package cifrador;

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

public class CifradoSimpleMonoalfabetico extends Applet {

  private static final long serialVersionUID = 1L;
  boolean isStandalone = false;
  private String blanco = "__________________________________________________";

  
  Panel Panel1 = new Panel();

  Label lTitulo = new Label();
  
  Label lAlfa = new Label();
  TextField tAlfa = new TextField();

  Label lPlano = new Label();
  TextField tPlano = new TextField();

  Label lClave = new Label();
  TextField tClave = new TextField();
  
  Label lCifrado = new Label();
  TextField tCifrado = new TextField();
  
  Label lError = new Label();
 
  Button btnCifrar = new Button();
  Button btnDesCifrar = new Button();
  Button btnBorrar = new Button();
  
  GridBagLayout gbl1 = new GridBagLayout();
  GridBagConstraints gbc1=new GridBagConstraints();

  BorderLayout borderLayout2 = new BorderLayout();
  GridLayout gridLayout1 = new GridLayout();
  //Construct the applet
  
  public CifradoSimpleMonoalfabetico() {
  }
//Initialize the applet
  
  public void init() {
	try {
	jbInit();
	}
	catch (Exception e) {
	e.printStackTrace();
	}
  }

  private void jbInit() throws Exception {
	 int ancho = Integer.parseInt(this.getParameter("WIDTH"));
	 int alto = Integer.parseInt(this.getParameter("HEIGHT"));
	 if (ancho < 400) ancho=400;
	 if (alto < 250) alto=250;
	 this.setSize(new Dimension(ancho, alto));
	 
	Panel1.setBackground(Color.lightGray);
	lTitulo.setText("Cifra de Sustitucion Simple Monoalfabética");
	lError.setText(blanco);

	lAlfa.setText("Alfabeto");
	tAlfa.setColumns(30);
	tAlfa.setEditable(true);
	tAlfa.setText("abcdefghijklmnñopqrstuvwxyz");

	lPlano.setText("Texto Plano");
	tPlano.setColumns(36);
	tPlano.setEditable(true);
	tPlano.setText("esto es una prueba");

	lClave.setText("Clave");
	tClave.setColumns(2);
	tClave.setEditable(true);
	tClave.setText("p");

	lCifrado.setText("TEXTO CIFRADO");
	tCifrado.setColumns(36);
	tCifrado.setEditable(true);
	tCifrado.setText("");

	btnCifrar.setFont(new Font("Dialog", 1, 14));
	btnCifrar.setLabel("Cifrar");
	btnCifrar.addActionListener(new java.awt.event.ActionListener() {
	  public void actionPerformed(ActionEvent e) {
		btnCifrar_actionPerformed(e);
	  }
	});

	btnDesCifrar.setLabel("Descifrar");
	btnDesCifrar.addActionListener(new java.awt.event.ActionListener() {
	  public void actionPerformed(ActionEvent e) {
		btnDesCifrar_actionPerformed(e);
	  }
	});
	btnBorrar.setLabel("Borrar");
	btnBorrar.addActionListener(new java.awt.event.ActionListener() {
	  public void actionPerformed(ActionEvent e) {
		btnBorrar_actionPerformed(e);
	  }
	});
	this.setLayout(gridLayout1);
	this.add(Panel1, null);

//panel 1
	  Panel1.setLayout(gbl1);

	gbc1.anchor=GridBagConstraints.CENTER;
	gbc1.gridwidth=1;
	gbc1.insets=new Insets(5,0,5,0);
	gbc1.gridwidth=GridBagConstraints.REMAINDER;
	Panel1.add(lTitulo, gbc1);

	gbc1.anchor=GridBagConstraints.WEST;
	gbc1.gridwidth=1;
	gbc1.insets=new Insets(5,0,5,0);
	Panel1.add(lAlfa, gbc1);
	gbc1.gridwidth=GridBagConstraints.REMAINDER;
	Panel1.add(tAlfa, gbc1);
	
	gbc1.anchor=GridBagConstraints.WEST;
	gbc1.gridwidth=1;
	gbc1.insets=new Insets(5,0,5,0);
	Panel1.add(lPlano, gbc1);
	gbc1.gridwidth=GridBagConstraints.REMAINDER;
	Panel1.add(tPlano, gbc1);
	
