refactor: prevent user from creating more than 5 profiles

backend/backend/apps/user/admin.py

@@ -3,11 +3,14 @@
 from django.utils.translation import gettext_lazy as _
 
 from .models import Profile, User
-from .forms import CustomUserAdminForm
+from .forms import CustomUserAdminForm, ProfileAdminForm
 
 
 @admin.register(User)
 class CustomUserAdmin(UserAdmin):
+    # form = CustomUserAdminForm
+    add_form = CustomUserAdminForm
+
     fieldsets = (
         (None, {'fields': ('email', 'password')}),
         (
@@ -36,13 +39,12 @@ class CustomUserAdmin(UserAdmin):
     ordering = ('email',)
     filter_horizontal = ()
 
-    # form = CustomUserAdminForm
-    add_form = CustomUserAdminForm
-
 
 @admin.register(Profile)
 class ProfileAdmin(admin.ModelAdmin):
-    list_display = ('username', 'user')
-    search_fields = ('username',)
+    form = ProfileAdminForm
+
+    list_display = ('username', 'user__email', 'date_created')
+    search_fields = ('username', 'user__email')
     ordering = ('-date_created',)
     readonly_fields = ('date_created',)

backend/backend/apps/user/forms.py

@@ -1,14 +1,15 @@
 from django import forms
 from django.forms import ModelForm
-from .models import User
+from django.utils.translation import gettext_lazy as _
+from .models import User, Profile
 
 
 class CustomUserAdminForm(ModelForm):
     password = forms.CharField(widget=forms.PasswordInput, required=False)
 
     class Meta:  # pyright: ignore [reportIncompatibleVariableOverride]
         model = User
-        fields = ('email', 'password', 'is_active', 'is_staff', 'is_superuser')
+        fields = '__all__'
 
     def save(self, commit=True):
         user = super().save(commit=False)
@@ -18,3 +19,17 @@ def save(self, commit=True):
         if commit:
             user.save()
         return user
+
+
+class ProfileAdminForm(ModelForm):
+    class Meta:  # pyright: ignore [reportIncompatibleVariableOverride]
+        model = Profile
+        fields = '__all__'
+
+    def clean(self):  # pyright: ignore [reportIncompatibleVariableOverride]
+        user = self.cleaned_data.get('user')
+
+        if self.instance.pk is None and user and user.profiles.count() >= 5:
+            self.add_error(None, _('A user cannot have more than 5 profiles.'))
+
+        return self.cleaned_data

backend/backend/apps/user/models.py

@@ -1,3 +1,4 @@
+from django.core.exceptions import ValidationError
 from django.db import models
 from django.contrib.auth.models import AbstractBaseUser, PermissionsMixin
 from django.utils.translation import gettext_lazy as _
@@ -33,7 +34,7 @@ class User(AbstractBaseUser, PermissionsMixin):
 
 
 class Profile(models.Model):
-    user = models.ForeignKey(User, on_delete=models.CASCADE)
+    user = models.ForeignKey(User, related_name='profiles', on_delete=models.CASCADE)
     username = models.CharField(_('username'), unique=True, max_length=25)
     avatar = models.ImageField(
         _('avatar'),
@@ -45,5 +46,14 @@ class Profile(models.Model):
     last_name = models.CharField(_('last name'), max_length=255, blank=True, null=True)
     date_created = models.DateTimeField(auto_now_add=True)
 
+    def save(self, *args, **kwargs):
+        if (
+            self.pk is None
+            and self.user.profiles.count()  # pyright: ignore [reportAttributeAccessIssue]
+            >= 5
+        ):
+            raise ValidationError("A user cannot have more than 5 profiles")
+        super().save(*args, **kwargs)
+
     def __str__(self):
-        return f"q/{self.username}"
+        return f"u/{self.username}"