package hello.demo;
import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.TextField;
import javafx.scene.layout.GridPane;
import javafx.stage.Stage;

import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;

public class Calculator extends Application {

    private TextField display;

    @Override
    public void start(Stage primaryStage) {
        primaryStage.setTitle("计算器");

        display = new TextField();
        display.setEditable(false);

        GridPane grid = new GridPane();
        grid.setPadding(new Insets(10));
        grid.setVgap(5);
        grid.setHgap(5);

        // 按钮定义，包括取余运算 "%"
        String[] buttons = {
                "7", "8", "9", "/",
                "4", "5", "6", "*",
                "1", "2", "3", "-",
                "0", "C", "=", "+",
                "%"
        };

        int index = 0;
        for (int row = 0; row < 5; row++) { // 修改行数以添加新按钮
            for (int col = 0; col < 4; col++) {
                if (index >= buttons.length) break; // 防止数组越界
                Button btn = new Button(buttons[index]);
                btn.setMinSize(50, 50);
                btn.setOnAction(e -> handleButtonClick(btn.getText()));
                grid.add(btn, col, row);
                index++;
            }
        }

        grid.add(display, 0, 5, 4, 1); // 显示区域在最后一行

        Scene scene = new Scene(grid, 250, 350);
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    private void handleButtonClick(String text) {
        if ("C".equals(text)) {
            display.clear();
        } else if ("=".equals(text)) {
            calculateResult();
        } else {
            display.appendText(text);
        }
    }

    private void calculateResult() {
        try {
            String input = display.getText();
            // 使用脚本引擎执行表达式
            ScriptEngineManager manager = new ScriptEngineManager();
            ScriptEngine engine = manager.getEngineByName("JavaScript");
            Object result = engine.eval(input);
            display.setText(result.toString());
        } catch (Exception e) {
            display.setText("错误");
        }
    }

    public static void main(String[] args) {
        launch(args);
    }
}