Implement basic Group handling (#3)

Co-authored-by: Tim Lorsbach <tim@lorsba.ch>
Reviewed-on: enviPath/enviPy#3

epdb/logic.py

@@ -44,15 +44,22 @@ class UserManager(object):
     def get_users():
         return []
 
+    @staticmethod
+    def get_user_lp(user_url: str):
+        uuid = user_url.strip().split('/')[-1]
+        return get_user_model().objects.get(uuid=uuid)
 
 class GroupManager(object):
 
     @staticmethod
-    def create_group(owner):
+    def create_group(current_user, name, description):
         g = Group()
-        g.name = 'enviPath Users'
-        g.description = 'All enviPath Users'
-        g.owner = owner
+        g.name = name
+        g.description = description
+        g.owner = current_user
+        g.save()
+
+        g.user_member.add(current_user)
         g.save()
 
         return g
@@ -78,6 +85,26 @@ class GroupManager(object):
     def get_groups(user):
         return Group.objects.filter(user_member=user)
 
+    @staticmethod
+    @transaction.atomic
+    def update_members(caller: User, group: Group, member: Union[User, Group], add_or_remove: str):
+
+        if caller != group.owner:
+            raise ValueError('Only the group Owner is allowed to add members!')
+
+        if isinstance(member, Group):
+            if add_or_remove == 'add':
+                group.group_member.add(member)
+            else:
+                group.group_member.remove(member)
+        else:
+            if add_or_remove == 'add':
+                group.user_member.add(member)
+            else:
+                group.user_member.remove(member)
+
+        group.save()
+
 
 class PackageManager(object):
     package_pattern = re.compile(r".*/package/[a-f0-9]{8}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{12}$")