feat: initial dashboard

app/base/views/dashboard.py

@@ -0,0 +1,83 @@
+from django.db.models import Q, F, Sum, Count, ExpressionWrapper, IntegerField
+from django.db.models.functions import Substr
+from django.views.generic import TemplateView
+
+from app.base.models import Booking, BookingType
+from app.base.models.trait import Trait
+from app.base.models.trait_mapping import TraitMapping
+from app.base.views.login import LoginRequired
+from app.base.views.model_views.base import ViewOptions
+
+from datetime import date
+from typing import Any
+
+
+class DashboardOptions(ViewOptions, LoginRequired):
+    icon = 'chart-line'
+    title = 'Dashboard'
+
+
+class DashboardView(DashboardOptions, TemplateView):
+    template_name = 'dashboard.html'
+
+    def get_context_data(self, **kwargs) -> 'dict[str, Any]':
+        context = super().get_context_data(**kwargs)
+        book_types = dict(BookingType.objects.values_list('key', 'label'))
+        trait_types = dict(Trait.objects.values_list('key', 'label'))
+
+        # Booking stats
+
+        book_by_type = stats_for_booking('type')
+        book_by_month = {}
+
+        for stat in stats_for_booking('month'):
+            year, month = stat['month'].split('-')
+            if year not in book_by_month:
+                book_by_month[year] = [[0, 0] for x in range(13)]
+            book_by_month[year][0][0] += stat['sum']
+            book_by_month[year][0][1] += stat['count']
+            book_by_month[year][int(month)][0] += stat['sum']
+            book_by_month[year][int(month)][1] += stat['count']
+
+        context['booking'] = {
+            'labels': book_types,
+            'by_type': book_by_type,
+            'by_month': book_by_month,
+        }
+        context['trait'] = {
+            'labels': trait_types,
+            'by_type': stats_for_traits(),
+        }
+        context['head'] = {
+            'bookings': Booking._meta.verbose_name_plural,
+            'booking_types': BookingType._meta.verbose_name_plural,
+            'traits': Trait._meta.verbose_name_plural,
+        }
+
+        return context
+
+
+def stats_for_booking(groupby: str):
+    _Q = Booking.objects.filter(Q(end_time__isnull=False)).annotate(
+        # for whatever reason django uses nano seconds
+        diff=ExpressionWrapper(
+            (F('end_time') - F('begin_time')) / 60_000_000,
+            output_field=IntegerField()),
+    ).filter(diff__lt=1440)  # filter 24+ hours. Probably wrong checkout
+
+    if groupby == 'month':
+        _Q = _Q.annotate(month=Substr('begin_time', 1, 7))  # YYYY-MM
+
+    return _Q.values(groupby).annotate(
+        sum=Sum('diff', output_field=IntegerField()),
+        count=Count(1),
+    ).values(groupby, 'sum', 'count').order_by(groupby)
+
+
+def stats_for_traits():
+    return TraitMapping.objects.filter(
+        Q(valid_from__lte=date.today()),
+        Q(valid_until=None) | Q(valid_until__gte=date.today()),
+    ).values('trait').annotate(
+        count=Count(1),
+    ).values('trait', 'count').order_by('trait')