add rest api for department

hr/api_urls.py

@@ -8,13 +8,14 @@
 from hr.api_views import (
     EmployeeViewSet,
     PositionViewSet,
-    SalaryCalculatorView,
+    SalaryCalculatorView, DepartmentViewSet,
 )
 
 
 router = DefaultRouter()
 router.register(r'employees', EmployeeViewSet)
 router.register(r'positions', PositionViewSet)
+router.register(r'department', DepartmentViewSet)
 
 urlpatterns = [
     path('', include(router.urls)),

hr/api_views.py

@@ -7,13 +7,14 @@
 from hr.calculate_salary import CalculateMonthRateSalary
 from hr.models import (
     Employee,
-    Position,
+    Position, Department,
 )
 from hr.pydantic_models import WorkingDays
 from hr.serializers import (
     EmployeeSerializer,
     PositionSerializer,
     SalarySerializer,
+    DepartmentSerializer,
 )
 
 
@@ -39,6 +40,15 @@ def position_count(self, request, pk=None):
         count = Employee.objects.filter(position=employee.position).count()
         return Response({'position_count': count})
 
+class DepartmentViewSet(viewsets.ModelViewSet):
+    queryset = Department.objects.all()
+    serializer_class = DepartmentSerializer
+
+    @action(detail=True, methods=['get'])
+    def employee_count(self, request, pk=None):
+        department = self.get_object()
+        count_emp = Employee.objects.filter(position__department=department).count()
+        return Response({'employee_count': count_emp})
 
 class PositionViewSet(viewsets.ModelViewSet):
     queryset = Position.objects.all()

hr/serializers.py

@@ -2,7 +2,7 @@
 
 from hr.models import (
     Employee,
-    Position,
+    Position, Department,
 )
 
 
@@ -25,3 +25,7 @@ class SalarySerializer(serializers.Serializer):
     sick_days = serializers.IntegerField(default=0)
     vacation_days = serializers.IntegerField(default=0)
 
+class DepartmentSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = Department
+        fields = ('id', 'name', 'parent_department')