Only show necessary timeframes on AK wall

Hides hours no upcoming AK is in.
For technical reasons, only one visible area can be displayed for all days, hence hours for one day might be visible even though the are not needed (but just for another day).
For improved visibility, cutoff will be with one hour offset.
This implements #206

AKPlan/templates/AKPlan/plan_wall.html

@@ -51,6 +51,8 @@
                     start: '{{ start | timezone:event.timezone | date:"Y-m-d H:i:s" }}',
                     end: '{{ end | timezone:event.timezone  | date:"Y-m-d H:i:s"}}',
                 },
+                slotMinTime: '{{ earliest_start_hour }}:00:00',
+                slotMaxTime: '{{ latest_end_hour }}:00:00',
                 eventDidMount: function(info) {
                     $(info.el).tooltip({title: info.event.extendedProps.description});
                 },

AKPlan/views.py

+from datetime import timedelta
+
 from django.conf import settings
 from django.shortcuts import redirect
 from django.urls import reverse_lazy
@@ -81,11 +83,11 @@ class PlanScreenView(PlanIndexView):
             return redirect(reverse_lazy("plan:plan_overview", kwargs={"event_slug": self.event.slug}))
         return s
 
-    """
     def get_queryset(self):
-        # Determine interesting range (some hours ago until some hours in the future as specified in the settings)
         now = datetime.now().astimezone(self.event.timezone)
+        # Wall during event: Adjust, show only parts in the future
         if self.event.start < now < self.event.end:
+            # Determine interesting range (some hours ago until some hours in the future as specified in the settings)
             self.start = now - timedelta(hours=settings.PLAN_WALL_HOURS_RETROSPECT)
         else:
             self.start = self.event.start
@@ -93,13 +95,31 @@ class PlanScreenView(PlanIndexView):
 
         # Restrict AK slots to relevant ones
         # This will automatically filter all rooms not needed for the selected range in the orginal get_context method
-        return super().get_queryset().filter(start__gt=self.start)
-    """
+        akslots = super().get_queryset().filter(start__gt=self.start)
+
+        # Find the earliest hour AKs start and end (handle 00:00 as 24:00)
+        self.earliest_start_hour = 23
+        self.latest_end_hour = 1
+        for akslot in akslots.all():
+            start_hour = akslot.start.astimezone(self.event.timezone).hour
+            if start_hour < self.earliest_start_hour:
+                # Use hour - 1 to improve visibility of date change
+                self.earliest_start_hour = max(start_hour - 1, 0)
+            end_hour = akslot.end.astimezone(self.event.timezone).hour
+            # Special case: AK starts before but ends after midnight -- show until midnight
+            if end_hour < start_hour:
+                self.latest_end_hour = 24
+            elif end_hour > self.latest_end_hour:
+                # Always use hour + 1, since AK may end at :xy and not always at :00
+                self.latest_end_hour = min(end_hour + 1, 24)
+        return akslots
 
     def get_context_data(self, *, object_list=None, **kwargs):
         context = super().get_context_data(object_list=object_list, **kwargs)
-        context["start"] = self.event.start
+        context["start"] = self.start
         context["end"] = self.event.end
+        context["earliest_start_hour"] = self.earliest_start_hour
+        context["latest_end_hour"] = self.latest_end_hour
         return context