feat: add discount_amount to payment_order and receipt_order, and change total_amount logic

api_v1/views/printing/serializers.py

@@ -4,25 +4,14 @@ Printing API 序列化器
 from rest_framework import serializers
 
 from api_v1.models import UploadedFile
+from api_v1.utils.media import build_public_media_url
 from printing import models
 from .services import PrintingOrderService, PrintingJobService
 from basic_info.models import Customer, Employee
-from django.conf import settings
 
 
 def _build_absolute_media_url(url: str | None, request):
-    if not url:
-        return None
-    if isinstance(url, str) and url.startswith(('http://', 'https://')):
-        return url
-    if not isinstance(url, str):
-        return None
-    if request:
-        if url.startswith('/'):
-            return request.build_absolute_uri(url)
-        media_prefix = (settings.MEDIA_URL or '/media/').rstrip('/')
-        return request.build_absolute_uri(f'{media_prefix}/{url.lstrip("/")}')
-    return url
+    return build_public_media_url(url, request=request)
 
 
 def _serialize_plate_images(raw_value, request):