stages/identification: optimise User lookup query

passbook/stages/identification/migrations/0003_auto_20200509_2025.py

@@ -0,0 +1,26 @@
+# Generated by Django 3.0.3 on 2020-05-09 20:25
+
+import django.contrib.postgres.fields
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("passbook_stages_identification", "0002_auto_20200509_1916"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="identificationstage",
+            name="user_fields",
+            field=django.contrib.postgres.fields.ArrayField(
+                base_field=models.CharField(
+                    choices=[("email", "E Mail"), ("username", "Username")],
+                    max_length=100,
+                ),
+                help_text="Fields of the user object to match against.",
+                size=None,
+            ),
+        ),
+    ]

passbook/stages/identification/stage.py

@@ -2,6 +2,7 @@
 from typing import List, Optional
 
 from django.contrib import messages
+from django.db.models import Q
 from django.http import HttpResponse
 from django.utils.translation import gettext as _
 from django.views.generic import FormView
@@ -20,7 +21,6 @@ LOGGER = get_logger()
 class IdentificationStageView(FormView, AuthenticationStage):
     """Form to identify the user"""
 
-    template_name = "login/form.html"
     form_class = IdentificationForm
 
     def get_template_names(self) -> List[str]:
@@ -31,6 +31,7 @@ class IdentificationStageView(FormView, AuthenticationStage):
         kwargs["config"] = CONFIG.y("passbook")
         kwargs["title"] = _("Log in to your account")
         kwargs["primary_action"] = _("Log in")
+        # TODO: show this based on the existence of an enrollment flow
         kwargs["show_sign_up_notice"] = CONFIG.y("passbook.sign_up.enabled")
         kwargs["sources"] = []
         sources = (
@@ -42,14 +43,16 @@ class IdentificationStageView(FormView, AuthenticationStage):
                 kwargs["sources"].append(ui_login_button)
         return super().get_context_data(**kwargs)
 
-    def get_user(self, uid_value) -> Optional[User]:
+    def get_user(self, uid_value: str) -> Optional[User]:
         """Find user instance. Returns None if no user was found."""
         current_stage: IdentificationStage = self.executor.current_stage
+        query = Q()
         for search_field in current_stage.user_fields:
-            users = User.objects.filter(**{search_field: uid_value})
-            if users.exists():
-                LOGGER.debug("Found user", user=users.first(), uid_field=search_field)
-                return users.first()
+            query |= Q(**{search_field: uid_value})
+        users = User.objects.filter(query)
+        if users.exists():
+            LOGGER.debug("Found user", user=users.first(), query=query)
+            return users.first()
         return None
 
     def form_valid(self, form: IdentificationForm) -> HttpResponse: