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

from app.models.base import Base


class SemanticCache(Base):
    __tablename__ = "semantic_cache"

    cache_key: Mapped[str] = mapped_column(Text, primary_key=True)
    model: Mapped[str] = mapped_column(Text, nullable=False, default="")
    query_text: Mapped[str] = mapped_column(Text, nullable=False, default="")
    response: Mapped[str] = mapped_column(Text, nullable=False)
    embedding: Mapped[str] = mapped_column(Text, nullable=False, default="[]")
    created_at: Mapped[float] = mapped_column(
        Float, server_default=func.extract("epoch", func.now())
    )
    expires_at: Mapped[float] = mapped_column(Float, nullable=False)
    hit_count: Mapped[int] = mapped_column(Integer, default=0)

    __table_args__ = (
        Index("idx_semantic_cache_expires", "expires_at"),
        Index("idx_semantic_cache_model", "model"),
    )