/* Credit: https://gist.github.com/mogsdad/e6795e438615d252584f */

var blob = DriveApp.getFileById(PDF_FILE_ID).getBlob();
var text = pdfToText(blob, { ocrLanguage: 'en' });
Logger.log(text);

/**
 * Convert pdf file (blob) to a text file on Drive, using built-in OCR.
 * By default, the text file will be placed in the root folder, with the same
 * name as source pdf (but extension 'txt'). Options:
 */

const convertPDFToText = (pdfFile, options) => {
  // Ensure Advanced Drive Service is enabled
  try {
    Drive.Files.list();
  } catch (e) {
    throw new Error("Enable 'Drive API' in Resources - Advanced Google Services.");
  }

  // Prepare resource object for file creation
  var parents = [];
  var pdfName = pdfFile.getName();

  var resource = {
    title: pdfName,
    mimeType: pdfFile.getContentType(),
    parents: parents,
  };

  // Save PDF as GDOC
  resource.title = pdfName.replace(/pdf$/, 'gdoc');
  var insertOpts = {
    ocr: true,
    ocrLanguage: options.ocrLanguage || 'en',
  };

  var gdocFile = Drive.Files.insert(resource, pdfFile, insertOpts);

  // Get text from GDOC
  var gdocDoc = DocumentApp.openById(gdocFile.id);
  var text = gdocDoc.getBody().getText();

  // Save text file, if requested
  resource.title = pdfName.replace(/pdf$/, 'txt');
  resource.mimeType = MimeType.PLAIN_TEXT;

  var textBlob = Utilities.newBlob(text, MimeType.PLAIN_TEXT, resource.title);
  var textFile = Drive.Files.insert(resource, textBlob);

  return text;
};