	 gbc1.anchor=GridBagConstraints.WEST;
	 gbc1.gridwidth=1;
	 gbc1.insets=new Insets(5,0,5,0);
	 Panel1.add(lClave, gbc1);
	 gbc1.gridwidth=GridBagConstraints.REMAINDER;
	 Panel1.add(tClave, gbc1);

	 gbc1.anchor=GridBagConstraints.WEST;
	 gbc1.gridwidth=1;
	 gbc1.insets=new Insets(5,0,5,0);
	 Panel1.add(lCifrado, gbc1);
	 gbc1.gridwidth=GridBagConstraints.REMAINDER;
	 Panel1.add(tCifrado, gbc1);

	 gbc1.anchor=GridBagConstraints.CENTER;
	 gbc1.gridwidth=1;
	 gbc1.insets=new Insets(5,0,5,0);
	 gbc1.gridwidth=GridBagConstraints.REMAINDER;
	 Panel1.add(lError, gbc1);

	 gbc1.anchor=GridBagConstraints.CENTER;
	 gbc1.gridwidth=1;
	 gbc1.insets=new Insets(25,0,5,0);
	 Panel1.add(btnCifrar, gbc1);
	 Panel1.add(btnDesCifrar, gbc1);
	 Panel1.add(btnBorrar, gbc1);
	 gbc1.gridwidth=GridBagConstraints.REMAINDER;
 }

  void btnCifrar_actionPerformed(ActionEvent e) {
	    int error = 0;
	    int posC = 0;
		lError.setText(blanco);
		String alfabeto = tAlfa.getText().toLowerCase();
		String entrada=tPlano.getText().toLowerCase();
		String clave=tClave.getText().toLowerCase();
		String xCifrado = "";
		if (clave.length() == 0){
			lError.setText("Debe poner la clave.");
			error = 1;
		}else{
			posC = alfabeto.lastIndexOf(clave.substring(0, 1)) ;
			if (posC == -1){
				lError.setText("El caracter de la clave no está en el alfabeto.");
				error = 1;
			}
		}
		if (error == 0){
			for(int i=0; i < entrada.length(); i++){
				if (entrada.substring(i, i+1).equals(" "))
				{
					xCifrado = xCifrado + " ";
				}else{
					int posP = alfabeto.lastIndexOf(entrada.substring(i, i+1)) ; 
					if (posP == -1)
						xCifrado = xCifrado + "?";
					else
						xCifrado = xCifrado + alfabeto.charAt((posC + posP) % alfabeto.length());
				}
			}
			tCifrado.setText(xCifrado.toUpperCase());
		}
  }

  void btnDesCifrar_actionPerformed(ActionEvent e) {
	    int error = 0;
	    int posC = 0;
		lError.setText(blanco);
		String alfabeto = tAlfa.getText().toLowerCase();
		String entrada="";
		String clave=tClave.getText().toLowerCase();
		String xCifrado = tCifrado.getText().toLowerCase();
		if (clave.length() == 0){
			lError.setText("Debe poner la clave.");
			error = 1;
		}else{
			posC = alfabeto.lastIndexOf(clave.substring(0, 1)) ;
			if (posC == -1){
				lError.setText("El caracter de la clave no está en el alfabeto.");
				error = 1;
			}
		}
		if (error == 0){
			for(int i=0; i < xCifrado.length(); i++){
				if (xCifrado.substring(i, i+1).equals(" "))
				{
					entrada = entrada + " ";
				}else{
					int posP = alfabeto.lastIndexOf(xCifrado.substring(i, i+1)) ; 
					if (posP == -1)
						entrada = entrada + "?";
					else
						entrada = entrada + alfabeto.charAt((27 + posP - posC) % alfabeto.length());
				}
			}
			tPlano.setText(entrada.toLowerCase());
		}
}


  void btnBorrar_actionPerformed(ActionEvent e) {
	tPlano.setText("");
	tCifrado.setText("");
	tClave.setText("");
  }
}