/***************************************************************
#Author: Kannan Balasubramanian
#Last Updated on: 11/22/2007
#Tool for querying jhat and redirect o/p to stdout or a file...
****************************************************************/

import java.net.*;
import java.io.*;
import java.util.*;

public class JQuery
{
    public static BufferedReader input = null;
    public static PrintWriter output = null;
    public static Socket socket = null;
    public static PrintStream stdout = System.out;

    public static void usage() {
       System.err.println("Usage: java JQuery <hostname> <port> [logfile]");
       System.err.println("E.g: java JQuery localhost 7001 log.txt");
    }

    public static void displayCommands() {
       System.err.println(".....................Commands......................");
       System.err.println("          /  ( all classes excluding plaform)");
       System.err.println("          showRoots");
       System.err.println("          allClassesWithPlatform");
       System.err.println("          showInstanceCounts");
       System.err.println("          showInstanceCounts/includePlatform");
       System.err.println("          histo");
       System.err.println("          finalizerSummary");
       System.err.println("          finalizerObjects");
       System.err.println("          oql/?query=<>");
       System.err.println("          oqlhelp");


       System.err.println("          <-help> <-h> <help>");
       System.err.println("          redirect <log file>");
       System.err.println("          redirect none (msgs goes to stdout)");
       System.err.println("          quit (exit JQuery)");
       System.err.println("...................................................");
       System.err.println("\n");
    }

    public static String validateOQLCommand(String str) {
       String inputString = str;
       if (inputString.indexOf('\n') != -1 || inputString.indexOf('\r') != -1) {
           inputString = inputString.substring(0, inputString.length()-2);
       }
       if (inputString.equals("/")) {
           return inputString + " .";
       }
       if (inputString.indexOf("?query") != -1) {
           //This is a query. Leave it as it is.
           return "/" + inputString + " .";
       }
       inputString = "/" + inputString + "/" + " ."; //hack. remove . later and fix it
       return inputString;
    }

    public static boolean validateCommand(String str) {
       String inputString = str.toLowerCase().trim();
       if (inputString.length() == 0) {
           System.err.println("No command specified ....");
           return false;
       }
       if (inputString.startsWith("-help") ||
           inputString.startsWith("help") || 
           inputString.equals("-h")) {
           displayCommands();
           return false;
       }
       if(inputString.equals("quit")) {
          if (socket != null) {
              try {
                 socket.close();
              } catch (Exception e) {
                 System.err.println(e);
              }
          }
          System.err.println("Exiting JQuery...");
          System.exit(0);
       }
       if (!inputString.startsWith("redirect")) {
           //it's a OQL command...
           return true;
       }
       StringTokenizer st = new StringTokenizer(inputString);
       String buf = null;
       if (st.hasMoreTokens()) {
           buf = st.nextToken();
           if (buf.equals("redirect")) {
               if (!st.hasMoreTokens()) {
                   System.err.println("invalid command... See -help");
                   return false;
               }
               buf = st.nextToken();
               try {
                   if (buf.equals("none")) {
                       System.setOut(stdout);
                       return false;
                   } else {
                       System.setOut(new PrintStream(new FileOutputStream(buf)));
                       return false;
                   }
               } catch (Exception e) {
                   System.err.println(e);
                   return false;
               }
           }
       }
       return true; //It's a OQL command
    }

    public static boolean updateSocketStreams(InetAddress addr, int port) {
       try {
          if (socket != null) {
              socket.close();
          }
          while (true) {
              try {
                  socket = new Socket(addr, port);
                  break;
              } catch (Exception ex) {
                  System.err.println("Socket not connected. Waiting...");
		  Thread.sleep(2000);
              }
          }
          if (input != null) {
              input.close();
          }
          input = new BufferedReader( new InputStreamReader(socket.getInputStream()));
          if (output != null) {
              output.close();
          }
          output = new PrintWriter(socket.getOutputStream(), true);
        } catch (Exception e) {
          e.printStackTrace();
          return false;
        }
        return true;
    }

    public static void main(String [] args)
    {
       if (args != null && args.length < 2) {
           usage();
           return;
       }
       if (args[0].equals("-h") || args[0].equals("-help")) {
           usage();
           return;
       }
       int port = -1;
       try {
           port = Integer.parseInt(args[1]);
       } catch (NumberFormatException ne) {
           System.err.println("Invalid port: " + args[1]);
           return;
       }
       if (args.length >= 3) {
           try {
             System.setOut(new PrintStream(new FileOutputStream(args[2])));
           } catch(Exception e) {
             System.err.println("Cannot write to log file: " + args[2] + " ...");
             return;
           }
       }
       try
       { 
          InetAddress address = null;
          //Take the default hostaddress, if no hostname is provided at the command line.
          if ( args != null && args.length > 0 )
          {
             address = InetAddress.getByName(args[0]);
          }
          else
          {
             address = InetAddress.getLocalHost();
          }
	  
          boolean bFlag = updateSocketStreams(address, port);
          if (bFlag) {
              System.err.println("Congrats... you are connected...\nStart sending messages now...");
              System.err.println("Type -help for list of commands supported...\n");
          }
          final BufferedReader stdinput = new BufferedReader(new InputStreamReader(System.in));

          //create a separate thread for listening to the socket. 
          Thread thread = new Thread()
          {
             public void run()
             {
                String inString = null;
                while (true)
                {
                   try
                   {
                     inString = input.readLine();
                     if (inString != null) {
                         System.out.println(inString);
                     } else {
                         Thread.sleep(1000);
                     }
                   }
                   catch(Exception e) {
                      //System.out.println("Thread: " + e.toString());
                   }
                   finally {
                      //System.out.println("Input socket done...");
                   }
                }
             }
          };
          thread.setDaemon(true);
          thread.start();

          String inputString; 
          //keep reading from the stdinput console and pass it on to the socket.
          while ((inputString = stdinput.readLine()) != null)
          {
             if (!validateCommand(inputString)) {
                 //it's a non OQL command. Hence no need to communicate to jhat 
                 continue;
             }
             updateSocketStreams(address, port);
             inputString = validateOQLCommand(inputString);
             output.println("GET " + inputString);
          }
          System.err.println("Output socket done...");
       }
       catch(Exception e)
       {
          System.err.println("exception: " + e.toString());
       }
    }
}