import java.applet.*;
import java.awt.*;
import javax.swing.*;

import java.awt.event.*;


public class GraphicsSampler extends JApplet implements Runnable{
    
	
    Thread animator;
    Color fill = Color.gray; // Equal red, green, and blue == gray
	Color outline = Color.black;            // Same as new Color(0, 0, 255)
	Color conditionDrift = Color.yellow;
	Color CurrentStateColor = Color.red;
	Color ruleColor = Color.blue;
	Color textcolor = Color.green;           // Same as new Color(255, 0, 0)
	Color BackgroundColor = Color.lightGray;
    Font fnTape = new Font("times", Font.BOLD, 30);;                       // The font we use for text
    Font fnRule = new Font("times", Font.PLAIN, 20);
    FontMetrics metrics;             // Information about font size
    Image image, background;         // Some images we draw with
    StateStructure TMStateInfo[] = new StateStructure[100];
    JTextField Text;
    String Language,CurrentState;
    String SourceURL = "";
    int CurrentIndex = 0;
    int CurrentStateID = -1;
    int IndexNum = 0;
    String CurrentInput = "";
    Input inputer;
    private static int uninitialized = -1;
    private static int initialized = 0;
    private static int running = 1;
    private static int emptyString = 2;
    int SystemState = uninitialized;
    int currentState = 0;   
    JToolBar tb = new JToolBar();
    JButton btLoad = new JButton("LOAD", new ImageIcon("load.png"));
    JButton btRun = new JButton("RUN", new ImageIcon("run.gif"));
    JButton btExit = new JButton ("EXIT", new ImageIcon("exit.gif"));
    ActionListener JML = new ActionListener()
    {
    	public void actionPerformed(ActionEvent e)
    	{
    		String temp = ((JButton)e.getSource()).getText();
    		if(temp.equalsIgnoreCase("exit"))
    		{
    			System.exit(0);
    		}
    		if(temp.equalsIgnoreCase("run"))
    		{
    			if(SystemState == initialized)
    			{
	    			SetInitialState();
	    			String txt = Text.getText();
	    			if(txt.length()==0){
	    				JPanel p = new JPanel();
	    				JOptionPane.showMessageDialog(p, "please input language int the bottom Textfield");

	    			}
	    			else
	    			{ 
	    				SystemState = running;
	    				Language = txt+"$";
	    			}
    			}
    			else
    			{
    				JPanel p = new JPanel();
    				JOptionPane.showMessageDialog(p, "please load first");
    			}
    			
    		}
    		if(temp.equalsIgnoreCase("load"))
    		{
    		
    			if(SystemState!=running)
    			{
    				JFileChooser filech = new JFileChooser();
    				JPanel p = new JPanel();
    			    int result =  filech.showOpenDialog(p);
    			    if(result ==JFileChooser.APPROVE_OPTION)
    			    {
    			        SourceURL = filech.getName(filech.getSelectedFile());
    			        System.out.println(SourceURL);
    			    	inputer = new Input(SourceURL);
    			    	IndexNum = inputer.intializeStateStructure(TMStateInfo);
    			    	if (Checkduplicate(TMStateInfo))
    			    	{
    			             SystemState = initialized;
    			    		//JOptionPane.showMessageDialog(p, "Turing Machine State Source File Error");
    			    	}
    			    }
    				repaint();
    				SystemState = initialized;
        			Language = "";
        			
    			}
    		
    		}
    	}
    };

    public void init() {
	// Initialize color resources.  Note the use of the Color() constructor
	// and the use of pre-defined color constants.
    	for(int i = 0;i<100;i++)
    		TMStateInfo[i] = new StateStructure();
    	metrics = this.getFontMetrics(fnTape);
    this.setSize(500, 500);
	this.setBackground(BackgroundColor);
	CurrentState = "q1";
	ComponentListener WL = new ComponentListener(){
		public void componentResized(ComponentEvent e)
		{
			repaint();
			setVisible(false);
			setVisible(true);
	     	Text.setVisible(false);
	    	Text.setVisible(true);
	   	    tb.setVisible(false);
		    tb.setVisible(true);
		 
		    repaint();

		}
		public void componentHidden(ComponentEvent e)
		{
			Text.setVisible(false);
	    	//Text.setVisible(true);
	   	    tb.setVisible(false);
		  //  mb.setVisible(true);
		}
		public void componentMoved(ComponentEvent e)
		{
			Text.setVisible(false);
	    	Text.setVisible(true);
	   	    tb.setVisible(false);
		    tb.setVisible(true);
		    repaint();
		}
		public void componentShown(ComponentEvent e)
		{
			Text.setVisible(false);
	    	Text.setVisible(true);
	   	    tb.setVisible(false);
		    tb.setVisible(true);
		    repaint();
		}
		
