/*-------------------------------------------------------------------------
*
* Copyright (c) 2004-2005, PostgreSQL Global Development Group
*
* IDENTIFICATION
*   $PostgreSQL: pgjdbc/org/postgresql/ds/common/BaseDataSource.java,v 1.7 2005/02/02 23:30:31 oliver Exp $
*
*-------------------------------------------------------------------------
*/
package org.postgresql.ds.common;

import javax.naming.*;
import java.io.PrintWriter;
import java.sql.*;

import java.io.ObjectOutputStream;
import java.io.ObjectInputStream;
import java.io.IOException;

/**
 * Base class for data sources and related classes.
 *
 * @author Aaron Mulder (ammulder@chariotsolutions.com)
 */
public abstract class BaseDataSource implements Referenceable
{
    // Load the normal driver, since we'll use it to actually connect to the
    // database.  That way we don't have to maintain the connecting code in
    // multiple places.
    static {
        try
        {
            Class.forName("org.postgresql.Driver");
        }
        catch (ClassNotFoundException e)
        {
            System.err.println("PostgreSQL DataSource unable to load PostgreSQL JDBC Driver");
        }
    }

    // Needed to implement the DataSource/ConnectionPoolDataSource interfaces
    private transient PrintWriter logger;
    // Don't track loginTimeout, since we'd just ignore it anyway

    // Standard properties, defined in the JDBC 2.0 Optional Package spec
    private String serverName = "localhost";
    private String databaseName;
    private String user;
    private String password;
    private int portNumber;
    private int prepareThreshold;
    private int loginTimeout; // in seconds

    /**
     * Gets a connection to the PostgreSQL database.  The database is identified by the
     * DataSource properties serverName, databaseName, and portNumber. The user to
     * connect as is identified by the DataSource properties user and password.
     *
     * @return A valid database connection.
     * @throws SQLException
     *     Occurs when the database connection cannot be established.
     */
    public Connection getConnection() throws SQLException
    {
        return getConnection(user, password);
    }

    /**
     * Gets a connection to the PostgreSQL database.  The database is identified by the
     * DataSource properties serverName, databaseName, and portNumber. The user to
     * connect as is identified by the arguments user and password, which override
     * the DataSource properties by the same name.
     *
     * @return A valid database connection.
     * @throws SQLException
     *     Occurs when the database connection cannot be established.
     */
    public Connection getConnection(String user, String password) throws SQLException
    {
        try
        {
            Connection con = DriverManager.getConnection(getUrl(), user, password);
            if (logger != null)
            {
                logger.println("Created a non-pooled connection for " + user + " at " + getUrl());
            }
            return con;
        }
        catch (SQLException e)
        {
            if (logger != null)
            {
                logger.println("Failed to create a non-pooled connection for " + user + " at " + getUrl() + ": " + e);
            }
            throw e;
        }
    }

    /**
     * @return the login timeout, in seconds.
     */
    public int getLoginTimeout() throws SQLException
    {
        return loginTimeout;
    }

    /**
     * Set the login timeout, in seconds.
     */
    public void setLoginTimeout(int i) throws SQLException
    {
        this.loginTimeout = i;
    }

    /**
     * Gets the log writer used to log connections opened.
     */
    public PrintWriter getLogWriter() throws SQLException
    {
        return logger;
    }

    /**
     * The DataSource will note every connection opened to the provided log writer.
     */
    public void setLogWriter(PrintWriter printWriter) throws SQLException
    {
        logger = printWriter;
    }

    /**
     * Gets the name of the host the PostgreSQL database is running on.
     */
    public String getServerName()
    {
        return serverName;
    }

    /**
     * Sets the name of the host the PostgreSQL database is running on.  If this
     * is changed, it will only affect future calls to getConnection.  The default
     * value is <tt>localhost</tt>.
     */
    public void setServerName(String serverName)
    {
        if (serverName == null || serverName.equals(""))
        {
            this.serverName = "localhost";
        }
        else
        {
            this.serverName = serverName;
        }
    }

    /**
     * Gets the name of the PostgreSQL database, running on the server identified
     * by the serverName property.
     */
    public String getDatabaseName()
    {
        return databaseName;
    }

