from sqlalchemy import Column, Integer, String, Text, ForeignKey, DateTime, Enum
from sqlalchemy.orm import relationship
from sqlalchemy.sql import func
from datetime import datetime
import enum

from app.db.database import Base


class MessageCreator(str, enum.Enum):
    """Enum for message creator"""
    USER = "USER"
    ASSISTANT = "ASSISTANT"


class Message(Base):
    """Message model"""
    __tablename__ = "messages"
    
    message_id = Column(Integer, primary_key=True, index=True, autoincrement=True)
    chat_id = Column(Integer, ForeignKey("chats.chat_id", ondelete="CASCADE"), nullable=False, index=True)
    created_by = Column(Enum(MessageCreator), nullable=False)
    text = Column(Text, nullable=True)
    file_paths = Column(Text, nullable=True)  # Store as JSON string
    created_at = Column(DateTime, nullable=False, default=func.now(), index=True)
    
    # Relationship
    chat = relationship("Chat", back_populates="messages")
    
    def __repr__(self):
        return f"<Message(message_id={self.message_id}, chat_id={self.chat_id}, created_by={self.created_by})>"