tweaks

backend/app/services/mix_calculator_filenames.py

@@ -3,8 +3,14 @@ from __future__ import annotations
 import re
 
 from app.models.mix_calculator import MixCalculatorSession
+from app.schemas.mix_calculator import MixCalculatorPreviewRead
 
 
 def mix_calculator_pdf_filename(session_record: MixCalculatorSession) -> str:
     raw = f"{session_record.session_number}_{session_record.client_name}_{session_record.product_name}.pdf"
     return re.sub(r"[^\w.\-]+", "_", raw)
+
+
+def mix_calculator_preview_pdf_filename(preview: MixCalculatorPreviewRead) -> str:
+    raw = f"MixCalculator_{preview.client_name}_{preview.product_name}_{preview.mix_date}.pdf"
+    return re.sub(r"[^\w.\-]+", "_", raw)