#169 Admin on teams

* adds admin column on team index view
* refactors Team model, so multiple members can become admins
* adds team migration for switch from fkey->m2m structure
* renames 'Group' to 'Permission' on user index view to avoid confusion between 'Groups' and Teams
* adds new autocomplete route for team-admin selection based on already selected members of the TeamForm

user/forms.py

@@ -230,7 +230,7 @@ class NewTeamModalForm(BaseModalForm):
             team = Team.objects.create(
                 name=self.cleaned_data.get("name", None),
                 description=self.cleaned_data.get("description", None),
-                admin=self.user,
+                admins__in=[self.user],
             )
             members = self.cleaned_data.get("members", User.objects.none())
             if self.user.id not in members:
@@ -244,23 +244,40 @@ class NewTeamModalForm(BaseModalForm):
 
 
 class EditTeamModalForm(NewTeamModalForm):
-    admin = forms.ModelChoiceField(
+    admins = forms.ModelMultipleChoiceField(
+        label=_("Admins"),
         label_suffix="",
-        label=_("Admin"),
         help_text=_("Administrators manage team details and members"),
-        queryset=User.objects.none(),
-        empty_label=None,
+        required=True,
+        queryset=User.objects.all(),
+        widget=autocomplete.ModelSelect2Multiple(
+            url="team-admin-autocomplete",
+            forward=[
+                "members",
+                "admins",
+            ],
+            attrs={
+                "data-placeholder": _("Click for selection"),
+            },
+        ),
     )
 
-    def __is_admin_valid(self):
-        admin = self.cleaned_data.get("admin", None)
-        members = self.cleaned_data.get("members", None)
-        _is_valid = admin in members
+    def __is_admins_valid(self):
+        admins = set(self.cleaned_data.get("admins", {}))
+        members = set(self.cleaned_data.get("members", {}))
+        _is_valid = admins.issubset(members)
 
         if not _is_valid:
             self.add_error(
-                "members",
-                _("Selected admin ({}) needs to be a member of this team.").format(admin.username)
+                "admins",
+                _("Selected admins need to be members of this team.")
+            )
+
+        _is_admin_length_valid = len(admins) > 0
+        if not _is_admin_length_valid:
+            self.add_error(
+                "admins",
+                _("There must be at least one admin on this team.")
             )
 
         return _is_valid
@@ -283,7 +300,7 @@ class EditTeamModalForm(NewTeamModalForm):
 
     def is_valid(self):
         super_valid = super().is_valid()
-        admin_valid = self.__is_admin_valid()
+        admin_valid = self.__is_admins_valid()
         return super_valid and admin_valid
 
     def __init__(self, *args, **kwargs):
@@ -293,13 +310,13 @@ class EditTeamModalForm(NewTeamModalForm):
         self.cancel_redirect = reverse("user:team-index")
 
         members = self.instance.users.all()
-        self.fields["admin"].queryset = members
+        #self.fields["admins"].queryset = members
 
         form_data = {
             "members": members,
             "name": self.instance.name,
             "description": self.instance.description,
-            "admin": self.instance.admin,
+            "admins": self.instance.admins.all(),
         }
         self.load_initial_data(form_data)
 
@@ -307,14 +324,16 @@ class EditTeamModalForm(NewTeamModalForm):
         with transaction.atomic():
             self.instance.name = self.cleaned_data.get("name", None)
             self.instance.description = self.cleaned_data.get("description", None)
-            self.instance.admin = self.cleaned_data.get("admin", None)
             self.instance.save()
             self.instance.users.set(self.cleaned_data.get("members", []))
+            self.instance.admins.set(self.cleaned_data.get("admins", []))
         return self.instance
 
 
 class RemoveTeamModalForm(RemoveModalForm):
-    pass
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.form_caption = _("ATTENTION!\n\nRemoving the team means all members will lose their access to data, based on this team! \n\nAre you sure to remove this team?")
 
 
 class LeaveTeamModalForm(RemoveModalForm):