1 files changed, 56 insertions, 0 deletions
diff --git a/app/services/packages/rpm/repository_metadata/build_repomd_xml_service.rb b/app/services/packages/rpm/repository_metadata/build_repomd_xml_service.rb
new file mode 100644
index 00000000000..cb80faa12c0
--- /dev/null
+++ b/app/services/packages/rpm/repository_metadata/build_repomd_xml_service.rb
@@ -0,0 +1,56 @@
+# frozen_string_literal: true
+module Packages
+  module Rpm
+    module RepositoryMetadata
+      class BuildRepomdXmlService
+        ROOT_ATTRIBUTES = {
+          xmlns: 'http://linux.duke.edu/metadata/repo',
+          'xmlns:rpm': 'http://linux.duke.edu/metadata/rpm'
+        }.freeze
+        ALLOWED_DATA_VALUE_KEYS = %i[checksum open-checksum location timestamp size open-size].freeze
+
+        # Expected `data` structure
+        #
+        # data = {
+        #   filelists: {
+        #     checksum: { type: "sha256", value: "123" },
+        #     location: { href: "repodata/123-filelists.xml.gz" },
+        #     ...
+        #   },
+        #   ...
+        # }
+        def initialize(data)
+          @data = data
+        end
+
+        def execute
+          Nokogiri::XML::Builder.new(encoding: 'UTF-8') do |xml|
+            xml.repomd(ROOT_ATTRIBUTES) do
+              xml.revision Time.now.to_i
+              build_data_info(xml)
+            end
+          end.to_xml
+        end
+
+        private
+
+        attr_reader :data
+
+        def build_data_info(xml)
+          data.each do |filename, info|
+            xml.data(type: filename) do
+              build_file_info(info, xml)
+            end
+          end
+        end
+
+        def build_file_info(info, xml)
+          info.slice(*ALLOWED_DATA_VALUE_KEYS).each do |key, attributes|
+            value = attributes.delete(:value)
+            xml.method_missing(key, value, attributes)
+          end
+        end
+      end
+    end
+  end
+end