add documents editor

app/controllers/template_documents_crop_controller.rb

@@ -0,0 +1,39 @@
+# frozen_string_literal: true
+
+class TemplateDocumentsCropController < ApplicationController
+  load_and_authorize_resource :template
+  before_action :load_attachment
+
+  rescue_from Leptonica::LeptonicaError do
+    render json: { error: I18n.t(:unable_to_save) }, status: :unprocessable_content
+  end
+
+  def index
+    render json: { corners: Leptonica.detect_document_corners(@attachment.download) }
+  end
+
+  def create
+    authorize!(:update, @template)
+
+    document = Templates::CreateDocumentCrop.call(@template, @attachment, crop_params)
+
+    render json: {
+      document: document.as_json(
+        methods: %i[metadata signed_key],
+        include: {
+          preview_images: { methods: %i[url metadata filename] }
+        }
+      )
+    }
+  end
+
+  private
+
+  def load_attachment
+    @attachment = @template.documents_attachments.find_by!(uuid: params[:attachment_uuid])
+  end
+
+  def crop_params
+    params.permit(:scan, :rotate, :flip_h, :flip_v, corners: [%i[x y]])
+  end
+end