from sqlalchemy import Column, Integer, String, DateTime, ForeignKey, UniqueConstraint
from sqlalchemy.sql import func
from database import Base


class ProductImage(Base):
    """Cloud-hosted copy of a local product's image, pushed by local_backend
    during menu sync. Used as a fallback on the public QR menu when the
    product has no digital_image_url override set."""
    __tablename__ = "product_images"

    id = Column(Integer, primary_key=True, index=True)
    site_id = Column(Integer, ForeignKey("sites.id"), nullable=False, index=True)
    product_id = Column(Integer, nullable=False)
    image_url = Column(String, nullable=False)
    image_hash = Column(String, nullable=False)
    updated_at = Column(DateTime(timezone=True), server_default=func.now(), onupdate=func.now())

    __table_args__ = (UniqueConstraint("site_id", "product_id", name="uq_product_images_site_product"),)