feat: add person stats to dashboard

app/base/views/dashboard.py

@@ -1,8 +1,11 @@
 from django.db.models import Q, F, Sum, Count, ExpressionWrapper, IntegerField
 from django.db.models.functions import Substr
+from django.db.models.lookups import LessThan
 from django.views.generic import TemplateView
 
-from app.base.models import Booking, BookingType, Trait, TraitMapping
+from app.base.models import (
+    Booking, BookingType, CourseVisit, Person, Trait, TraitMapping
+)
 from app.base.views.login import LoginRequired
 from app.base.views.model_views.base import ViewOptions
 
@@ -23,30 +26,20 @@ class DashboardView(DashboardOptions, TemplateView):
         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,
+            'by_type': stats_for_booking('type'),
         }
         context['trait'] = {
             'labels': trait_types,
             'by_type': stats_for_traits(),
         }
+        context['person'] = {
+            'by_count': stats_for_person_count(),
+        }
+        context['by_month'] = stats_by_month()
         context['head'] = {
+            'person': Person._meta.verbose_name_plural,
             'bookings': Booking._meta.verbose_name_plural,
             'booking_types': BookingType._meta.verbose_name_plural,
             'traits': Trait._meta.verbose_name_plural,
@@ -55,9 +48,59 @@ class DashboardView(DashboardOptions, TemplateView):
         return context
 
 
+def stats_for_person_count():
+    today = date.today()
+    last_year = today.replace(year=today.year - 1)
+
+    stats = Person.objects.aggregate(
+        total=Count(1),
+        single_visit=Sum(LessThan(
+            # TODO: other DBs dont use microseconds
+            ExpressionWrapper(F('last_visit') - F('created'),
+                              output_field=IntegerField()),
+            3 * 86_400_000_000)),  # 3 days
+        long_not_seen=Sum(Q(last_visit__lt=last_year)),
+    )
+
+    stats['no_booking'] = stats['total'] - Booking.objects.aggregate(
+        c=Count('user', distinct=True))['c']
+    stats['no_course'] = stats['total'] - CourseVisit.objects.aggregate(
+        c=Count('participant', distinct=True))['c']
+
+    return stats
+
+
+def stats_by_month():
+    stats = {}
+
+    for stat in stats_for_person_by_month():
+        year, month = stat['month'].split('-')
+        if year not in stats:
+            stats[year] = [[0, 0, 0] for x in range(13)]
+        stats[year][0][2] += stat['count']
+        stats[year][int(month)][2] += stat['count']
+
+    for stat in stats_for_booking('month'):
+        year, month = stat['month'].split('-')
+        if year not in stats:
+            stats[year] = [[0, 0, 0] for x in range(13)]
+        stats[year][0][0] += stat['sum']
+        stats[year][0][1] += stat['count']
+        stats[year][int(month)][0] += stat['sum']
+        stats[year][int(month)][1] += stat['count']
+
+    return sorted(stats.items(), reverse=True)
+
+
+def stats_for_person_by_month():
+    return Person.objects.values(
+        month=Substr('created', 1, 7),  # YYYY-MM
+    ).annotate(count=Count(1)).order_by('month')
+
+
 def stats_for_booking(groupby: str):
     _Q = Booking.objects.filter(Q(end_time__isnull=False)).annotate(
-        # for whatever reason django uses nano seconds
+        # TODO: other DBs dont use microseconds
         diff=ExpressionWrapper(
             (F('end_time') - F('begin_time')) / 60_000_000,
             output_field=IntegerField()),