unique constraint for only one hostmask enabled at a time

this replaces the need for a game+hostmask unique constraint, with this
change, a player can only have one active character they're playing
with anyway, regardless of how many games there are

Signed-off-by: Brian S. Stephan <bss@incorporeal.org>

idlerpg/migrations/0007_remove_character_one_player_character_per_game_and_more.py

@@ -0,0 +1,26 @@
+# Generated by Django 5.0.5 on 2024-05-14 16:07
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('idlerpg', '0006_alter_character_status'),
+    ]
+
+    operations = [
+        migrations.RemoveConstraint(
+            model_name='character',
+            name='one_player_character_per_game',
+        ),
+        migrations.AddField(
+            model_name='character',
+            name='enabled',
+            field=models.BooleanField(default=True),
+        ),
+        migrations.AddConstraint(
+            model_name='character',
+            constraint=models.UniqueConstraint(condition=models.Q(('enabled', True)), fields=('hostmask',), name='one_enabled_character_at_a_time'),
+        ),
+    ]

idlerpg/models.py

@@ -95,6 +95,7 @@ class Character(models.Model):
     password = models.CharField(max_length=256)
     hostmask = models.CharField(max_length=256)
     status = models.CharField(max_length=8, choices=CHARACTER_STATUSES, default='OFFLINE')
+    enabled = models.BooleanField(default=True)
 
     character_class = models.CharField(max_length=30)
     level = models.PositiveIntegerField(default=0)
@@ -119,7 +120,8 @@ class Character(models.Model):
         """Options for the Character and its objects."""
 
         constraints = [
-            models.UniqueConstraint("game", "hostmask", name="one_player_character_per_game"),
+            models.UniqueConstraint(fields=['hostmask'], condition=models.Q(enabled=True),
+                                    name='one_enabled_character_at_a_time'),
         ]
 
     def __str__(self):

tests/test_idlerpg_character.py

@@ -7,6 +7,8 @@ import logging
 from datetime import timedelta
 from unittest.mock import patch
 
+from django.db import transaction
+from django.db.utils import IntegrityError
 from django.test import TestCase
 from django.utils import timezone
 
@@ -152,6 +154,27 @@ class CharacterTest(TestCase):
         assert new_char.last_login == register_time
         assert new_char.password[0:13] == 'pbkdf2_sha256'
 
+    def test_cant_register_twice(self):
+        """Test that we get a unique constraint error if we try to make a second enabled character."""
+        game = Game.objects.get(pk=1)
+
+        register_time = timezone.now()
+        with patch('django.utils.timezone.now', return_value=register_time):
+            new_char = Character.objects.register('new1', game, 'pass', 'bss!bss@test_double_register', 'unit tester')
+        with self.assertRaises(IntegrityError):
+            with transaction.atomic():
+                Character.objects.register('new2', game, 'pass', 'bss!bss@test_double_register', 'unit tester')
+
+        # try again with the first character un-enabled
+        new_char.enabled = False
+        new_char.save()
+
+        register_time = timezone.now()
+        with patch('django.utils.timezone.now', return_value=register_time):
+            newer_char = Character.objects.register('new2', game, 'pass', 'bss!bss@test_double_register', 'unit tester')
+
+        assert new_char.hostmask == newer_char.hostmask
+
     def test_level_up(self):
         """Test the level up functionality."""
         char = Character.objects.get(pk=1)