var mysql = require('mysql2/promise')

var pool = null

function getPool() {
  if (pool) return pool

  pool = mysql.createPool({
    host: process.env.DB_HOST || 'localhost',
    port: parseInt(process.env.DB_PORT || '3306'),
    user: process.env.DB_USER || 'root',
    password: process.env.DB_PASSWORD || '',
    database: process.env.DB_NAME || 'hox',
    waitForConnections: true,
    connectionLimit: 10,
    charset: 'utf8mb4'
  })

  return pool
}

async function query(sql, params) {
  var p = getPool()
  var [rows] = await p.execute(sql, params)
  return rows
}

async function insert(sql, params) {
  var p = getPool()
  var [result] = await p.execute(sql, params)
  return result
}

async function update(sql, params) {
  var p = getPool()
  var [result] = await p.execute(sql, params)
  return result
}

module.exports = {
  query: query,
  insert: insert,
  update: update,
  getPool: getPool
}