package database;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * Create a persistent database connection.
 *
 * @author Maurice Laveaux
 */
public class DBConnection {

    /* The interface to the postgresql database connection. */
    private Connection m_connection;

    public DBConnection(final String hostaddress,
            final String port,
            final String databasename,
            final String username,
            final String password) {

        String url = "jdbc:postgresql://" + hostaddress + ":" + port + "/" + databasename;

        try {
            m_connection = DriverManager.getConnection(url, username, password);
        } catch (SQLException ex) {
            //TODO: retry when db connection fails or something.
            throw new RuntimeException("cannot connect to host: " + url);
        }
    }

    /**
     * prepares a statement.
     *
     * @param query The query to prepare.
     * @return A prepared statement.
     */
    public PreparedStatement create(final String query) throws SQLException {
        return m_connection.prepareStatement(query);
    }

    /**
     * Closes the connection if it exists.
     */
    public void close() {
        if (m_connection != null) {
            try {
                m_connection.close();
            } catch (SQLException ex) {
                /* TODO: what to do here else. */
                Logger.getLogger(DBConnection.class.getName()).log(Level.SEVERE, null, ex);
            }
        }
    }
}