import java.awt.*;
import java.util.*;
import javax.swing.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

class MyCanvas extends JComponent 
{
  //String list = "5, 6, 7, 8";
  int top;
  int middle = 2;
  int bottom = 3;
  
    public void getNums(int n)
  {
      top = n;
  }
  
  // This is for drawing the "Stack"
  public void paint(Graphics g) 
  {
    // Basic dimensions and the lines
    g.drawRect (10, 40, 200, 230);
    g.drawLine (10, 111, 210, 111);
    g.drawLine (10, 190, 210, 190); 
    // Headers and such
    g.setFont(new Font("Arial", Font.BOLD, 20));
    g.drawString ("Cache:", 15, 26);
    g.drawString ("" + top, 105, 80);
    g.drawString ("" + middle, 105, 160);
    g.drawString ("" + bottom, 105, 240);
    g.drawString ("Input:", 260, 26);
  }
  

}
/////////////////////////////////////////////////

// Uses a linked hashmap to aid in insertion.
class LRUCache<K, V> extends LinkedHashMap<K, V> 
{ 
    public int size;
    
    // Constructor method (Private)
    public LRUCache(int size){
        //Size, default load factor
        super(size, 0.75f, true);
        //Sets the size
        this.size = size;
    }
    
    //Creates a new instance of the Cache
    public static <K, V> LRUCache<K, V> newInstance(int size)
    {
        // Returns the new cache with designated size.
        return new LRUCache<K, V>(size);
    }
    
    
    // Overrided LinkedHashMap's removeEldestEntry method
    @Override
    protected boolean removeEldestEntry(Map.Entry<K, V> eldest)
    {
         return size() > size;
    }
    
    public String setAndReturn(int num)
    {
      LRUCache<String, String> runCache = LRUCache.newInstance(3);
      String newNum = Integer.toString(num);
      runCache.put(newNum, newNum);
      String returnValue = runCache.toString();
      return returnValue;
    }
    
}

////////////////////////////////////////////////


// The actual handler for the GUI
public class GUI extends JFrame
{
  Scanner in = new Scanner(System.in);
  
  JLabel jl;
  JLabel jlTop;
  JLabel jlMid;
  JLabel jlBot;
  
  JButton jb;
  JPanel jp;
  JTextField jt;
  


  // This method controls the frame itself
  public GUI()
  {
    this.setTitle("LRU Demonstration");
    this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    this.setBounds(30, 30, 500, 400);
    this.getContentPane().add(new MyCanvas());
    this.setVisible(true);
    

    
    // Setup of the text field/button
    jp = new JPanel();
    jl = new JLabel();
    jlTop = new JLabel();
    jlMid = new JLabel();
    jlBot = new JLabel();
    jt = new JTextField("5", 10);
    jp.add(jt);
    
    jb = new JButton("Add to Cache");
    jp.add(jb);
    
    // Setup of the button getting information.
    jb.addActionListener(new ActionListener()
    {
      public void actionPerformed(ActionEvent e)
      {
         //jp.setBackground(Color.BLACK);
         String input = jt.getText();
         jl.setText(input);
         jlTop.setText(input);
      }
    });
    
    
    jp.add(jl, jlTop);
    add(jp, BorderLayout.SOUTH);
    
  }
  
  // The main method simply creates an instance of the GUI
public static void main(String[] a) 
  {  
	  String userLength = JOptionPane.showInputDialog("Enter a value for the size of the cache");
	  
	  LRUCache<String, String> runCache = LRUCache.newInstance(Integer.parseInt(userLength));
	  
	  for(int i=0; i<10; i++)
	  {
		  String userInput = JOptionPane.showInputDialog("Enter a value into the cache");
		  runCache.put(userInput, userInput);
        String output = runCache.toString();
		  JOptionPane.showMessageDialog(null, "Cache: \n(Bottom, Middle, Top)\n" + output);
	  }
  }
}