♻️(backend) refactor post hackathon to a first working version

This project was copied and hacked to make a POC in a 2-day hackathon.
We need to clean and refactor things in order to get a first version
of the product we want.

src/backend/core/admin.py

@@ -1,22 +1,11 @@
-"""Admin classes and registrations for Magnify's core app."""
+"""Admin classes and registrations for core app."""
 from django.contrib import admin
+from django.contrib.auth import admin as auth_admin
+from django.utils.translation import gettext_lazy as _
 
 from . import models
 
 
-class IdentityInline(admin.TabularInline):
-    """Inline admin class for user identities."""
-
-    model = models.Identity
-    extra = 0
-
-
-@admin.register(models.User)
-class UserAdmin(admin.ModelAdmin):
-    """User admin interface declaration."""
-
-    inlines = (IdentityInline,)
-
 
 class TemplateAccessInline(admin.TabularInline):
     """Inline admin class for template accesses."""
@@ -25,6 +14,65 @@ class TemplateAccessInline(admin.TabularInline):
     extra = 0
 
 
+@admin.register(models.User)
+class UserAdmin(auth_admin.UserAdmin):
+    """Admin class for the User model"""
+
+    fieldsets = (
+        (
+            None,
+            {
+                "fields": (
+                    "id",
+                    "admin_email",
+                    "password",
+                )
+            },
+        ),
+        (_("Personal info"), {"fields": ("sub", "email", "language", "timezone")}),
+        (
+            _("Permissions"),
+            {
+                "fields": (
+                    "is_active",
+                    "is_device",
+                    "is_staff",
+                    "is_superuser",
+                    "groups",
+                    "user_permissions",
+                ),
+            },
+        ),
+        (_("Important dates"), {"fields": ("created_at", "updated_at")}),
+    )
+    add_fieldsets = (
+        (
+            None,
+            {
+                "classes": ("wide",),
+                "fields": ("email", "password1", "password2"),
+            },
+        ),
+    )
+    inlines = (TemplateAccessInline,)
+    list_display = (
+        "id",
+        "sub",
+        "admin_email",
+        "email",
+        "is_active",
+        "is_staff",
+        "is_superuser",
+        "is_device",
+        "created_at",
+        "updated_at",
+    )
+    list_filter = ("is_staff", "is_superuser", "is_device", "is_active")
+    ordering = ("is_active", "-is_superuser", "-is_staff", "-is_device", "-updated_at")
+    readonly_fields = ("id", "sub", "email", "created_at", "updated_at")
+    search_fields = ("id", "sub", "admin_email", "email")
+
+
 @admin.register(models.Template)
 class TemplateAdmin(admin.ModelAdmin):
     """Template admin interface declaration."""