	};
	this.addComponentListener(WL);

	 btLoad.addActionListener(JML);
	 btRun.addActionListener(JML);
	 btExit.addActionListener(JML); 
	 tb.add(btLoad);
	 tb.add(btRun);
	 tb.add(btExit);
	 Text = new JTextField(30);
	 
	 Container cp =  getContentPane();
	 cp.setLayout(new BorderLayout());
 	 
	 cp.add(BorderLayout.NORTH,tb);
	 cp.add(BorderLayout.SOUTH,Text);
	 
	 setVisible(false);
	 setVisible(true);
	 tb.setVisible(false);
	 tb.setVisible(true);
	 Text.setVisible(false);
	 Text.setVisible(true);
    }

   //  This method is called whenever the applet needs to be drawn or redrawn
    public void paint(Graphics g) {
	g.setFont(fnTape);  // Specify the font we'll be using throughout
	super.paint(g);
	this.setBackground(BackgroundColor);

	if(this.SystemState==running)
	{
		ShowLanguage(Language, g,TMStateInfo[0]);
		if(CurrentState.equalsIgnoreCase("qreject"))
		{
			ShowResult(g,"Reject");
			this.SystemState = initialized;
		}
		if(CurrentState.equalsIgnoreCase("qaccept"))
		{
			ShowResult(g,"Accept");
			this.SystemState = initialized;
		}
	}
	boolean match = false;
	for(int i = 0;i< IndexNum;i++)
	{
		
		if((this.SystemState==running)&&(TMStateInfo[i].NextState(Language, CurrentIndex, CurrentState)))
		{
			this.ShowRule(g, TMStateInfo[i]);
			match = true;
			CurrentState = TMStateInfo[i].stateToTransfer;
			
			String temp = Language.substring(0, CurrentIndex)+TMStateInfo[i].edit+Language.substring(CurrentIndex+1, Language.length());
			Language = temp;
			if(TMStateInfo[i].LRaction.equalsIgnoreCase("L"))
				CurrentIndex--;
			else
				CurrentIndex++;
			//ClearLanguage(Language,g,TMStateInfo[i]);
			g.finalize();
			//g.dispose();

		
			break;
		}
	}
	if((!match)&&(SystemState==running))
	{
		SystemState = initialized;
		String temp =String.format("no suitable rule for current input %s under current state %s", Language.substring(CurrentIndex, CurrentIndex+1), CurrentState);
		
		JOptionPane.showMessageDialog(this, temp);
	}
 }
    protected void centerText(String s1, String s2, Graphics g, Color c,
			      int x, int y, int w, int h)
    {
	int height = metrics.getHeight();  // How tall is the font?
	int ascent = metrics.getAscent();  // Where is the font baseline?
	int width1=0, width2 = 0, x0=0, x1=0, y0=0, y1=0;
	width1 = metrics.stringWidth(s1);  // How wide are the strings?
	if (s2 != null) width2 = metrics.stringWidth(s2);
	x0 = x + (w - width1)/2;           // Center the strings horizontally
	x1 = x + (w - width2)/2;
	if (s2 == null)                    // Center one string vertically
	    y0 = y + (h - height)/2 + ascent;
	else {                             // Center two strings vertically
	    y0 = y + (h - (int)(height * 2.2))/2 + ascent;
	    y1 = y0 + (int)(height * 1.2);
	}
	g.setColor(c);                     // Set the color
	g.drawString(s1, x0, y0);          // Draw the strings
	if (s2 != null) g.drawString(s2, x1, y1);
    }
    
    
    protected void ClearLanguage(String s1,Graphics g, StateStructure TMState)
    {
    	if(SystemState==running){
	    	int height = metrics.getHeight();  // How tall is the font?
	    	int tempWidth;// Where is the font baseline?
	    	int x0 = (1024)/2;
	    	int y0 = (768)/2;
	    	int tempx = 0;
	    	int tempy = y0;
	    	String TempString = "";
	    	if (this.CurrentIndex>0)
	    	{
	    		TempString = Language.substring(0,CurrentIndex);
	    	//	g.setColor(outline);
	    	//	g.drawString(TempString,tempx,tempy);
	    	}

	    	TempString = TempString+ CurrentState;

	    	TempString = Language.substring(CurrentIndex, CurrentIndex+1);

	    	if(this.CurrentIndex<Language.length()-1)
	    	{
	    		TempString = TempString+Language.substring(CurrentIndex+1,Language.length());
	    	}
	    	tempx = metrics.stringWidth(TempString);
	    	tempy = metrics.getHeight();
	    //	g.setColor(Color.black);
	    	//g.fillRect(x0, y0-tempy, tempx, tempy);
	    	g.clearRect(x0, y0-tempy, tempx, tempy);
    	}	
    	
