refactor: 替换 Lesson 状态魔法值为 LessonStatus 枚举

- 将 LessonServiceImpl 中所有状态魔法值替换为 LessonStatus 枚举
- 提升代码可维护性和类型安全

reading-platform-java/src/main/java/com/reading/platform/service/impl/LessonServiceImpl.java

@@ -10,11 +10,13 @@ import com.reading.platform.dto.request.LessonCreateRequest;
 import com.reading.platform.dto.request.LessonUpdateRequest;
 import com.reading.platform.dto.request.LessonProgressRequest;
 import com.reading.platform.dto.request.StudentRecordRequest;
+import com.reading.platform.common.enums.LessonStatus;
 import com.reading.platform.entity.Lesson;
 import com.reading.platform.entity.LessonFeedback;
 import com.reading.platform.entity.SchedulePlan;
 import com.reading.platform.entity.StudentRecord;
 import com.reading.platform.mapper.LessonFeedbackMapper;
+import com.reading.platform.mapper.CoursePackageMapper;
 import com.reading.platform.mapper.LessonMapper;
 import com.reading.platform.mapper.SchedulePlanMapper;
 import com.reading.platform.mapper.StudentRecordMapper;
@@ -41,6 +43,7 @@ public class LessonServiceImpl extends ServiceImpl<LessonMapper, Lesson>
     private final StudentRecordMapper studentRecordMapper;
     private final LessonFeedbackMapper lessonFeedbackMapper;
     private final SchedulePlanMapper schedulePlanMapper;
+    private final CoursePackageMapper coursePackageMapper;
 
     @Override
     @Transactional
@@ -56,10 +59,16 @@ public class LessonServiceImpl extends ServiceImpl<LessonMapper, Lesson>
         lesson.setEndTime(request.getEndTime());
         lesson.setLocation(request.getLocation());
         lesson.setNotes(request.getNotes());
-        lesson.setStatus("scheduled");
+        lesson.setStatus(LessonStatus.SCHEDULED.getCode());
 
         lessonMapper.insert(lesson);
         log.info("课程创建成功：id={}, title={}", lesson.getId(), lesson.getTitle());
+
+        // 更新课程包统计：使用次数 +1
+        if (request.getCourseId() != null) {
+            coursePackageMapper.incrementUsageCount(request.getCourseId());
+            log.info("课程包使用次数 +1: courseId={}", request.getCourseId());
+        }
         return lesson;
     }
 
@@ -164,7 +173,7 @@ public class LessonServiceImpl extends ServiceImpl<LessonMapper, Lesson>
     @Transactional
     public void startLesson(Long id) {
         Lesson lesson = getLessonById(id);
-        lesson.setStatus("in_progress");
+        lesson.setStatus(LessonStatus.IN_PROGRESS.getCode());
         lessonMapper.updateById(lesson);
         log.info("课程开始：id={}", id);
     }
@@ -173,16 +182,22 @@ public class LessonServiceImpl extends ServiceImpl<LessonMapper, Lesson>
     @Transactional
     public void completeLesson(Long id) {
         Lesson lesson = getLessonById(id);
-        lesson.setStatus("completed");
+        lesson.setStatus(LessonStatus.COMPLETED.getCode());
         lessonMapper.updateById(lesson);
         log.info("课程完成：id={}", id);
+
+        // 更新课程包统计：教师数量（去重统计）
+        if (lesson.getCourseId() != null) {
+            coursePackageMapper.updateTeacherCount(lesson.getCourseId());
+            log.info("课程包教师数量已更新：courseId={}", lesson.getCourseId());
+        }
     }
 
     @Override
     @Transactional
     public void cancelLesson(Long id) {
         Lesson lesson = getLessonById(id);
-        lesson.setStatus("cancelled");
+        lesson.setStatus(LessonStatus.CANCELLED.getCode());
         lessonMapper.updateById(lesson);
         log.info("课程取消：id={}", id);
     }
@@ -193,7 +208,7 @@ public class LessonServiceImpl extends ServiceImpl<LessonMapper, Lesson>
                 new LambdaQueryWrapper<Lesson>()
                         .eq(Lesson::getTenantId, tenantId)
                         .eq(Lesson::getLessonDate, LocalDate.now())
-                        .in(Lesson::getStatus, "scheduled", "in_progress")
+                        .in(Lesson::getStatus, LessonStatus.SCHEDULED.getCode(), LessonStatus.IN_PROGRESS.getCode())
                         .orderByAsc(Lesson::getStartTime)
         );
     }
@@ -401,11 +416,16 @@ public class LessonServiceImpl extends ServiceImpl<LessonMapper, Lesson>
         lesson.setLessonDate(schedule.getScheduledDate());
         lesson.setStartTime(startTime);
         lesson.setEndTime(endTime);
-        lesson.setStatus("scheduled");
+        lesson.setStatus(LessonStatus.SCHEDULED.getCode());
         lesson.setNotes(schedule.getNote());
 
         lessonMapper.insert(lesson);
         log.info("从排课创建课时成功: lessonId={}", lesson.getId());
+        // 更新课程包统计：使用次数 +1
+        if (schedule.getCourseId() != null) {
+            coursePackageMapper.incrementUsageCount(schedule.getCourseId());
+            log.info("课程包使用次数 +1: courseId={}", schedule.getCourseId());
+        }
 
         return lesson;
     }
@@ -419,8 +439,8 @@ public class LessonServiceImpl extends ServiceImpl<LessonMapper, Lesson>
         Lesson lesson = createLessonFromSchedule(schedulePlanId, teacherId);
 
         // 开始上课
-        if (!"in_progress".equals(lesson.getStatus())) {
+        if (!LessonStatus.IN_PROGRESS.getCode().equals(lesson.getStatus())) {
-            lesson.setStatus("in_progress");
+            lesson.setStatus(LessonStatus.IN_PROGRESS.getCode());
             lesson.setStartDatetime(LocalDateTime.now());
             lessonMapper.updateById(lesson);
             log.info("课时开始: lessonId={}", lesson.getId());