package jisuanji;

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

public class CalculatorGUI extends JFrame implements ActionListener {
    private JTextField display;
    private JPanel panel;
    private JButton[] numberButtons;
    private JButton[] functionButtons;
    private JButton addButton, subButton, mulButton, divButton, modButton, equalsButton, clearButton;
    private Calculator calculator;

    public CalculatorGUI() {
        calculator = new Calculator();
        setTitle("Simple Calculator");
        setSize(400, 500);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLocationRelativeTo(null);

        display = new JTextField();
        display.setEditable(false);
        display.setFont(new Font("Arial", Font.BOLD, 24));
        add(display, BorderLayout.NORTH);

        panel = new JPanel();
        panel.setLayout(new GridLayout(5, 4, 10, 10));

        // 数字按钮
        numberButtons = new JButton[10];
        for (int i = 0; i < 10; i++) {
            numberButtons[i] = new JButton(String.valueOf(i));
            numberButtons[i].setFont(new Font("Arial", Font.BOLD, 24));
            numberButtons[i].addActionListener(this);
            panel.add(numberButtons[i]);
        }

        // 功能按钮
        addButton = new JButton("+");
        subButton = new JButton("-");
        mulButton = new JButton("*");
        divButton = new JButton("/");
        modButton = new JButton("%");
        equalsButton = new JButton("=");
        clearButton = new JButton("C");

        addButton.setFont(new Font("Arial", Font.BOLD, 24));
        subButton.setFont(new Font("Arial", Font.BOLD, 24));
        mulButton.setFont(new Font("Arial", Font.BOLD, 24));
        divButton.setFont(new Font("Arial", Font.BOLD, 24));
        modButton.setFont(new Font("Arial", Font.BOLD, 24));
        equalsButton.setFont(new Font("Arial", Font.BOLD, 24));
        clearButton.setFont(new Font("Arial", Font.BOLD, 24));

        addButton.addActionListener(this);
        subButton.addActionListener(this);
        mulButton.addActionListener(this);
        divButton.addActionListener(this);
        modButton.addActionListener(this);
        equalsButton.addActionListener(this);
        clearButton.addActionListener(this);

        panel.add(addButton);
        panel.add(subButton);
        panel.add(mulButton);
        panel.add(divButton);
        panel.add(modButton);
        panel.add(equalsButton);
        panel.add(clearButton);

        // 空白按钮占位
        JButton space1 = new JButton(" ");
        JButton space2 = new JButton(" ");
        panel.add(space1);
        panel.add(space2);

        add(panel, BorderLayout.CENTER);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        for (int i = 0; i < 10; i++) {
            if (e.getSource() == numberButtons[i]) {
                display.setText(display.getText() + i);
            }
        }

        if (e.getSource() == addButton) {
            currentOperation = '+';
            firstNumber = Double.parseDouble(display.getText());
            display.setText("");
        } else if (e.getSource() == subButton) {
            currentOperation = '-';
            firstNumber = Double.parseDouble(display.getText());
            display.setText("");
        } else if (e.getSource() == mulButton) {
            currentOperation = '*';
            firstNumber = Double.parseDouble(display.getText());
            display.setText("");
        } else if (e.getSource() == divButton) {
            currentOperation = '/';
            firstNumber = Double.parseDouble(display.getText());
            display.setText("");
        } else if (e.getSource() == modButton) {
            currentOperation = '%';
            firstNumber = Double.parseDouble(display.getText());
            display.setText("");
        } else if (e.getSource() == equalsButton) {
            secondNumber = Double.parseDouble(display.getText());
            double result = 0;
            switch (currentOperation) {
                case '+':
                    result = calculator.add(firstNumber, secondNumber);
                    break;
                case '-':
                    result = calculator.subtract(firstNumber, secondNumber);
                    break;
                case '*':
                    result = calculator.multiply(firstNumber, secondNumber);
                    break;
                case '/':
                    try {
                        result = calculator.divide(firstNumber, secondNumber);
                    } catch (ArithmeticException ex) {
                        display.setText("错误: 除数不能为零");
                        return;
                    }
                    break;
                case '%':
                    try {
                        result = calculator.modulus(firstNumber, secondNumber);
                    } catch (ArithmeticException ex) {
                        display.setText("错误: 除数不能为零");
                        return;
                    }
                    break;
            }
            display.setText(String.valueOf(result));
            currentOperation = '\0'; // 重置操作符
        } else if (e.getSource() == clearButton) {
            display.setText("");
            currentOperation = '\0'; // 重置操作符
            firstNumber = 0;
            secondNumber = 0;
        }
    }

    private char currentOperation = '\0';
    private double firstNumber = 0;
    private double secondNumber = 0;

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> {
            CalculatorGUI calculatorGUI = new CalculatorGUI();
            calculatorGUI.setVisible(true);
        });
    }
}