/* Utils based on http://youmightnotneedjquery.com/ */
/* JQuery ready */
function ready(fn) {
  if (document.readyState != 'loading'){
    fn();
  } else if (document.addEventListener) {
    document.addEventListener('DOMContentLoaded', fn);
  } else {
    document.attachEvent('onreadystatechange', function() {
      if (document.readyState != 'loading')
        fn();
    });
  }
}

/* JQuery addClass */
function addClass (el, className) {
  if (el.classList) {
    el.classList.add(className);
  } else {
    var current = el.className, found = false;
    var all = current.split(' ');
    for(var i=0; i<all.length, !found; i++) found = all[i] === className;
    if(!found) {
      if(current === '') el.className = className;
      else el.className += ' ' + className;
    }
  }
}

/* JQuery removeClass */
function removeClass (el, className) {
  if (el.classList)
    el.classList.remove(className);
  else
    el.className = el.className.replace(new RegExp('(^|\\b)' + className.split(' ').join('|') + '(\\b|$)', 'gi'), ' ');
}

/* JQuery hasClass */
function hasClass (el, className) {
  if (el.classList)
    return el.classList.contains(className);
  else
    return new RegExp('(^| )' + className + '( |$)', 'gi').test(el.className);
}

/* JQuery on */
function addEventListener(el, eventName, handler) {
  if (el.addEventListener) {
    el.addEventListener(eventName, handler);
  } else {
    el.attachEvent('on' + eventName, function(){
      handler.call(el);
    });
  }
}
/* Utils end */

/* Script start here */
ready(function () {
  const wrapper = document.getElementById('wrapper')
  const toggler = document.getElementById('theme-toggler')

  if (localStorage.theme) {
    addClass(wrapper, localStorage.theme)
  } else {
    addClass(wrapper, 'light-mode')
  }

  addEventListener(toggler, 'click', function () {
    if (hasClass(wrapper, 'light-mode')) {
      removeClass(wrapper, 'light-mode')
      addClass(wrapper, 'night-mode')

      localStorage.theme = 'night-mode'
    } else {
      removeClass(wrapper, 'night-mode')
      addClass(wrapper, 'light-mode')

      localStorage.theme = 'light-mode'
    }
  })
})
/* End */