/* SCCS  @(#)NslShell.java	1.9---09/01/99--00:19:28 */

/* Copyright:
   Copyright (c) 1998 University of Southern California Brain Project.
   This software may be freely copied provided the top level
   COPYRIGHT file is included with each such copy.
   Emai:l nsl@java.usc.edu.
*/
/**
   @author Nikunj Mehta
*/

package nslj.src.nsls.struct;

import java.awt.*;
import java.awt.event.*;

public class NslShell extends TextArea {
  String command;
  String currentCommand;
  Executive callback;
  String prompt  = "nsls% ";
  String prompt2 = "> ";
  String temp ="";
  int beginning = prompt.length();
  int start;
  boolean mouseEnable = true;
  boolean select = false;
  NslCommandList commands;
  MouseAdapter ma;
  SelectEventHandler my;
  boolean commandExecuted = false;
  boolean executing = false;

  public NslShell(Executive e) {
    super("", 15, 45, SCROLLBARS_VERTICAL_ONLY);
    setText(prompt);
    command = "";
    currentCommand = "";
    start = beginning;
    callback = e;

    addKeyListener(new ShellEventHandler());
    addMouseListener(ma = new MouseAdapter() {
      public void mousePressed(MouseEvent e) {
      if (!mouseEnable)
	e.consume();
      }
    });
    my = new SelectEventHandler();
    addFocusListener(new ShellEventHandler());
    commands = new NslCommandList();
  }

  int lastPos;
  public void setSelectFlag(boolean value) {
  	if (value) {
  	        /* lastPos = getCaretPosition();*/
		removeMouseListener(ma);
		addMouseListener(my);
	} else {
		select(0,0);
		setCaretPosition(start);
		removeMouseListener(my);
		addMouseListener(ma);
	}
	select = value;
  }

  public void paste(String text) {
  	//System.out.println("Start insertion");

  	char array[] = text.toCharArray();

  	int i= 0, len = text.length();
  	String temp;

  	while (i<len) {
  	    temp = "";
  	    while(i<len && array[i]!='\n') {
  	    	temp += "" + array[i];
  	    	i++;
  	    }

  	    append(temp);

  	    if (i<len && array[i] == '\n') {
		   dispatchEvent(new KeyEvent(this,
  				   KeyEvent.KEY_PRESSED,
  				   System.currentTimeMillis(),
  				   Event.KEY_PRESS, KeyEvent.VK_ENTER ));
    	    }

    	    i++;
    	    if (i<len && array[i]=='\r') {
  	    	i++;
  	    }
  	}
  }

    public void nslPrintln(String msg) {
    	// check if the last element is a prompt
    	// if it is clear it an paint it at the end
    	String temp="";
    	int len = getText().length();
    	if (start!=len) {
    	    temp = getText().substring(start,len);
    	}
    	int tempLen = temp.length();
    	String command = msg +"\n" + prompt + temp;
    	//if (!commandExecuted) {
    	   // command += temp;
	    //System.out.println("Substituing "+ getText().substring(len - 6 - tempLen ,len) +
	   // 		       " with " + command);
	    replaceRange(command, len - 6 - tempLen ,len);
	    start = getText().length()-tempLen;
	/*} else {
	    append("\n"+command);
    	    System.out.println("Adding enter " + command);
	    commandExecuted = false;
	    start = getText().length();
	}*/
	setCaretPosition(start+tempLen);
    }

    public void nslPrint(String msg) {
    	String temp="";
    	int len = getText().length();
    	if (start!=len) {
    	    temp = getText().substring(start,len);
    	}
    	int tempLen = temp.length();
    	String command = msg + prompt + temp;
    	//if (!commandExecuted) {
    	//    command += temp;
	//    System.out.println("Substituing "+ getText().substring(len - 6 - tempLen ,len) +
	//    		       "with" + command);
	    replaceRange(command, len - 6 - temp.length() ,len);
	    start = getText().length()-tempLen;
	/*} else {
	    append("\n"+command);
    	    System.out.println("Adding enter " + command);
	    commandExecuted = false;
	    start = getText().length();
	}*/
	setCaretPosition(start+tempLen);
    }

  private class SelectEventHandler extends MouseAdapter {
  	public void mousePressed(MouseEvent e) {
  		if ((e.getModifiers() & (e.BUTTON2_MASK|e.BUTTON3_MASK)) != 0) {
  			e.consume();
  		}
  	}
  }

  private class ShellEventHandler extends KeyAdapter implements FocusListener {
    String result;

    public void keyPressed(KeyEvent evt) {
      if (select) {
         evt.consume();
         return;
      }

      int mod = evt.getModifiers();
      if (mod == evt.ALT_MASK ||
	  mod == evt.CTRL_MASK ||
	  mod == evt.META_MASK)
	evt.consume();

      switch (evt.getKeyCode()) {
      case KeyEvent.VK_ENTER:
      //case evt.VK_ENTER:
	command = getText().substring(start);
	currentCommand = currentCommand + command;
	if (callback != null) {
	  if (callback.interp.commandComplete(currentCommand)) {

	      append("\n"+prompt);
	      start = getText().length();
	      setCaretPosition(start);
	      // commandExecuted=true;
	      //System.out.println("Running "+currentCommand+" = "+commandExecuted);
	      result = callback.execute_line(currentCommand);
	      if (result.length() != 0) {
	      	nslPrintln(result);
	      }

	      // commandExecuted = false;

	      if (!currentCommand.equals("")) {
	          commands.add(currentCommand);
	      }
	      currentCommand = "";

	  } else {
	      append("\n" + prompt2);
	      currentCommand = currentCommand + "\n";
	  }
	  start = getText().length();
	  setCaretPosition(start);
	}

	evt.consume();
	break;
      case KeyEvent.VK_BACK_SPACE:
      case KeyEvent.VK_LEFT:
      //case evt.VK_BACK_SPACE:
      //case evt.VK_LEFT:
	if (getCaretPosition() < start + 1)
	  evt.consume();
	break;

      //case evt.VK_UP:
      case KeyEvent.VK_UP:
	  command = commands.prev();
	  //setText(getText().substring(0,start).concat(command));
	  int len = getText().length();
	  replaceRange(command,start,len);
	  setCaretPosition(start);
	  evt.consume();
	  break;
      //case evt.VK_DOWN:
      case KeyEvent.VK_DOWN:
	  command = commands.next();
	  setText(getText().substring(0,start).concat(command));
	  setCaretPosition(start);
	  evt.consume();
	  break;
      case KeyEvent.VK_PAGE_UP:
      case KeyEvent.VK_PAGE_DOWN:
      //case evt.VK_PAGE_UP:
      //case evt.VK_PAGE_DOWN:
	evt.consume();
	break;
      case KeyEvent.VK_HOME:
      //case evt.VK_HOME:
	  setCaretPosition(start);
	  evt.consume();
	  break;
      case KeyEvent.VK_RIGHT:
      //case evt.VK_RIGHT:
	break;
      }


    }

    public void focusGained(FocusEvent e) {
      mouseEnable = false;
      setCaretPosition(start);
    }

    public void focusLost(FocusEvent e) {
      mouseEnable = true;
/*    if (!select) {
          start = getCaretPosition();
      }*/
    }
  }
}