"""文章服务"""
from datetime import datetime
from slugify import slugify
from app import db
from app.models import Article, Category, Tag


class ArticleService:
    """文章业务逻辑"""
    
    @staticmethod
    def get_published_list(page=1, per_page=10, category_id=None, tag_id=None):
        """获取已发布文章列表"""
        query = Article.query.filter_by(is_published=True)
        
        if category_id:
            query = query.filter_by(category_id=category_id)
        if tag_id:
            query = query.join(Article.tags).filter(Tag.id == tag_id)
        
        return query.order_by(Article.published_at.desc()).paginate(
            page=page, per_page=per_page, error_out=False
        )
    
    @staticmethod
    def get_by_slug(slug):
        """通过slug获取文章"""
        article = Article.query.filter_by(slug=slug, is_published=True).first()
        if article:
            # 增加浏览次数
            article.view_count += 1
            db.session.commit()
        return article
    
    @staticmethod
    def get_by_id(article_id):
        """通过ID获取文章"""
        return Article.query.get(article_id)
    
    @staticmethod
    def get_all_list(page=1, per_page=20, is_published=None):
        """获取所有文章列表（后台用）"""
        query = Article.query
        if is_published is not None:
            query = query.filter_by(is_published=is_published)
        return query.order_by(Article.updated_at.desc()).paginate(
            page=page, per_page=per_page, error_out=False
        )
    
    @staticmethod
    def create(title, content, summary=None, author_id=None, category_id=None, tag_ids=None, 
               cover_image=None, is_published=False):
        """创建文章"""
        # 生成唯一slug
        slug = slugify(title)
        count = Article.query.filter(Article.slug.like(f'{slug}%')).count()
        if count > 0:
            slug = f'{slug}-{count + 1}'
        
        article = Article(
            title=title,
            slug=slug,
            content=content,
            summary=summary or content[:200] + '...' if len(content) > 200 else content,
            author_id=author_id,
            category_id=category_id,
            cover_image=cover_image,
            is_published=is_published,
            published_at=datetime.utcnow() if is_published else None
        )
        
        # 添加标签
        if tag_ids:
            tags = Tag.query.filter(Tag.id.in_(tag_ids)).all()
            article.tags = tags
        
        db.session.add(article)
        db.session.commit()
        return article
    
    @staticmethod
    def update(article_id, **kwargs):
        """更新文章"""
        article = Article.query.get(article_id)
        if not article:
            return None
        
        # 处理发布状态变化
        if 'is_published' in kwargs and kwargs['is_published'] and not article.is_published:
            kwargs['published_at'] = datetime.utcnow()
        
        # 处理标签
        tag_ids = kwargs.pop('tag_ids', None)
        if tag_ids is not None:
            tags = Tag.query.filter(Tag.id.in_(tag_ids)).all()
            article.tags = tags
        
        # 更新其他字段
        for key, value in kwargs.items():
            if hasattr(article, key):
                setattr(article, key, value)
        
        db.session.commit()
        return article
    
    @staticmethod
    def delete(article_id):
        """删除文章"""
        article = Article.query.get(article_id)
        if article:
            db.session.delete(article)
            db.session.commit()
            return True
        return False
    
    @staticmethod
    def get_hot_articles(limit=5):
        """获取热门文章"""
        return Article.query.filter_by(is_published=True)\
            .order_by(Article.view_count.desc())\
            .limit(limit).all()
    
    @staticmethod
    def get_recent_articles(limit=5):
        """获取最新文章"""
        return Article.query.filter_by(is_published=True)\
            .order_by(Article.published_at.desc())\
            .limit(limit).all()