"""
会话表 — 独立于 chat_messages 管理会话元数据
"""
from sqlalchemy import Column, String, Text, Integer, DateTime, Boolean, ForeignKey, func
from sqlalchemy.dialects.mysql import CHAR
from app.core.database import Base
import uuid


class AgentSession(Base):
    """Agent 会话表"""
    __tablename__ = "agent_sessions"

    id = Column(CHAR(36), primary_key=True, default=lambda: str(uuid.uuid4()), comment="会话ID")
    user_id = Column(CHAR(36), nullable=True, index=True, comment="用户ID")
    workspace_id = Column(CHAR(36), ForeignKey("workspaces.id"), nullable=True, index=True, comment="工作区ID")
    agent_id = Column(CHAR(36), nullable=True, index=True, comment="Agent ID")
    title = Column(String(200), nullable=True, comment="会话标题")
    is_pinned = Column(Boolean, default=False, comment="是否置顶")
    created_at = Column(DateTime, default=func.now(), comment="创建时间")
    updated_at = Column(DateTime, default=func.now(), onupdate=func.now(), comment="更新时间")

    def __repr__(self):
        return f"<AgentSession(id={self.id}, title={self.title}, pinned={self.is_pinned})>"