chunyu_project/article/serializers.py

from adrf.serializers import (
    ModelSerializer, CharField, IntegerField, ImageField, DateTimeField,
    JSONField, SerializerMethodField,
)
from rest_framework import serializers
from .models import Article, ArticleComment, ArticleLike, ArticleFavorite, ArticleCommentLike


class ArticleCommentSerializer(ModelSerializer):
    user_id = IntegerField(source='user.id', read_only=True)
    user_name = CharField(source='user.first_name', read_only=True)
    user_avatar = ImageField(source='user.avatar', read_only=True)
    user_location = CharField(source='user.location', read_only=True)
    parent_user_name = SerializerMethodField()
    replies = SerializerMethodField()
    is_liked = SerializerMethodField()
    # read_only=True 必须字段级声明：DRF/adrf 的 Meta.read_only_fields 对显式声明字段无效
    created_at = DateTimeField(format='%Y-%m-%d %H:%M', read_only=True)

    class Meta:
        model = ArticleComment
        fields = ['id', 'user_id', 'user_name', 'user_avatar', 'user_location', 'content', 'parent', 'parent_user_name', 'likes', 'created_at', 'replies', 'is_liked']
        read_only_fields = ['likes', 'created_at']

    async def get_parent_user_name(self, obj):
        if obj.parent_id:
            # 异步加载父评论作者，避免外键懒加载
            parent = await ArticleComment.objects.select_related('user').aget(pk=obj.parent_id)
            return parent.user.first_name or parent.user.username
        return ''

    async def get_replies(self, obj):
        if obj.parent_id is None:
            replies = [r async for r in obj.replies.all()]
            return [await ArticleCommentSerializer(r, context=self.context).adata for r in replies]
        return []

    async def get_is_liked(self, obj):
        request = self.context.get('request')
        if request and request.user.is_authenticated:
            return await ArticleCommentLike.objects.filter(user=request.user, comment=obj).aexists()
        return False


class ArticleListSerializer(ModelSerializer):
    author_name = CharField(source='author.first_name', read_only=True)
    author_avatar = ImageField(source='author.avatar', read_only=True)
    author_user_id = serializers.PrimaryKeyRelatedField(source='author', read_only=True)
    comments_count = SerializerMethodField()
    read_time = SerializerMethodField()
    is_hot = SerializerMethodField()
    is_new = SerializerMethodField()
    is_following = SerializerMethodField()
    publish_date = DateTimeField(source='created_at', format='%Y-%m-%d', read_only=True)
    image = SerializerMethodField()

    class Meta:
        model = Article
        fields = [
            'id', 'title', 'excerpt', 'category', 'author_name', 'author_avatar',
            'author_user_id', 'views', 'likes', 'comments_count', 'publish_date', 'image', 'tags',
            'read_time', 'is_featured', 'is_hot', 'is_new', 'is_top', 'status',
            'is_following',
        ]

    async def get_is_following(self, obj):
        request = self.context.get('request')
        if request and request.user.is_authenticated:
            from user.models import Follow
            return await Follow.objects.filter(follower=request.user, following=obj.author_id).aexists()
        return False

    async def get_comments_count(self, obj):
        return await obj.comments.acount()

    async def get_read_time(self, obj):
        if obj.content:
            word_count = len(obj.content)
            minutes = max(1, word_count // 300)
            return f'{minutes} 分钟'
        return '1 分钟'

    async def get_is_hot(self, obj):
        return obj.views > 1000 or obj.likes > 100

    async def get_is_new(self, obj):
        from django.utils import timezone
        import datetime
        return (timezone.now() - obj.created_at).days < 7

    async def get_image(self, obj):
        if obj.cover_image:
            request = self.context.get('request')
            if request:
                return request.build_absolute_uri(obj.cover_image.url)
            return obj.cover_image.url
        return ''


class ArticleDetailSerializer(ModelSerializer):
    author_name = CharField(source='author.first_name', read_only=True)
    author_avatar = ImageField(source='author.avatar', read_only=True)
    author_bio = CharField(source='author.bio', read_only=True, default='')
    author_user_id = serializers.PrimaryKeyRelatedField(source='author', read_only=True)
    comments_count = SerializerMethodField()
    favorites_count = SerializerMethodField()
    read_time = SerializerMethodField()
    publish_date = DateTimeField(source='created_at', format='%Y-%m-%d %H:%M', read_only=True)
    update_date = DateTimeField(source='updated_at', format='%Y-%m-%d %H:%M', read_only=True)
    image = SerializerMethodField()
    is_liked = SerializerMethodField()
    is_favorited = SerializerMethodField()
    is_following = SerializerMethodField()
    related_articles = SerializerMethodField()
    comments = SerializerMethodField()
    comments_pagination = SerializerMethodField()

