Start implementation of OAuth client

users/models.py

@@ -2,6 +2,10 @@
 # Copyright (C) 2017-2019 by BDE ENS Paris-Saclay
 # SPDX-License-Identifier: GPL-3.0-or-later
 
+from datetime import datetime
+
+from authlib.integrations.django_client import OAuth
+from django.conf import settings
 from django.contrib.auth.models import AbstractUser
 from django.db import models
 from django.utils import timezone
@@ -44,3 +48,61 @@ class User(AbstractUser):
     def is_member(self):
         # FIXME Use NK20
         return True
+
+
+class AccessToken(models.Model):
+    owner = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        on_delete=models.CASCADE,
+        null=True,
+        default=None,
+        verbose_name=_('owner'),
+    )
+
+    access_token = models.CharField(
+        max_length=32,
+        verbose_name=_('access token'),
+    )
+
+    expires_in = models.PositiveSmallIntegerField(
+        verbose_name=_('expires in'),
+    )
+
+    scopes = models.CharField(
+        max_length=255,
+        verbose_name=_('scopes'),
+    )
+
+    refresh_token = models.CharField(
+        max_length=32,
+        verbose_name=_('refresh token'),
+    )
+
+    expires_at = models.DateTimeField(
+        verbose_name=_('expires at'),
+    )
+
+    def refresh(self):
+        """
+        Refresh the access token.
+        """
+        oauth = OAuth()
+        oauth.register('notekfet')
+        # Get the OAuth client
+        oauth_client = oauth.notekfet._get_oauth_client()
+        # Actually refresh the token
+        token = oauth_client.refresh_token(oauth.notekfet.access_token_url,
+                                           refresh_token=self.refresh_token)
+        self.access_token = token['access_token']
+        self.expires_in = token['expires_in']
+        self.scopes = token['scope']
+        self.refresh_token = token['refresh_token']
+        self.expires_at = timezone.utc.fromutc(
+            datetime.fromtimestamp(token['expires_at'])
+        )
+
+        self.save()
+
+    class Meta:
+        verbose_name = _('access token')
+        verbose_name_plural = _('access tokens')