backend/models/conversation.py

from sqlalchemy import Column, Integer, String, Text, DateTime, ForeignKey, JSON, Float
from sqlalchemy.sql import func
from sqlalchemy.orm import relationship
from core.database import Base

class Conversation(Base):
    __tablename__ = "conversations"

    id = Column(Integer, primary_key=True, index=True)
    agent_id = Column(Integer, ForeignKey("agents.id", ondelete="CASCADE"), nullable=False)
    user_id = Column(Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=False)
    created_at = Column(DateTime(timezone=True), server_default=func.now())
    updated_at = Column(DateTime(timezone=True), server_default=func.now(), onupdate=func.now())

    # Relationships
    agent = relationship("Agent", back_populates="conversations")
    messages = relationship("Message", back_populates="conversation", cascade="all, delete-orphan")

class Message(Base):
    __tablename__ = "messages"

    id = Column(Integer, primary_key=True, index=True)
    conversation_id = Column(Integer, ForeignKey("conversations.id", ondelete="CASCADE"), nullable=False)
    role = Column(String, nullable=False)  # user, assistant
    content = Column(Text, nullable=False)
    
    # Advanced features
    multimodal_data = Column(JSON, nullable=True)  # Images, audio paths
    explainability_data = Column(JSON, nullable=True)  # Reasoning traces
    confidence = Column(Float, nullable=True)
    
    timestamp = Column(DateTime(timezone=True), server_default=func.now())
    
    conversation = relationship("Conversation", back_populates="messages")