from sqlalchemy import Column, Integer, String, Text, DateTime, ForeignKey
from sqlalchemy.orm import relationship
from datetime import datetime
from .database import Base

class ChatSession(Base):
    __tablename__ = 'chat_sessions'

    id = Column(Integer, primary_key=True, index=True)
    session_id = Column(String(64), unique=True, index=True, nullable=False)
    name = Column(String(100), default="New Chat", nullable=False)
    created_at = Column(DateTime, default=datetime.utcnow, nullable=False)

    messages = relationship("ChatMessage", back_populates="session")

class ChatMessage(Base):
    __tablename__ = 'chat_messages'

    id = Column(Integer, primary_key=True, index=True)
    session_pk = Column(Integer, ForeignKey('chat_sessions.id'), nullable=False)
    role = Column(String(16), nullable=False)  # 'user' | 'assistant'
    content = Column(Text, nullable=False)
    # JSON-encoded list of citation URLs; null/empty => no chips
    sources_json = Column(Text, nullable=True, default='[]')
    # JSON-encoded list of inline image attachments for user messages.
    attachments_json = Column(Text, nullable=True, default='[]')
    created_at = Column(DateTime, default=datetime.utcnow, nullable=False)

    session = relationship("ChatSession", back_populates="messages")