Add catalog service

app/controllers/marcxml_controller.rb

@@ -0,0 +1,25 @@
+class MarcxmlController < ApplicationController #:nodoc:
+  before_action :set_marcxml_resource
+
+  def catkey
+    render plain: @marcxml.catkey
+  end
+
+  def marcxml
+    render xml: @marcxml.marcxml
+  end
+
+  def mods
+    render xml: @marcxml.mods
+  end
+
+  private
+
+  def set_marcxml_resource
+    @marcxml = MarcxmlResource.find_by(**marcxml_resource_params)
+  end
+
+  def marcxml_resource_params
+    params.slice(:barcode, :catkey).to_unsafe_h.symbolize_keys
+  end
+end

app/models/marcxml_resource.rb

@@ -0,0 +1,32 @@
+# MARC resource model for retrieving and transforming MARC records
+class MarcxmlResource
+  MARC_TO_MODS_XSLT = Nokogiri::XSLT(File.read(File.join(Rails.root, 'app', 'xslt', 'MARC21slim2MODS3-6.xsl')))
+
+  def self.find_by(catkey: nil, barcode: nil)
+    if catkey
+      new(catkey: catkey)
+    elsif barcode
+      solr = RSolr.connect(url: Settings.CATALOG.SOLR_URL)
+      response = solr.get('barcode', params: { n: barcode })
+      catkey = response[:response][:docs].first[:id]
+
+      new(catkey: catkey)
+    else
+      raise ArgumentError, 'Must supply either a catkey or barcode'
+    end
+  end
+
+  attr_reader :catkey
+
+  def initialize(catkey:)
+    @catkey = catkey
+  end
+
+  def mods
+    MARC_TO_MODS_XSLT.transform(Nokogiri::XML(marcxml)).to_xml
+  end
+
+  def marcxml
+    Faraday.get(Settings.CATALOG.MARCXML_URL % { catkey: catkey }).body
+  end
+end