import java.io.IOException;
import java.util.*;

/**
 * 题目生成器类
 */
public class QuestionGenerator {
    private User user;
    private String role;

    public QuestionGenerator(User user, String role) {
        this.user = user;
        this.role = role;
    }

    public void generateQuestions(int questionCount) throws IOException {
        // 获取策略
        QuestionStrategy strategy = QuestionStrategyFactory.getStrategy(role);

        // 读出该用户所有历史题目
        Set<String> existingQuestions = FileUtils.loadExistingQuestions(user.getUsername());
        Set<String> newQuestionsSet = new HashSet<>();
        List<MathQuestion> questions = new ArrayList<>();

        System.out.println("以下为生成的题目列表:\n");

        int i = 1;
        int tryCount = 0;
        while (questions.size() < questionCount) {
            String questionText = strategy.generateQuestion();
            tryCount++;
            if (existingQuestions.contains(questionText) || newQuestionsSet.contains(questionText)) {
                // 如果题库太小可能死循环，这里设置最大尝试次数
                if (tryCount > questionCount * 100) {
                    System.out.println("题库不足，无法生成足够不重复的题目");
                    break;
                }
                continue;
            }

            newQuestionsSet.add(questionText);
            MathQuestion question = new MathQuestion(i, questionText);
            questions.add(question);
            System.out.println("题号 " + i + "：" + questionText + "\n");
            i++;
        }

        String fileName = FileUtils.generateFileName();
        FileUtils.saveQuestionsToFile(user.getUsername(), fileName, questions);
    }
}