from .users import User
from . import Base

from sqlalchemy import (
    Column, Integer, String, Text, JSON, Enum,
    TIMESTAMP, ForeignKey, Index, func, text
)
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import relationship


class Post(Base):
    __tablename__ = 'posts'
    __table_args__ = (
        # 索引
        Index('idx_posts_heat', 'heat'),
        # MySQL 引擎、字符集、校对规则、表注释
        {
            'mysql_engine': 'InnoDB',
            'mysql_charset': 'utf8mb4',
            'mysql_collate': 'utf8mb4_general_ci',
            'comment': '内容帖子表'
        }
    )

    def to_dict(self):
        return {
            'id': self.id if self.id else None,
            'user_id': self.user_id if self.user_id else None,
            'topic_id': self.topic_id if self.topic_id else None,
            'type': self.type if self.type else None,
            'title': self.title if self.title else None,
            'content': self.content if self.content else None,
            'media_urls': self.media_urls if self.media_urls else None,
            'status': self.status if self.status else None,
            'heat': self.heat if self.heat else None,
            'created_at': self.created_at.isoformat() if self.created_at else None,
            'updated_at': self.updated_at.isoformat() if self.updated_at else None
        }


    id = Column(
        Integer,
        primary_key=True,
        autoincrement=True,
        comment='帖子ID'
    )
    user_id = Column(
        Integer,
        ForeignKey('users.id', ondelete='CASCADE'),
        nullable=False,
        index=True,
        comment='作者ID'
    )
    topic_id = Column(
        Integer,
        ForeignKey('topics.id', ondelete='SET NULL'),
        nullable=True,
        index=True,
        comment='所属话题ID'
    )
    type = Column(
        Enum('text', 'image', 'video', 'document', name='post_type'),
        nullable=False,
        server_default=text("'text'"),
        comment='内容类型'
    )
    title = Column(
        String(255),
        nullable=False,
        comment='标题'
    )
    content = Column(
        Text,
        nullable=False,
        comment='正文内容'
    )
    media_urls = Column(
        JSON,
        nullable=True,
        comment='媒体资源URL数组'
    )
    status = Column(
        Enum('draft', 'pending', 'published', 'deleted', 'rejected', name='post_status'),
        nullable=False,
        server_default=text("'draft'"),
        comment='状态'
    )
    heat = Column(
        Integer,
        nullable=False,
        server_default=text('0'),
        comment='热度值'
    )
    created_at = Column(
        TIMESTAMP,
        nullable=True,
        server_default=func.current_timestamp(),
        comment='创建时间'
    )
    updated_at = Column(
        TIMESTAMP,
        nullable=True,
        server_default=func.current_timestamp(),
        onupdate=func.current_timestamp(),
        comment='更新时间'
    )

    # 可选：与 User/Topic 模型的关系（需要在 User、Topic 中也定义 back_populates）
    # user = relationship('User', back_populates='posts')
    # topic = relationship('Topic', back_populates='posts')