import mysql from 'mysql2/promise';
import { config } from './config.mjs';

let pool;

export function getPool() {
  if (!pool) {
    pool = mysql.createPool({
      ...config.db,
      waitForConnections: true,
      connectionLimit: 10,
      queueLimit: 0,
      charset: 'utf8mb4',
      timezone: 'Z',
      dateStrings: ['DATE'],
    });
  }
  return pool;
}

/** Consulta que devuelve filas. */
export async function q(sql, params = []) {
  const [rows] = await getPool().execute(sql, params);
  return rows;
}

/** Consulta que devuelve la primera fila o null. */
export async function q1(sql, params = []) {
  const rows = await q(sql, params);
  return rows[0] ?? null;
}

/** INSERT/UPDATE/DELETE; devuelve el ResultSetHeader. */
export async function exec(sql, params = []) {
  const [res] = await getPool().execute(sql, params);
  return res;
}

export async function cerrar() {
  if (pool) await pool.end();
  pool = undefined;
}