from datetime import datetime
from src.extensions import db

class Chat(db.Model):
    __tablename__ = 'chats'
    
    id = db.Column(db.Integer, primary_key=True)
    user_id = db.Column(db.Integer, db.ForeignKey('login.id', ondelete='CASCADE'), nullable=False)
    agent_id = db.Column(db.Integer, db.ForeignKey('agente.id', ondelete='CASCADE'), nullable=False)
    title = db.Column(db.String(120), nullable=True)
    created_at = db.Column(db.DateTime, default=datetime.utcnow)
    model = db.Column(db.String(120), nullable=True)
    
    user = db.relationship('User', back_populates='chats')
    agent = db.relationship('Agente', back_populates='chats')
    messages = db.relationship('Message', back_populates='chat', cascade='all, delete-orphan')
    
    def __repr__(self):
        return f'<Chat {self.id}>'
    
    def to_dict(self):
        return {
            'id': self.id,
            'user_id': self.user_id,
            'agent_id': self.agent_id,
            'title': self.title,
            'created_at': self.created_at.isoformat(),
            'message_count': len(self.messages)
        }