policies/*: remove Policy.negate, order, timeout (#39)

policies: rewrite engine to use PolicyBinding for order/negate/timeout
policies: rewrite engine to use PolicyResult instead of tuple

passbook/flows/planner.py

@@ -1,7 +1,7 @@
 """Flows Planner"""
 from dataclasses import dataclass, field
 from time import time
-from typing import Any, Dict, List, Optional, Tuple
+from typing import Any, Dict, List, Optional
 
 from django.core.cache import cache
 from django.http import HttpRequest
@@ -11,6 +11,7 @@ from passbook.core.models import User
 from passbook.flows.exceptions import EmptyFlowException, FlowNonApplicableException
 from passbook.flows.models import Flow, Stage
 from passbook.policies.engine import PolicyEngine
+from passbook.policies.types import PolicyResult
 
 LOGGER = get_logger()
 
@@ -51,8 +52,8 @@ class FlowPlanner:
         self.use_cache = True
         self.flow = flow
 
-    def _check_flow_root_policies(self, request: HttpRequest) -> Tuple[bool, List[str]]:
-        engine = PolicyEngine(self.flow.policies.all(), request.user, request)
+    def _check_flow_root_policies(self, request: HttpRequest) -> PolicyResult:
+        engine = PolicyEngine(self.flow, request.user, request)
         engine.build()
         return engine.result
 
@@ -64,9 +65,9 @@ class FlowPlanner:
         LOGGER.debug("f(plan): Starting planning process", flow=self.flow)
         # First off, check the flow's direct policy bindings
         # to make sure the user even has access to the flow
-        root_passing, root_passing_messages = self._check_flow_root_policies(request)
-        if not root_passing:
-            raise FlowNonApplicableException(root_passing_messages)
+        root_result = self._check_flow_root_policies(request)
+        if not root_result.passing:
+            raise FlowNonApplicableException(*root_result.messages)
         # Bit of a workaround here, if there is a pending user set in the default context
         # we use that user for our cache key
         # to make sure they don't get the generic response
@@ -106,11 +107,10 @@ class FlowPlanner:
             .select_related()
         ):
             binding = stage.flowstagebinding_set.get(flow__pk=self.flow.pk)
-            engine = PolicyEngine(binding.policies.all(), user, request)
+            engine = PolicyEngine(binding, user, request)
             engine.request.context = plan.context
             engine.build()
-            passing, _ = engine.result
-            if passing:
+            if engine.passing:
                 LOGGER.debug("f(plan): Stage passing", stage=stage, flow=self.flow)
                 plan.stages.append(stage)
         end_time = time()