partner_program/src/main/java/com/example/myapp/controller/ExamController.java

package com.example.myapp.controller;

import com.example.myapp.Main;
import com.example.myapp.model.Exam;
import com.example.myapp.model.Question;
import com.example.myapp.service.ExamService;
import javafx.fxml.FXML;
import javafx.scene.control.*;

public class ExamController {
  @FXML private Label questionNumberLabel;
  @FXML private Label questionTextLabel;
  @FXML private RadioButton optionARadio;
  @FXML private RadioButton optionBRadio;
  @FXML private RadioButton optionCRadio;
  @FXML private RadioButton optionDRadio;
  @FXML private Label optionALabel;
  @FXML private Label optionBLabel;
  @FXML private Label optionCLabel;
  @FXML private Label optionDLabel;
  @FXML private Button previousBtn;
  @FXML private Button nextBtn;
  @FXML private Button submitBtn;
  @FXML private ProgressIndicator progressIndicator;

  private String email;
  private ExamService examService = ExamService.getInstance();
  private int currentQuestionIndex = 0;
  private ToggleGroup optionsToggleGroup;

  // 添加初始化方法，使用 @FXML 注解确保在FXML加载后立即执行
  @FXML
  public void initialize() {
    // 在这里初始化 ToggleGroup，确保在FXML加载完成后立即执行
    this.optionsToggleGroup = new ToggleGroup();

    optionARadio.setToggleGroup(optionsToggleGroup);
    optionBRadio.setToggleGroup(optionsToggleGroup);
    optionCRadio.setToggleGroup(optionsToggleGroup);
    optionDRadio.setToggleGroup(optionsToggleGroup);

    // 设置默认禁用状态
    previousBtn.setDisable(true);
    submitBtn.setDisable(true);
  }

  public void initExam(String email) {
    this.email = email;

    // 确保有考试数据
    Exam exam = examService.getCurrentExam(email);
    if (exam == null || exam.getQuestions().isEmpty()) {
      showAlert("错误", "没有找到考试数据，请重新选择学段");
      try {
        Main.showGradeSelection(email);
      } catch (Exception e) {
        e.printStackTrace();
      }
      return;
    }

    loadQuestion(0);
  }

  @FXML
  public void onPreviousQuestion() {
    saveCurrentAnswer();
    if (currentQuestionIndex > 0) {
      loadQuestion(currentQuestionIndex - 1);
    }
  }

  @FXML
  public void onNextQuestion() {
    saveCurrentAnswer();
    Exam exam = examService.getCurrentExam(email);
    if (currentQuestionIndex < exam.getQuestions().size() - 1) {
      loadQuestion(currentQuestionIndex + 1);
    }
  }

  @FXML
  public void onSubmitExam() {
    saveCurrentAnswer();

    // 计算分数
    int score = examService.calculateScore(email);

    // 显示分数界面
    try {
      Main.showScorePage(email, score);
    } catch (Exception e) {
      e.printStackTrace();
    }
  }

  private void loadQuestion(int index) {
    Exam exam = examService.getCurrentExam(email);
    if (exam == null || index < 0 || index >= exam.getQuestions().size()) {
      return;
    }

    currentQuestionIndex = index;
    Question question = exam.getQuestions().get(index);

    // 更新界面
    questionNumberLabel.setText("第 " + (index + 1) + " 题 / 共 " + exam.getQuestions().size() + " 题");
    questionTextLabel.setText(question.getQuestionText());
    optionALabel.setText("A. " + question.getOptionA());
    optionBLabel.setText("B. " + question.getOptionB());
    optionCLabel.setText("C. " + question.getOptionC());
    optionDLabel.setText("D. " + question.getOptionD());

    // 清除选择
    optionsToggleGroup.selectToggle(null);

    // 恢复用户之前的选择
    if (question.getUserAnswer() != null) {
      switch (question.getUserAnswer()) {
        case "A": optionARadio.setSelected(true); break;
        case "B": optionBRadio.setSelected(true); break;
        case "C": optionCRadio.setSelected(true); break;
        case "D": optionDRadio.setSelected(true); break;
      }
    }

    // 更新按钮状态
    previousBtn.setDisable(index == 0);
    nextBtn.setDisable(index == exam.getQuestions().size() - 1);
    submitBtn.setDisable(index != exam.getQuestions().size() - 1);

    // 更新进度
    progressIndicator.setProgress((double) (index + 1) / exam.getQuestions().size());
  }

  private void saveCurrentAnswer() {
    // 添加空值检查
    if (optionsToggleGroup == null) {
      return;
    }

    RadioButton selectedRadio = (RadioButton) optionsToggleGroup.getSelectedToggle();
    if (selectedRadio != null) {
      String answer = "";
      if (selectedRadio == optionARadio) answer = "A";
      else if (selectedRadio == optionBRadio) answer = "B";
      else if (selectedRadio == optionCRadio) answer = "C";
      else if (selectedRadio == optionDRadio) answer = "D";

      examService.submitAnswer(email, currentQuestionIndex, answer);
    }
  }

  private void showAlert(String title, String message) {
    Alert alert = new Alert(Alert.AlertType.ERROR);
    alert.setTitle(title);
    alert.setHeaderText(null);
    alert.setContentText(message);
    alert.showAndWait();
  }
}