(function (global, factory) {
  if (typeof define === "function" && define.amd) {
    define(['module', 'exports'], factory);
  } else if (typeof exports !== "undefined") {
    factory(module, exports);
  } else {
    var mod = {
      exports: {}
    };
    factory(mod, mod.exports);
    global.wow = mod.exports;
  }
})(this, function (module, exports) {
  'use strict';

  object.defineproperty(exports, "__esmodule", {
    value: true
  });

  var _class, _temp;

  function _classcallcheck(instance, constructor) {
    if (!(instance instanceof constructor)) {
      throw new typeerror("cannot call a class as a function");
    }
  }

  var _createclass = function () {
    function defineproperties(target, props) {
      for (var i = 0; i < props.length; i++) {
        var descriptor = props[i];
        descriptor.enumerable = descriptor.enumerable || false;
        descriptor.configurable = true;
        if ("value" in descriptor) descriptor.writable = true;
        object.defineproperty(target, descriptor.key, descriptor);
      }
    }

    return function (constructor, protoprops, staticprops) {
      if (protoprops) defineproperties(constructor.prototype, protoprops);
      if (staticprops) defineproperties(constructor, staticprops);
      return constructor;
    };
  }();

  function isin(needle, haystack) {
    return haystack.indexof(needle) >= 0;
  }

  function extend(custom, defaults) {
    for (var key in defaults) {
      if (custom[key] == null) {
        var value = defaults[key];
        custom[key] = value;
      }
    }
    return custom;
  }

  function ismobile(agent) {
    return (/android|webos|iphone|ipad|ipod|blackberry|iemobile|opera mini/i.test(agent)
    );
  }

  function createevent(event) {
    var bubble = arguments.length <= 1 || arguments[1] === undefined ? false : arguments[1];
    var cancel = arguments.length <= 2 || arguments[2] === undefined ? false : arguments[2];
    var detail = arguments.length <= 3 || arguments[3] === undefined ? null : arguments[3];

    var customevent = void 0;
    if (document.createevent != null) {
      // w3c dom
      customevent = document.createevent('customevent');
      customevent.initcustomevent(event, bubble, cancel, detail);
    } else if (document.createeventobject != null) {
      // ie dom < 9
      customevent = document.createeventobject();
      customevent.eventtype = event;
    } else {
      customevent.eventname = event;
    }

    return customevent;
  }

  function emitevent(elem, event) {
    if (elem.dispatchevent != null) {
      // w3c dom
      elem.dispatchevent(event);
    } else if (event in (elem != null)) {
      elem[event]();
    } else if ('on' + event in (elem != null)) {
      elem['on' + event]();
    }
  }

  function addevent(elem, event, fn) {
    if (elem.addeventlistener != null) {
      // w3c dom
      elem.addeventlistener(event, fn, false);
    } else if (elem.attachevent != null) {
      // ie dom
      elem.attachevent('on' + event, fn);
    } else {
      // fallback
      elem[event] = fn;
    }
  }

  function removeevent(elem, event, fn) {
    if (elem.removeeventlistener != null) {
      // w3c dom
      elem.removeeventlistener(event, fn, false);
    } else if (elem.detachevent != null) {
      // ie dom
      elem.detachevent('on' + event, fn);
    } else {
      // fallback
      delete elem[event];
    }
  }

  function getinnerheight() {
    if ('innerheight' in window) {
      return window.innerheight;
    }

    return document.documentelement.clientheight;
  }

  // minimalistic weakmap shim, just in case.
  var weakmap = window.weakmap || window.mozweakmap || function () {
    function weakmap() {
      _classcallcheck(this, weakmap);

      this.keys = [];
      this.values = [];
    }

    _createclass(weakmap, [{
      key: 'get',
      value: function get(key) {
        for (var i = 0; i < this.keys.length; i++) {
          var item = this.keys[i];
          if (item === key) {
            return this.values[i];
          }
        }
        return undefined;
      }
    }, {
      key: 'set',
      value: function set(key, value) {
        for (var i = 0; i < this.keys.length; i++) {
          var item = this.keys[i];
          if (item === key) {
            this.values[i] = value;
            return this;
          }
        }
        this.keys.push(key);
        this.values.push(value);
        return this;
      }
    }]);

    return weakmap;
  }();

  // dummy mutationobserver, to avoid raising exceptions.
  var mutationobserver = window.mutationobserver || window.webkitmutationobserver || window.mozmutationobserver || (_temp = _class = function () {
    function mutationobserver() {
      _classcallcheck(this, mutationobserver);

      if (typeof console !== 'undefined' && console !== null) {
        console.warn('mutationobserver is not supported by your browser.');
        console.warn('wow.js cannot detect dom mutations, please call .sync() after loading new content.');
      }
    }

    _createclass(mutationobserver, [{
      key: 'observe',
      value: function observe() {}
    }]);

    return mutationobserver;
  }(), _class.notsupported = true, _temp);

