admin: add API to list tasks and schedule retry

passbook/admin/api/tasks.py

@@ -0,0 +1,61 @@
+"""Tasks API"""
+from importlib import import_module
+
+from django.contrib import messages
+from django.http.response import Http404
+from django.utils.translation import gettext_lazy as _
+from drf_yasg.utils import swagger_auto_schema
+from rest_framework.decorators import action
+from rest_framework.fields import CharField, DateTimeField, IntegerField, ListField
+from rest_framework.permissions import IsAdminUser
+from rest_framework.request import Request
+from rest_framework.response import Response
+from rest_framework.serializers import Serializer
+from rest_framework.viewsets import ViewSet
+
+from passbook.lib.tasks import TaskInfo
+
+
+class TaskSerializer(Serializer):
+    """Serialize TaskInfo and TaskResult"""
+
+    task_name = CharField()
+    task_description = CharField()
+    task_finish_timestamp = DateTimeField(source="finish_timestamp")
+
+    status = IntegerField(source="result.status.value")
+    messages = ListField(source="result.messages")
+
+    def create(self, request: Request) -> Response:
+        raise NotImplementedError
+
+    def update(self, request: Request) -> Response:
+        raise NotImplementedError
+
+
+class TaskViewSet(ViewSet):
+    """Read-only view set that returns all background tasks"""
+
+    permission_classes = [IsAdminUser]
+
+    @swagger_auto_schema(responses={200: TaskSerializer(many=True)})
+    def list(self, request: Request) -> Response:
+        """List current messages and pass into Serializer"""
+        return Response(TaskSerializer(TaskInfo.all().values(), many=True).data)
+
+    @action(detail=True, methods=["post"])
+    # pylint: disable=invalid-name
+    def retry(self, request: Request, pk=None) -> Response:
+        """Retry task"""
+        task = TaskInfo.by_name(pk)
+        if not task:
+            raise Http404
+        task_module = import_module(task.task_call_module)
+        task_func = getattr(task_module, task.task_call_func)
+        task_func.delay(*task.task_call_args, **task.task_call_kwargs)
+        messages.success(self.request, _("Successfully re-scheduled Task!"))
+        return Response(
+            {
+                "successful": True,
+            }
+        )