await pool.query('SELECT * FROM sw_sub_assets');
    const [permSw] = await pool.query('SELECT * FROM sw_perm_assets');
    const [cloud] = await pool.query('SELECT * FROM cloud_assets');
    const [swUsers] = await pool.query('SELECT * FROM sw_users');
    const [logs] = await pool.query('SELECT * FROM asset_logs ORDER BY date DESC');

    res.json({
      pc, server, storage, equip, mobile,
      subSw, permSw, cloud,
      swUsers,
      logs
    });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// Save Hardware Asset (PC, Server, Storage, etc.)
app.post('/api/hardware/save', async (req, res) => {
  const asset = req.body;
  const type = asset.type;
  let table = '';

  if (type === '개인PC' || type === 'PC') table = 'pc_assets';
  else if (type === '서버') table = 'server_assets';
  else if (type === '스토리지') table = 'storage_assets';
  else if (type === '모바일' || type === '모바일기기') table = 'mobile_assets';
  else table = 'equip_assets';

  try {
    // Check if exists
    const [rows] = await pool.query(`SELECT id FROM ${table} WHERE id = ?`, [asset.id]);
    
    const data = { ...asset };
    delete data.id;
    delete data.type;

    if (rows.length > 0) {
      await pool.query(`UPDATE ${table} SET ? WHERE id = ?`, [data, asset.id]);
    } else {
      await pool.query(`INSERT INTO ${table} SET ?`, [{ id: asset.id, ...data }]);
    }
    res.json({ success: true });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// Save Software Asset
app.post('/api/software/save', async (req, res) => {
  const asset = req.body;
  const table = asset.type === '구독SW' ? 'sw_sub_assets' : (asset.type === '영구SW' ? 'sw_perm_assets' : 'cloud_assets');
  
  try {
    const [rows] = await pool.query(`SELECT id FROM ${table} WHERE id = ?`, [asset.id]);
    const data = { ...asset };
    delete data.id;
    delete data.type;

    if (rows.length > 0) {
      await pool.query(`UPDATE ${table} SET ? WHERE id = ?`, [data, asset.id]);
    } else {
      await pool.query(`INSERT INTO ${table} SET ?`, [{ id: asset.id, ...data }]);
    }
    res.json({ success: true });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// Delete Asset
app.delete('/api/asset/:type/:id', async (req, res) => {
  const { type, id } = req.params;
  let table = '';
  
  if (type === '개인PC' || type === 'PC') table = 'pc_assets';
  else if (type === '서버') table = 'server_assets';
  else if (type === '스토리지') table = 'storage_assets';
  else if (type === '모바일' || type === '모바일기기') table = 'mobile_assets';
  else if (type === '전산비품' || type === '기타자산') table = 'equip_assets';
  else if (type === '구독SW') table = 'sw_sub_assets';
  else if (type === '영구SW') table = 'sw_perm_assets';
  else if (type === '클라우드') table = 'cloud_assets';

  try {
    await pool.query(`DELETE FROM ${table} WHERE id = ?`, [id]);
    // Also delete logs and users if needed
    if (table.includes('sw')) await pool.query('DELETE FROM sw_users WHERE sw_id = ?', [id]);
    await pool.query('DELETE FROM asset_logs WHERE asset_id = ?', [id]);
    
    res.json({ success: true });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// Log Save
app.post('/api/logs/save', async (req, res) => {
  const log = req.body;
  try {
    const [rows] = await pool.query('SELECT id FROM asset_logs WHERE id = ?', [log.id]);
    if (rows.length > 0) {
      await pool.query('UPDATE asset_logs SET ? WHERE id = ?', [log, log.id]);
    } else {
      await pool.query('INSERT INTO asset_logs SET ?', [log]);
    }
    res.json({ success: true });
  } catch (err) { res.status(500).json({ error: err.message }); }
});

// SW User Save
app.post('/api/sw-users/save', async (req, res) => {
  const user = req.body;
  try {
    const [rows] = await pool.query('SELECT id FROM sw_users WHERE id = ?', [user.id]);
    if (rows.length > 0) {
      await pool.query('UPDATE sw_users SET ? WHERE id = ?', [user, user.id]);
    } else {
      await pool.query('INSERT INTO sw_users SET ?', [user]);
    }
    res.json({ success: true });
  } catch (err) { res.status(500).json({ error: err.message }); }
});

app.post('/api/sw-users/batch', async (req, res) => {
  const { swId, users } = req.body;
  try {
    await pool.query('DELETE FROM sw_users WHERE sw_id = ?', [swId]);
    for (const u of users) {
      await pool.query('INSERT INTO sw_users SET ?', { ...u, sw_id: swId });
    }
    res.json({ success: true });
  } catch (err) { res.status(500).json({ error: err.message }); }
});

// 자산번호 생성 API
app.get('/api/generate-asset-code', async (req, res) => {
  const { prefix } = req.query;
  if (!prefix) return res.status(400).json({ error: 'Prefix is required' });
  
  try {
    const tables = [
      'pc_assets', 'server_assets', 'storage_assets', 'equip_assets', 'mobile_assets', 
      'sw_sub_assets', 'sw_perm_assets'
    ];
    let maxNum = 0;
    
    for (const table of tables) {
      const [rows] = await pool.query(`SELECT asset_code FROM ${table} WHERE asset_code LIKE ?`, [`${prefix}%`]);
      rows.forEach(r => {
        const numPart = r.asset_code.replace(prefix, '');
        const num = parseInt(numPart);
        if (!isNaN(num) && num > maxNum) maxNum = num;
      });
    }
    
    const nextCode = `${prefix}${(maxNum + 1).toString().padStart(3, '0')}`;
    res.json({ nextCode });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

const PORT = process.env.PORT || 3000;
app.listen(PORT, () => {
  console.log(`🚀 ITAM Dedicated API Server running on http://localhost:${PORT}`);
});