backend/app/models.py

"""ORM models: upload sessions, room images, and generation records."""
from __future__ import annotations

import datetime as dt
import uuid

from sqlalchemy import DateTime, ForeignKey, Integer, String, Text
from sqlalchemy.orm import Mapped, mapped_column, relationship

from .db import Base


def _uuid() -> str:
    return uuid.uuid4().hex


class UploadSession(Base):
    """One upload action containing a gallery of room photos."""

    __tablename__ = "upload_sessions"

    id: Mapped[str] = mapped_column(String(32), primary_key=True, default=_uuid)
    created_at: Mapped[dt.datetime] = mapped_column(DateTime, default=dt.datetime.utcnow)

    images: Mapped[list["RoomImage"]] = relationship(
        back_populates="session", cascade="all, delete-orphan"
    )


class RoomImage(Base):
    """A single normalized room photo belonging to an upload session."""

    __tablename__ = "room_images"

    id: Mapped[str] = mapped_column(String(32), primary_key=True, default=_uuid)
    session_id: Mapped[str] = mapped_column(ForeignKey("upload_sessions.id"))
    filename: Mapped[str] = mapped_column(String(255))
    path: Mapped[str] = mapped_column(String(512))       # absolute disk path
    rel_path: Mapped[str] = mapped_column(String(512))   # path relative to /static
    width: Mapped[int] = mapped_column(Integer)
    height: Mapped[int] = mapped_column(Integer)
    created_at: Mapped[dt.datetime] = mapped_column(DateTime, default=dt.datetime.utcnow)

    session: Mapped[UploadSession] = relationship(back_populates="images")


class Generation(Base):
    """A generated (redesigned) room image and its inputs."""

    __tablename__ = "generations"

    id: Mapped[str] = mapped_column(String(32), primary_key=True, default=_uuid)
    session_id: Mapped[str] = mapped_column(String(32))
    image_id: Mapped[str] = mapped_column(String(32))
    item_ids: Mapped[str] = mapped_column(Text)          # comma-separated catalog ids
    provider: Mapped[str] = mapped_column(String(32))
    output_path: Mapped[str] = mapped_column(String(512))
    output_rel_path: Mapped[str] = mapped_column(String(512))
    created_at: Mapped[dt.datetime] = mapped_column(DateTime, default=dt.datetime.utcnow)