add pos header validation middleware

apps/pos_device/middlewares.py

@@ -0,0 +1,30 @@
+from rest_framework.exceptions import APIException
+from django.utils.timezone import now
+
+from apps.pos_device.models import DeviceVersion, ProviderCompany, Sessions
+
+
+class POSDeviceMiddleware:
+    REQUIRED_HEADERS = [
+        'device-id', 'device-mac', 'device-serial', 'device-name',
+        'device-sdk', 'device-provider', 'device-version',
+        'device-vname', 'device-lng', 'device-lot'  # noqa
+    ]
+
+    def __init__(self, get_response):
+        self.get_response = get_response
+
+    def __call__(self, request, *args, **kwargs):
+        pass
+
+    def is_post_request(self, request):  # noqa
+        """ check if is pos request """
+
+        has_device_headers = request.headers.get('device-id') and request.headers.get('device-mac')
+        is_pos_api_path = request.path.startswith('/api/pos/')
+        return has_device_headers or is_pos_api_path
+
+    def validate_pos_request(self, request):
+        """ validate request headers from pos device """
+
+        data = {key: request.headers.get(key) for key in self.REQUIRED_HEADERS}