/* ----------------------------------------------------------------------------
 Copyright (c) 2003 jSNMP Enterprises, All Rights Reserved Worldwide
 ------------------------------------------------------------------------------

   Disclaimer: This software is provided AS IS, and without any warranty
               other than those which may be provided in a separate
               writing specifically referencing the software contained
               herein.  All other warranties, except those which may be
               provided separately in writing, are expressly disclaimed.
               WITHOUT LIMITING THE GENERALITY OF THE FOREGOING, THERE IS
               NO WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR
               PURPOSE which is given with respect to this software or the
               operability thereof.

   ------------------------------------------------------------------------
 */


// ------------------------------ Package -------------------------------------

// ------------------------------ Imports -------------------------------------
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import java.net.*;
import java.io.UnsupportedEncodingException;

import com.outbackinc.services.protocol.snmp.*;
import com.outbackinc.services.protocol.snmp.CSM.*;


/**
 * Sample which illustrates how to use the jSNMP within a browser.
 * Note: A fully JDK 1.1-compliant browser is required for this
 * example.  <p>
 *
 *
 * Here's an example HTML file with an applet tag: <p>
 * <p>
 * <pre>
 *   &lt;html>&lt;body>
 *   &lt;applet code="SnmpV1WalkerApplet" height=400 width=500>
 *   &lt;/applet>
 *   &lt;/body>&lt;/html>
 * </pre>
 * <p>
 *
 * Note: The CLASSPATH must be initialized correctly before
 * starting the browser.
 */
public class SnmpV1WalkerApplet
extends Applet
implements SnmpCustomer, SnmpTrapListener, Runnable, ActionListener
{
    // ------------------------------ Constants ---------------------------------

    // ------------------------------ Class variables ---------------------------

    // ------------------------------ Member (instance) variables ---------------

    private SnmpService                             m_service;
    private SnmpServiceConfiguration                m_serviceConfiguration;
    private String[]                                m_szLastOID;
    private int                                     m_iNumRetrieved;
    private SnmpAuthoritativeSession                m_cSnmpRemoteAuthoritativeSession;
    private SnmpOrderInfo                           m_orderinfo;
    private int                                     m_iOrderNumStart;
    private String                                  m_szManagedHost = null;


    private TextArea                                m_textArea = null;
    private Thread                                  m_runThread = null;
    private TextArea                                m_trapOutput = null;

    private Button                                  m_start = null;
    private Button                                  m_stop = null;
    private TextField                               m_hostField = null;
    private TextField                               m_communityField = null;
    private boolean                                 m_bWalking = false;

    
    // ------------------------------ Methods -----------------------------------

    /**
     *
     */
    public SnmpV1WalkerApplet()
    {
        m_szLastOID = new String[1];
        m_szLastOID[0] = "1.3.6";
        m_iOrderNumStart = 1;
    }


    /**
     *
     */
    public void init()
    {
        // Create the ui...
        initUI();

        // Initialize the jSNMP core...
        try {
            initService();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }


    private void initUI()
    {
        setBackground(Color.lightGray);

        m_hostField = new TextField(10);
        m_communityField = new TextField(10);
        m_start = new Button("Start");
        m_stop = new Button("Stop");

        m_stop.setEnabled(false);
        m_hostField.addActionListener(this);
        m_communityField.addActionListener(this);
        m_start.addActionListener(this);
        m_stop.addActionListener(this);

        GridBagLayout gridbag = new GridBagLayout();
        GridBagConstraints c = new GridBagConstraints();

        setLayout(gridbag);
        c.fill = GridBagConstraints.BOTH;
        c.weightx = 1.0;
        
        c.gridwidth = GridBagConstraints.REMAINDER;
        Label label = new Label(" ");
        gridbag.setConstraints(label, c);
        add(label);

        // host and community editbox fields
        c.gridwidth = 1;
        label = new Label("SNMP Agent Host: ", Label.RIGHT);
        gridbag.setConstraints(label, c);
        add(label);
        
        gridbag.setConstraints(m_hostField, c);
        add(m_hostField);
    
        label = new Label("Read Community: ", Label.RIGHT);
        gridbag.setConstraints(label, c);
        add(label);
        
        gridbag.setConstraints(m_communityField, c);
        add(m_communityField);
    
        c.gridwidth = GridBagConstraints.REMAINDER;
        label = new Label(" ");
        gridbag.setConstraints(label, c);
        add(label);
        
