add end_time

problemset/migrations/0007_problemset_end_time.py

@@ -0,0 +1,18 @@
+# Generated by Django 6.0 on 2026-03-16 15:32
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('problemset', '0006_remove_is_displayed_field'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='problemset',
+            name='end_time',
+            field=models.DateTimeField(blank=True, null=True, verbose_name='截止时间'),
+        ),
+    ]

problemset/models.py

@@ -26,6 +26,8 @@ class ProblemSet(models.Model):
     status = models.TextField(
         default="draft", verbose_name="状态"
     )  # active, archived, draft
+    # 截止时间（到期后自动解除防作弊隐藏）
+    end_time = models.DateTimeField(null=True, blank=True, verbose_name="截止时间")
 
     class Meta:
         db_table = "problemset"

problemset/serializers.py

@@ -92,6 +92,7 @@ class ProblemSetListSerializer(serializers.ModelSerializer):
             "create_time",
             "difficulty",
             "status",
+            "end_time",
             "problems_count",
             "user_progress",
             "badges",
@@ -148,6 +149,7 @@ class CreateProblemSetSerializer(serializers.Serializer):
     description = serializers.CharField()
     difficulty = serializers.CharField(default="Easy")
     status = serializers.CharField(default="active")
+    end_time = serializers.DateTimeField(required=False)
 
 
 class EditProblemSetSerializer(serializers.Serializer):
@@ -159,6 +161,7 @@ class EditProblemSetSerializer(serializers.Serializer):
     difficulty = serializers.CharField(required=False)
     status = serializers.CharField(required=False)
     visible = serializers.BooleanField(required=False)
+    end_time = serializers.DateTimeField(required=False, allow_null=True)
 
 
 class ProblemSetProblemSerializer(serializers.ModelSerializer):

submission/serializers.py

@@ -1,6 +1,10 @@
+from django.db import models
+from django.utils import timezone
+
 from .models import Submission
 from utils.api import serializers
 from utils.serializers import LanguageNameChoiceField
+from problemset.models import ProblemSetProgress
 
 
 class CreateSubmissionSerializer(serializers.Serializer):
@@ -50,4 +54,36 @@ class SubmissionListSerializer(serializers.ModelSerializer):
         # 没传user或为匿名user
         if self.user is None or not self.user.is_authenticated:
             return False
-        return obj.check_user_permission(self.user)
+        if not obj.check_user_permission(self.user):
+            return False
+        # 题单防作弊：用户加入了包含该题目的 active 题单时，隐藏加入前的提交链接
+        # 如果该题目已在题单中做出来了，则恢复显示
+        if obj.user_id == self.user.id and self.user.is_regular_user():
+            progress = self._get_problemset_progress(obj.problem_id)
+            if (
+                progress
+                and obj.create_time < progress.join_time
+                and str(obj.problem_id) not in progress.progress_detail
+            ):
+                return False
+        return True
+
+    def _get_problemset_progress(self, problem_id):
+        """查询用户是否加入了包含该题目的 active 题单，带缓存避免 N+1"""
+        if not hasattr(self, "_problemset_progress_cache"):
+            self._problemset_progress_cache = {}
+        if problem_id not in self._problemset_progress_cache:
+            self._problemset_progress_cache[problem_id] = (
+                ProblemSetProgress.objects.filter(
+                    user=self.user,
+                    problemset__status="active",
+                    problemset__problemsetproblem__problem_id=problem_id,
+                )
+                .filter(
+                    models.Q(problemset__end_time__isnull=True)
+                    | models.Q(problemset__end_time__gt=timezone.now())
+                )
+                .only("join_time", "progress_detail")
+                .first()
+            )
+        return self._problemset_progress_cache[problem_id]