add screen reader mode

lib/document_metadatas.rb

@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+module DocumentMetadatas
+  module_function
+
+  def find_or_create_for_document(document, account_id:)
+    checksum = document.blob.checksum
+
+    metadata   = DocumentMetadata.find_by(account_id:, blob_checksum: checksum)
+    metadata ||= DocumentMetadata.create!(account_id:, blob_checksum: checksum, text_runs: build_text_runs(document))
+
+    metadata
+  rescue ActiveRecord::RecordNotUnique
+    retry
+  end
+
+  def build_text_runs(document)
+    number_of_pages = document.metadata.dig('pdf', 'number_of_pages').to_i
+
+    return {} if number_of_pages.zero?
+
+    Pdfium::Document.open_bytes(document.download) do |doc|
+      (0...doc.page_count).each_with_object({}) do |page_index, acc|
+        page = doc.get_page(page_index)
+
+        acc[page_index] = page.text_objects.map do |node|
+          { text: node.content, x: node.x, y: node.y, w: node.w, h: node.h, font_size: node.font_size }
+        end
+      ensure
+        page&.close
+      end
+    end
+  end
+end