From b967bef0245912739b0102d554c0506bb893be33 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mart=C3=ADn=20Miranda?= <debianitram@gmail.com>
Date: Fri, 6 Nov 2020 01:24:39 -0300
Subject: [PATCH] Added configuration and signal to give more flexibility when
 creating the user.

---
 src/django_keycloak/app_settings.py          |  8 +++
 src/django_keycloak/services/oidc_profile.py | 62 ++++++++++++++++----
 src/django_keycloak/signals.py               |  5 ++
 3 files changed, 64 insertions(+), 11 deletions(-)
 create mode 100644 src/django_keycloak/signals.py

diff --git a/src/django_keycloak/app_settings.py b/src/django_keycloak/app_settings.py
index 10562e6..8ae66b3 100644
--- a/src/django_keycloak/app_settings.py
+++ b/src/django_keycloak/app_settings.py
@@ -10,3 +10,11 @@
 # Profile
 KEYCLOAK_REMOTE_USER_MODEL = 'django_keycloak.remote_user.KeycloakRemoteUser'
 KEYCLOAK_PERMISSIONS_METHOD = 'role'  # 'role' of 'resource'
+
+
+KEYCLOAK_ALWAYS_UPDATE_USER = False
+KEYCLOAK_USERNAME_ATTR = 'sub'
+KEYCLOAK_USER_ATTR_MAP = {
+    'first_name': 'given_name',
+    'last_name': 'family_name',
+}
diff --git a/src/django_keycloak/services/oidc_profile.py b/src/django_keycloak/services/oidc_profile.py
index 2313231..b385b84 100644
--- a/src/django_keycloak/services/oidc_profile.py
+++ b/src/django_keycloak/services/oidc_profile.py
@@ -16,6 +16,7 @@
 
 
 import django_keycloak.services.realm
+from django_keycloak.signals import keycloak_populate_user
 
 logger = logging.getLogger(__name__)
 
@@ -75,9 +76,40 @@ def get_or_create_from_id_token(client, id_token):
         client=client, id_token_object=id_token_object)
 
 
-def update_or_create_user_and_oidc_profile(client, id_token_object):
+def get_or_build_user(id_token_object):
+    UserModel = get_user_model()
+
+    built = False
+    lookup = {UserModel.USERNAME_FIELD: id_token_object[settings.KEYCLOAK_USERNAME_ATTR]}
+
+    try:
+        user = UserModel.objects.get(**lookup)
+    except UserModel.DoesNotExist:
+        user = UserModel(**lookup)
+        built = True
+
+    return user, built
+
+
+def _populate_user_from_attributes(user, id_token_object):
+    email_field_name = get_user_model().get_email_field_name()
+
+    if email_field_name not in settings.KEYCLOAK_USER_ATTR_MAP:
+        settings.KEYCLOAK_USER_ATTR_MAP.update(**{email_field_name: 'email'})
+
+    for field, attr in settings.KEYCLOAK_USER_ATTR_MAP.items():
+        try:
+            value = id_token_object[attr]
+        except (TypeError, LookupError):
+            logger.warning('Does not exists value for attribute {}'.format(attr))
+        else:
+            setattr(user, field, value)
+
+
+def update_or_create_user_and_oidc_profile(client, id_token_object, force_populate=False):
     """
 
+    :param force_populate: boolean
     :param client:
     :param id_token_object:
     :return:
@@ -100,16 +132,24 @@ def update_or_create_user_and_oidc_profile(client, id_token_object):
         return oidc_profile
 
     with transaction.atomic():
-        UserModel = get_user_model()
-        email_field_name = UserModel.get_email_field_name()
-        user, _ = UserModel.objects.update_or_create(
-            username=id_token_object['sub'],
-            defaults={
-                email_field_name: id_token_object.get('email', ''),
-                'first_name': id_token_object.get('given_name', ''),
-                'last_name': id_token_object.get('family_name', '')
-            }
-        )
+        save_user = False
+        user, built = get_or_build_user(id_token_object)
+
+        should_populate = force_populate or settings.KEYCLOAK_ALWAYS_UPDATE_USER or built
+
+        if should_populate:
+            logger.info('Populating Django user {}'.format(user))
+            _populate_user_from_attributes(user, id_token_object)
+            save_user = True
+
+            # Give the client a chance to finish populating the user just before saving.
+            keycloak_populate_user.send(
+                type('KeycloakSignal', (object, ), {}),
+                user=user
+            )
+
+        if save_user or built:
+            user.save()
 
         oidc_profile, _ = OpenIdConnectProfileModel.objects.update_or_create(
             sub=id_token_object['sub'],
diff --git a/src/django_keycloak/signals.py b/src/django_keycloak/signals.py
new file mode 100644
index 0000000..bc9c50a
--- /dev/null
+++ b/src/django_keycloak/signals.py
@@ -0,0 +1,5 @@
+from django.dispatch import Signal
+
+# Allows clients to perform custom user population.
+# Passed arguments: user
+keycloak_populate_user = Signal()