From 6e26f663387c9e8a4799accba49b9e89c0c1d285 Mon Sep 17 00:00:00 2001
From: Therainclouds <245141853@qq.com>
Date: Thu, 12 Feb 2026 22:00:17 +0800
Subject: [PATCH] n

---
 backend/community/serializers.py | 16 ++++++++++++++++
 backend/community/views.py       |  4 +++-
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/backend/community/serializers.py b/backend/community/serializers.py
index a1f5724..33539ba 100644
--- a/backend/community/serializers.py
+++ b/backend/community/serializers.py
@@ -1,15 +1,31 @@
 from rest_framework import serializers
 from .models import Activity, ActivitySignup, Topic, Reply, TopicMedia, Announcement
 from shop.serializers import WeChatUserSerializer, ESP32ConfigSerializer, ServiceSerializer, VCCourseSerializer
+from .utils import get_current_wechat_user
 
 class ActivitySerializer(serializers.ModelSerializer):
     display_banner_url = serializers.ReadOnlyField()
     signup_form_config = serializers.SerializerMethodField()
+    current_signups = serializers.SerializerMethodField()
+    has_signed_up = serializers.SerializerMethodField()
     
     class Meta:
         model = Activity
         fields = '__all__'
 
+    def get_current_signups(self, obj):
+        # 统计非取消状态的报名人数
+        return obj.signups.exclude(status='cancelled').count()
+
+    def get_has_signed_up(self, obj):
+        request = self.context.get('request')
+        if not request:
+            return False
+        user = get_current_wechat_user(request)
+        if user:
+            return obj.signups.filter(user=user).exists()
+        return False
+
     def get_signup_form_config(self, obj):
         # 1. 优先使用 JSON 配置
         if obj.signup_form_config:
diff --git a/backend/community/views.py b/backend/community/views.py
index e9f9a88..c854d72 100644
--- a/backend/community/views.py
+++ b/backend/community/views.py
@@ -34,7 +34,9 @@ class ActivityViewSet(viewsets.ReadOnlyModelViewSet):
         if ActivitySignup.objects.filter(activity=activity, user=user).exists():
             return Response({'error': '您已报名该活动'}, status=400)
         
-        if activity.signups.count() >= activity.max_participants:
+        # Check limit (exclude cancelled)
+        current_count = activity.signups.exclude(status='cancelled').count()
+        if current_count >= activity.max_participants:
              return Response({'error': '活动名额已满'}, status=400)
         
         # Get signup info