Use resourceful routes for api trace data

app/controllers/api/traces/data_controller.rb

@@ -0,0 +1,36 @@
+module Api
+  module Traces
+    class DataController < ApiController
+      before_action :set_locale
+      before_action :authorize
+
+      authorize_resource :trace
+
+      before_action :offline_error
+
+      def show
+        trace = Trace.visible.find(params[:trace_id])
+
+        if trace.public? || trace.user == current_user
+          if request.format == Mime[:xml]
+            send_data(trace.xml_file.read, :filename => "#{trace.id}.xml", :type => request.format.to_s, :disposition => "attachment")
+          elsif request.format == Mime[:gpx]
+            send_data(trace.xml_file.read, :filename => "#{trace.id}.gpx", :type => request.format.to_s, :disposition => "attachment")
+          elsif trace.file.attached?
+            redirect_to rails_blob_path(trace.file, :disposition => "attachment")
+          else
+            send_file(trace.trace_name, :filename => "#{trace.id}#{trace.extension_name}", :type => trace.mime_type, :disposition => "attachment")
+          end
+        else
+          head :forbidden
+        end
+      end
+
+      private
+
+      def offline_error
+        report_error "GPX files offline for maintenance", :service_unavailable if Settings.status == "gpx_offline"
+      end
+    end
+  end
+end