package calc;

import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class Calculator extends JFrame implements ActionListener {

    private JButton[] buttons;
    private JTextField field;
    private ArrayList<Double> numbers;
    private double result;
    private boolean plus, min;

    public Calculator() {
        buttons = new JButton[15];
        numbers = new ArrayList<>();
        plus = false;
        min = false;
        createButtons();
        createPanel();
    }

    public static void main(String[] args) {
        JFrame frame = new Calculator();
        frame.setTitle("Calculator");
        frame.setSize(500, 600);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }

    private void createButtons() {
        for (int i = 0; i < buttons.length; i++) {
            if (i == 10) {
                buttons[i] = new JButton(".");
            } else if (i == 11) {
                buttons[i] = new JButton("+");
            } else if (i == 12) {
                buttons[i] = new JButton("-");
            } else if (i == 13) {
                buttons[i] = new JButton("=");
            } else if (i == 14) {
                buttons[i] = new JButton("Clear");
            } else {
                buttons[i] = new JButton(i + "");
            }
            buttons[i].addActionListener(this);
        }
    }

    private void createPanel() {
        JPanel panel = new JPanel();
        panel.setLayout(null);
        field = new JTextField();
        Font f = new Font("SanSerif", Font.BOLD, 40);
        field.setFont(f);
        field.setBounds(50, 30, 385, 60);
        panel.add(field);
        int k = 0;
        for (int i = 0; i < 4; i++) {
            for (int j = 0; j < 4; j++) {
                buttons[k].setBounds(j * 100 + 55, i * 100 + 140, 75, 60);
                panel.add(buttons[k]);
                if (k < 14) {
                    k++;
                }
            }
        }
        add(panel);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        for (int i = 0; i < buttons.length; i++) {
            if (e.getSource().equals(buttons[i]) && i < 11) {
                field.setText(buttons[i].getText());
                numbers.add(Double.parseDouble(field.getText()));
                operation();
            }
        }
        if (e.getSource() == buttons[11]) {
            plus = true;
        } else if (e.getSource() == buttons[12]) {
            min = true;
        } else if (e.getSource() == buttons[13]) {
            field.setText("" + result);
        } else if (e.getSource() == buttons[14]) {
            field.setText("");
            numbers.clear();
            plus = false;
            min = false;
        }

    }

    public double operation() {
        for (int i = 0; i < numbers.size(); i++) {
            System.out.println(numbers.get(i));
        }
        System.out.println("");
        if (plus) {
            result = numbers.get(0) + numbers.get(1);
            numbers.clear();
            numbers.add(result);
            plus = false;
        }
        if (min) {
            result = numbers.get(0) - numbers.get(1);
            numbers.clear();
            numbers.add(result);
            min = false;
        }

        return result;
    }
}