Improve time-related stuff

Add created_at to all models
Add modified_at to Session
Get rid of custom now() function
Make sure aware datetime is used everywhere

common/time.py

@@ -1,12 +1,5 @@
 import re
-from datetime import datetime, timedelta
+from datetime import timedelta
-from zoneinfo import ZoneInfo
-
-from django.conf import settings
-
-
-def now() -> datetime:
-    return datetime.now(ZoneInfo(settings.TIME_ZONE))
 
 
 def _safe_timedelta(duration: timedelta | int | None):

games/migrations/0031_device_created_at_edition_created_at_game_created_at_and_more.py

@@ -0,0 +1,44 @@
+# Generated by Django 4.1.5 on 2023-11-15 13:51
+
+from django.db import migrations, models
+import django.utils.timezone
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("games", "0030_alter_purchase_name"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="device",
+            name="created_at",
+            field=models.DateTimeField(default=django.utils.timezone.now),
+        ),
+        migrations.AddField(
+            model_name="edition",
+            name="created_at",
+            field=models.DateTimeField(default=django.utils.timezone.now),
+        ),
+        migrations.AddField(
+            model_name="game",
+            name="created_at",
+            field=models.DateTimeField(default=django.utils.timezone.now),
+        ),
+        migrations.AddField(
+            model_name="platform",
+            name="created_at",
+            field=models.DateTimeField(default=django.utils.timezone.now),
+        ),
+        migrations.AddField(
+            model_name="purchase",
+            name="created_at",
+            field=models.DateTimeField(default=django.utils.timezone.now),
+        ),
+        migrations.AddField(
+            model_name="session",
+            name="created_at",
+            field=models.DateTimeField(default=django.utils.timezone.now),
+        ),
+    ]

games/migrations/0032_alter_session_options_session_modified_at_and_more.py

@@ -0,0 +1,52 @@
+# Generated by Django 4.1.5 on 2023-11-15 18:02
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("games", "0031_device_created_at_edition_created_at_game_created_at_and_more"),
+    ]
+
+    operations = [
+        migrations.AlterModelOptions(
+            name="session",
+            options={"get_latest_by": "timestamp_start"},
+        ),
+        migrations.AddField(
+            model_name="session",
+            name="modified_at",
+            field=models.DateTimeField(auto_now=True),
+        ),
+        migrations.AlterField(
+            model_name="device",
+            name="created_at",
+            field=models.DateTimeField(auto_now_add=True),
+        ),
+        migrations.AlterField(
+            model_name="edition",
+            name="created_at",
+            field=models.DateTimeField(auto_now_add=True),
+        ),
+        migrations.AlterField(
+            model_name="game",
+            name="created_at",
+            field=models.DateTimeField(auto_now_add=True),
+        ),
+        migrations.AlterField(
+            model_name="platform",
+            name="created_at",
+            field=models.DateTimeField(auto_now_add=True),
+        ),
+        migrations.AlterField(
+            model_name="purchase",
+            name="created_at",
+            field=models.DateTimeField(auto_now_add=True),
+        ),
+        migrations.AlterField(
+            model_name="session",
+            name="created_at",
+            field=models.DateTimeField(auto_now_add=True),
+        ),
+    ]

games/models.py

@@ -1,10 +1,9 @@
 from common.time import format_duration
-from datetime import datetime, timedelta
+from datetime import timedelta
-from django.conf import settings
 from django.db import models
 from django.core.exceptions import ValidationError
+from django.utils import timezone
 from django.db.models import F, Manager, Sum
-from zoneinfo import ZoneInfo
 
 
 class Game(models.Model):
@@ -12,6 +11,7 @@ class Game(models.Model):
     sort_name = models.CharField(max_length=255, null=True, blank=True, default=None)
     year_released = models.IntegerField(null=True, blank=True, default=None)
     wikidata = models.CharField(max_length=50, null=True, blank=True, default=None)
+    created_at = models.DateTimeField(auto_now_add=True)
 
     def __str__(self):
         return self.name
@@ -42,6 +42,7 @@ class Edition(models.Model):
     )
     year_released = models.IntegerField(null=True, blank=True, default=None)
     wikidata = models.CharField(max_length=50, null=True, blank=True, default=None)
+    created_at = models.DateTimeField(auto_now_add=True)
 
     def __str__(self):
         return self.sort_name
@@ -128,6 +129,7 @@ class Purchase(models.Model):
         blank=True,
         related_name="related_purchases",
     )
+    created_at = models.DateTimeField(auto_now_add=True)
 
     def __str__(self):
         additional_info = [
@@ -156,6 +158,7 @@ class Purchase(models.Model):
 class Platform(models.Model):
     name = models.CharField(max_length=255)
     group = models.CharField(max_length=255, null=True, blank=True, default=None)
+    created_at = models.DateTimeField(auto_now_add=True)
 
     def __str__(self):
         return self.name
@@ -173,6 +176,9 @@ class SessionQuerySet(models.QuerySet):
 
 
 class Session(models.Model):
+    class Meta:
+        get_latest_by = "timestamp_start"
+
     purchase = models.ForeignKey("Purchase", on_delete=models.CASCADE)
     timestamp_start = models.DateTimeField()
     timestamp_end = models.DateTimeField(blank=True, null=True)
@@ -186,6 +192,8 @@ class Session(models.Model):
         default=None,
     )
     note = models.TextField(blank=True, null=True)
+    created_at = models.DateTimeField(auto_now_add=True)
+    modified_at = models.DateTimeField(auto_now=True)
 
     objects = SessionQuerySet.as_manager()
 
