feat: store and update last_visit in person model

app/base/migrations/0005_person_last_visit.py

@@ -0,0 +1,48 @@
+# Generated by Django 4.2 on 2023-06-08 08:07
+
+from django.db import migrations
+from app.base.forms.fields import DateField
+from datetime import date
+
+
+def calc_last_visit(apps, schema_editor):
+    Person = apps.get_model('base', 'Person')
+    Booking = apps.get_model('base', 'Booking')
+    CourseVisit = apps.get_model('base', 'CourseVisit')
+
+    max_dates = {}
+    zero = date.fromtimestamp(0)
+
+    for (pk, day) in Booking.objects.values_list('user', 'begin_time__date'):
+        max_dates[pk] = max(day, max_dates.get(pk, zero))
+
+    for (pk1, pk2, day) in CourseVisit.objects.values_list(
+            'participant', 'teacher', 'date'):
+        max_dates[pk1] = max(day, max_dates.get(pk1, zero))
+        max_dates[pk2] = max(day, max_dates.get(pk2, zero))
+
+    for person in Person.objects.all():
+        person.last_visit = max(person.created, max_dates.get(person.pk, zero))
+        person.save()
+
+
+def noop(apps, schema_editor):
+    pass  # allow reverse migrate because field will be just deleted
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('base', '0004_person_created_merge_street'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='person',
+            name='last_visit',
+            field=DateField(verbose_name='Letzter Besuch', editable=False,
+                            default=date.fromtimestamp(0)),
+            preserve_default=False,
+        ),
+        migrations.RunPython(calc_last_visit, noop),
+    ]

app/base/models/booking.py

@@ -41,6 +41,26 @@ class Booking(models.Model):
             to_current_timezone(self.end_time).strftime('%H:%M')
             if self.end_time else '')
 
+    def save(self, *args, **kwargs):
+        # update last_visit time of all involved persons
+        prev = Booking.objects.get(pk=self.pk) if self.pk else None
+
+        rv = super().save(*args, **kwargs)
+
+        if prev and prev.user != self.user:
+            prev.user.update_last_visit(None)
+        if not prev or prev.user != self.user or \
+                prev.begin_time.date() != self.begin_time.date():
+            self.user.update_last_visit(self.begin_time.date())
+
+        return rv
+
+    def delete(self, *args, **kwargs):
+        rv = super().delete(*args, **kwargs)
+        # update last_visit time for person
+        self.user.update_last_visit(None)
+        return rv
+
     @property
     def duration(self) -> 'int|None':
         if self.end_time:
@@ -54,11 +74,6 @@ class Booking(models.Model):
         traits = set(x[0] for x in traits)
         return self.type.price_with_traits(self.duration or 0, traits)
 
-    @staticmethod
-    def latest_checkin_query(for_user: 'Person|OuterRef'):
-        objects = Booking.objects.filter(user=for_user)
-        return objects.order_by('-begin_time').values('begin_time')[:1]
-
     @staticmethod
     def currently_open_checkin(for_user: 'Person|OuterRef') -> 'Booking|None':
         return Booking.objects.filter(

app/base/models/course_visit.py

@@ -33,3 +33,39 @@ class CourseVisit(models.Model):
 
     def get_absolute_url(self):
         return reverse('course-visit:detail', kwargs={'pk': self.pk})
+
+    def save(self, *args, **kwargs):
+        # update last_visit time of all involved persons
+        old_date: 'date|None' = None
+        old_list: 'list[Person]' = []
+
+        if self.pk:
+            prev = CourseVisit.objects.get(pk=self.pk)
+            old_date = prev.date
+            old_list.append(prev.participant)
+            if prev.teacher:
+                old_list.append(prev.teacher)
+
+        rv = super().save(*args, **kwargs)
+
+        new_date = self.date
+        new_list: 'list[Person]' = [self.participant]
+        if self.teacher:
+            new_list.append(self.teacher)
+
+        for person in old_list:
+            if person not in new_list:
+                person.update_last_visit(None)
+        for person in new_list:
+            if person not in old_list or old_date != new_date:
+                person.update_last_visit(new_date)
+
+        return rv
+
+    def delete(self, *args, **kwargs):
+        rv = super().delete(*args, **kwargs)
+        # update last_visit time of all involved persons
+        self.participant.update_last_visit(None)
+        if self.teacher:
+            self.teacher.update_last_visit(None)
+        return rv

app/base/models/person.py

@@ -3,17 +3,20 @@ from django.db.models import Q
 from django.urls import reverse
 
