frontend/CollaboratorListItem.vue: disable dropdown and deactivate bu…

…tton if not manager

But allow deactivating your own CampCollaboration, as long as
you are not the last manager.
Prohibit the removal of the last manager.

Issue: ecamp#1415

frontend/src/components/camp/CollaboratorListItem.vue

@@ -38,11 +38,11 @@
         :my="0"
         dense
         vee-rules="required"
-        :disabled="disabled" />
+        :disabled="disabled || isLastManager" />
     </v-list-item-action>
     <v-list-item-action class="ml-2">
       <button-delete
-        v-if="!disabled"
+        :disabled="(disabled && !isOwnCampCollaboration) || isLastManager"
         icon="mdi-cancel"
         @click="api.del(collaborator)">
         {{ $tc("components.camp.collaboratorListItem.deactivate") }}
@@ -67,6 +67,22 @@ export default {
   data: () => ({
     resendingEmail: false
   }),
+  computed: {
+    isLastManager () {
+      const camp = this.collaborator.camp()
+      const isManager = this.collaborator.role === 'manager'
+      const lastManager = camp
+        ?.campCollaborations()
+        ?.items
+        ?.filter(collaborator => collaborator.status === 'established')
+        .filter(collaborator => collaborator.role === 'manager')
+        .length <= 1
+      return isManager && lastManager
+    },
+    isOwnCampCollaboration () {
+      return this.api.get().profile().user().id === this.collaborator.user().id
+    }
+  },
   methods: {
     resendInvitation () {
       this.resendingEmail = true