如何使用drf创建评论系统

from django.db import models
from django.contrib.auth.models import User

class Comment(models.Model):
    user = models.ForeignKey(User, on_delete=models.CASCADE)
    content = models.TextField()
    created_at = models.DateTimeField(auto_now_add=True)
    post = models.ForeignKey('Post', on_delete=models.CASCADE, related_name='comments')

class Post(models.Model):
    title = models.CharField(max_length=200)
    content = models.TextField()
    author = models.ForeignKey(User, on_delete=models.CASCADE)
    created_at = models.DateTimeField(auto_now_add=True)

from rest_framework import serializers
from .models import Comment, Post

class CommentSerializer(serializers.ModelSerializer):
    class Meta:
        model = Comment
        fields = ['id', 'user', 'content', 'created_at']

class PostSerializer(serializers.ModelSerializer):
    comments = CommentSerializer(many=True, read_only=True)

    class Meta:
        model = Post
        fields = ['id', 'title', 'content', 'author', 'created_at', 'comments']

from rest_framework import viewsets
from .models import Comment, Post
from .serializers import CommentSerializer, PostSerializer

class CommentViewSet(viewsets.ModelViewSet):
    queryset = Comment.objects.all()
    serializer_class = CommentSerializer

class PostViewSet(viewsets.ModelViewSet):
    queryset = Post.objects.all()
    serializer_class = PostSerializer

from django.urls import path, include
from rest_framework.routers import DefaultRouter
from .views import CommentViewSet, PostViewSet

router = DefaultRouter()
router.register(r'comments', CommentViewSet)
router.register(r'posts', PostViewSet)

urlpatterns = [
    path('', include(router.urls)),
]

class CommentSerializer(serializers.ModelSerializer):
    parent_comment = serializers.PrimaryKeyRelatedField(queryset=Comment.objects.all(), required=False)

    class Meta:
        model = Comment
        fields = ['id', 'user', 'content', 'created_at', 'parent_comment']

from rest_framework import permissions

class IsOwnerOrReadOnly(permissions.BasePermission):
    def has_object_permission(self, request, view, obj):
        if request.method in permissions.SAFE_METHODS:
            return True
        return obj.user == request.user

class CommentViewSet(viewsets.ModelViewSet):
    queryset = Comment.objects.all()
    serializer_class = CommentSerializer
    permission_classes = [IsOwnerOrReadOnly]