// Adds a new button (RELOAD) to the menu which executes the getAccessToken-function
// and thus triggers a reload of the iLv-function
function onOpen() {
  var sheet = SpreadsheetApp.getActiveSpreadsheet();
  var entries = [{
    name : "Update Now!",
    functionName : "getAccessToken"
  }];
  sheet.addMenu("↻ RELOAD", entries);
};


// Writes the current date into cell 'Z1'
// Requests a new access_token and writes it into cell 'Z2'
// Access tokens expire after 24 hours.
function getAccessToken() {
  var apiusername = 'c937ee086498497696e5af033fd1932f';
  var apisecretkey = '83qMA17Ohk4RtZAhgMYZ6Z1SrS7wTcw5';
  var url ='https://eu.battle.net/oauth/token';
  var options = {
    method: 'post',
    headers : {"Authorization" : " Basic " + Utilities.base64Encode(apiusername + ":" + apisecretkey)},
    payload: {
      "grant_type": "client_credentials",
      "scope": "basic+user"
    }
  };
  var response = UrlFetchApp.fetch(url, options);
  var access_token = JSON.parse(response.toString()).access_token;

  SpreadsheetApp.getActiveSpreadsheet().getRange('Z2').setValue(access_token);
  SpreadsheetApp.getActiveSpreadsheet().getRange('Z1').setValue(new Date().toString());
}

// iLv returns the itemlevel and azerite-level of the WoW-Character in the cell to the left
// date: changes with every push of the RELOAD-Button, thus forcing a reload - otherwise unused
// realmName: optional, defaults to 'eredar', should be given if toon is on another realm
// count: controls number of request-attempts (should not be set manually)
function iLv(date, realmName, count) {

  // load toonName from the left cell
  var sheet = SpreadsheetApp.getActiveSpreadsheet();
  var leftCellNum = sheet.getActiveRange().offset(0, -1).getA1Notation();
  var toonName = sheet.getRange(leftCellNum).getValue();

  // ignore empty fields
  if (toonName == "") return "";

  // default Realm is Onyxia
  if (!realmName) realmName = "blackhand";

  // prevent spam
  Utilities.sleep(Math.floor((Math.random() * 5000) + 1000));

  // remove unwanted characters
  toonName = toonName.replace(/[\u200B-\u200D\uFEFF]/g, '');
  realmName = realmName.replace(/[\u200B-\u200D\uFEFF]/g, '');

  // OAuth authentication token, required for the api call
  // written into Z2 by getAccessToken(), which is called by the update-Button
  var access_token = SpreadsheetApp.getActiveSpreadsheet().getRange('Z2').getValue();

  try { // make the api call
    var toonJSON = UrlFetchApp.fetch("https://eu.api.blizzard.com/wow/character/"+realmName+"/"+toonName+"?fields=items&locale=en_EU&access_token="+access_token);
    var toon = JSON.parse(toonJSON.toString());
    return ""+toon.items.averageItemLevelEquipped+" - "+(toon.items.neck.azeriteItem.azeriteLevel+(toon.items.neck.azeriteItem.azeriteExperience/toon.items.neck.azeriteItem.azeriteExperienceRemaining)).toFixed(1);

  } catch (err) { // if failed, try again
    if (!count) count = 0;
    if (count > 4) return "TODO"; // quit after 4 failed attempts
    else return iLv(date, realmName, count+1);
  }
}