  // getcomputedstyle shim, from http://stackoverflow.com/a/21797294
  var getcomputedstyle = window.getcomputedstyle || function getcomputedstyle(el) {
    var getcomputedstylerx = /(\-([a-z]){1})/g;
    return {
      getpropertyvalue: function getpropertyvalue(prop) {
        if (prop === 'float') {
          prop = 'stylefloat';
        }
        if (getcomputedstylerx.test(prop)) {
          prop.replace(getcomputedstylerx, function (_, _char) {
            return _char.touppercase();
          });
        }
        var currentstyle = el.currentstyle;

        return (currentstyle != null ? currentstyle[prop] : void 0) || null;
      }
    };
  };

  var wow = function () {
    function wow() {
      var options = arguments.length <= 0 || arguments[0] === undefined ? {} : arguments[0];

      _classcallcheck(this, wow);

      this.defaults = {
        boxclass: 'wow',
        animateclass: 'animated',
        offset: 0,
        mobile: false,
        live: true,
        callback: null,
        scrollcontainer: null,
        resetanimation: true
      };

      this.animate = function animatefactory() {
        if ('requestanimationframe' in window) {
          return function (callback) {
            return window.requestanimationframe(callback);
          };
        }
        return function (callback) {
          return callback();
        };
      }();

      this.vendors = ['moz', 'webkit'];

      this.start = this.start.bind(this);
      this.resetanimation = this.resetanimation.bind(this);
      this.scrollhandler = this.scrollhandler.bind(this);
      this.scrollcallback = this.scrollcallback.bind(this);
      this.scrolled = true;
      this.config = extend(options, this.defaults);
      if (options.scrollcontainer != null) {
        this.config.scrollcontainer = document.queryselector(options.scrollcontainer);
      }
      // map of elements to animation names:
      this.animationnamecache = new weakmap();
      this.wowevent = createevent(this.config.boxclass);
    }

    _createclass(wow, [{
      key: 'init',
      value: function init() {
        this.element = window.document.documentelement;
        if (isin(document.readystate, ['interactive', 'complete'])) {
          this.start();
        } else {
          addevent(document, 'domcontentloaded', this.start);
        }
        this.finished = [];
      }
    }, {
      key: 'start',
      value: function start() {
        var _this = this;

        this.stopped = false;
        this.boxes = [].slice.call(this.element.queryselectorall('.' + this.config.boxclass));
        this.all = this.boxes.slice(0);
        if (this.boxes.length) {
          if (this.disabled()) {
            this.resetstyle();
          } else {
            for (var i = 0; i < this.boxes.length; i++) {
              var box = this.boxes[i];
              this.applystyle(box, true);
            }
          }
        }
        if (!this.disabled()) {
          addevent(this.config.scrollcontainer || window, 'scroll', this.scrollhandler);
          addevent(window, 'resize', this.scrollhandler);
          this.interval = setinterval(this.scrollcallback, 50);
        }
        if (this.config.live) {
          var mut = new mutationobserver(function (records) {
            for (var j = 0; j < records.length; j++) {
              var record = records[j];
              for (var k = 0; k < record.addednodes.length; k++) {
                var node = record.addednodes[k];
                _this.dosync(node);
              }
            }
            return undefined;
          });
          mut.observe(document.body, {
            childlist: true,
            subtree: true
          });
        }
      }
    }, {
      key: 'stop',
      value: function stop() {
        this.stopped = true;
        removeevent(this.config.scrollcontainer || window, 'scroll', this.scrollhandler);
        removeevent(window, 'resize', this.scrollhandler);
        if (this.interval != null) {
          clearinterval(this.interval);
        }
      }
    }, {
      key: 'sync',
      value: function sync() {
        if (mutationobserver.notsupported) {
          this.dosync(this.element);
        }
      }
    }, {
      key: 'dosync',
      value: function dosync(element) {
        if (typeof element === 'undefined' || element === null) {
          element = this.element;
        }
        if (element.nodetype !== 1) {
          return;
        }
        element = element.parentnode || element;
        var iterable = element.queryselectorall('.' + this.config.boxclass);
        for (var i = 0; i < iterable.length; i++) {
          var box = iterable[i];
          if (!isin(box, this.all)) {
            this.boxes.push(box);
            this.all.push(box);
            if (this.stopped || this.disabled()) {
              this.resetstyle();
            } else {
              this.applystyle(box, true);
            }
            this.scrolled = true;
          }
        }
      }
    }, {
      key: 'show',
      value: function show(box) {
        this.applystyle(box);
        box.classname = box.classname + ' ' + this.config.animateclass;
        if (this.config.callback != null) {
          this.config.callback(box);
        }
        emitevent(box, this.wowevent);

        if (this.config.resetanimation) {
          addevent(box, 'animationend', this.resetanimation);
          addevent(box, 'oanimationend', this.resetanimation);
          addevent(box, 'webkitanimationend', this.resetanimation);
          addevent(box, 'msanimationend', this.resetanimation);
        }