        // buttons
        label = new Label(" ");
        gridbag.setConstraints(label, c);
        add(label);

        c.gridwidth = 1;
        label = new Label(" ");
        gridbag.setConstraints(label, c);
        add(label);

        gridbag.setConstraints(m_start, c);
        add(m_start);

        label = new Label(" ");
        gridbag.setConstraints(label, c);
        add(label);

        gridbag.setConstraints(m_stop, c);
        add(m_stop);

        c.gridwidth = GridBagConstraints.REMAINDER;
        label = new Label(" ");
        gridbag.setConstraints(label, c);
        add(label);
 
        c.gridwidth = GridBagConstraints.REMAINDER;
        label = new Label(" ");
        gridbag.setConstraints(label, c);
        add(label);

        c.gridwidth = GridBagConstraints.REMAINDER;
        c.weighty = 3;
        m_textArea = new TextArea();
        gridbag.setConstraints(m_textArea, c);
        add(m_textArea);
       
        c.weightx = GridBagConstraints.REMAINDER;
        c.weighty = 1;
        m_trapOutput = new TextArea();
        gridbag.setConstraints(m_trapOutput, c);
        add(m_trapOutput);      
    }


    private void initService() 
        throws Exception
    {
        m_service = SnmpLocalInterfaces.getService();
        m_serviceConfiguration = SnmpLocalInterfaces.getServiceConfiguration(m_service);
        m_serviceConfiguration.setBufferDelay(0);

        SnmpTrapProfile stdProfile;
        stdProfile = SnmpLocalInterfaces.getTrapProfileFactory().createSnmpTrapProfile(162);
        m_service.addTrapListenerProfile(this, stdProfile);
    }

    /**
     * The walk begins here...
     */
    public void run()
    {
        System.out.println("Walking MIB Tree of " + m_szManagedHost);
        updateText("Walking MIB Tree of " + m_szManagedHost);
        getNext();
    }


    /* *
     * Update the UI with a new text string...
     */
    private synchronized void updateText(String s)
    {
        // Clear the text area periodically...
        
        if (m_textArea.getText().length() > 5000)
        {
            m_textArea.setText("");
        }

        // Append the new string to the existing text...

        m_textArea.append(s + "\n");
    }

    /* *
     * Update the UI with a new text string...
     */
    private synchronized void updateTrapText(String s)
    {
        // Clear the text area periodically...
        
        if (m_trapOutput.getText().length() > 500)
        {
            m_trapOutput.setText("");
        }

        // Append the new string to the existing text...

        m_trapOutput.append(s + "\n");
    }


    // -- ActionListener interface
    
    public synchronized void actionPerformed(ActionEvent event)
    {
        if (event.getSource() == m_start)
        {
            // Upon a "start signal", clear the display, grab the
            // managed host from the UI, initialize the walk variables,
            // and start the run thread.
        
            try
            {
                m_szManagedHost = m_hostField.getText();
                String szCommunity = m_communityField.getText();
                if (m_szManagedHost.length() <= 0)
                {
                    System.out.println("Empty host");
                    updateText("Empty host");
                }
                else if (szCommunity.length() <= 0)
                {
                    System.out.println("Empty community");
                    updateText("Empty community");
                }
                else
                {
                    updateText(" ");
                    m_orderinfo = new SnmpOrderInfo(2, 3, 0);
                    CSMSecurityInfo secInfo;
                    try
                    {
                        secInfo = new CSMSecurityInfo(szCommunity.getBytes("ASCII"), szCommunity.getBytes("ASCII"));
                    }
                    catch(UnsupportedEncodingException uee)
                    {
                        secInfo = new CSMSecurityInfo(szCommunity.getBytes(), szCommunity.getBytes());
                    }

