/*
 * jQuery Expander plugin
 * Version 0.4  (12/09/2008)
 * @requires jQuery v1.1.1+
 *
 * Dual licensed under the MIT and GPL licenses:
 * http://www.opensource.org/licenses/mit-license.php
 * http://www.gnu.org/licenses/gpl.html
 *
 * slicePoint - the number of characters at which the contents will be sliced into two parts. Note: any tag names in the HTML that appear inside the sliced element before the slicePoint will be counted along with the text characters.
 * widow - a threshold of sorts for whether to initially hide/collapse part of the element's contents. If after slicing the contents in two there are fewer words in the second part than the value set by widow, we won't bother hiding/collapsing anything.
 * expandText - text displayed in a link instead of the hidden part of the element. clicking this will expand/show the hidden/collapsed text
 * expandPrefix - text to come before the expand link                              
 * collapseTimer - number of milliseconds after text has been expanded at which to collapse the text again
 * expandEffect - animation effects
 * expandSpeed - speed in milliseconds of the animation effect for expanding the text
 * userCollapse - allow the user to re-collapse the expanded text.
 * userCollapseText - text to use for the link to re-collapse the text
 * userCollapsePrefix - text to come before the re-collapse link
 * beforeExpand - function that is called immediately upon expanding, before the expand occurs
 * afterExpand - function that is called after the details have finished expanding
 * onCollapse - function that is called when the details are collapsed (immediately after)
 */


(function($) {

  $.fn.expander = function(options) {

    var opts = $.extend({}, $.fn.expander.defaults, options);
    var delayedCollapse;
    return this.each(function() {
      var $this = $(this);
      var o = $.meta ? $.extend({}, opts, $this.data()) : opts;
     	var cleanedTag, startTags, endTags;	
     	var allText = $this.html();
     	var startText = allText.slice(0, o.slicePoint).replace(/\w+$/,'');
     	startTags = startText.match(/<\w[^>]*>/g);
   	  if (startTags) {startText = allText.slice(0,o.slicePoint + startTags.join('').length).replace(/\w+$/,'');}
   	  
     	if (startText.lastIndexOf('<') > startText.lastIndexOf('>') ) {
     	  startText = startText.slice(0,startText.lastIndexOf('<'));
     	}
     	var endText = allText.slice(startText.length);    	  
     	// create necessary expand/collapse elements if they don't already exist
   	  if (!$('span.details', this).length) {
        // end script if text length isn't long enough.
       	if ( endText.replace(/\s+$/,'').split(' ').length < o.widow ) { return; }
       	// otherwise, continue...    
       	if (endText.indexOf('</') > -1) {
         	endTags = endText.match(/<(\/)?[^>]*>/g);
          for (var i=0; i < endTags.length; i++) {

            if (endTags[i].indexOf('</') > -1) {
              var startTag, startTagExists = false;
              for (var j=0; j < i; j++) {
                startTag = endTags[j].slice(0, endTags[j].indexOf(' ')).replace(/(\w)$/,'$1>');
                if (startTag == rSlash(endTags[i])) {
                  startTagExists = true;
                }
              }              
              if (!startTagExists) {
                startText = startText + endTags[i];
                var matched = false;
                for (var s=startTags.length - 1; s >= 0; s--) {
                  if (startTags[s].slice(0, startTags[s].indexOf(' ')).replace(/(\w)$/,'$1>') == rSlash(endTags[i]) 
                  && matched == false) {
                    cleanedTag = cleanedTag ? startTags[s] + cleanedTag : startTags[s];
                    matched = true;
                  }
                };
              }
            }
          }

          endText = cleanedTag && cleanedTag + endText || endText;
        }
     	  $this.html([
     		startText,
     		'<span class="read-more">',
     		o.expandPrefix,
       		'<a href="#">',
       		  o.expandText,
       		'</a>',
        '</span>',
     		'<span class="details">',
     		  endText,
     		'</span>'
     		].join('')
     	  );
      }
      var $thisDetails = $('span.details', this),
        $readMore = $('span.read-more', this);
   	  $thisDetails.hide();
 	    $readMore.find('a').click(function() {
 	      $readMore.hide();

 	      if (o.expandEffect === 'show' && !o.expandSpeed) {
          o.beforeExpand($this);
 	        $thisDetails.show();
          o.afterExpand($this);
          delayCollapse(o, $thisDetails);
 	      } else {
          o.beforeExpand($this);
 	        $thisDetails[o.expandEffect](o.expandSpeed, function() {
            $thisDetails.css({zoom: ''});
            o.afterExpand($this);
            delayCollapse(o, $thisDetails);
 	        });
 	      }
        return false;
 	    });
      if (o.userCollapse) {
        $this
        .find('span.details').append('<span class="re-collapse">' + o.userCollapsePrefix + '<a href="#">' + o.userCollapseText + '</a></span>');
        $this.find('span.re-collapse a').click(function() {

          clearTimeout(delayedCollapse);
          var $detailsCollapsed = $(this).parents('span.details');
          reCollapse($detailsCollapsed);
          o.onCollapse($this, true);
          return false;
        });
      }
    });
    function reCollapse(el) {
       el.hide()
        .prev('span.read-more').show();
    }
    function delayCollapse(option, $collapseEl) {
      if (option.collapseTimer) {
        delayedCollapse = setTimeout(function() {  
          reCollapse($collapseEl);
          option.onCollapse($collapseEl.parent(), false);
          },
          option.collapseTimer
        );
      }
    }
    function rSlash(rString) {
      return rString.replace(/\//,'');
    }    
  };
  // plugin defaults
  $.fn.expander.defaults = {
    slicePoint				: 100,
    widow					: 4,
    expandText				: 'read more',
    expandPrefix			: '&hellip; ',
    collapseTimer			: 0,
    expandEffect			: 'fadeIn',
    expandSpeed				: '',
    userCollapse			: true,
    userCollapseText		: '[collapse expanded text]',
    userCollapsePrefix		: ' ',
    beforeExpand			: function($thisEl) {},
    afterExpand				: function($thisEl) {},
    onCollapse				: function($thisEl, byUser) {}
  };
})(jQuery);