add revisions

lib/template_versions.rb

@@ -0,0 +1,76 @@
+# frozen_string_literal: true
+
+module TemplateVersions
+  SERIALIZE_PARAMS = {
+    only: %i[id created_at],
+    include: { author: { only: %i[email], methods: %i[full_name] } }
+  }.freeze
+
+  DATA_FIELDS = %i[name schema submitters variables_schema fields].freeze
+
+  module_function
+
+  def find_or_create_for(template, author:)
+    data = build_data(template)
+    sha1 = Digest::SHA1.hexdigest(data.to_json)
+
+    version   = template.template_versions.find_by(sha1:)
+    version ||= template.template_versions.create!(data:, sha1:, author:)
+
+    version
+  rescue ActiveRecord::RecordNotUnique
+    retry
+  end
+
+  def serialize(version)
+    data = version.data.dup
+
+    data['documents'] = serialize_documents(version.template, data['schema'].to_a)
+    data['dynamic_documents'] = serialize_dynamic_documents(version.template, data['dynamic_documents'].to_a)
+
+    version.as_json(SERIALIZE_PARAMS).merge('data' => data)
+  end
+
+  def build_data(template)
+    dynamic_uuids = template.schema.select { |e| e['dynamic'] }.pluck('attachment_uuid')
+
+    dynamic_documents =
+      if dynamic_uuids.present?
+        template.dynamic_documents.where(uuid: dynamic_uuids).as_json(only: %i[uuid body])
+      else
+        []
+      end
+
+    template.as_json(only: DATA_FIELDS).merge('dynamic_documents' => dynamic_documents)
+  end
+
+  def serialize_documents(template, schema)
+    return [] if schema.blank?
+
+    template.documents_attachments
+            .where(uuid: schema.pluck('attachment_uuid'))
+            .preload(:blob, preview_images_attachments: :blob)
+            .as_json(
+              only: %i[id uuid],
+              methods: %i[metadata signed_key],
+              include: { preview_images: { only: %i[id], methods: %i[url metadata filename] } }
+            )
+  end
+
+  def serialize_dynamic_documents(template, dynamic_docs)
+    return [] if dynamic_docs.blank?
+
+    dynamic_docs_index = template.dynamic_documents
+                                 .where(uuid: dynamic_docs.pluck('uuid'))
+                                 .preload(attachments_attachments: :blob)
+                                 .index_by(&:uuid)
+
+    dynamic_docs.map do |attrs|
+      document = dynamic_docs_index[attrs['uuid']]
+
+      attachments_data = document.attachments_attachments.as_json(only: %i[uuid], methods: %i[url metadata filename])
+
+      attrs.merge('head' => document.head, 'attachments' => attachments_data)
+    end
+  end
+end