from sqlalchemy import text,  Index, Float, Integer, Text, func
from sqlalchemy.orm import Mapped, mapped_column

from app.models.base import Base


class RagDocument(Base):
    __tablename__ = "rag_documents"

    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
    session_id: Mapped[str] = mapped_column(Text, nullable=False)
    content: Mapped[str] = mapped_column(Text, nullable=False)
    metadata_: Mapped[str] = mapped_column("metadata", Text, default="{}")
    embedding: Mapped[str | None] = mapped_column(Text, nullable=True)
    chunk_index: Mapped[int] = mapped_column(Integer, default=0)
    expires_at: Mapped[float] = mapped_column(Float, nullable=False)
    created_at: Mapped[str] = mapped_column(Text, server_default=text("CURRENT_TIMESTAMP"))

    __table_args__ = (Index("idx_rag_docs_session", "session_id", "expires_at"),)