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

public final class Mandelbrot1 extends Applet implements MouseListener,ActionListener {

    Button paint;
    Button repaint;
    TextField textfield;
    int iter=0;
    private int max_iter=100;
    private Color[] colors=new Color[75];
    private double centerX=0.0;
    private double centerY=0.0;
    private double zoom=1.0;
    private int mouseX;
    private int mouseY;
    public void init() {
        setName("Mandelbrot");
        setSize(800,600);
        paint=new Button();
        paint.setLabel("Paint");
        repaint=new Button();
        repaint.setLabel("Repaint");
        textfield=new TextField();
        textfield.setText("");
        add(textfield);
        add(paint);
        add(repaint);
        paint.addActionListener(this);
        repaint.addActionListener(this);

        addMouseListener(this);
        for(int i=0; i<colors.length; i++) {
            int c=2*i*256/colors.length;
            if(c>255)
                c=511-c;
            colors[i] = new Color(c, c, 78);
        }
    }
    public void paint(Graphics g){
        Dimension size=getSize();
        this.paint.setSize(60,20);
        this.paint.setLocation(340, 0);
        this.repaint.setSize(60,20);
        this.repaint.setLocation(370,580);
        this.textfield.setSize(60,20);
        this.textfield.setLocation(400, 0);
        for (int y=0; y<size.height; y++) {
            for (int x=0; x<size.width; x++) {
                double r=zoom / Math.min(size.width, size.height);
                Complex z=new Complex(2.5*(x*r+centerX)-2.0, 1.25-2.5*(y*r+centerY));
                int value=mandelbrot(z);
                g.setColor(colors[value%colors.length]);
                g.drawLine(x, y, x, y);
            }
        }
    }
    public void update(Graphics g) {
        paint(g);
    }
    private int mandelbrot(Complex z0) { //pętla do poprawienia
        Complex z=new Complex(z0);
        for(int t=0; t<iter; t++)
        {
            if(z.abs()>2.0) return t;
            z.mul(z).add(z0);
        }
        return max_iter;
    }
    public void mousePressed(MouseEvent e) {
        mouseX=e.getX();
        mouseY=e.getY();
    }
    public void mouseReleased(MouseEvent e) {
        int x=e.getX();
        int y=e.getY();
        if((e.getModifiers()&InputEvent.BUTTON1_MASK)!= 0) {
            if(x!= mouseX&&y!=mouseY) {
                int w=getSize().width;
                int h=getSize().height;
                centerX+=zoom*Math.min(x, mouseX)/Math.min(w, h);
                centerY+=zoom*Math.min(y, mouseY)/Math.min(w, h);
                zoom*=Math.max((double)Math.abs(x-mouseX)/w,(double)Math.abs(y-mouseY)/h);
            }
        }
        repaint();
    }
    public void mouseClicked(MouseEvent e) {}
    public void mouseEntered(MouseEvent e) {}
    public void mouseExited(MouseEvent e) {}
    @Override
    public void actionPerformed(ActionEvent e) {
        if(e.getSource()==paint){
            int temp=toInt(textfield,textfield.getText());
            if(temp>max_iter){
                System.out.println("Liczba przekracza maksymalną liczbę iteracji.");
            }
            if(temp<0){
                System.out.println("Liczba mniejsza niż minimalna liczba iteracji.");
            }
            else{
                iter=temp;
                repaint();
            }
        }
        else if(e.getSource()==repaint){
            centerX=centerY=0.0;
            zoom=1.0;
            repaint();
        }
    }

    private int toInt(TextField input, String message)
    {
        try
        {
            int num=Integer.parseInt(input.getText());
            System.out.println("Input: "+num+" is a number");
            return num;
        }catch(NumberFormatException e)
        {
            System.out.println("Error: "+message+ " is not a number");
            return 0;
        }
    }
}