init

backend/product/serializers.py

@@ -0,0 +1,155 @@
+from rest_framework import serializers
+from rest_framework.validators import UniqueValidator
+
+from trznice.utils import RoundedDateTimeField
+from .models import Product, EventProduct
+from booking.models import Event
+# from booking.serializers import EventSerializer
+
+class ProductSerializer(serializers.ModelSerializer):
+    code = serializers.CharField(
+        required=False,
+        allow_null=True,
+        allow_blank=True,
+        help_text="Unikátní číselný kód produktu (volitelné)",
+    )
+    events = serializers.SerializerMethodField(help_text="Seznam akcí (eventů), ve kterých se tento produkt prodává.")
+
+    class Meta:
+        model = Product
+        fields = ["id", "name", "code", "events"]
+        read_only_fields = ["id"]
+        extra_kwargs = {
+            "name": {
+                "help_text": "Název zboží (max. 255 znaků).",
+                "required": True,
+            },
+            "code": {
+                "help_text": "Unikátní kód zboží (např. 'FOOD-001'). Volitelné; pokud vyplněno, musí být jedinečný.",
+                "required": False,
+                "allow_null": True,
+                "allow_blank": True,
+            },
+        }
+
+    def validate_name(self, value):
+        value = value.strip()
+        
+        if not value:
+            raise serializers.ValidationError("Název Zboží (Produktu) nemůže být prázdný.")
+        
+        if len(value) > 255:
+            raise serializers.ValidationError("Název nesmí být delší než 255 znaků.")
+        return value
+
+    def validate_code(self, value):
+        # Accept empty/null
+        if value in (None, ""):
+            return None
+        # Uniqueness manual check (since we removed built-in validator to permit null/blank)
+        qs = Product.objects.filter(code=value)
+        if self.instance:
+            qs = qs.exclude(pk=self.instance.pk)
+        if qs.exists():
+            raise serializers.ValidationError("Produkt s tímto kódem už existuje.")
+        return value
+
+    def get_events(self, obj):
+        # Expect prefetch: event_products__event
+        events = []
+        # Access prefetched related if available to avoid N+1
+        event_products = getattr(obj, 'event_products_all', None)
+        if event_products is None:
+            # Fallback query (should be avoided if queryset is optimized)
+            event_products = obj.event_products.select_related('event').all()
+        for ep in event_products:
+            if ep.event_id and hasattr(ep, 'event'):
+                events.append({"id": ep.event_id, "name": ep.event.name})
+        return events
+
+
+class EventProductSerializer(serializers.ModelSerializer):
+    product = ProductSerializer(read_only=True)
+    product_id = serializers.PrimaryKeyRelatedField(
+        queryset=Product.objects.all(), write_only=True
+    )
+
+    start_selling_date = RoundedDateTimeField()
+    end_selling_date = RoundedDateTimeField()
+
+    class Meta:
+        model = EventProduct
+        fields = [
+            'id',
+            'product',         # nested read-only
+            'product_id',      # required in POST/PUT
+            'event',
+            'start_selling_date',
+            'end_selling_date',
+        ]
+
+        read_only_fields = ["id", "product"]
+        extra_kwargs = {
+            "product": {
+                "help_text": "Detail zboží (jen pro čtení).",
+                "required": False,
+                "read_only": True,
+            },
+            "product_id": {
+                "help_text": "ID zboží, které je povoleno prodávat na akci.",
+                "required": True,
+                "write_only": True,
+            },
+            "event": {
+                "help_text": "ID akce (Event), pro kterou je zboží povoleno.",
+                "required": True,
+            },
+            "start_selling_date": {
+                "help_text": "Začátek prodeje v rámci akce (musí spadat do [event.start, event.end]).",
+                "required": True,
+            },
+            "end_selling_date": {
+                "help_text": "Konec prodeje v rámci akce (po start_selling_date, také v rámci [event.start, event.end]).",
+                "required": True,
+            },
+        }
+
+
+    def create(self, validated_data):
+        validated_data["product"] = validated_data.pop("product_id")
+        return super().create(validated_data)
+    
+    def validate(self, data):
+        product = data.get("product_id")
+        event = data.get("event")
+        start = data.get("start_selling_date")
+        end = data.get("end_selling_date")
+
+        if start >= end:
+            raise serializers.ValidationError("Datum začátku prodeje musí být dříve než jeho konec.")
+
+        if event and (start < event.start or end > event.end):
+            raise serializers.ValidationError("Prodej zboží musí být v rámci trvání akce.")
+
+        # When updating, exclude self instance
+        instance_id = self.instance.id if self.instance else None
+
+        # Check for overlapping EventProducts for the same product/event
+        overlapping = EventProduct.objects.exclude(id=instance_id).filter(
+            event=event,
+            product_id=product,
+            start_selling_date__lt=end,
+            end_selling_date__gt=start,
+        )
+        if overlapping.exists():
+            raise serializers.ValidationError("Toto zboží už se prodává v tomto období na této akci.")
+
+        # # Check for duplicate product-event pair
+        # duplicate = EventProduct.objects.exclude(id=instance_id).filter(
+        #     event=event,
+        #     product_id=product,
+        # )
+        # if duplicate.exists():
+        #     raise serializers.ValidationError(f"V rámci akce {event} už je {product} zaregistrováno.")
+
+        return data