feat: add mine and class filters to statistics page

app/routes/students.py

@@ -380,11 +380,37 @@ def import_students():
 @main_bp.route("/api/statistics/students")
 def get_student_statistics():
     """获取学员统计数据"""
-    # 全体学员数量
-    total_students = Student.query.count()
+    # 获取筛选参数
+    mine_filter = request.args.get("mine", "false") == "true"
+    class_id_filter = request.args.get("class_id", type=int)
+    current_user_id = session.get("user_id")
 
-    # 全体问题记录
-    problems = StudentProblem.query.all()
+    # 基础查询：班级
+    class_query = Class.query.filter_by(active=True)
+    if mine_filter and current_user_id:
+        class_query = class_query.filter_by(teacher_id=current_user_id)
+    if class_id_filter:
+        class_query = class_query.filter_by(id=class_id_filter)
+    classes = class_query.all()
+
+    # 获取班级IDs
+    class_ids = [c.id for c in classes]
+
+    # 学员过滤
+    student_query = Student.query
+    if class_ids:
+        student_query = student_query.filter(Student.class_id.in_(class_ids))
+    else:
+        student_query = student_query.filter(Student.id == -1)  # 无班级时返回空
+    students = student_query.all()
+    student_ids = [s.id for s in students]
+
+    # 全体学员数量
+    total_students = len(students)
+
+    # 问题记录过滤
+    problem_query = StudentProblem.query.filter(StudentProblem.student_id.in_(student_ids)) if student_ids else StudentProblem.query.filter(StudentProblem.id == -1)
+    problems = problem_query.all()
 
     # 问题级别分布（来自 StudentProblem.level）
     levels = ["启蒙", "入门", "进阶", "熟练", "精通"]
@@ -400,7 +426,6 @@ def get_student_statistics():
             severity_dist[p.severity] += 1
 
     # 各班级学员数量
-    classes = Class.query.filter_by(active=True).all()
     class_student_count = []
     for c in classes:
         class_student_count.append({