    }
    protected void ShowResult(Graphics g, String Result)
    {
    	int height = metrics.getHeight();  // How tall is the font?
    	int tempWidth;// Where is the font baseline?
    	int x0 = this.getWidth()/2;
    	int y0 = this.getHeight()/2+100;
    	g.setFont(fnRule);
    	g.setColor(ruleColor);
    	FontMetrics metrics = this.getFontMetrics(fnRule);
    	x0 -= metrics.stringWidth(Result)/2;
    	g.drawOval(x0-metrics.stringWidth(Result)/2, (int)(y0-1.5*metrics.getHeight()), 2*metrics.stringWidth(Result), 2*metrics.getHeight());
    	g.drawString(Result, x0, y0);
    }
    protected void ShowRule(Graphics g, StateStructure TMState)
    {
    	int height = metrics.getHeight();  // How tall is the font?
    	int tempWidth;// Where is the font baseline?
    	int x0 = this.getWidth()/2;
    	int y0 = this.getHeight()/2+100;
    	String result = "(" +TMState.currentState+" , "+ TMState.input +")"
    	          + " -> (" + TMState.stateToTransfer +" , " + TMState.edit 
    	          + " , " + TMState.LRaction+")";
    	g.setFont(fnRule);
    	g.setColor(ruleColor);
    	FontMetrics metrics = this.getFontMetrics(fnRule);
    	x0 -= metrics.stringWidth(result)/2;
    	g.drawString(result, x0, y0);
    	
    }
    protected void ShowLanguage(String s1, Graphics g, StateStructure TMState)
    {
    	if(SystemState==running){
	    	int height = metrics.getHeight();  // How tall is the font?
	    	int tempWidth;// Where is the font baseline?
	    	int x0 = this.getWidth()/2;
	    	int y0 = this.getHeight()/2;
	    	int tempx = x0;
	    	int tempy = y0;
	    	String TempString = "";
	    	g.setFont(fnTape);
	    	if (this.CurrentIndex>0)
	    	{
	    		TempString = Language.substring(0,CurrentIndex);
	    		tempWidth = metrics.stringWidth(TempString);
	    		tempx = x0-tempWidth;
	    		g.setColor(outline);
	    		g.drawString(TempString,tempx,tempy);
	    	}
	    	tempWidth = metrics.stringWidth(TempString);
	    	tempx = tempx+ tempWidth;
	    	TempString = CurrentState;
	    	g.setColor(CurrentStateColor);
	    	g.drawString(TempString, tempx, y0);
	    	if(CurrentIndex<Language.length())
	    	{
		     	tempWidth = metrics.stringWidth(TempString);
		    	tempx = tempx+ tempWidth;
		    	TempString = Language.substring(CurrentIndex, CurrentIndex+1);
		    	g.setColor(CurrentStateColor);
		    	g.drawString(TempString, tempx, y0);
		    	tempWidth = metrics.stringWidth(TempString);
	    	}
	    	if(this.CurrentIndex<Language.length()-1)
	    	{
	    		TempString = Language.substring(CurrentIndex+1,Language.length());
	            tempx = tempx+tempWidth;
	    		g.setColor(outline);
	    		g.drawString(TempString,tempx,tempy);
	    	}
	    	g.setColor(Color.cyan);
	    	g.drawLine(0, tempy-height/2-5, this.getWidth()-1, tempy-height/2-5);
	    	g.drawLine(0, tempy+5, this.getWidth()-1, tempy+5);
    	}	
    	
    }
    public  void animate()
    {
	    if(SystemState == -1)
	    	return;
	    else if(SystemState == 0)
	    {
	    	SetInitialState();
	    }
	    else if(SystemState == running)
	    {
	    	repaint();
	    	
	    }
    }
    public void start()
    {
    	animator = new Thread(this);
    	animator.start();
    	
    }
    public void run()
    {
    	while(true){
    	        animate();
    	        try{
    		    Thread.sleep(2000);
    	        }
    		    catch(InterruptedException e)
    		    {
    		    }
    	    
    	}
    }
    private void SetInitialState()
    {
    	CurrentState = "q1";
    	CurrentStateID = -1;
    	Language = "";
    	CurrentIndex = 0;
    
    }
    public boolean Checkduplicate(StateStructure[] TMStateInfo)
    {
    	for(int i = 0;i< IndexNum;i++)
    		for(int j = i+1;j<IndexNum;j++)
    		{
    			if((TMStateInfo[i].input.equalsIgnoreCase(TMStateInfo[j].input))&&(TMStateInfo[i].currentState.equalsIgnoreCase( TMStateInfo[j].currentState)))
    			{
    				String message = String.format("the %d line contradict with the %d line in the Turing Machine source file, Please check it", i,j);
    			   
    			    JOptionPane.showMessageDialog(this, message);
    			    return false;
    			}
    		}
    	return true;
    	
    }
    
    
    
}