    class Meta:
        model = Article
        fields = [
            'id', 'title', 'excerpt', 'content', 'category', 'tags', 'image',
            'author_name', 'author_avatar', 'author_bio', 'author_user_id',
            'views', 'likes', 'favorites_count', 'comments_count', 'publish_date',
            'update_date', 'read_time', 'is_featured', 'is_top', 'status', 'editor_mode',
            'is_liked', 'is_favorited', 'is_following', 'related_articles', 'comments', 'comments_pagination',
        ]

    async def get_comments_count(self, obj):
        return await obj.comments.acount()

    async def get_favorites_count(self, obj):
        return await obj.article_favorites.acount()

    async def get_read_time(self, obj):
        if obj.content:
            word_count = len(obj.content)
            minutes = max(1, word_count // 300)
            return f'{minutes} 分钟'
        return '1 分钟'

    async def get_image(self, obj):
        if obj.cover_image:
            request = self.context.get('request')
            if request:
                return request.build_absolute_uri(obj.cover_image.url)
            return obj.cover_image.url
        return ''

    async def get_is_liked(self, obj):
        request = self.context.get('request')
        if request and request.user.is_authenticated:
            return await ArticleLike.objects.filter(user=request.user, article=obj).aexists()
        return False

    async def get_is_favorited(self, obj):
        request = self.context.get('request')
        if request and request.user.is_authenticated:
            return await ArticleFavorite.objects.filter(user=request.user, article=obj).aexists()
        return False

    async def get_is_following(self, obj):
        request = self.context.get('request')
        if request and request.user.is_authenticated:
            from user.models import Follow
            return await Follow.objects.filter(follower=request.user, following=obj.author_id).aexists()
        return False

    async def get_related_articles(self, obj):
        queryset = Article.objects.filter(status='published').exclude(id=obj.id)
        related = queryset.filter(category=obj.category)[:4]
        related_list = [a async for a in related]
        if len(related_list) < 4:
            remaining = 4 - len(related_list)
            extra = queryset.filter(tags__overlap=obj.tags or []).exclude(
                id__in=[a.id for a in related_list]
            )[:remaining]
            related_list = related_list + [a async for a in extra]
        return [await ArticleListSerializer(a, context=self.context).adata for a in related_list]

    async def get_comments(self, obj):
        request = self.context.get('request')
        page_size = int(request.query_params.get('comment_page_size', 10)) if request else 10
        page = int(request.query_params.get('comment_page', 1)) if request else 10
        top_comments = obj.comments.filter(parent__isnull=True)
        start = (page - 1) * page_size
        end = start + page_size
        comments_page = [c async for c in top_comments[start:end]]
        return [await ArticleCommentSerializer(c, context=self.context).adata for c in comments_page]

    async def get_comments_pagination(self, obj):
        request = self.context.get('request')
        page_size = int(request.query_params.get('comment_page_size', 10)) if request else 10
        top_count = await obj.comments.filter(parent__isnull=True).acount()
        return {
            'count': top_count,
            'next': top_count > page_size,
        }


class ArticleCreateUpdateSerializer(ModelSerializer):
    tags = JSONField(required=False, default=list)

    class Meta:
        model = Article
        fields = ['title', 'excerpt', 'content', 'category', 'tags', 'cover_image', 'status', 'editor_mode']
        read_only_fields = ['status']

    async def acreate(self, validated_data):
        validated_data['author'] = self.context['request'].user
        return await super().acreate(validated_data)


class ArticleManageSerializer(ModelSerializer):
    author_name = CharField(source='author.first_name', read_only=True)
    comments_count = SerializerMethodField()
    favorites_count = SerializerMethodField()
    summary = CharField(source='excerpt', read_only=True)
    publish_date = DateTimeField(source='created_at', format='%Y-%m-%d', read_only=True)
    update_date = DateTimeField(source='updated_at', format='%Y-%m-%d', read_only=True)

    class Meta:
        model = Article
        fields = [
            'id', 'title', 'summary', 'status', 'views', 'likes',
            'comments_count', 'favorites_count', 'publish_date', 'update_date',
            'category', 'tags', 'is_top', 'author_name',
        ]

    async def get_comments_count(self, obj):
        return await obj.comments.acount()

    async def get_favorites_count(self, obj):
        return await obj.article_favorites.acount()