Expose some settings for Trainwreck DB rotation

tailbone/templates/trainwreck/transactions/configure.mako

@@ -3,13 +3,44 @@
 
 <%def name="form_content()">
 
+  <h3 class="block is-size-3">Rotation</h3>
+  <div class="block" style="padding-left: 2rem;">
+
+    <b-field message="There is only one Trainwreck DB, unless rotation is used.">
+      <b-checkbox name="trainwreck.use_rotation"
+                  v-model="simpleSettings['trainwreck.use_rotation']"
+                  native-value="true"
+                  @input="settingsNeedSaved = true">
+        Rotate Databases
+      </b-checkbox>
+    </b-field>
+
+    <b-field grouped>
+      <b-field label="Current Years"
+               message="How many years (max) to keep in &quot;current&quot; DB.  Default is 2 if not set.">
+        <b-input name="trainwreck.current_years"
+                 v-model="simpleSettings['trainwreck.current_years']"
+                 @input="settingsNeedSaved = true">
+        </b-input>
+      </b-field>
+    </b-field>
+
+  </div>
+
   <h3 class="block is-size-3">Hidden Databases</h3>
   <div class="block" style="padding-left: 2rem;">
+    <p class="block">
+      The selected DBs will be hidden from the DB picker when viewing
+      Trainwreck data.
+    </p>
     % for key, engine in six.iteritems(trainwreck_engines):
         <b-field>
           <b-checkbox name="hidedb_${key}"
                       v-model="hiddenDatabases['${key}']"
                       native-value="true"
+                      % if key == 'default':
+                      disabled
+                      % endif
                       @input="settingsNeedSaved = true">
             ${key}
           </b-checkbox>

tailbone/views/trainwreck/base.py

@@ -384,6 +384,19 @@ class TransactionView(MasterView):
             'engines_data': engines_data,
         })
 
+    def configure_get_simple_settings(self):
+        return [
+
+            # rotation
+            {'section': 'trainwreck',
+             'option': 'use_rotation',
+             'type': bool},
+            {'section': 'trainwreck',
+             'option': 'current_years',
+             'type': int},
+
+        ]
+
     def configure_get_context(self):
         context = super(TransactionView, self).configure_get_context()