业务服务模块

src/com/mathgenerator/service/PaperService.java

@@ -0,0 +1,63 @@
+package com.mathgenerator.service;
+
+import com.mathgenerator.generator.JuniorHighSchoolGenerator;
+import com.mathgenerator.generator.PrimarySchoolGenerator;
+import com.mathgenerator.generator.QuestionGenerator;
+import com.mathgenerator.generator.SeniorHighSchoolGenerator;
+import com.mathgenerator.model.Level;
+import com.mathgenerator.auth.User;
+import com.mathgenerator.storage.FileManager;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+/**
+ * 业务逻辑核心，负责协调生成和存储。
+ */
+public class PaperService {
+    private final FileManager fileManager;
+
+    public PaperService(FileManager fileManager) {
+        this.fileManager = fileManager;
+    }
+
+    /**
+     * 创建并保存一份完整的试卷。
+     * @param user 用户对象
+     * @param count 题目数量
+     * @param currentLevel 当前选择的难度等级
+     */
+    public void createAndSavePaper(User user, int count, Level currentLevel) {
+        QuestionGenerator generator = createGenerator(currentLevel);
+        Set<String> existingQuestions = fileManager.loadExistingQuestions(user.username());
+        List<String> newPaper = new ArrayList<>();
+        Set<String> generatedInSession = new HashSet<>();
+
+        System.out.println("正在生成题目，请稍候...");
+        while (newPaper.size() < count) {
+            String question = generator.generateSingleQuestion();
+            if (!existingQuestions.contains(question) && !generatedInSession.contains(question)) {
+                newPaper.add(question);
+                generatedInSession.add(question);
+            }
+        }
+
+        try {
+            String filePath = fileManager.savePaper(user.username(), newPaper);
+            System.out.println("成功！" + count + "道" + currentLevel.getChineseName() + "数学题目已生成。");
+            System.out.println("文件已保存至: " + filePath);
+        } catch (IOException e) {
+            System.err.println("错误：保存文件失败 - " + e.getMessage());
+        }
+    }
+
+    private QuestionGenerator createGenerator(Level level) {
+        return switch (level) {
+            case PRIMARY -> new PrimarySchoolGenerator();
+            case JUNIOR_HIGH -> new JuniorHighSchoolGenerator();
+            case SENIOR_HIGH -> new SeniorHighSchoolGenerator();
+        };
+    }
+}