Vorrania/backend/app/routers/products.py

from fastapi import APIRouter, Depends, HTTPException, status
from fastapi.responses import Response
from sqlalchemy.orm import Session

from ..crud import product_to_out
from ..database import get_db
from ..deps import get_current_user, require_admin
from ..models import Barcode, BaseUnit, Category, Group, Product, ProductImage, User
from ..off import lookup_barcode
from ..schemas import BarcodeCreate, LookupResult, ProductCreate, ProductOut, ProductUpdate
from ..services import images
from ..services.categories import suggest_category
from .categories import descendant_ids
from ..services.conversion import ConversionError, resolve_product_unit
from ..services.group_codes import detach as detach_group_code, sync as sync_group_code

router = APIRouter(prefix="/products", tags=["products"])


@router.get("", response_model=list[ProductOut])
def list_products(
    q: str | None = None,
    category_id: int | None = None,
    db: Session = Depends(get_db),
    _: User = Depends(get_current_user),
) -> list[ProductOut]:
    """Artikel auflisten, optional nach Name und Kategorie eingegrenzt.

    ``category_id=0`` liefert die Artikel ohne Kategorie. Bei einer echten
    Kategorie zählen die Unterkategorien mit: Wer auf "Süßwaren" filtert, will
    auch "Schokolade" sehen.
    """
    query = db.query(Product)
    if q:
        like = f"%{q}%"
        query = query.filter(Product.name.ilike(like))
    if category_id == 0:
        query = query.filter(Product.category_id.is_(None))
    elif category_id is not None:
        query = query.filter(Product.category_id.in_(descendant_ids(db, category_id)))
    products = query.order_by(Product.name).all()
    return [product_to_out(db, p) for p in products]


@router.get("/lookup", response_model=LookupResult)
def lookup(
    barcode: str,
    db: Session = Depends(get_db),
    _: User = Depends(get_current_user),
) -> LookupResult:
    """Barcode auflösen: Produkt (Haupt- oder Alias-Code), Gruppen-Code, sonst OFF."""
    code = barcode.strip()

    existing = db.query(Product).filter(Product.barcode == code).first()
    if existing is None:
        alias = db.query(Barcode).filter(Barcode.code == code).first()
        if alias is not None and alias.product_id:
            existing = db.get(Product, alias.product_id)
    if existing:
        return LookupResult(found=True, existing_product=product_to_out(db, existing))

    # Code kann einer Gruppe zugeordnet sein (z.B. alle Mehl-Marken in "Mehl").
    group_id = group_name = None
    alias = db.query(Barcode).filter(Barcode.code == code).first()
    if alias is not None and alias.group_id:
        group = db.get(Group, alias.group_id)
        if group is not None:
            group_id, group_name = group.id, group.name

    suggestion = lookup_barcode(code)
    # Die OFF-Einordnung steuert die KATEGORIE (Ueberblick), nicht die Gruppe.
    category = suggest_category(db, suggestion)
    category_id = category.id if category else None
    category_name = category.name if category else None
    if suggestion:
        return LookupResult(
            found=True, suggestion=suggestion, group_id=group_id, group_name=group_name,
            category_id=category_id, category_name=category_name,
        )
    return LookupResult(found=False, group_id=group_id, group_name=group_name)


@router.get("/{product_id}", response_model=ProductOut)
def get_product(
    product_id: int,
    db: Session = Depends(get_db),
    _: User = Depends(get_current_user),
) -> ProductOut:
    product = db.get(Product, product_id)
    if product is None:
        raise HTTPException(status.HTTP_404_NOT_FOUND, "Produkt nicht gefunden")
    return product_to_out(db, product)


@router.get("/{product_id}/off", response_model=LookupResult)
def off_vergleich(
    product_id: int,
    db: Session = Depends(get_db),
    _: User = Depends(get_current_user),
) -> LookupResult:
    """Open Food Facts erneut befragen – auch für einen bereits angelegten Artikel.

    ``/lookup`` kann das nicht: Kennt es den Barcode schon, meldet es den eigenen
    Artikel und fragt OFF gar nicht erst. Zum Vergleichen braucht es aber genau
    die fremden Daten.

