MyMathQuiz_UI/src/main/java/com/student/mathquiz/service/QuizServiceImpl.java

package com.student.mathquiz.service;

import com.student.mathquiz.constant.UserType;
import com.student.mathquiz.model.Question;
import com.student.mathquiz.persistence.FileSaver;
import com.student.mathquiz.persistence.QuestionChecker;
import com.student.mathquiz.question.QuestionGenerator;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

public class QuizServiceImpl implements IQuizService {

  private List<com.student.mathquiz.question.Question> generatedQuestions;
  private List<Question> quizQuestions;
  private List<Integer> userAnswers;
  private int currentQuestionIndex;

  // 在 QuizServiceImpl.java 中

  @Override
  public void generateQuiz(String level, int count, String userEmail) {
    System.out.println("        --> 【QuizService】: 进入 generateQuiz 方法。");
    UserType userType = UserType.fromDisplayName(level);
    if (userType == null) {
      System.err.println("        --> 【QuizService】: 错误！无效的难度级别: " + level);
      throw new IllegalArgumentException("无效的难度级别: " + level);
    }

    QuestionGenerator generator = QuestionGenerator.getGeneratorByUserType(userType);

    Set<String> questionContentSet = new HashSet<>();
    generatedQuestions = new ArrayList<>();

    // 我们把 maxTries 提到外面，方便观察
    int maxTries = count * 20;
    int currentTry = 0;

    System.out.println("        --> 【QuizService】: 准备进入循环生成题目，最大尝试次数: " + maxTries);

    while (generatedQuestions.size() < count && currentTry < maxTries) {
      currentTry++; // 每次循环都计数

      // 每循环20次打印一次日志，防止刷屏，又能看到进度
      if (currentTry % 20 == 0) {
        System.out.println("        --> 【QuizService】: 循环中... 已尝试 " + currentTry + " 次, 已生成 " + generatedQuestions.size() + " 道题。");
      }

      com.student.mathquiz.question.Question newQuestion = generator.generateQuestion();//
      String content = newQuestion.getContent();

      if (!questionContentSet.contains(content) && !QuestionChecker.isDuplicate(userEmail, content)) {
        questionContentSet.add(content);
        generatedQuestions.add(newQuestion);
      }
    }

    System.out.println("        --> 【QuizService】: 循环结束！最终尝试 " + currentTry + " 次, 成功生成 " + generatedQuestions.size() + " 道题。");

    if (generatedQuestions.size() < count) {
      System.err.println("        --> 【QuizService】: 警告: 题库不足或重复率过高，只生成了 " + generatedQuestions.size() + " 道题。");
    }

    // ... 后面的代码不变 ...
    this.quizQuestions = new ArrayList<>();
    for (com.student.mathquiz.question.Question q : generatedQuestions) {
      this.quizQuestions.add(new Question(q.getContent(), q.getOptions(), q.getCorrectAnswerIndex()));
    }

    FileSaver.saveQuestions(userEmail, generatedQuestions);
    this.userAnswers = new ArrayList<>();
    this.currentQuestionIndex = 0;
    System.out.println("        --> 【QuizService】: generateQuiz 方法执行完毕！");
  }


  @Override
  public Question getCurrentQuestion() {
    if (quizQuestions == null || currentQuestionIndex >= quizQuestions.size()) return null;
    return quizQuestions.get(currentQuestionIndex);
  }

  @Override
  public boolean isLastQuestion() {
    return currentQuestionIndex == quizQuestions.size() - 1;
  }

  @Override
  public void submitAnswer(int selectedOptionIndex) {
    userAnswers.add(selectedOptionIndex);
    if (!isLastQuestion()) currentQuestionIndex++;
  }

  @Override
  public int calculateScore() {
    int correctCount = 0;
    for (int i = 0; i < quizQuestions.size(); i++) {
      if (i < userAnswers.size() && quizQuestions.get(i).getCorrectAnswerIndex() == userAnswers.get(i)) {
        correctCount++;
      }
    }
    if (quizQuestions.isEmpty()) return 0;
    return (int) ((double) correctCount / quizQuestions.size() * 100);
  }

  @Override
  public int getTotalQuestionCount() { return quizQuestions != null ? quizQuestions.size() : 0; }
  @Override
  public int getCurrentQuestionIndex() { return currentQuestionIndex; }
}