import mysql from "mysql2/promise";
let cachedPool;
let connectionCount = 0;

function getPool() {
  if (!cachedPool) {
    cachedPool = mysql.createPool({
      host: process.env.DB_HOST,
      user: process.env.DB_USER,
      password: process.env.DB_PASSWORD,
      database: process.env.DB_NAME,
      port: process.env.DB_PORT,
      connectionLimit: 20,
      waitForConnections: true,
      queueLimit: 10,
      connectTimeout: 5000,
      idleTimeout: 60000,
    });

    // Ereignisse für das Protokollieren der Verbindungsstatistiken
    let maxUsed = 0;

    cachedPool.on("acquire", () => {
      connectionCount++;
      // Debug-Logging entfernt
      if (connectionCount > maxUsed) {
        maxUsed = connectionCount;
      }
    });
    cachedPool.on("release", () => {
      connectionCount--;
    });
    cachedPool.on("enqueue", () => {
      // Debug-Logging entfernt
    });
  }
  return cachedPool;
}

export function closePool() {
  if (cachedPool) {
    cachedPool.end(() => {
      console.log("All pool connections closed.");
    });
    cachedPool = null;
  }
}

export default getPool;