backend/knowledge/models.py

from sqlalchemy import Column, Integer, String, DateTime, Text, JSON, Float, ForeignKey
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import relationship
from datetime import datetime

Base = declarative_base()

class Document(Base):
    __tablename__ = "documents"
    id = Column(Integer, primary_key=True)
    doc_id = Column(String(64), unique=True, nullable=False)
    title = Column(String(256), nullable=False)
    source_type = Column(String(32), nullable=False)
    source_path = Column(String(512), nullable=True)
    meta = Column(JSON, default={})               # renamed from metadata
    created_at = Column(DateTime, default=datetime.utcnow)
    chunks = relationship("Chunk", back_populates="document")

class Chunk(Base):
    __tablename__ = "chunks"
    id = Column(Integer, primary_key=True)
    chunk_id = Column(String(64), unique=True, nullable=False)
    doc_id = Column(Integer, ForeignKey("documents.id"))
    content = Column(Text, nullable=False)
    embedding = Column(JSON, nullable=True)
    chunk_index = Column(Integer, default=0)
    meta = Column(JSON, default={})               # renamed from metadata
    created_at = Column(DateTime, default=datetime.utcnow)
    document = relationship("Document", back_populates="chunks")