        return box;
      }
    }, {
      key: 'applystyle',
      value: function applystyle(box, hidden) {
        var _this2 = this;

        var duration = box.getattribute('data-wow-duration');
        var delay = box.getattribute('data-wow-delay');
        var iteration = box.getattribute('data-wow-iteration');

        return this.animate(function () {
          return _this2.customstyle(box, hidden, duration, delay, iteration);
        });
      }
    }, {
      key: 'resetstyle',
      value: function resetstyle() {
        for (var i = 0; i < this.boxes.length; i++) {
          var box = this.boxes[i];
          box.style.visibility = 'visible';
        }
        return undefined;
      }
    }, {
      key: 'resetanimation',
      value: function resetanimation(event) {
        if (event.type.tolowercase().indexof('animationend') >= 0) {
          var target = event.target || event.srcelement;
          target.classname = target.classname.replace(this.config.animateclass, '').trim();
        }
      }
    }, {
      key: 'customstyle',
      value: function customstyle(box, hidden, duration, delay, iteration) {
        if (hidden) {
          this.cacheanimationname(box);
        }
        box.style.visibility = hidden ? 'hidden' : 'visible';

        if (duration) {
          this.vendorset(box.style, { animationduration: duration });
        }
        if (delay) {
          this.vendorset(box.style, { animationdelay: delay });
        }
        if (iteration) {
          this.vendorset(box.style, { animationiterationcount: iteration });
        }
        this.vendorset(box.style, { animationname: hidden ? 'none' : this.cachedanimationname(box) });

        return box;
      }
    }, {
      key: 'vendorset',
      value: function vendorset(elem, properties) {
        for (var name in properties) {
          if (properties.hasownproperty(name)) {
            var value = properties[name];
            elem['' + name] = value;
            for (var i = 0; i < this.vendors.length; i++) {
              var vendor = this.vendors[i];
              elem['' + vendor + name.charat(0).touppercase() + name.substr(1)] = value;
            }
          }
        }
      }
    }, {
      key: 'vendorcss',
      value: function vendorcss(elem, property) {
        var style = getcomputedstyle(elem);
        var result = style.getpropertycssvalue(property);
        for (var i = 0; i < this.vendors.length; i++) {
          var vendor = this.vendors[i];
          result = result || style.getpropertycssvalue('-' + vendor + '-' + property);
        }
        return result;
      }
    }, {
      key: 'animationname',
      value: function animationname(box) {
        var aname = void 0;
        try {
          aname = this.vendorcss(box, 'animation-name').csstext;
        } catch (error) {
          // opera, fall back to plain property value
          aname = getcomputedstyle(box).getpropertyvalue('animation-name');
        }

        if (aname === 'none') {
          return ''; // svg/firefox, unable to get animation name?
        }

        return aname;
      }
    }, {
      key: 'cacheanimationname',
      value: function cacheanimationname(box) {
        // https://bugzilla.mozilla.org/show_bug.cgi?id=921834
        // box.dataset is not supported for svg elements in firefox
        return this.animationnamecache.set(box, this.animationname(box));
      }
    }, {
      key: 'cachedanimationname',
      value: function cachedanimationname(box) {
        return this.animationnamecache.get(box);
      }
    }, {
      key: 'scrollhandler',
      value: function scrollhandler() {
        this.scrolled = true;
      }
    }, {
      key: 'scrollcallback',
      value: function scrollcallback() {
        if (this.scrolled) {
          this.scrolled = false;
          var results = [];
          for (var i = 0; i < this.boxes.length; i++) {
            var box = this.boxes[i];
            if (box) {
              if (this.isvisible(box)) {
                this.show(box);
                continue;
              }
              results.push(box);
            }
          }
          this.boxes = results;
          if (!this.boxes.length && !this.config.live) {
            this.stop();
          }
        }
      }
    }, {
      key: 'offsettop',
      value: function offsettop(element) {
        // svg elements don't have an offsettop in firefox.
        // this will use their nearest parent that has an offsettop.
        // also, using ('offsettop' of element) causes an exception in firefox.
        while (element.offsettop === undefined) {
          element = element.parentnode;
        }
        var top = element.offsettop;
        while (element.offsetparent) {
          element = element.offsetparent;
          top += element.offsettop;
        }
        return top;
      }
    }, {
      key: 'isvisible',
      value: function isvisible(box) {
        var offset = box.getattribute('data-wow-offset') || this.config.offset;
        var viewtop = this.config.scrollcontainer && this.config.scrollcontainer.scrolltop || window.pageyoffset;
        var viewbottom = viewtop + math.min(this.element.clientheight, getinnerheight()) - offset;
        var top = this.offsettop(box);
        var bottom = top + box.clientheight;

        return top <= viewbottom && bottom >= viewtop;
      }
    }, {
      key: 'disabled',
      value: function disabled() {
        return !this.config.mobile && ismobile(navigator.useragent);
      }
    }]);

    return wow;
  }();

  exports.default = wow;
  module.exports = exports['default'];
});