                    SnmpAuthoritativeSessionFactory cSnmpAuthoritativeSessionFactory = SnmpLocalInterfaces.getAuthoritativeSessionFactory();
                    m_cSnmpRemoteAuthoritativeSession = cSnmpAuthoritativeSessionFactory.createRemoteAuthoritativeSession(m_szManagedHost,
                                                                                                             161,
                                                                                                             SnmpConstants.SNMP_VERSION_1,
                                                                                                             secInfo);
            
                    m_iNumRetrieved = 0;            
                    m_szLastOID[0] = "1.3.6";
                    m_bWalking = true;
                    m_start.setEnabled(false);
                    m_stop.setEnabled(true);
                    m_runThread = new Thread(this);
                    m_runThread.start();            
                }
            }
            catch(UnknownHostException uhe)
            {
                String szOutString = new String("Unknown host: " + m_szManagedHost);
                System.out.println(szOutString);
                updateText(szOutString);
            }
            catch(SnmpSecurityException sse)
            {
                System.out.println("Failed to create CSMSecurityInfo");
                updateText("Failed to create CSMSecurityInfo");
            }
        }
        else if (event.getSource() == m_stop)
        {
            // Stop the walk...
            
            m_bWalking = false;
            m_start.setEnabled(true);
            m_stop.setEnabled(false);
        }
            
    }
    
    // -- SnmpCustomer Implementation

    /**
     * callback for delivering successes.  In this case the implementation
     * is to print out the Object ID received and then use it for the basis
     * for the get-next request
     */
    public synchronized void deliverSuccessfulOrder(int iOrderNum,
                                                    SnmpVarBind vb)
    {
        String szOutString = new String(iOrderNum + ": " + vb.getName() + " (" + vb.getStringValue() + ")");
        System.out.println(szOutString);
        updateText(szOutString);
        
        if (m_szLastOID[0].compareTo(vb.getName()) != 0)
        {
            m_szLastOID[0] = vb.getName();

            if (m_bWalking) {
                getNext();
            }
        }
        else
        {
            System.out.println("Finished");
            updateText("Finished");

            m_start.setEnabled(true);
            m_stop.setEnabled(false);
        }
    }

    /**
     * callback for failures.  In this case if a failure is received,
     * stop walking the MIB
     */
    public void deliverFailedOrder(int iOrderNum, int iErrorStatus)
    {
        String szOutString = new String(iOrderNum + ": order failed (" + SnmpConstants.errorIDToString(iErrorStatus) + ")");
        System.out.println(szOutString);
        System.out.println("Ending MIB Walk");

        updateText(szOutString);
        updateText("Ending MIB Walk");

        m_start.setEnabled(true);
        m_stop.setEnabled(false);
    }

    /**
     * gets the next object from the remote agent.  Demonstrates
     * placing orders with the snmp service
     */
    public void getNext()
    {
        m_iOrderNumStart = m_service.placeGetNextOrder(m_cSnmpRemoteAuthoritativeSession,
                                                       m_orderinfo,
                                                       false,
                                                       m_szLastOID,
                                                       this,
                                                       m_iOrderNumStart);
    }


    // -- SnmpTrapListener
    
    public void trapReceived(SnmpTrapEvent trap)
    {
        //Prints out all the information contained in the trap
        String szTrapType;
        if (trap.getType() == SnmpConstants.SNMP_TRAP)
        {
            szTrapType = new String("a SNMPv1 trap");
        }
        else
        {
            szTrapType = new String("an unexpected type (" + trap.getType() + " is not a SNMPv1 trap)");
        }
                 
        String szOutString = new String("\nReceived " + szTrapType + " ...\n"
                                        + "\tPort : " + trap.getPort()
                                        + "\n\tGenerating Agent : " + trap.getAgentIPAddress()
                                        + "\n\tSending Agent : " + trap.getSendersIPAddress()
                                        + "\n\tTime Stamp : " + trap.getTimeStamp()
                                        + "\n\tEnterprise OID : " + trap.getEnterpriseOID()
                                        + "\n\tTrap Type : " + trap.getTrapType());
        updateTrapText(szOutString);
                
        if (trap.getNumberOfVarBinds() > 0)
        {
            updateTrapText("\tVarBinds:");
        }
        
        for (int i = 0; i < trap.getNumberOfVarBinds(); i++)
        {
            SnmpVarBind vb = trap.getVarBind(i);
            szOutString = new String("\t\t" + vb.getName() + " (" + vb.getStringValue() + ")");
            updateTrapText(szOutString);
        }

    }
}