package server;

import java.io.FileInputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.util.Properties;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * Handles the connection to our database server
 *
 * @author Stuart
 *
 */
public class Database {

    private static final Logger LOG = Logger.getLogger(Database.class.getName());
    private static Properties props = new Properties();
    private static Connection conn = null;
    private static long lastUsed = System.currentTimeMillis();

    /**
     * Create
     *
     * @param _props
     *            database properties
     * @throws Exception
     *             error creating a new connection
     */
    public static void init() throws Exception {
        LOG.log(Level.INFO, "initiating database connection...");
        try {
            FileInputStream fis = new FileInputStream("database.xml");
            props.loadFromXML(fis);
        } catch (Exception e) {
            LOG.log(Level.SEVERE, "error loading database properties", e);
            throw new Exception("error loading database properties");
        }
        connect();
    }

    private static void connect() throws Exception {
        LOG.log(Level.INFO, "connecting to database...");
        try {
            Class.forName("com.mysql.jdbc.Driver").newInstance();
        } catch (Exception e) {
            LOG.log(Level.SEVERE, "error loading mysql driver", e);
            throw new Exception("error loading mysql driver");
        }
        try {
            conn = DriverManager.getConnection("jdbc:mysql://" + props.getProperty("host") + ":"
                            + props.getProperty("port") + "/"
                            + props.getProperty("name"),
                    props.getProperty("username"),
                    props.getProperty("password"));
        } catch (Exception e) {
            LOG.log(Level.SEVERE, "error connecting to database", e);
            throw new Exception("error connecting to database "
                    + e.getMessage());
        }
    }

    /**
     * Get the database connection, renews the connection if the connection has
     * not been used for 5 minutes
     *
     * @return the connection
     * @throws Exception
     *             error getting the connection
     */
    public static Connection getConnection() throws Exception {
        if (conn == null) {
            throw new Exception("connection is null");
        }
        if (System.currentTimeMillis() - lastUsed > 300000) {
            try {
                lastUsed = System.currentTimeMillis();
                conn.close();
                connect();
            } catch (Exception e) {
                LOG.log(Level.SEVERE, "error refreshing database connection", e);
                throw new Exception("error refreshing database connection");
            }
        }
        return conn;
    }

    /**
     * Close the database connection
     *
     * @throws Exception
     *             error closing the database connection
     */
    public static void close() throws Exception {
        if (conn == null) {
            throw new Exception("connection is null");
        }
        conn.close();
    }

}