    /**
     * Sets the name of the PostgreSQL database, running on the server identified
     * by the serverName property. If this is changed, it will only affect
     * future calls to getConnection.
     */
    public void setDatabaseName(String databaseName)
    {
        this.databaseName = databaseName;
    }

    /**
     * Gets a description of this DataSource-ish thing.  Must be customized by
     * subclasses.
     */
    public abstract String getDescription();

    /**
     * Gets the user to connect as by default. If this is not specified, you must
     * use the getConnection method which takes a user and password as parameters.
     */
    public String getUser()
    {
        return user;
    }

    /**
     * Sets the user to connect as by default. If this is not specified, you must
     * use the getConnection method which takes a user and password as parameters.
     * If this is changed, it will only affect future calls to getConnection.
     */
    public void setUser(String user)
    {
        this.user = user;
    }

    /**
     * Gets the password to connect with by default.  If this is not specified but a
     * password is needed to log in, you must use the getConnection method which takes
     * a user and password as parameters.
     */
    public String getPassword()
    {
        return password;
    }

    /**
     * Sets the password to connect with by default.  If this is not specified but a
     * password is needed to log in, you must use the getConnection method which takes
     * a user and password as parameters.  If this is changed, it will only affect
     * future calls to getConnection.
     */
    public void setPassword(String password)
    {
        this.password = password;
    }

    /**
     * Gets the port which the PostgreSQL server is listening on for TCP/IP
     * connections.
     *
     * @return The port, or 0 if the default port will be used.
     */
    public int getPortNumber()
    {
        return portNumber;
    }

    /**
     * Gets the port which the PostgreSQL server is listening on for TCP/IP
     * connections.  Be sure the -i flag is passed to postmaster when PostgreSQL
     * is started. If this is not set, or set to 0, the default port will be used.
     */
    public void setPortNumber(int portNumber)
    {
        this.portNumber = portNumber;
    }

    /**
     * Sets the default threshold for enabling server-side prepare.
     * See {@link org.postgresql.PGConnection#setPrepareThreshold(int)} for details.
     *
     * @param count the number of times a statement object must be reused before server-side
     *   prepare is enabled.
     */
    public void setPrepareThreshold(int count)
    {
        this.prepareThreshold = count;
    }

    /**
     * Gets the default threshold for enabling server-side prepare.
     *
     * @see #setPrepareThreshold(int)
     */
    public int getPrepareThreshold()
    {
        return prepareThreshold;
    }

    /**
     * Generates a DriverManager URL from the other properties supplied.
     */
    private String getUrl()
    {
        return
            "jdbc:postgresql://" + serverName + (portNumber == 0 ? "" : ":" + portNumber) + "/" + databaseName +
            "?loginTimeout=" + loginTimeout + "&prepareThreshold=" + prepareThreshold;
    }

    /**
     * Generates a reference using the appropriate object factory.
     */
    protected Reference createReference() {
        return new Reference(
                   getClass().getName(),
                   PGObjectFactory.class.getName(),
                   null);
    }

    public Reference getReference() throws NamingException
    {
        Reference ref = createReference();
        ref.add(new StringRefAddr("serverName", serverName));
        if (portNumber != 0)
        {
            ref.add(new StringRefAddr("portNumber", Integer.toString(portNumber)));
        }
        ref.add(new StringRefAddr("databaseName", databaseName));
        if (user != null)
        {
            ref.add(new StringRefAddr("user", user));
        }
        if (password != null)
        {
            ref.add(new StringRefAddr("password", password));
        }
        
        ref.add(new StringRefAddr("prepareThreshold", Integer.toString(prepareThreshold)));
        ref.add(new StringRefAddr("loginTimeout", Integer.toString(loginTimeout)));
        return ref;
    }

    protected void writeBaseObject(ObjectOutputStream out) throws IOException
    {
        out.writeObject(serverName);
        out.writeObject(databaseName);
        out.writeObject(user);
        out.writeObject(password);
        out.writeInt(portNumber);
        out.writeInt(prepareThreshold);
        out.writeInt(loginTimeout);
    }

    protected void readBaseObject(ObjectInputStream in) throws IOException, ClassNotFoundException
    {
        serverName = (String)in.readObject();
        databaseName = (String)in.readObject();
        user = (String)in.readObject();
        password = (String)in.readObject();
        portNumber = in.readInt();
        prepareThreshold = in.readInt();
        loginTimeout = in.readInt();
    }

}