1 files changed, 47 insertions, 0 deletions
diff --git a/lib/gitlab/composer/version_index.rb b/lib/gitlab/composer/version_index.rb
new file mode 100644
index 00000000000..de9a17a453f
--- /dev/null
+++ b/lib/gitlab/composer/version_index.rb
@@ -0,0 +1,47 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Composer
+    class VersionIndex
+      include API::Helpers::RelatedResourcesHelpers
+
+      def initialize(packages)
+        @packages = packages
+      end
+
+      def as_json(_options = nil)
+        { 'packages' => { @packages.first.name => package_versions_map } }
+      end
+
+      def sha
+        Digest::SHA256.hexdigest(to_json)
+      end
+
+      private
+
+      def package_versions_map
+        @packages.each_with_object({}) do |package, map|
+          map[package.version] = package_metadata(package)
+        end
+      end
+
+      def package_metadata(package)
+        json = package.composer_metadatum.composer_json
+
+        json.merge('dist' => package_dist(package), 'uid' => package.id, 'version' => package.version)
+      end
+
+      def package_dist(package)
+        sha = package.composer_metadatum.target_sha
+        archive_api_path = api_v4_projects_packages_composer_archives_package_name_path({ id: package.project_id, package_name: package.name, format: '.zip' }, true)
+
+        {
+          'type' => 'zip',
+          'url' => expose_url(archive_api_path) + "?sha=#{sha}",
+          'reference' => sha,
+          'shasum' => ''
+        }
+      end
+    end
+  end
+end