    Neben dem Haupt-Barcode werden die zusätzlichen EAN-Codes durchprobiert –
    oft ist nur einer davon bei OFF hinterlegt.
    """
    product = db.get(Product, product_id)
    if product is None:
        raise HTTPException(status.HTTP_404_NOT_FOUND, "Produkt nicht gefunden")

    codes = [product.barcode] if product.barcode else []
    codes += [
        b.code
        for b in db.query(Barcode).filter(Barcode.product_id == product_id).all()
        if b.code not in codes
    ]
    if not codes:
        raise HTTPException(
            status.HTTP_400_BAD_REQUEST,
            "Dieser Artikel hat keinen Barcode – ohne den kann Open Food Facts nichts finden.",
        )

    for code in codes:
        suggestion = lookup_barcode(code)
        if suggestion:
            category = suggest_category(db, suggestion)
            return LookupResult(
                found=True,
                suggestion=suggestion,
                category_id=category.id if category else None,
                category_name=category.name if category else None,
            )
    return LookupResult(found=False)


@router.get("/{product_id}/image")
def get_product_image(
    product_id: int,
    db: Session = Depends(get_db),
    _: User = Depends(get_current_user),
) -> Response:
    """Artikelbild aus der eigenen Datenbank – nie von Open Food Facts.

    Anders als das Logo verlangt diese Route eine Anmeldung: Aus den Bildern
    liesse sich sonst ohne Konto ablesen, was im Vorrat liegt.
    """
    product = db.get(Product, product_id)
    if product is None:
        raise HTTPException(status.HTTP_404_NOT_FOUND, "Produkt nicht gefunden")

    bild = images.ensure(db, product)
    if bild is None:
        raise HTTPException(status.HTTP_404_NOT_FOUND, "Kein Bild vorhanden")
    return Response(
        content=bild.data,
        media_type=bild.content_type,
        headers={
            "Cache-Control": "private, max-age=300",
            "ETag": f'"bild-{product_id}-{int(bild.updated_at.timestamp())}"',
        },
    )


@router.post("", response_model=ProductOut, status_code=status.HTTP_201_CREATED)
def create_product(
    payload: ProductCreate,
    db: Session = Depends(get_db),
    _: User = Depends(require_admin),
) -> ProductOut:
    if payload.barcode:
        exists = db.query(Product).filter(Product.barcode == payload.barcode).first()
        if exists:
            raise HTTPException(
                status.HTTP_409_CONFLICT, "Ein Produkt mit diesem Barcode existiert bereits"
            )
    base_unit = payload.base_unit
    display_unit_id = None
    if payload.unit_id is not None:
        try:
            base_unit, display_unit_id = resolve_product_unit(db, payload.unit_id)
        except ConversionError as exc:
            raise HTTPException(status.HTTP_400_BAD_REQUEST, str(exc)) from exc
    product = Product(
        barcode=payload.barcode or None,
        name=payload.name,
        brand=payload.brand,
        image_url=payload.image_url,
        base_unit=base_unit,
        display_unit_id=display_unit_id,
        package_size=payload.package_size,
        package_label=payload.package_label or None,
        date_precision=payload.date_precision.value,
        group_id=payload.group_id,
        category_id=payload.category_id,
        min_stock=payload.min_stock,
        min_stock_unit_id=payload.min_stock_unit_id,
        min_stock_in_packages=bool(payload.min_stock_in_packages),
        source="manual",
    )
    db.add(product)
    db.flush()                      # product.id fuer den Gruppen-Code
    sync_group_code(db, product)
    if product.image_url:
        # Gleich beim Anlegen holen. Schlaegt es fehl, entsteht kein Fehler:
        # Ein fehlendes Bild darf das Anlegen eines Artikels nicht verhindern.
        images.store(db, product, product.image_url)
    db.commit()
    db.refresh(product)
    return product_to_out(db, product)


