/*!
  jQuery Autosize v1.16.7
  (c) 2013 Jack Moore - jacklmoore.com
  updated: 2013-03-20
  license: http://www.opensource.org/licenses/mit-license.php
*/


(function ($) {
  var
  defaults = {
    className: 'autosizejs',
    append: '',
    callback: false
  },
  hidden = 'hidden',
  borderBox = 'border-box',
  lineHeight = 'lineHeight',
  supportsScrollHeight,

  // border:0 is unnecessary, but avoids a bug in FireFox on OSX (http://www.jacklmoore.com/autosize#comment-851)
  copy = '<textarea tabindex="-1" style="position:absolute; top:-999px; left:0; right:auto; bottom:auto; border:0; -moz-box-sizing:content-box; -webkit-box-sizing:content-box; box-sizing:content-box; word-wrap:break-word; height:0 !important; min-height:0 !important; width: 0; overflow:hidden;"/>',

  // line-height is conditionally included because IE7/IE8/old Opera do not return the correct value.
  copyStyle = [
    'fontFamily',
    'fontSize',
    'fontWeight',
    'fontStyle',
    'letterSpacing',
    'textTransform',
    'wordSpacing',
    'textIndent'
  ],
  oninput = 'oninput',
  onpropertychange = 'onpropertychange',

  // to keep track which textarea is being mirrored when adjust() is called.
  mirrored,

  // the mirror element, which is used to calculate what size the mirrored element should be.
  mirror = $(copy).data('autosize', true)[0];

  // test that line-height can be accurately copied.
  mirror.style.lineHeight = '99px';
  if ($(mirror).css(lineHeight) === '99px') {
    copyStyle.push(lineHeight);
  }
  mirror.style.lineHeight = '';

  $.fn.autosize = function (options) {
    options = $.extend({}, defaults, options || {});

    if (mirror.parentNode !== document.body) {
      $(document.body).append(mirror);

      mirror.value = "\n\n\n";
      mirror.scrollTop = 9e4;
      supportsScrollHeight = mirror.scrollHeight === mirror.scrollTop + mirror.clientHeight;
    }

    return this.each(function () {
      var
      ta = this,
      $ta = $(ta),
      minHeight,
      active,
      resize,
      boxOffset = 0,
      callback = $.isFunction(options.callback);

      if ($ta.data('autosize')) {
        // exit if autosize has already been applied, or if the textarea is the mirror element.
        return;
      }

      if ($ta.css('box-sizing') === borderBox || $ta.css('-moz-box-sizing') === borderBox || $ta.css('-webkit-box-sizing') === borderBox){
        boxOffset = $ta.outerHeight() - $ta.height();
      }

      minHeight = Math.max(parseInt($ta.css('minHeight'), 10) - boxOffset, $ta.height());

      resize = ($ta.css('resize') === 'none' || $ta.css('resize') === 'vertical') ? 'none' : 'horizontal';

      $ta.css({
        overflow: hidden,
        overflowY: hidden,
        wordWrap: 'break-word',
        resize: resize
      }).data('autosize', true);

      function initMirror() {
        mirrored = ta;
        mirror.className = options.className;

        // mirror is a duplicate textarea located off-screen that
        // is automatically updated to contain the same text as the
        // original textarea.  mirror always has a height of 0.
        // This gives a cross-browser supported way getting the actual
        // height of the text, through the scrollTop property.
        $.each(copyStyle, function(i, val){
          mirror.style[val] = $ta.css(val);
        });
      }

      // Using mainly bare JS in this function because it is going
      // to fire very often while typing, and needs to very efficient.
      function adjust() {
        var height, overflow, original;

        if (mirrored !== ta) {
          initMirror();
        }

        // the active flag keeps IE from tripping all over itself.  Otherwise
        // actions in the adjust function will cause IE to call adjust again.
        if (!active) {
          active = true;
          mirror.value = ta.value + options.append;
          mirror.style.overflowY = ta.style.overflowY;
          original = parseInt(ta.style.height,10);

          // Update the width in case the original textarea width has changed
          // A floor of 0 is needed because IE8 returns a negative value for hidden textareas, raising an error.
          mirror.style.width = Math.max($ta.width(), 0) + 'px';

          if (supportsScrollHeight) {
            height = mirror.scrollHeight;
          } else { // IE6 & IE7
            mirror.scrollTop = 0;
            mirror.scrollTop = 9e4;
            height = mirror.scrollTop;
          }

          var maxHeight = parseInt($ta.css('maxHeight'), 10);
          // Opera returns '-1px' when max-height is set to 'none'.
          maxHeight = maxHeight && maxHeight > 0 ? maxHeight : 9e4;
          if (height > maxHeight) {
            height = maxHeight;
            overflow = 'scroll';
          } else if (height < minHeight) {
            height = minHeight;
          }
          height += boxOffset;
          ta.style.overflowY = overflow || hidden;

          if (original !== height) {
            ta.style.height = height + 'px';
            if (callback) {
              options.callback.call(ta,ta);
            }
          }

          // This small timeout gives IE a chance to draw it's scrollbar
          // before adjust can be run again (prevents an infinite loop).
          setTimeout(function () {
            active = false;
          }, 1);
        }
      }

      if (onpropertychange in ta) {
        if (oninput in ta) {
          // Detects IE9.  IE9 does not fire onpropertychange or oninput for deletions,
          // so binding to onkeyup to catch most of those occassions.  There is no way that I
          // know of to detect something like 'cut' in IE9.
          ta[oninput] = ta.onkeyup = adjust;
        } else {
          // IE7 / IE8
          ta[onpropertychange] = adjust;
        }
      } else {
        // Modern Browsers
        ta[oninput] = adjust;
      }

      $(window).on('resize', function(){
        active = false;
        adjust();
      });

      // Allow for manual triggering if needed.
      $ta.on('autosize', function(){
        active = false;
        adjust();
      });

      // Call adjust in case the textarea already contains text.
      adjust();
    });
  };
}(window.jQuery || window.Zepto));