require("dotenv").config({ path: require("path").resolve(__dirname, "../.env") });

const mysql = require("mysql2");
const pool = mysql.createPool({
	// connectionLimit: process.env.CONNECTIONLIMIT,
	host: process.env.DBHOST,
	port: process.env.DBPORT,
	user: process.env.DBUSER,
	password: process.env.DBPASSWORD,
	database: process.env.DATABASE,
	connectionLimit: 10,
	connectTimeout: 20000,
	acquireTimeout: 20000,
	// acquireTimeout: Number(process.env.ACQRTIMEOUT), // in ms
});

pool.getConnection((err, conn) => {
	if (err) {
		if (err.code === "PROTOCOL_CONNECTION_LOST") {
			console.error("Koneksi database ditutup.");
		}
		if (err.code === "ER_CON_COUNT_ERROR") {
			console.error("Basis data memiliki terlalu banyak koneksi.");
		}
		if (err.code === "ECONNREFUSED") {
			console.error("Koneksi database ditolak.");
		}
		console.error(err);
	}
	if (conn) conn.release();
	return;
});

// pool.on('acquire', function (connection) {
//   console.log('Connection %d acquired', connection.threadId);
// });

// pool.on('connection', function (connection) {
//   console.log('Connection %d connect', connection.threadId);
// });

// pool.on('release', function (connection) {
//   console.log('Connection %d released', connection.threadId);
// });

// --- The Deadlock Optimizer ---
// This function wraps your queries and retries them if a deadlock occurs
const queryWithRetry = async (sql, params, retries = 3) => {
	for (let attempt = 1; attempt <= retries; attempt++) {
		try {
			return await pool.execute(sql, params);
		} catch (err) {
			const isDeadlock = err.code === 'ER_LOCK_DEADLOCK' || err.errno === 1213;

			if (isDeadlock && attempt < retries) {
				console.warn(`Deadlock detected. Retry attempt ${attempt}...`);
				// Wait slightly longer each time (Exponential Backoff)
				await new Promise(res => setTimeout(res, attempt * 100));
				continue;
			}
			throw err; // If not a deadlock or out of retries, throw
		}
	}
};

module.exports = {
	pool,
	query: queryWithRetry
};


module.exports = pool;