Refactor the REST API app

Remove the APIRoot view.

Remove the Endpoint class.

Remove the EndpointSerializer.

Move API documentation generation from the root urls module
to the app's urls module.

Update the app API URL generation to be based on viewsets
instead of an custom api_urls list.

Remove MayanObjectPermissionsFilter and replace it with
MayanViewSetObjectPermissionsFilter which allows mapping
a required permission to a specific viewset action.

Signed-off-by: Roberto Rosario <Roberto.Rosario@mayan-edms.com>

mayan/apps/rest_api/api_views.py

@@ -1,31 +1,11 @@
 from __future__ import unicode_literals
 
-from rest_framework import renderers
+from drf_yasg.views import get_schema_view
+
+from rest_framework import permissions, renderers
 from rest_framework.authtoken.views import ObtainAuthToken
-from rest_framework.views import APIView
-from rest_framework.response import Response
-from rest_framework.schemas.generators import EndpointEnumerator
 
-from .classes import Endpoint
-from .serializers import EndpointSerializer
-
-
-class APIRoot(APIView):
-    swagger_schema = None
-
-    def get(self, request, format=None):
-        """
-        get: Return a list of all endpoints.
-        """
-        endpoint_enumerator = EndpointEnumerator()
-
-        endpoints = []
-        for url in sorted(set([entry[0].split('/')[2] for entry in endpoint_enumerator.get_api_endpoints()])):
-            if url:
-                endpoints.append(Endpoint(label=url))
-
-        serializer = EndpointSerializer(endpoints, many=True)
-        return Response(serializer.data)
+from .schemas import openapi_info
 
 
 class BrowseableObtainAuthToken(ObtainAuthToken):
@@ -33,3 +13,11 @@ class BrowseableObtainAuthToken(ObtainAuthToken):
     Obtain an API authentication token.
     """
     renderer_classes = (renderers.BrowsableAPIRenderer, renderers.JSONRenderer)
+
+
+schema_view = get_schema_view(
+    openapi_info,
+    validators=['flex', 'ssv'],
+    public=True,
+    permission_classes=(permissions.AllowAny,),
+)