From c066f07e9855089104ee5776b452fab30eed02f8 Mon Sep 17 00:00:00 2001
From: Elisha Rosensweig <elisha.rosensweig@nokia.com>
Date: Wed, 10 Feb 2016 15:58:14 +0200
Subject: [PATCH] evaluator processor initial outline

Change-Id: Ibc7da2622aa95055c9b34fbf164aa08a871f13eb
---
 vitrage/evaluator/scenario.py             | 76 +++++++++++++++++++++++
 vitrage/evaluator/template_query_utils.py | 40 ++++++++++++
 2 files changed, 116 insertions(+)
 create mode 100644 vitrage/evaluator/scenario.py
 create mode 100644 vitrage/evaluator/template_query_utils.py

diff --git a/vitrage/evaluator/scenario.py b/vitrage/evaluator/scenario.py
new file mode 100644
index 000000000..6a04a89bb
--- /dev/null
+++ b/vitrage/evaluator/scenario.py
@@ -0,0 +1,76 @@
+# Copyright 2016 - Nokia
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+
+class Scenario(object):
+
+    TYPE_ENTITY = 'entity'
+    TYPE_RELATE = 'relationship'
+
+    def __init__(self):
+        pass
+
+    def get_condition(self):
+        """Returns the condition for this scenario.
+
+        Each condition should be formatted in DNF (Disjunctive Normal Form),
+        e.g., (X and Y) or (X and Z) or (X and V and not W)...
+        where X, Y, Z, V, W are either entities or relationships
+        For details: https://en.wikipedia.org/wiki/Disjunctive_normal_form
+
+        :return: condition
+        """
+        entity = 'replace with vertex'
+
+        relationship = 'replace with edge'
+
+        mock_entity = (entity, self.TYPE_ENTITY, True)
+        mock_relationship = (relationship, self.TYPE_RELATE, False)
+
+        # single "and" clause between entity and relationship
+        return [(mock_entity, mock_relationship)]
+
+    def get_actions(self):
+        """Returns the action specifications for this scenario.
+
+        :return: list of actions to perform
+        :rtype: ActionSpecs
+        """
+        action_spec = ActionSpecs()
+        return [action_spec]
+
+
+class ActionSpecs(object):
+
+    def get_type(self):
+        return 'action type str'
+
+    def get_targets(self):
+        """Returns dict of template_ids to apply action on
+
+        :return: dict of string:template_id
+        :rtype: dict
+        """
+
+        # e.g., for adding edge, need two ids. for alarms, will need only one.
+        return {'source': 'source template_id',
+                'target': 'target template_id'}
+
+    def get_properties(self):
+        """Returns the properties relevant to the action.
+
+        :return: dictionary of properties relevant to the action.
+        :rtype: dict
+        """
+        return {'prop_key': 'prop_val'}
diff --git a/vitrage/evaluator/template_query_utils.py b/vitrage/evaluator/template_query_utils.py
new file mode 100644
index 000000000..1b8fb327c
--- /dev/null
+++ b/vitrage/evaluator/template_query_utils.py
@@ -0,0 +1,40 @@
+# Copyright 2016 - Nokia
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+import vitrage.evaluator.scenario as scenario
+
+
+class ScenarioManager(object):
+
+    def get_relevant_scenarios(self, element_before, element_now):
+        """Returns scenarios triggered by an event.
+
+        Returned scenarios are divided into two disjoint lists, based on the
+        element state (before/now) that triggered the scenario condition.
+
+        Note that this should intuitively mean that the "before" scenarios will
+        activate their "undo" operation, while the "now" will activate the
+        "execute" operation.
+
+        :param element_before:
+        :param element_now:
+        :return:
+        :rtype: dict
+        """
+
+        trigger_id_before = 'template_id of trigger for before scenario'
+        trigger_id_now = 'template_id of trigger for now scenario'
+
+        return {'before': [(scenario.Scenario(), trigger_id_before)],
+                'now': [(scenario.Scenario(), trigger_id_now)]}