Refactor zones

#475

app/controllers/admin/dns/zones_controller.rb

@@ -1,7 +1,7 @@
 module Admin
   module DNS
     class ZonesController < AdminController
-      load_and_authorize_resource(class: DNS::Zone)
+      authorize_resource(class: 'DNS::Zone')
       before_action :load_zone, only: %i[edit update destroy]
 
       def index
@@ -49,10 +49,21 @@ module Admin
       end
 
       def zone_params
-        params.require(:zone).permit(
-          :origin, :ttl, :refresh, :retry, :expire, :minimum_ttl, :email,
-          :master_nameserver, :ns_records, :a_records, :a4_records
-        )
+        allowed_params = %i[
+          origin
+          ttl
+          refresh
+          retry
+          expire
+          minimum_ttl
+          email
+          master_nameserver
+          ns_records
+          a_records
+          a4_records
+        ]
+
+        params.require(:zone).permit(*allowed_params)
       end
 
       def redirect_to_index

app/models/dns/zone.rb

@@ -1,16 +1,13 @@
 module DNS
   class Zone < ActiveRecord::Base
+    self.auto_html5_validation = false
+
     validates :origin, :ttl, :refresh, :retry, :expire, :minimum_ttl, :email, :master_nameserver, presence: true
     validates :ttl, :refresh, :retry, :expire, :minimum_ttl, numericality: { only_integer: true }
     validates :origin, uniqueness: true
 
-    before_destroy :check_for_dependencies
-
-    def check_for_dependencies
-      dc = Domain.where("name ILIKE ?", "%.#{origin}").count
-      return if dc == 0
-      errors.add(:base, I18n.t('there_are_count_domains_in_this_zone', count: dc))
-      false
+    before_destroy do
+      !used?
     end
 
     def self.generate_zonefiles
@@ -37,6 +34,10 @@ module DNS
       pluck(:origin)
     end
 
+    def used?
+      Domain.uses_zone?(self)
+    end
+
     def to_s
       origin
     end

app/models/domain.rb

@@ -724,5 +724,9 @@ class Domain < ActiveRecord::Base
   def self.delete_candidates
     where("#{attribute_alias(:delete_time)} < ?", Time.zone.now)
   end
+
+  def self.uses_zone?(zone)
+    exists?(["name ILIKE ?", "%.#{zone.origin}"])
+  end
 end
 # rubocop: enable Metrics/ClassLength

app/views/admin/dns/zones/_form.haml

@@ -8,10 +8,10 @@
           .col-md-4.control-label
             = f.label :origin
           .col-md-8
-            - if zone.persisted?
-              = f.text_field :origin, class: 'form-control', disabled: true
-            - else
+            - if f.object.new_record?
               = f.text_field :origin, class: 'form-control', required: true
+            - else
+              = f.text_field :origin, class: 'form-control', disabled: true
 
         .form-group
           .col-md-4.control-label
@@ -69,7 +69,7 @@
 
         .form-group
           .col-md-4.control-label
-            = f.label :a4_records, t(:a4_records)
+            = f.label :a4_records
           .col-md-8
             = f.text_area :a4_records, class: 'form-control', rows: 8