@@ -194,10 +202,10 @@ class Session(models.Model):
         return f"{str(self.purchase)} {str(self.timestamp_start.date())} ({self.duration_formatted()}{mark})"
 
     def finish_now(self):
-        self.timestamp_end = datetime.now(ZoneInfo(settings.TIME_ZONE))
+        self.timestamp_end = timezone.now()
 
     def start_now():
-        self.timestamp_start = datetime.now(ZoneInfo(settings.TIME_ZONE))
+        self.timestamp_start = timezone.now()
 
     def duration_seconds(self) -> timedelta:
         manual = timedelta(0)
@@ -250,6 +258,7 @@ class Device(models.Model):
     ]
     name = models.CharField(max_length=255)
     type = models.CharField(max_length=3, choices=DEVICE_TYPES, default=UNKNOWN)
+    created_at = models.DateTimeField(auto_now_add=True)
 
     def __str__(self):
         return f"{self.name} ({self.get_type_display()})"

games/views.py

@@ -1,4 +1,4 @@
-from common.time import format_duration, now as now_with_tz
+from common.time import format_duration
 from common.utils import safe_division
 from datetime import datetime, timedelta
 from django.conf import settings
@@ -7,6 +7,7 @@ from django.db.models.functions import TruncDate
 from django.http import HttpRequest, HttpResponse, HttpResponseRedirect
 from django.shortcuts import redirect, render
 from django.urls import reverse
+from django.utils import timezone
 from typing import Callable, Any
 from zoneinfo import ZoneInfo
 
@@ -32,19 +33,15 @@ def model_counts(request):
 
 
 def stats_dropdown_year_range(request):
-    result = {
+    result = {"stats_dropdown_year_range": range(timezone.now().year, 1999, -1)}
-        "stats_dropdown_year_range": range(
-            datetime.now(ZoneInfo(settings.TIME_ZONE)).year, 1999, -1
-        )
-    }
     return result
 
 
 def add_session(request, purchase_id=None):
     context = {}
-    initial = {"timestamp_start": now_with_tz()}
+    initial = {"timestamp_start": timezone.now()}
 
-    last = Session.objects.all().last()
+    last = Session.objects.last()
     if last != None:
         initial["purchase"] = last.purchase
 
@@ -155,13 +152,11 @@ def view_game(request, game_id=None):
         .order_by("year_released")
     )
 
-    sessions = Session.objects.filter(purchase__edition__game=game).order_by(
+    sessions = Session.objects.filter(purchase__edition__game=game)
-        "timestamp_start"
-    )
     session_count = sessions.count()
 
-    playrange_start = sessions.first().timestamp_start.strftime("%b %Y")
+    playrange_start = sessions.earliest().timestamp_start.strftime("%b %Y")
-    playrange_end = sessions.last().timestamp_start.strftime("%b %Y")
+    playrange_end = sessions.latest().timestamp_start.strftime("%b %Y")
 
     playrange = (
         playrange_start
@@ -225,15 +220,11 @@ def related_purchase_by_edition(request):
 
 @use_custom_redirect
 def start_game_session(request, game_id: int):
-    last_session = (
+    last_session = Session.objects.filter(purchase__edition__game_id=game_id).latest()
-        Session.objects.filter(purchase__edition__game_id=game_id)
-        .order_by("-timestamp_start")
-        .first()
-    )
     session = SessionForm(
         {
             "purchase": last_session.purchase.id,
-            "timestamp_start": now_with_tz(),
+            "timestamp_start": timezone.now(),
             "device": last_session.device,
         }
     )
@@ -246,7 +237,7 @@ def start_session_same_as_last(request, last_session_id: int):
     session = SessionForm(
         {
             "purchase": last_session.purchase.id,
-            "timestamp_start": now_with_tz(),
+            "timestamp_start": timezone.now(),
             "device": last_session.device,
         }
     )
@@ -296,19 +287,18 @@ def list_sessions(
         context["title"] = "This year"
     else:
         # by default, sort from newest to oldest
-        dataset = Session.objects.all().order_by("-timestamp_start")
+        dataset = Session.objects.order_by("-timestamp_start")
 
     for session in dataset:
         if session.timestamp_end == None and session.duration_manual == timedelta(
             seconds=0
         ):
-            session.timestamp_end = datetime.now(ZoneInfo(settings.TIME_ZONE))
+            session.timestamp_end = timezone.now()
             session.unfinished = True
 
     context["total_duration"] = dataset.total_duration_formatted()
     context["dataset"] = dataset
-    # cannot use dataset[0] here because that might be only partial QuerySet
+    context["last"] = Session.objects.latest()
-    context["last"] = Session.objects.all().order_by("timestamp_start").last()
 
     return render(request, "list_sessions.html", context)
 
@@ -318,7 +308,7 @@ def stats(request, year: int = 0):
     if selected_year:
         return HttpResponseRedirect(reverse("stats_by_year", args=[selected_year]))
     if year == 0:
-        year = now_with_tz().year
+        year = timezone.now().year
     this_year_sessions = Session.objects.filter(timestamp_start__year=year)
     selected_currency = "CZK"
     unique_days = (
@@ -451,7 +441,7 @@ def stats(request, year: int = 0):
 
 def add_purchase(request, edition_id=None):
     context = {}
-    initial = {"date_purchased": now_with_tz()}
+    initial = {"date_purchased": timezone.now()}
 
     if request.method == "POST":
         form = PurchaseForm(request.POST or None, initial=initial)