//     zepto.js
//     (c) 2010-2016 thomas fuchs
//     zepto.js may be freely distributed under the mit license.

;(function($){
  var touch = {},
    touchtimeout, taptimeout, swipetimeout, longtaptimeout,
    longtapdelay = 750,
    gesture

  function swipedirection(x1, x2, y1, y2) {
    return math.abs(x1 - x2) >=
      math.abs(y1 - y2) ? (x1 - x2 > 0 ? 'left' : 'right') : (y1 - y2 > 0 ? 'up' : 'down')
  }

  function longtap() {
    longtaptimeout = null
    if (touch.last) {
      touch.el.trigger('longtap')
      touch = {}
    }
  }

  function cancellongtap() {
    if (longtaptimeout) cleartimeout(longtaptimeout)
    longtaptimeout = null
  }

  function cancelall() {
    if (touchtimeout) cleartimeout(touchtimeout)
    if (taptimeout) cleartimeout(taptimeout)
    if (swipetimeout) cleartimeout(swipetimeout)
    if (longtaptimeout) cleartimeout(longtaptimeout)
    touchtimeout = taptimeout = swipetimeout = longtaptimeout = null
    touch = {}
  }

  function isprimarytouch(event){
    return (event.pointertype == 'touch' ||
      event.pointertype == event.mspointer_type_touch)
      && event.isprimary
  }

  function ispointereventtype(e, type){
    return (e.type == 'pointer'+type ||
      e.type.tolowercase() == 'mspointer'+type)
  }

  $(document).ready(function(){
    var now, delta, deltax = 0, deltay = 0, firsttouch, _ispointertype

    if ('msgesture' in window) {
      gesture = new msgesture()
      gesture.target = document.body
    }

    $(document)
      .bind('msgestureend', function(e){
        var swipedirectionfromvelocity =
          e.velocityx > 1 ? 'right' : e.velocityx < -1 ? 'left' : e.velocityy > 1 ? 'down' : e.velocityy < -1 ? 'up' : null
        if (swipedirectionfromvelocity) {
          touch.el.trigger('swipe')
          touch.el.trigger('swipe'+ swipedirectionfromvelocity)
        }
      })
      .on('touchstart mspointerdown pointerdown', function(e){
        if((_ispointertype = ispointereventtype(e, 'down')) &&
          !isprimarytouch(e)) return
        firsttouch = _ispointertype ? e.originalevent : e.originalevent.touches[0]
        if (e.originalevent.touches && e.originalevent.touches.length === 1 && touch.x2) {
          // clear out touch movement data if we have it sticking around
          // this can occur if touchcancel doesn't fire due to preventdefault, etc.
          touch.x2 = undefined
          touch.y2 = undefined
        }
        now = date.now()
        delta = now - (touch.last || now)
        touch.el = $('tagname' in firsttouch.target ?
          firsttouch.target : firsttouch.target.parentnode)
        touchtimeout && cleartimeout(touchtimeout)
        touch.x1 = firsttouch.pagex
        touch.y1 = firsttouch.pagey
        if (delta > 0 && delta <= 250) touch.isdoubletap = true
        touch.last = now
        longtaptimeout = settimeout(longtap, longtapdelay)
        // adds the current touch contact for ie gesture recognition
        if (gesture && _ispointertype) gesture.addpointer(e.pointerid)
      })
      .on('touchmove mspointermove pointermove', function(e){
        if((_ispointertype = ispointereventtype(e, 'move')) &&
          !isprimarytouch(e)) return
        firsttouch = _ispointertype ? e.originalevent : e.originalevent.touches[0]
        cancellongtap()
        touch.x2 = firsttouch.pagex
        touch.y2 = firsttouch.pagey

        deltax += math.abs(touch.x1 - touch.x2)
        deltay += math.abs(touch.y1 - touch.y2)
      })
      .on('touchend mspointerup pointerup', function(e){
        if((_ispointertype = ispointereventtype(e, 'up')) &&
          !isprimarytouch(e)) return
        cancellongtap()

        // swipe
        if ((touch.x2 && math.abs(touch.x1 - touch.x2) > 30) ||
            (touch.y2 && math.abs(touch.y1 - touch.y2) > 30))

          swipetimeout = settimeout(function() {
            if (touch.el){
              touch.el.trigger('swipe')
              touch.el.trigger('swipe' + (swipedirection(touch.x1, touch.x2, touch.y1, touch.y2)))
            }
            touch = {}
          }, 0)

        // normal tap
        else if ('last' in touch)
          // don't fire tap when delta position changed by more than 30 pixels,
          // for instance when moving to a point and back to origin
          if (deltax < 30 && deltay < 30) {
            // delay by one tick so we can cancel the 'tap' event if 'scroll' fires
            // ('tap' fires before 'scroll')
            taptimeout = settimeout(function() {

              // trigger universal 'tap' with the option to canceltouch()
              // (canceltouch cancels processing of single vs double taps for faster 'tap' response)
              var event = $.event('tap')
              event.canceltouch = cancelall
              // [by paper] fix -> "typeerror: 'undefined' is not an object (evaluating 'touch.el.trigger'), when double tap
              if (touch.el) touch.el.trigger(event)

              // trigger double tap immediately
              if (touch.isdoubletap) {
                if (touch.el) touch.el.trigger('doubletap')
                touch = {}
              }

              // trigger single tap after 250ms of inactivity
              else {
                touchtimeout = settimeout(function(){
                  touchtimeout = null
                  if (touch.el) touch.el.trigger('singletap')
                  touch = {}
                }, 250)
              }
            }, 0)
          } else {
            touch = {}
          }
          deltax = deltay = 0

      })
      // when the browser window loses focus,
      // for example when a modal dialog is shown,
      // cancel all ongoing events
      .on('touchcancel mspointercancel pointercancel', cancelall)

    // scrolling the window indicates intention of the user
    // to scroll, not tap or swipe, so cancel all ongoing events
    $(window).on('scroll', cancelall)
  })

  ;['swipe', 'swipeleft', 'swiperight', 'swipeup', 'swipedown',
    'doubletap', 'tap', 'singletap', 'longtap'].foreach(function(eventname){
    $.fn[eventname] = function(callback){ return this.on(eventname, callback) }
  })
})(jquery)