adding

apps/bizapps/api/serializers.py

@@ -0,0 +1,58 @@
+from rest_framework import serializers
+
+from apps.bizapps.models import Appointment, Customer, LedgerEntry, Product, StockMovement
+
+
+class CustomerSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = Customer
+        fields = ["id", "name", "phone", "email", "address", "notes", "updated_at"]
+        read_only_fields = ["updated_at"]
+
+
+class LedgerEntrySerializer(serializers.ModelSerializer):
+    class Meta:
+        model = LedgerEntry
+        fields = ["id", "entry_type", "title", "amount", "category", "entry_date", "note", "updated_at"]
+        read_only_fields = ["updated_at"]
+
+
+class ProductSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = Product
+        fields = [
+            "id",
+            "name",
+            "sku",
+            "category",
+            "quantity",
+            "unit_price",
+            "low_stock_threshold",
+            "notes",
+            "updated_at",
+        ]
+        read_only_fields = ["updated_at"]
+
+
+class StockMovementSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = StockMovement
+        fields = ["id", "delta", "quantity_after", "note", "created_at"]
+        read_only_fields = fields
+
+
+class AdjustStockSerializer(serializers.Serializer):
+    delta = serializers.FloatField()
+    note = serializers.CharField(max_length=255, required=False, allow_blank=True, default="")
+
+    def validate_delta(self, value):
+        if value == 0:
+            raise serializers.ValidationError("مقدار تغییر نمی‌تواند صفر باشد.")
+        return value
+
+
+class AppointmentSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = Appointment
+        fields = ["id", "customer_name", "customer_phone", "title", "start_at", "status", "notes", "updated_at"]
+        read_only_fields = ["updated_at"]

apps/bizapps/api/views.py

@@ -0,0 +1,130 @@
+from django.db import transaction
+from rest_framework import generics, status
+from rest_framework.exceptions import NotFound
+from rest_framework.permissions import IsAuthenticated
+from rest_framework.response import Response
+from rest_framework.views import APIView
+
+from apps.billing.permissions import HasActiveFeature
+from apps.bizapps.models import Appointment, Customer, LedgerEntry, Product, StockMovement
+
+from .serializers import (
+    AdjustStockSerializer,
+    AppointmentSerializer,
+    CustomerSerializer,
+    LedgerEntrySerializer,
+    ProductSerializer,
+    StockMovementSerializer,
+)
+
+# همه‌ی این ریزاپ‌ها با جم فعال می‌شوند (یا دوره‌ی آزمایشی) — `feature_key`
+# روی هر ویو مشخص می‌کند HasActiveFeature باید چه چیزی را چک کند.
+# permission_classes اینجا Base است تا زیرکلاس‌ها فراموش نکنند.
+
+
+class _UserScopedListCreateView(generics.ListCreateAPIView):
+    permission_classes = [IsAuthenticated, HasActiveFeature]
+
+    def get_queryset(self):
+        return self.model.objects.filter(user=self.request.user)
+
+    def perform_create(self, serializer):
+        serializer.save(user=self.request.user)
+
+
+class _UserScopedDetailView(generics.RetrieveUpdateDestroyAPIView):
+    permission_classes = [IsAuthenticated, HasActiveFeature]
+
+    def get_queryset(self):
+        return self.model.objects.filter(user=self.request.user)
+
+
+class CustomerListCreateView(_UserScopedListCreateView):
+    model = Customer
+    serializer_class = CustomerSerializer
+    feature_key = "customers"
+
+
+class CustomerDetailView(_UserScopedDetailView):
+    model = Customer
+    serializer_class = CustomerSerializer
+    feature_key = "customers"
+
+
+class LedgerEntryListCreateView(_UserScopedListCreateView):
+    model = LedgerEntry
+    serializer_class = LedgerEntrySerializer
+    feature_key = "ledger"
+
+
+class LedgerEntryDetailView(_UserScopedDetailView):
+    model = LedgerEntry
+    serializer_class = LedgerEntrySerializer
+    feature_key = "ledger"
+
+
+class ProductListCreateView(_UserScopedListCreateView):
+    model = Product
+    serializer_class = ProductSerializer
+    feature_key = "inventory"
+
+
+class ProductDetailView(_UserScopedDetailView):
+    model = Product
+    serializer_class = ProductSerializer
+    feature_key = "inventory"
+
+
+class ProductAdjustStockView(APIView):
+    """تعدیل اتمیک موجودی (+/-) + یک ردیف تاریخچه — به‌جای این‌که کلاینت
+    مستقیم quantity جدید را PATCH کند (که هیچ تاریخچه‌ای نمی‌سازد و اگر دو
+    درخواست هم‌زمان بیایند می‌تواند یکی را گم کند)."""
+
+    permission_classes = [IsAuthenticated, HasActiveFeature]
+    feature_key = "inventory"
+
+    @transaction.atomic
+    def post(self, request, pk):
+        try:
+            product = Product.objects.select_for_update().get(pk=pk, user=request.user)
+        except Product.DoesNotExist:
+            raise NotFound("کالا یافت نشد.")
+
+        serializer = AdjustStockSerializer(data=request.data)
+        serializer.is_valid(raise_exception=True)
+        delta = serializer.validated_data["delta"]
+
+        product.quantity += delta
+        product.save(update_fields=["quantity", "updated_at"])
+        StockMovement.objects.create(
+            product=product,
+            delta=delta,
+            quantity_after=product.quantity,
+            note=serializer.validated_data.get("note", ""),
+        )
+        return Response(ProductSerializer(product).data, status=status.HTTP_200_OK)
+
+
+class ProductMovementsView(generics.ListAPIView):
+    """تاریخچه‌ی تغییرات موجودی یک کالا — جدیدترین اول."""
+
+    serializer_class = StockMovementSerializer
+    permission_classes = [IsAuthenticated, HasActiveFeature]
+    feature_key = "inventory"
+
+    def get_queryset(self):
+        return StockMovement.objects.filter(
+            product_id=self.kwargs["pk"], product__user=self.request.user
+        )
+
+
+class AppointmentListCreateView(_UserScopedListCreateView):
+    model = Appointment
+    serializer_class = AppointmentSerializer
+    feature_key = "booking"
+
+
+class AppointmentDetailView(_UserScopedDetailView):
+    model = Appointment
+    serializer_class = AppointmentSerializer
+    feature_key = "booking"