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

public class BaseConversion2 {

    // 将指定进制的数字转换为十进制
    public static int convertToDecimal(String number, int base) {
        int decimalValue = 0;
        int power = 1; // 初始值为1，对应于base^0

        for (int i = number.length() - 1; i >= 0; i--) {
            char digit = number.charAt(i);
            int digitValue = Character.isDigit(digit)
                    ? digit - '0'
                    : Character.toUpperCase(digit) - 'A' + 10; // A-F

            decimalValue += digitValue * power;
            power *= base; // 更新权重
        }

        return decimalValue;
    }

    // 将十进制转换为指定进制
    public static String convertFromDecimal(int number, int base) {
        if (number == 0) return "0"; // 特殊情况处理

        StringBuilder result = new StringBuilder();
        while (number > 0) {
            int remainder = number % base;
            result.append(remainder < 10 ? (char) ('0' + remainder) : (char) ('A' + remainder - 10));
            number /= base;
        }

        return result.reverse().toString(); // 反转结果
    }

    // 主方法，创建用户界面
    public static void main(String[] args) {
        JFrame frame = new JFrame("基数转换器");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(400, 300);
        frame.setLayout(new GridLayout(5, 2));

        // 创建界面组件
        JLabel sourceBaseLabel = new JLabel("源进制 (2-16):");
        JTextField sourceBaseField = new JTextField();

        JLabel targetBaseLabel = new JLabel("目标进制 (2-16):");
        JTextField targetBaseField = new JTextField();

        JLabel numberLabel = new JLabel("要转换的数字:");
        JTextField numberField = new JTextField();

        JButton convertButton = new JButton("转换");
        JLabel resultLabel = new JLabel("转换结果:");

        // 事件处理
        convertButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                try {
                    int sourceBase = Integer.parseInt(sourceBaseField.getText());
                    int targetBase = Integer.parseInt(targetBaseField.getText());
                    String number = numberField.getText().toUpperCase();

                    // 输入验证
                    if (!isValidInput(number, sourceBase)) {
                        resultLabel.setText("请输入有效的数字!");
                        return;
                    }

                    int decimalValue = convertToDecimal(number, sourceBase);
                    String result = convertFromDecimal(decimalValue, targetBase);

                    resultLabel.setText("转换结果: " + result);
                } catch (NumberFormatException ex) {
                    resultLabel.setText("进制应为数字，且范围为 2-16!");
                } catch (Exception ex) {
                    resultLabel.setText("转换过程中发生错误: " + ex.getMessage());
                }
            }
        });

        // 添加组件到框架
        frame.add(sourceBaseLabel);
        frame.add(sourceBaseField);
        frame.add(targetBaseLabel);
        frame.add(targetBaseField);
        frame.add(numberLabel);
        frame.add(numberField);
        frame.add(convertButton);
        frame.add(resultLabel);

        frame.setVisible(true);
    }

    // 检查用户输入的数字是否有效
    private static boolean isValidInput(String number, int base) {
        for (char digit : number.toCharArray()) {
            int digitValue = Character.isDigit(digit)
                    ? digit - '0'
                    : Character.toUpperCase(digit) - 'A' + 10;

            if (digitValue < 0 || digitValue >= base) {
                return false; // 数字超出进制范围
            }
        }
        return true; // 输入有效
    }
}