fix all problems

problemset/views/oj.py

@@ -336,7 +336,7 @@ class ProblemSetUserProgressAPI(APIView):
         completed_count = stats["completed"]
         avg_progress = stats["avg_progress"] or 0
 
-        # 获取分页参数，用于预先收集当前页需要的问题ID
+        # 获取分页参数
         try:
             limit = int(request.GET.get("limit", "10"))
         except ValueError:
@@ -348,20 +348,42 @@ class ProblemSetUserProgressAPI(APIView):
         if offset < 0:
             offset = 0
 
-        # 只从当前页的数据中收集问题ID，避免遍历所有记录
+        # 提前获取题单的所有题目（用于前端显示未完成题目和序列化器）
+        # 使用 select_related 和 only 优化查询，只选择需要的字段
+        all_problemset_problems = (
+            ProblemSetProblem.objects.filter(problemset=problem_set)
+            .select_related("problem")
+            .only("problem__id", "problem___id", "problem__title", "order")
+            .order_by("order")
+        )
+        
+        # 构建题单所有题目的数据结构和映射
+        all_problems_list = []
+        all_problems_map = {}
+        for psp in all_problemset_problems:
+            problem_data = {
+                "id": psp.problem.id,
+                "_id": psp.problem._id,
+                "title": psp.problem.title,
+            }
+            all_problems_list.append(problem_data)
+            # 用于序列化器查找，key 使用字符串格式（与 progress_detail 的 key 格式一致）
+            all_problems_map[str(psp.problem.id)] = psp.problem
+
+        # 从当前页的数据中收集已完成的问题ID，用于序列化器
         paginated_progresses = list(progresses[offset : offset + limit])
-        all_problem_ids = set()
+        completed_problem_ids = set()
         for progress in paginated_progresses:
             if progress.progress_detail:
-                all_problem_ids.update(progress.progress_detail.keys())
+                # progress_detail 的 key 是字符串格式的 problem_id
+                completed_problem_ids.update(progress.progress_detail.keys())
 
-        # 批量加载当前页所需的问题
-        problems_dict = {}
-        if all_problem_ids:
-            problems = Problem.objects.filter(id__in=all_problem_ids).only(
-                "id", "_id", "title"
-            )
-            problems_dict = {str(problem.id): problem for problem in problems}
+        # 从已加载的题单题目中构建 problems_dict，避免重复查询
+        problems_dict = {
+            pid: all_problems_map[pid]
+            for pid in completed_problem_ids
+            if pid in all_problems_map
+        }
 
         # 将预加载的问题字典存储到 request 中，供序列化器使用
         request._problems_dict_cache = problems_dict
@@ -376,14 +398,7 @@ class ProblemSetUserProgressAPI(APIView):
             "avg_progress": round(avg_progress, 2),
         }
 
-        # 返回问题 ID 列表
-        data["problems"] = [
-            {
-                "id": problem.id,
-                "_id": problem._id,
-                "title": problem.title,
-            }
-            for problem in problems_dict.values()
-        ]
+        # 返回题单的所有题目
+        data["problems"] = all_problems_list
 
         return self.success(data)