Wolt Reader.gs

function searchAndReadPDFs() {
  var threads = GmailApp.search("from:[email protected] has:attachment filename:pdf");
  for (var thread of threads){
    Logger.log(thread.getId());
    var foundCodes = []; // TODO use Set

    for (var message of thread.getMessages()){
      for (var attachment of message.getAttachments()) {
          Logger.log(message.getSubject());
          Logger.log(message.getDate());
          Logger.log(attachment.getName());
        
          var raw_content = getRawPDFContent(message.getId(), (attachment.getName()));
          var b64 = Utilities.base64Decode(raw_content);
          var string_content = b64.getDataAsString();
          Logger.log(string_content);
          while ((match =  /CODE:(s*(\S+)\s*)/gi.exec(string_content)) !== null) {
            foundCodes.push(match[1]);
          }
          
          if (foundCodes.length > 0) {
            Logger.log("Found " + foundCodes.length + " code(s):");
            foundCodes.forEach(function(code, index) {
              Logger.log("Code " + (index + 1) + ": " + code);
            });
          } else {
            Logger.log("No codes found in " + attachment.getName());
          }



        }
    }
  }
}
function getRawPDFContent(messageId, attachmentName) {
  var rawContent = Gmail.Users.Messages.get('me', messageId, {format: 'raw'}).raw;
  
  // Find the attachment in the raw content
  var attachmentIndex = rawContent.indexOf('Content-Disposition: attachment; filename="' + attachmentName + '"');
  if (attachmentIndex === -1) return null;
  
  var contentTypeIndex = rawContent.indexOf('Content-Type: application/pdf', attachmentIndex);
  if (contentTypeIndex === -1) return null;
  
  var contentStart = rawContent.indexOf('\r\n\r\n', contentTypeIndex) + 4;
  var contentEnd = rawContent.indexOf('--', contentStart);
  
  return rawContent.substring(contentStart, contentEnd);
}