/**
 * jquery.textSelect jQuery Custom Event v0.2
 * http://jamesmgreene.github.com/jquery.textSelect/
 *
 * Copyright © 2012: James Greene (Team Gunmetal, Inc.)
 * Released under the MIT license.
 * http://www.opensource.org/licenses/mit-license.php
 */

(function($, win) {
  var doc = win.document,
      $doc = $(doc),
      textSelectBindingCount = 0,
      mouseDownRegistrar = {},
      customEventNamespace = ".textSelect",
      defaultNamespaces = customEventNamespace + ".default";

  $.event.special.textSelect = {
    /* Invoked each time this event is bound */
    add: function(handleObj) {
      // If this is the first "textSelect" binding on the page, we also need to enable the default handler on the
      // document root in order to make this particular event possible.
      if (0 === textSelectBindingCount++) {
        $doc.on("mouseup" + defaultNamespaces, function($event) {
          console.log("document.mouseup [Final bubble! No additional handlers will be invoked]");
          mouseDownRegistrar = {};
        });
      }
      var namespaces = customEventNamespace + (handleObj.namespace ? "." + handleObj.namespace : ""),
          selector = handleObj.selector,
          $this = $(this);

      $this.on("mousedown" + namespaces, selector, function($event) {
        mouseDownRegistrar[this] = $event;
      });

      $this.on("mouseup" + namespaces, selector, function($event) {
        var behaviors = $.event.special.textSelect.behaviors;
        if (mouseDownRegistrar[this] && !!behaviors.getSelectedText()) {
          var $startSelectionEvent = mouseDownRegistrar[this],
              $eventType = $event.type,
              $eventRelatedTarget = $event.relatedTarget,
              $eventData = $event.data,
              customEventData;

          // The following is effectively a stopPropagation for the textSelect event bubble
          mouseDownRegistrar = {};

          // Update the event object
          $event.type = handleObj.origType;
          $event.relatedTarget = $startSelectionEvent.target;

          // Request custom event data, if any is desired, and merge it into the main event data.
          // Due to curiosities of the jQuery.event.dispatch function, the object we would want as $event.data
          // must be stored in handleObj.data instead [which jQuery then forcibly copies into $event.data].
          customEventData = behaviors.getCustomEventData($event);
          handleObj.data = $.extend(true, {}, $eventData, handleObj.data, customEventData);

          // Let jQuery handle the triggering of "textSelect" event handlers
          $.event.dispatch.apply(this, arguments);

          // Revert the event back to its previous state for bubbling
          $event.type = $eventType;
          $event.relatedTarget = $eventRelatedTarget;
          $event.data = $eventData;
        }
      });
    },

    /* Invoked each time this event is unbound */
    remove: function(handleObj) {
      // If this is the last "textSelect" unbinding on the page, we should also disable the
      // default handler on the document root as it is no longer necessary.
      if (0 === --textSelectBindingCount) {
        $doc.off(defaultNamespaces);
      }
      var namespaces = customEventNamespace + (handleObj.namespace ? "." + handleObj.namespace : ""),
          selector = handleObj.selector,
          $this = $(this);

      $this.off("mousedown" + namespaces, selector);
      $this.off("mouseup" + namespaces, selector);
    },

    /* Invoked each time a manual call to "trigger" or "triggerHandler" is made for this event type */
    trigger: function($event, data) {
      var $this = $(this);

      // Simulate mousedown
      $this.trigger("mousedown");

      // Simulate the text selection
      $.event.special.textSelect.behaviors.selectText(this);

      // Simulate mouseup
      $this.trigger("mouseup");

      // Prevent the normal handling (bubbling) of this event
      return false;
    },


    /* Add some jQueryUI-style default behavior implementations that can be overridden */
    options: {
      /* This behavior will not be overridden unless it is to address bugs or use a third party library (Rangy) */
      getSelectedText: function() {
        var text = "";
        if (win.getSelection) {
          var sel = win.getSelection(),
              ranges = [],
              r;
          for (r = 0; r < sel.rangeCount; r++) {
            ranges.push(sel.getRangeAt(r).toString());
          }
          text = ranges.join("");
        }
        else if (doc.selection) {
          text = doc.selection.createRange().text;
        }
        return text;
      },

      /* This behavior will not be overridden unless it is to address bugs or use a third party library (Rangy) */
      getSelectedHtml: function() {
        var html = "";
        if (win.getSelection) {
          var sel = win.getSelection(),
              $shell = $("<div></div>"),
              ranges = [],
              $rangeContents,
              r;
          for (r = 0; r < sel.rangeCount; r++) {
            $rangeContents = $shell.empty().append(sel.getRangeAt(r).cloneContents());
            // Remove empty nodes, which tend to plague the end of selection range HTML in most browsers
            $rangeContents.filter(function() {
              return $.trim($(this).html()) == '';
            }).remove();
            ranges.push($rangeContents.html());
          }
          html = ranges.join("");
        }
        else if (doc.selection) {
          html = doc.selection.createRange().htmlText;
        }
        return html;
      },

      /* This behavior will not be overridden unless it is to address bugs or use a third party library (Rangy) */
      selectText: function(el) {
        var range;
        if (win.getSelection) {
          var TEXT_NODE = typeof(Node) !== "undefined" ? Node.TEXT_NODE : 3,
              $textNodeDescendants = $(el).contents().filter(function() {
                return this.nodeType == TEXT_NODE;
              }),
              firstTextNode = $textNodeDescendants.first().get(0),
              lastTextNode = $textNodeDescendants.last().get(0),
              sel = win.getSelection();

          if (sel.rangeCount > 0) {
            sel.removeAllRanges();
          }
          range = doc.createRange();
          range.setStart(firstTextNode, 0);
          range.setEnd(lastTextNode, lastTextNode.nodeValue.length);
          sel.addRange(range);
        }
        else if (doc.selection) {
          doc.selection.empty();
          range = el.createTextRange();
          range.select();
        }
      },
      
      /* This behavior is for determining if there is currently an active [and valid] text selection. Used
       by mobile to monitor selection changes after the initial selection [because no additional events 
       will fire while the user is expanding their selection (ugh!)]. */
      hasSelection: function() {
        return !!($.event.special.textSelect.options.getSelectedText());
      },

      /* This behavior will be the most desirable to override as you may want more data specific to this event
       than the default implementation is offering, such as NOT fetching the selectedHtml. */
      getCustomEventData: function($event) {
        var currentlySelectedText = $.event.special.textSelect.options.getSelectedText(),
            currentlySelectedHtml = $.event.special.textSelect.options.getSelectedHtml();
        return {
          text: currentlySelectedText,
          html: currentlySelectedHtml
        };
      },
      
      /* This behavior handles the "touchstart" and "touchend" events, respectively converting them into "mousedown" and
       "mouseup" events. If you are using a library that already does this (e.g. "jquery-touchable",
       "jquery.ui.touch-punch", etc.), then you should override this behavior to do nothing (i.e. an empty function). */
      mapTouchEventsToMouseEvents: function() {
        
      }
    }
  };
})(jQuery, this);