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

dotenv.config();

// Fix per __dirname in ES Modules
const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

// Configurazione DB con gestione esplicita della porta e casting a numero
const dbConfig = {
  host: process.env.DB_HOST || 'db',
  port: Number(process.env.DB_PORT) || 3306, // Importante: converte la stringa ENV in numero
  user: process.env.DB_USER || 'omni_user',
  password: process.env.DB_PASSWORD || 'omni_pass',
  database: process.env.DB_NAME || 'omnisupport',
  waitForConnections: true,
  connectionLimit: 10,
  queueLimit: 0,
  multipleStatements: true // Necessario per eseguire schema.sql che contiene più query
};

const pool = mysql.createPool(dbConfig);

export const query = async (sql, params) => {
  try {
    const [results] = await pool.execute(sql, params);
    return results;
  } catch (error) {
    console.error('Database query error:', error);
    throw error;
  }
};

export const checkConnection = async () => {
  try {
    const connection = await pool.getConnection();
    await connection.ping();
    connection.release();
    // Log che conferma l'host e la porta utilizzati (utile per debug esterni)
    console.log(`✅ Connected to MySQL Database at ${dbConfig.host}:${dbConfig.port}`);
    return true;
  } catch (error) {
    console.error(`❌ Database connection failed (${dbConfig.host}:${dbConfig.port}):`, error.message);
    return false;
  }
};

export const initDb = async () => {
  try {
    console.log(`🔌 Attempting connection to database at ${dbConfig.host}:${dbConfig.port}...`);
    
    // Verifica che la connessione sia attiva prima di provare a inizializzare
    const isConnected = await checkConnection();
    if (!isConnected) {
        console.error("❌ Skipping initialization due to connection failure.");
        return;
    }

    // Controlla se la tabella 'agents' esiste già
    // Se esiste, assumiamo che il DB sia già popolato e non facciamo nulla per evitare sovrascritture
    const [rows] = await pool.query("SHOW TABLES LIKE 'agents'");
    
    if (Array.isArray(rows) && rows.length > 0) {
      console.log('ℹ️ Database tables already exist. Skipping initialization.');
      return;
    }

    console.log('⚠️ Database empty or uninitialized. Running schema.sql...');

    const schemaPath = path.join(__dirname, 'schema.sql');
    const schemaSql = fs.readFileSync(schemaPath, 'utf8');

    // Eseguiamo lo script SQL completo
    await pool.query(schemaSql);

    console.log('✅ Database initialized successfully with schema and seed data.');
    console.log('👤 Superadmin created: fcarra79@gmail.com');

  } catch (error) {
    console.error('❌ Failed to initialize database:', error);
  }
};