@router.patch("/{product_id}", response_model=ProductOut)
def update_product(
    product_id: int,
    payload: ProductUpdate,
    db: Session = Depends(get_db),
    _: User = Depends(require_admin),
) -> ProductOut:
    product = db.get(Product, product_id)
    if product is None:
        raise HTTPException(status.HTTP_404_NOT_FOUND, "Produkt nicht gefunden")

    data = payload.model_dump(exclude_unset=True)
    if "barcode" in data and data["barcode"]:
        clash = (
            db.query(Product)
            .filter(Product.barcode == data["barcode"], Product.id != product_id)
            .first()
        )
        if clash:
            raise HTTPException(
                status.HTTP_409_CONFLICT, "Ein anderes Produkt hat diesen Barcode bereits"
            )
    # Einheit: unit_id (falls gesetzt) bestimmt base_unit + Anzeigeeinheit.
    if "unit_id" in data:
        unit_id = data.pop("unit_id")
        data.pop("base_unit", None)  # unit_id hat Vorrang
        if unit_id is None:
            product.display_unit_id = None
        else:
            try:
                product.base_unit, product.display_unit_id = resolve_product_unit(db, unit_id)
            except ConversionError as exc:
                raise HTTPException(status.HTTP_400_BAD_REQUEST, str(exc)) from exc
    if data.get("min_stock_in_packages") is None:
        data.pop("min_stock_in_packages", None)  # Spalte ist NOT NULL
    if data.get("date_precision") is None:
        data.pop("date_precision", None)         # Spalte ist NOT NULL
    else:
        data["date_precision"] = data["date_precision"].value
    alte_bildadresse = product.image_url
    for field, value in data.items():
        setattr(product, field, value)
    # Gruppe oder Barcode koennen sich geaendert haben - Code nachziehen.
    sync_group_code(db, product)
    if "image_url" in data and data["image_url"] != alte_bildadresse:
        # Neue Adresse heisst neues Bild – die alte Kopie waere sonst dauerhaft
        # falsch, weil ``ensure`` nur nachlaedt, wenn gar keine Kopie da ist.
        alt = db.get(ProductImage, product.id)
        if alt is not None:
            db.delete(alt)
            db.flush()
        if product.image_url:
            images.store(db, product, product.image_url)
    db.commit()
    db.refresh(product)
    return product_to_out(db, product)


@router.post("/{product_id}/barcodes", response_model=ProductOut, status_code=status.HTTP_201_CREATED)
def add_product_barcode(
    product_id: int,
    payload: BarcodeCreate,
    db: Session = Depends(get_db),
    _: User = Depends(require_admin),
) -> ProductOut:
    """Weiteren EAN-Code zu einem Produkt hinzufügen."""
    product = db.get(Product, product_id)
    if product is None:
        raise HTTPException(status.HTTP_404_NOT_FOUND, "Produkt nicht gefunden")
    code = payload.code.strip()
    if db.query(Barcode).filter(Barcode.code == code).first() or (
        db.query(Product).filter(Product.barcode == code).first()
    ):
        raise HTTPException(status.HTTP_409_CONFLICT, "Dieser Code ist bereits vergeben")
    db.add(Barcode(code=code, note=(payload.note or None), product_id=product.id))
    db.commit()
    db.refresh(product)
    return product_to_out(db, product)


@router.delete("/{product_id}/barcodes/{code}", status_code=status.HTTP_204_NO_CONTENT)
def delete_product_barcode(
    product_id: int,
    code: str,
    db: Session = Depends(get_db),
    _: User = Depends(require_admin),
) -> None:
    entry = (
        db.query(Barcode)
        .filter(Barcode.product_id == product_id, Barcode.code == code)
        .first()
    )
    if entry is None:
        raise HTTPException(status.HTTP_404_NOT_FOUND, "Code nicht gefunden")
    db.delete(entry)
    db.commit()


@router.delete("/{product_id}", status_code=status.HTTP_204_NO_CONTENT)
def delete_product(
    product_id: int,
    db: Session = Depends(get_db),
    _: User = Depends(require_admin),
) -> None:
    product = db.get(Product, product_id)
    if product is None:
        raise HTTPException(status.HTTP_404_NOT_FOUND, "Produkt nicht gefunden")
    detach_group_code(db, product)
    db.delete(product)
    db.commit()