1 files changed, 123 insertions, 0 deletions
diff --git a/app/services/packages/maven/metadata/sync_service.rb b/app/services/packages/maven/metadata/sync_service.rb
new file mode 100644
index 00000000000..a6534aa706d
--- /dev/null
+++ b/app/services/packages/maven/metadata/sync_service.rb
@@ -0,0 +1,123 @@
+# frozen_string_literal: true
+
+module Packages
+  module Maven
+    module Metadata
+      class SyncService < BaseContainerService
+        include Gitlab::Utils::StrongMemoize
+
+        alias_method :project, :container
+
+        MAX_FILE_SIZE = 10.megabytes.freeze
+
+        def execute
+          return error('Blank package name') unless package_name
+          return error('Not allowed') unless Ability.allowed?(current_user, :destroy_package, project)
+          return error('Non existing versionless package') unless versionless_package_for_versions
+          return error('Non existing metadata file for versions') unless metadata_package_file_for_versions
+
+          if metadata_package_file_for_plugins
+            result = update_plugins_xml
+
+            return result if result.error?
+          end
+
+          update_versions_xml
+        end
+
+        private
+
+        def update_versions_xml
+          update_xml(
+            kind: :versions,
+            package_file: metadata_package_file_for_versions,
+            service_class: CreateVersionsXmlService,
+            payload_empty_field: :empty_versions
+          )
+        end
+
+        def update_plugins_xml
+          update_xml(
+            kind: :plugins,
+            package_file: metadata_package_file_for_plugins,
+            service_class: CreatePluginsXmlService,
+            payload_empty_field: :empty_plugins
+          )
+        end
+
+        def update_xml(kind:, package_file:, service_class:, payload_empty_field:)
+          return error("Metadata file for #{kind} is too big") if package_file.size > MAX_FILE_SIZE
+
+          package_file.file.use_open_file do |file|
+            result = service_class.new(metadata_content: file, package: package_file.package)
+                                  .execute
+
+            next result unless result.success?
+            next success("No changes for #{kind} xml") unless result.payload[:changes_exist]
+
+            if result.payload[payload_empty_field]
+              package_file.package.destroy!
+              success("Versionless package for #{kind} destroyed")
+            else
+              AppendPackageFileService.new(metadata_content: result.payload[:metadata_content], package: package_file.package)
+                                      .execute
+            end
+          end
+        end
+
+        def metadata_package_file_for_versions
+          strong_memoize(:metadata_file_for_versions) do
+            metadata_package_file_for(versionless_package_for_versions)
+          end
+        end
+
+        def versionless_package_for_versions
+          strong_memoize(:versionless_package_for_versions) do
+            versionless_package_named(package_name)
+          end
+        end
+
+        def metadata_package_file_for_plugins
+          strong_memoize(:metadata_package_file_for_plugins) do
+            metadata_package_file_for(versionless_package_named(package_name_for_plugins))
+          end
+        end
+
+        def metadata_package_file_for(package)
+          return unless package
+
+          package.package_files
+                 .with_file_name(Metadata.filename)
+                 .recent
+                 .first
+        end
+
+        def versionless_package_named(name)
+          project.packages
+                 .maven
+                 .displayable
+                 .with_name(name)
+                 .with_version(nil)
+                 .first
+        end
+
+        def package_name
+          params[:package_name]
+        end
+
+        def package_name_for_plugins
+          group = versionless_package_for_versions.maven_metadatum.app_group
+          group.tr('.', '/')
+        end
+
+        def error(message)
+          ServiceResponse.error(message: message)
+        end
+
+        def success(message)
+          ServiceResponse.success(message: message)
+        end
+      end
+    end
+  end
+end