var width = 150;
var widthStr = (width * 10).toString();

//When the script is installed, create our extension menu
function onInstall() {
  createUI();
}

//When the script is opened, create our extension menu
function onOpen() {
  createUI();
}

function createUI(){
  var ui = DocumentApp.getUi();
  
  //Text to display in UI
  var ui_text = 'Replace <<QR>> With QR Codes';

  //Exact name of the function to be run when the UI is clicked
  var ui_function = 'qr';

  //Create the Addon Menu with specified text and function
  ui.createAddonMenu()
      .addItem(ui_text, ui_function)
      .addToUi();
}

function callAPI() {

  //This is the qurl (QR URL) this will be the URL we want the QR code to point to
  var qurl = DocumentApp.getActiveDocument().getUrl();

  //This is the URL we need to make an HTTP POST request to.
  var url = "https://api.qr-code-generator.com/v1/create?access-token=" + token;

  //These are the options we send with our POST request.
  var options = {
    "method": "post", //We don't need to GET just POST
    "payload":{ //What are we telling the API
    "frame_name": "no-frame", //We don't want a frame for our QR Codes
    "qr_code_text": qurl, //We cant the code to link to the qurl
    "image_format": "PNG", //Our format is PNG (JPG also works)
    "qr_code_logo": "no-logo", //No logo (We can't upload an MCLS logo or I would try to do that)
    "image_width":widthStr, //Image Width and Height (QR codes are squares so this is fine)
    "download":1 //Data return type, leave this as 1
    }
  };

  //Make our HTTP POST request using UrlFetchApp and return the Binary Image Data
  var response = UrlFetchApp.fetch(url, options);
  return response;
}

function qr(){

  /* 
  https://stackoverflow.com/questions/74877202/convert-binary-image-to-image-and-insert-into-google-doc-google-apps-script
  */

  //Replace specified searchText with a specified Binary Image Data (image)
  var replaceTextToImage = function (body, searchText, image, width) {
    var next = body.findText(searchText);
    if (!next) return;
    var r = next.getElement(); //Get the next instance of searchText from our body
    r.asText().setText(""); //Replace the text with a blank strink
    var img = r.getParent().asParagraph().insertInlineImage(0, image); //Convert Binary Image Data to InlineImage data
    if (width && typeof width == "number") { //Set image dimensions
      var w = img.getWidth();
      var h = img.getHeight();
      img.setWidth(width);
      img.setHeight(width * h / w);
    }
    return next; //Return the element with the InlineImage data
  };

  //This is the text we will be replacing with our QR code
  var replaceText = "<<QR>>";

  var doc = DocumentApp.getActiveDocument(); //Get the current document
  var body = doc.getBody(); //Get the Body
  var head = doc.getHeader(); //Header
  var foot = doc.getFooter(); //and Footer sections of the document
  
  var code = callAPI(); //Call our API and get our QR code image as Binary Image Data
  var blob = code.getBlob(); //Create a blob from that data

  do { //Replaces our replaceText with our image in the Header of the document
    var next = replaceTextToImage(head, replaceText, blob, width);
  } while (next);

  do { //Replaces our replaceText with our image in the Body of the document
    var next = replaceTextToImage(body, replaceText, blob, width);
  } while (next);

  do { //Replaces our replaceText with our image in the Footer of the document
    var next = replaceTextToImage(foot, replaceText, blob, width);
  } while (next);
}