mport org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.h2.jdbcx.JdbcConnectionPool;

import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Properties;

public class ConnectionManager {

    private static final Logger log = LogManager
            .getLogger(ConnectionManager.class.getName());

    public static Connection getConnection() {
        log.traceEntry();
        try {
            return ConnectionManager.getInstance().getConnection();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        log.traceExit();
        return null;
    }

    private static JdbcConnectionPool connectionPool;

    private static synchronized JdbcConnectionPool getInstance() {
        log.traceEntry();
        if (connectionPool == null) {
            Properties properties = new Properties();
            try (InputStream in = Files.newInputStream(
                    Paths.get("./src/main/resources/jdbc.properties"))) {
                properties.load(in);
            } catch (IOException e) {
                e.printStackTrace();
            }

            String url = properties.getProperty("jdbc.url");
            String username = properties.getProperty("jdbc.username");
            String password = properties.getProperty("jdbc.password");

            connectionPool = JdbcConnectionPool.create(url, username, password);

        }
        log.traceExit();
        return connectionPool;
    }
}