/**
 * hoverIntent is similar to jQuery's built-in "hover" method except that
 * instead of firing the handlerIn function immediately, hoverIntent checks
 * to see if the user's mouse has slowed down (beneath the sensitivity
 * threshold) before firing the event. The handlerOut function is only
 * called after a matching handlerIn.
 *
 * hoverIntent r7 // 2013.03.11 // jQuery 1.9.1+
 * http://cherne.net/brian/resources/jquery.hoverIntent.html
 *
 * You may use hoverIntent under the terms of the MIT license. Basically that
 * means you are free to use hoverIntent as long as this header is left intact.
 * Copyright 2007, 2013 Brian Cherne
 *
 * // basic usage ... just like .hover()
 * .hoverIntent( handlerIn, handlerOut )
 * .hoverIntent( handlerInOut )
 *
 * // basic usage ... with event delegation!
 * .hoverIntent( handlerIn, handlerOut, selector )
 * .hoverIntent( handlerInOut, selector )
 *
 * // using a basic configuration object
 * .hoverIntent( config )
 *
 * @param  handlerIn   function OR configuration object
 * @param  handlerOut  function OR selector for delegation OR undefined
 * @param  selector    selector OR undefined
 * @author Brian Cherne <brian(at)cherne(dot)net>
 **/
(function($) {
  $.fn.hoverIntent = function(handlerIn, handlerOut, selector) {

    // default configuration values
    var cfg = {
      interval: 100,
      sensitivity: 7,
      timeout: 0
    };

    if (typeof handlerIn === 'object') {
      cfg = $.extend(cfg, handlerIn);
    } else if ($.isFunction(handlerOut)) {
      cfg = $.extend(cfg, {over: handlerIn, out: handlerOut, selector: selector});
    } else {
      cfg = $.extend(cfg, {over: handlerIn, out: handlerIn, selector: handlerOut});
    }

    // instantiate variables
    // cX, cY = current X and Y position of mouse, updated by mousemove event
    // pX, pY = previous X and Y position of mouse, set by mouseover and polling interval
    var cX, cY, pX, pY;

    // A private function for getting mouse position
    var track = function(ev) {
      cX = ev.pageX;
      cY = ev.pageY;
    };

    // A private function for comparing current and previous mouse position
    var compare = function(ev, ob) {
      ob.hoverIntent_t = clearTimeout(ob.hoverIntent_t);
      // compare mouse positions to see if they've crossed the threshold
      if ((Math.abs(pX - cX) + Math.abs(pY - cY)) < cfg.sensitivity) {
        $(ob).off('mousemove.hoverIntent',track);
        // set hoverIntent state to true (so mouseOut can be called)
        ob.hoverIntent_s = 1;
        return cfg.over.apply(ob,[ev]);
      } else {
        // set previous coordinates for next time
        pX = cX; pY = cY;
        // use self-calling timeout, guarantees intervals are spaced out properly (avoids JavaScript timer bugs)
        ob.hoverIntent_t = setTimeout(function() {compare(ev, ob);} , cfg.interval);
      }
    };

    // A private function for delaying the mouseOut function
    var delay = function(ev, ob) {
      ob.hoverIntent_t = clearTimeout(ob.hoverIntent_t);
      ob.hoverIntent_s = 0;
      return cfg.out.apply(ob,[ev]);
    };

    // A private function for handling mouse 'hovering'
    var handleHover = function(e) {
      // copy objects to be passed into t (required for event object to be passed in IE)
      var ev = jQuery.extend({},e);
      var ob = this;

      // cancel hoverIntent timer if it exists
      if (ob.hoverIntent_t) { ob.hoverIntent_t = clearTimeout(ob.hoverIntent_t); }

      // if e.type == "mouseenter"
      if (e.type == 'mouseenter') {
        // set "previous" X and Y position based on initial entry point
        pX = ev.pageX; pY = ev.pageY;
        // update "current" X and Y position based on mousemove
        $(ob).on('mousemove.hoverIntent',track);
        // start polling interval (self-calling timeout) to compare mouse coordinates over time
        if (ob.hoverIntent_s != 1) { ob.hoverIntent_t = setTimeout(function() {compare(ev,ob);} , cfg.interval);}

        // else e.type == "mouseleave"
      } else {
        // unbind expensive mousemove event
        $(ob).off('mousemove.hoverIntent',track);
        // if hoverIntent state is true, then call the mouseOut function after the specified delay
        if (ob.hoverIntent_s == 1) { ob.hoverIntent_t = setTimeout(function() {delay(ev,ob);} , cfg.timeout);}
      }
    };

    // listen for mouseenter and mouseleave
    return this.on({'mouseenter.hoverIntent': handleHover,'mouseleave.hoverIntent': handleHover}, cfg.selector);
  };
})(jQuery);
