feat(backend): add FastAPI backend — procurement, inventory domain, Casdoor auth, PM arrival endpoints

backend/app/routers/brands.py

@@ -0,0 +1,94 @@
+"""Brands CRUD. (name, country) is UNIQUE (uq_brands_name_country)."""
+from fastapi import APIRouter, Depends, Query
+from sqlalchemy import func, select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.db.engine import get_db
+from app.models.catalog import Brand, BrandMaterial
+from app.schemas.catalog import BrandCreate, BrandUpdate
+from app.utils.errors import ConflictError, NotFoundError
+from app.utils.pagination import paginate, sort_query
+from app.utils.serialization import to_iso
+
+router = APIRouter(prefix="/brands", tags=["brands"])
+
+
+def brand_to_dict(brand: Brand) -> dict:
+    return {
+        "id": str(brand.id),
+        "name": brand.name,
+        "country": brand.country,
+        "created_at": to_iso(brand.created_at),
+    }
+
+
+@router.get("")
+async def list_brands(
+    page: int = Query(1, ge=1),
+    page_size: int = Query(20, ge=1, le=100),
+    q: str | None = None,
+    country: str | None = None,
+    sort: str | None = None,
+    db: AsyncSession = Depends(get_db),
+):
+    stmt = select(Brand)
+    if q:
+        stmt = stmt.where(Brand.name.ilike(f"%{q}%"))
+    if country:
+        stmt = stmt.where(Brand.country == country)
+    stmt = sort_query(stmt, Brand, sort)
+    items, meta = await paginate(stmt, page, page_size, db)
+    return {"data": [brand_to_dict(b) for b in items], "meta": meta}
+
+
+@router.post("", status_code=201)
+async def create_brand(payload: BrandCreate, db: AsyncSession = Depends(get_db)):
+    rows = (await db.execute(select(Brand).where(Brand.name == payload.name))).scalars().all()
+    if any(b.country == payload.country for b in rows):
+        raise ConflictError("برندی با این نام و کشور قبلاً ثبت شده است")
+    brand = Brand(name=payload.name, country=payload.country)
+    db.add(brand)
+    await db.flush()
+    return {"data": brand_to_dict(brand)}
+
+
+@router.get("/{brand_id}")
+async def get_brand(brand_id, db: AsyncSession = Depends(get_db)):
+    brand = await db.get(Brand, brand_id)
+    if brand is None:
+        raise NotFoundError("برند یافت نشد")
+    return {"data": brand_to_dict(brand)}
+
+
+@router.patch("/{brand_id}")
+async def update_brand(brand_id, payload: BrandUpdate, db: AsyncSession = Depends(get_db)):
+    brand = await db.get(Brand, brand_id)
+    if brand is None:
+        raise NotFoundError("برند یافت نشد")
+    new_name = payload.name if payload.name is not None else brand.name
+    new_country = payload.country if payload.country is not None else brand.country
+    rows = (await db.execute(select(Brand).where(Brand.name == new_name, Brand.id != brand_id))).scalars().all()
+    if any(b.country == new_country for b in rows):
+        raise ConflictError("برندی با این نام و کشور قبلاً ثبت شده است")
+    if payload.name is not None:
+        brand.name = payload.name
+    if payload.country is not None:
+        brand.country = payload.country
+    await db.flush()
+    return {"data": brand_to_dict(brand)}
+
+
+@router.delete("/{brand_id}")
+async def delete_brand(brand_id, db: AsyncSession = Depends(get_db)):
+    brand = await db.get(Brand, brand_id)
+    if brand is None:
+        raise NotFoundError("برند یافت نشد")
+    # Recommendation (b) from P2-4: block instead of silently cascading associations.
+    linked = await db.scalar(
+        select(func.count()).select_from(BrandMaterial).where(BrandMaterial.brand_id == brand_id)
+    )
+    if linked:
+        raise ConflictError(f"این برند با {linked} متریال مرتبط است و قابل حذف نیست")
+    await db.delete(brand)
+    await db.flush()
+    return {"data": {"id": str(brand_id), "deleted": True}}