HartOMat/plan.md

Plan: Duplicate Product Detection

Context

When importing products via Excel or STEP upload, there's no warning when a product already exists with a different STEP file. This can lead to accidental overwrites or confusion. The feature adds non-blocking warnings (yellow badges, toasts) at import time.

Detection Scenarios

1. Excel preview: Product exists in DB with a different STEP file linked → warning icon
2. Excel preview: Same product in two rows with different name_cad_modell → conflict badge
3. STEP upload on product: Replacing an existing STEP file on a product that has renders → toast warning
4. All warnings are non-blocking — user can still proceed

Affected Files

File	Change
backend/app/services/excel_import.py	Add STEP conflict detection in preview_excel_rows()
backend/app/api/routers/uploads.py	Extend preview response with conflict fields
backend/app/api/routers/products.py	Add render-count warning to CAD upload response
frontend/src/api/uploads.ts	Update TypeScript interfaces
frontend/src/pages/Upload.tsx	Display conflict warnings in preview table
frontend/src/api/products.ts	Add warning fields to CAD upload response type
frontend/src/pages/ProductDetail.tsx	Show toast warnings on STEP replacement

Tasks

[ ] Task 1: Backend — STEP conflict detection in Excel preview

• File: backend/app/services/excel_import.py
• What: In preview_excel_rows(), after the product lookup:
  1. If product exists and has cad_file_id, load the CadFile and compare original_name (stem) with the Excel row's name_cad_modell
  2. If they differ → set step_conflict=True with details
  3. Track name_cad_modell per product key in the seen dict
  4. If same product appears again with different name_cad_modell → set cad_name_conflict=True
• Also: Add selectinload(Product.cad_file) to lookup_product() in backend/app/domains/products/service.py
• Dependencies: None

[ ] Task 2: Backend — Extend preview response models

• File: backend/app/api/routers/uploads.py
• What: Add to the preview row dict and response:
  • step_conflict: bool, step_conflict_existing_name: str | None, step_conflict_excel_name: str | None
  • cad_name_conflict: bool, cad_name_conflict_other_name: str | None, cad_name_conflict_row: int | None
  • Response-level: step_conflict_count: int, cad_name_conflict_count: int
• Dependencies: Task 1

[ ] Task 3: Backend — Render warning on product STEP replacement

• File: backend/app/api/routers/products.py
• What: In upload_product_cad(), before replacing cad_file_id:
  1. Check if product already has a different cad_file_id
  2. Count existing MediaAssets (renders) for this product
  3. Add warnings: list[str] and existing_render_count: int to response
• Dependencies: None

[ ] Task 4: Frontend — Update API types

• File: frontend/src/api/uploads.ts
• What: Add conflict fields to ExcelPreviewRow and ExcelPreviewResult interfaces
• Also: frontend/src/api/products.ts — add warnings?: string[] and existing_render_count?: number to ProductCadUploadResponse
• Dependencies: Tasks 2, 3

[ ] Task 5: Frontend — Show conflict warnings in Upload preview

• File: frontend/src/pages/Upload.tsx
• What:
  1. Add StatCards for step_conflict_count and cad_name_conflict_count (amber color, AlertTriangle icon)
  2. In the preview table rows: yellow warning icon with tooltip for step_conflict and cad_name_conflict
• Dependencies: Task 4

[ ] Task 6: Frontend — Show warnings on STEP replacement

• File: frontend/src/pages/ProductDetail.tsx
• What: In cadUploadMut.onSuccess, check response for warnings and show toast.warning() for each
• Dependencies: Task 4

Migration Check

No — all detection is computed from existing data.

Order

1. Backend Tasks 1+2 (Excel preview conflicts)
2. Backend Task 3 (STEP replacement warning)
3. Frontend Tasks 4+5+6 (types + UI)