 from app.base.forms.fields import DateField
-from app.base.models.course import Course
 from app.base.models.booking import Booking
+from app.base.models.course import Course
+from app.base.models.course_visit import CourseVisit
 
 from datetime import datetime, date
 from typing import TYPE_CHECKING
 if TYPE_CHECKING:
-    from app.base.models import Account, Note, CourseVisit, TraitMapping
+    from app.base.models import Account, Note, TraitMapping
 
 
 class Person(models.Model):
     created: 'models.DateField[date]' = DateField('Angelegt', editable=False)
+    last_visit: 'models.DateField[date]' = DateField(
+        'Letzter Besuch', editable=False)
 
     uuid = models.CharField('Karten-ID', max_length=200, blank=True)
     first_name = models.CharField('Vorname', max_length=200)
@@ -55,6 +58,7 @@ class Person(models.Model):
     def save(self, *args, **kwargs):
         if not self.pk:
             self.created = date.today()
+            self.last_visit = date.today()
         return super().save(*args, **kwargs)
 
     @property
@@ -76,15 +80,32 @@ class Person(models.Model):
         return self.traits_at_date(datetime.now()).values_list(
             'pk', 'trait__key', 'trait__label')
 
+    @property
+    def current_checkin(self):
+        return Booking.currently_open_checkin(self)
+
     def traits_at_date(self, date: datetime):
         return self.traits.filter(
             Q(valid_from__lte=date),
             Q(valid_until__gte=date) | Q(valid_until=None))
 
-    def last_check_in(self) -> 'datetime|None':
+    def lookup_last_visit(self) -> date:
-        obj = Booking.latest_checkin_query(self).first()
+        ''' Return newest date from either booking, course, or created. '''
-        return obj['begin_time'] if obj else None
+        last_booking = Booking.objects.filter(
+            user=self).order_by('-begin_time').first()
+        last_course = CourseVisit.objects.filter(
+            Q(participant=self) | Q(teacher=self)).order_by('-date').first()
+        available_dates = [self.created]
+        if last_booking:
+            available_dates.append(last_booking.begin_time.date())
+        if last_course:
+            available_dates.append(last_course.date)
+        return max(available_dates)
 
-    @property
+    def update_last_visit(self, new_visit: 'date|None') -> None:
-    def current_checkin(self):
+        if self.last_visit == new_visit:
-        return Booking.currently_open_checkin(self)
+            return  # no need to update
+        if not new_visit or new_visit < self.last_visit:
+            new_visit = self.lookup_last_visit()
+        self.last_visit = new_visit
+        self.save()

app/base/views/model_views/person.py

@@ -1,9 +1,6 @@
-from django.db.models import OuterRef, Subquery
 from django.urls import path
 
-from app.base.models.booking import Booking
+from app.base.models import Booking, Person, Transaction
-from app.base.models.transaction import Transaction
-from app.base.models.person import Person
 from app.base.views.login import LoginRequired
 from app.base.views.model_views.base import (
     ModelDetailView, ModelListView, ModelCreateView, ModelUpdateView,
@@ -37,30 +34,26 @@ class PersonOptions(ViewOptions[Person], LoginRequired):
         'trait': 'traits__pk',
         'course': 'courses__pk',
     }
-    list_columns = ['display_name', 'birth_date', 'last_check_in']
+    list_columns = ['display_name', 'birth_date', 'last_visit']
     list_render = {
-        'display_name': {'verbose_name': 'Nutzer:in'},
+        'display_name': {
+            'verbose_name': 'Nutzer:in'
+        },
         'birth_date': {
             'verbose_name': 'Geburtsjahr',
             'date_format': 'Y',
         },
-        'last_check_in': {
+        'last_visit': {
-            'verbose_name': 'Letzter Besuch',
+            'date_format': 'D. d. M y',
-            'date_format': 'D. d. M y, H:i',
         },
     }
 
 
 class PersonListView(PersonOptions, ModelListView):
     icon = 'users'
-    ordering = ('-last_check_in',)
+    ordering = ('-last_visit',)
     search_fields = ['uuid', 'first_name', 'last_name']
 
-    def get_queryset(self):
-        query = Subquery(Booking.latest_checkin_query(OuterRef('pk')))
-        rv = Person.objects.annotate(last_check_in=query)
-        return rv.order_by(*self.ordering)
-
 
 class PersonCreateView(PersonOptions, ModelCreateView):
     # on_success = 'person:detail', '{.pk}'  # the default anyway