routing simulation: use ajax to load gateways

Author: dmitry-sinina

app/views/routing_simulation/_form.html.erb

@@ -1,7 +1,8 @@
 <%= semantic_form_for dc, :url => '/routing_simulation', :method => :get do |form| %>
     <%= form.semantic_errors *form.object.errors.attribute_names %>
     <%= form.inputs do %>
-        <%= form.input :auth_id, label:"Authorized gateway", collection: Gateway.where("incoming_auth_password is not null and allow_origination"), as: :select, include_blank: 'None', input_html: { class: 'tom-select' } %>
+        <% auth_gw_collection = form.object.auth_id ? Gateway.where(id: form.object.auth_id) : [] %>
+        <%= form.input :auth_id, label: "Authorized gateway", collection: auth_gw_collection, as: :select, include_blank: 'None', input_html: { class: 'tom-select-ajax', 'data-path': '/gateways/search?q[allow_origination_eq]=true&q[incoming_auth_password_not_null]=1' } %>
         <%= form.input :transport_protocol_id, collection: Equipment::TransportProtocol.all, as: :select, include_blank: false %>
         <%= form.input :interface, input_html: { value: form.object.interface || YetiConfig.routing_simulation_default_interface } %>
         <%= form.input :remote_ip %>