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

backend/app/services/file_service.py

@@ -0,0 +1,76 @@
+"""Invoice / proforma attachments — metadata in `quote_attachments`, bytes in MinIO.
+
+Multi-file contract: a quote may hold any number of attachments per kind
+(invoice / proforma). Every upload creates a new DB row and a new object
+(object key `{quote_id}/{kind}/{attachment_id}` inside the MinIO bucket).
+"""
+import uuid
+
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.models.files import QuoteAttachment
+from app.services import storage
+from app.utils.errors import NotFoundError
+
+
+def _object_key(quote_id: uuid.UUID, kind: str, attachment_id: uuid.UUID) -> str:
+    return f"{quote_id}/{kind}/{attachment_id}"
+
+
+async def create(
+    db: AsyncSession,
+    quote_id: uuid.UUID,
+    kind: str,
+    file_name: str,
+    content: bytes,
+    mime_type: str,
+) -> QuoteAttachment:
+    """Upload the bytes to MinIO, then persist the metadata row."""
+    attachment_id = uuid.uuid4()
+    object_key = _object_key(quote_id, kind, attachment_id)
+    await storage.put_object(object_key, content, mime_type)
+    attachment = QuoteAttachment(
+        id=attachment_id,
+        quote_id=quote_id,
+        kind=kind,
+        file_name=file_name,
+        mime_type=mime_type,
+        size_bytes=len(content),
+        object_key=object_key,
+    )
+    db.add(attachment)
+    try:
+        await db.flush()
+    except Exception:
+        # Metadata insert failed — best-effort cleanup of the orphan object.
+        await storage.remove_object(object_key)
+        raise
+    return attachment
+
+
+async def list_for(db: AsyncSession, quote_id: uuid.UUID, kind: str) -> list[QuoteAttachment]:
+    result = await db.execute(
+        select(QuoteAttachment)
+        .where(QuoteAttachment.quote_id == quote_id, QuoteAttachment.kind == kind)
+        .order_by(QuoteAttachment.uploaded_at)
+    )
+    return list(result.scalars().all())
+
+
+async def get(db: AsyncSession, attachment_id: uuid.UUID) -> QuoteAttachment:
+    attachment = await db.get(QuoteAttachment, attachment_id)
+    if attachment is None:
+        raise NotFoundError("فایل پیوست یافت نشد")
+    return attachment
+
+
+async def read_bytes(attachment: QuoteAttachment) -> bytes:
+    """Stream the object bytes from MinIO."""
+    return await storage.get_object_bytes(attachment.object_key)
+
+
+async def remove(db: AsyncSession, attachment: QuoteAttachment) -> None:
+    """Delete the object from MinIO (best-effort) and the metadata row."""
+    await storage.remove_object(attachment.object_key)
+    await db.delete(attachment)