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

public class BaseConverter {

    private static final char[] DIGITS = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};

    /**
     * 将给定进制的字符串转换为十进制整数
     *
     * @param str 给定进制的字符串表示
     * @param base 给定进制的基数
     * @return 十进制整数
     */
    public static int toDecimal(String str, int base) {
        int result = 0;
        int power = 0;

        for (int i = str.length() - 1; i >= 0; i--) {
            char c = str.charAt(i);
            int digit = Character.isDigit(c) ? c - '0' : c - 'A' + 10;
            result += digit * Math.pow(base, power++);
        }
        return result;
    }

    /**
     * 将十进制整数转换为目标进制的字符串
     *
     * @param decimal 十进制整数
     * @param targetBase 目标进制的基数
     * @return 目标进制的字符串表示
     */
    public static String fromDecimal(int decimal, int targetBase) {
        if (decimal == 0) {
            return "0";
        }

        StringBuilder result = new StringBuilder();
        while (decimal > 0) {
            result.insert(0, DIGITS[decimal % targetBase]);
            decimal /= targetBase;
        }

        return result.toString();
    }

    /**
     * 将任意进制的数转换为另一个任意进制的数
     *
     * @param str 给定进制的字符串表示
     * @param sourceBase 给定进制的基数
     * @param targetBase 目标进制的基数
     * @return 目标进制的字符串表示
     */
    public static String convertBase(String str, int sourceBase, int targetBase) {
        int decimalValue = toDecimal(str, sourceBase);
        return fromDecimal(decimalValue, targetBase);
    }

    /**
     * 主方法，用于测试
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(() -> {
            new BaseConverterGUI();
        });
    }

    // GUI 类
    public static class BaseConverterGUI extends JFrame {

        private JTextField inputField;
        private JComboBox<Integer> sourceBaseBox;
        private JComboBox<Integer> targetBaseBox;
        private JButton convertButton;
        private JLabel resultLabel;

        public BaseConverterGUI() {
            setTitle("进制转换器");
            setSize(400, 200);
            setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            setLocationRelativeTo(null); // 居中显示
            setLayout(new GridBagLayout());

            GridBagConstraints gbc = new GridBagConstraints();

            // 输入框
            gbc.gridx = 0;
            gbc.gridy = 0;
            gbc.anchor = GridBagConstraints.EAST;
            gbc.insets = new Insets(5, 5, 5, 5);
            add(new JLabel("输入数据（例如 A1）:"), gbc);

            gbc.gridx = 1;
            gbc.gridy = 0;
            gbc.fill = GridBagConstraints.HORIZONTAL;
            gbc.weightx = 1;
            gbc.anchor = GridBagConstraints.WEST;
            inputField = new JTextField();
            add(inputField, gbc);

            // 源进制下拉菜单
            gbc.gridx = 0;
            gbc.gridy = 1;
            gbc.fill = GridBagConstraints.NONE;
            gbc.weightx = 0;
            gbc.anchor = GridBagConstraints.EAST;
            add(new JLabel("源进制数（例如 16）:"), gbc);

            gbc.gridx = 1;
            gbc.gridy = 1;
            gbc.fill = GridBagConstraints.HORIZONTAL;
            gbc.weightx = 1;
            gbc.anchor = GridBagConstraints.WEST;
            List<Integer> bases = Arrays.asList(2, 4, 8, 10, 16, 32);
            sourceBaseBox = new JComboBox<>(bases.toArray(new Integer[0]));
            add(sourceBaseBox, gbc);

            // 目标进制下拉菜单
            gbc.gridx = 0;
            gbc.gridy = 2;
            gbc.fill = GridBagConstraints.NONE;
            gbc.weightx = 0;
            gbc.anchor = GridBagConstraints.EAST;
            add(new JLabel("目标进制数（例如 2）:"), gbc);

            gbc.gridx = 1;
            gbc.gridy = 2;
            gbc.fill = GridBagConstraints.HORIZONTAL;
            gbc.weightx = 1;
            gbc.anchor = GridBagConstraints.WEST;
            targetBaseBox = new JComboBox<>(bases.toArray(new Integer[0]));
            add(targetBaseBox, gbc);

            // 转换按钮
            gbc.gridx = 1;
            gbc.gridy = 3;
            gbc.fill = GridBagConstraints.NONE;
            gbc.weightx = 0;
            gbc.anchor = GridBagConstraints.CENTER;
            convertButton = new JButton("转换");
            add(convertButton, gbc);

            // 结果标签
            gbc.gridx = 0;
            gbc.gridy = 4;
            gbc.gridwidth = 2;
            gbc.fill = GridBagConstraints.HORIZONTAL;
            gbc.weightx = 1;
            gbc.anchor = GridBagConstraints.LINE_START;
            resultLabel = new JLabel("转换结果：");
            add(resultLabel, gbc);

            // 添加监听器到按钮
            convertButton.addActionListener(new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    try {
                        String input = inputField.getText().toUpperCase();
                        int sourceBase = (Integer) sourceBaseBox.getSelectedItem();
                        int targetBase = (Integer) targetBaseBox.getSelectedItem();
                        String result = convertBase(input, sourceBase, targetBase);
                        resultLabel.setText("转换结果：" + result);
                    } catch (Exception ex) {
                        JOptionPane.showMessageDialog(BaseConverterGUI.this, "输入错误，请检查后重试！", "错误", JOptionPane.ERROR_MESSAGE);
                    }
                }
            });

            pack(); // 自动调整大小以适应所有组件
            setVisible(true);
        }
    }
}