/* Copyright (c) 2007 Brandon Aaron (brandon.aaron@gmail.com || http://brandonaaron.net)
 * Dual licensed under the MIT (http://www.opensource.org/licenses/mit-license.php)
 * and GPL (http://www.opensource.org/licenses/gpl-license.php) licenses.
 *
 * Version: 1.0.2
 * Requires jQuery 1.1.3+
 * Docs: http://docs.jquery.com/Plugins/livequery
 */

(function($) {

$.extend($.fn, {
  livequery: function(type, fn, fn2) {
    var self = this, q;

    // Handle different call patterns
    if ($.isFunction(type))
    {
      fn2 = fn;
      fn = type;
      type = undefined;
    }

    // See if Live Query already exists
    $.each( $.livequery.queries, function(i, query) {
      if (self.selector === query.selector &&
          self.context === query.context &&
          type === query.type &&
          (!fn || fn.$lqguid === query.fn.$lqguid) &&
          (!fn2 || fn2.$lqguid === query.fn2.$lqguid) )
      {
          // Found the query, exit the each loop
          return (q = query) && false;
      }
    });

    // Create new Live Query if it wasn't found
    q = q || new $.livequery(this.selector, this.context, type, fn, fn2);

    // Make sure it is running
    q.stopped = false;

    // Run it
    $.livequery.run( q.id );

    // Contnue the chain
    return this;
  },

  expire: function(type, fn, fn2) {
    var self = this;

    // Handle different call patterns
    if ($.isFunction(type))
    {
      fn2 = fn;
      fn = type;
      type = undefined;
    }

    // Find the Live Query based on arguments and stop it
    $.each( $.livequery.queries, function(i, query) {
      if (self.selector === query.selector &&
          self.context === query.context &&
          (!type || type === query.type) &&
          (!fn || fn.$lqguid === query.fn.$lqguid) &&
          (!fn2 || fn2.$lqguid === query.fn2.$lqguid) &&
          !this.stopped )
      {
          $.livequery.stop(query.id);
      }
    });

    // Continue the chain
    return this;
  }
});

$.livequery = function(selector, context, type, fn, fn2) {
  this.selector = selector;
  this.context  = context || document;
  this.type     = type;
  this.fn       = fn;
  this.fn2      = fn2;
  this.elements = [];
  this.stopped  = false;

  // The id is the index of the Live Query in $.livequery.queries
  this.id = $.livequery.queries.push(this)-1;

  // Mark the functions for matching later on
  fn.$lqguid = fn.$lqguid || $.livequery.guid++;
  if (fn2) {
    fn2.$lqguid = fn2.$lqguid || $.livequery.guid++;
  }

  // Return the Live Query
  return this;
};

$.livequery.prototype = {
  stop: function() {
    var query = this;

    if ( this.type )
    {
      // Unbind all bound events
      this.elements.unbind(this.type, this.fn);
    }
    else if (this.fn2)
    {
      // Call the second function for all matched elements
      this.elements.each(function(i, el) {
        query.fn2.apply(el);
      });
    }

    // Clear out matched elements
    this.elements = [];

    // Stop the Live Query from running until restarted
    this.stopped = true;
  },

  run: function() {
    // Short-circuit if stopped
    if ( this.stopped ) { return; }
    var query = this;

    var oEls = this.elements,
      els  = $(this.selector, this.context),
      nEls = els.not(oEls);

    // Set elements to the latest set of matched elements
    this.elements = els;

    if (this.type) {
      // Bind events to newly matched elements
      nEls.bind(this.type, this.fn);

      // Unbind events to elements no longer matched
      if (oEls.length > 0) {
        $.each(oEls, function(i, el) {
          if ( $.inArray(el, els) < 0 )
          {
            $.event.remove(el, query.type, query.fn);
          }
        });
      }
    }
    else {
      // Call the first function for newly matched elements
      nEls.each(function() {
        query.fn.apply(this);
      });

      // Call the second function for elements no longer matched
      if ( this.fn2 && oEls.length > 0 )
      {
        $.each(oEls, function(i, el) {
          if ( $.inArray(el, els) < 0 )
          {
            query.fn2.apply(el);
          }
        });
      }
    }
  }
};

$.extend($.livequery, {
  guid: 0,
  queries: [],
  queue: [],
  running: false,
  timeout: null,

  checkQueue: function() {
    if ( $.livequery.running && $.livequery.queue.length ) {
      var length = $.livequery.queue.length;
      // Run each Live Query currently in the queue
      while ( length-- )
      {
        $.livequery.queries[ $.livequery.queue.shift() ].run();
      }
    }
  },

  pause: function() {
    // Don't run anymore Live Queries until restarted
    $.livequery.running = false;
  },

  play: function() {
    // Restart Live Queries
    $.livequery.running = true;
    // Request a run of the Live Queries
    $.livequery.run();
  },

  registerPlugin: function() {
    $.each( arguments, function(i,n) {
      // Short-circuit if the method doesn't exist
      if (!$.fn[n]) { return; }

      // Save a reference to the original method
      var old = $.fn[n];

      // Create a new method
      $.fn[n] = function() {
        // Call the original method
        var r = old.apply(this, arguments);

        // Request a run of the Live Queries
        $.livequery.run();

        // Return the original methods result
        return r;
      };
    });
  },

  run: function(id) {
    if (id !== undefined) {
      // Put the particular Live Query in the queue if it doesn't already exist
      if ( $.inArray(id, $.livequery.queue) < 0 )
      {
        $.livequery.queue.push( id );
      }
    }
    else
    {
      // Put each Live Query in the queue if it doesn't already exist
      $.each( $.livequery.queries, function(id) {
        if ( $.inArray(id, $.livequery.queue) < 0 )
        {
          $.livequery.queue.push( id );
        }
      });
    }

    // Clear timeout if it already exists
    if ($.livequery.timeout) { clearTimeout($.livequery.timeout); }
    // Create a timeout to check the queue and actually run the Live Queries
    $.livequery.timeout = setTimeout($.livequery.checkQueue, 50);
  },

  stop: function(id) {
    if (id !== undefined)
    {
      // Stop are particular Live Query
      $.livequery.queries[ id ].stop();
    }
    else
    {
      // Stop all Live Queries
      $.each( $.livequery.queries, function(id) {
        $.livequery.queries[ id ].stop();
      });
    }
  }
});

// Register core DOM manipulation methods
$.livequery.registerPlugin('append', 'prepend', 'after', 'before', 'wrap', 'attr', 'removeAttr', 'addClass', 'removeClass', 'toggleClass', 'empty', 'remove');

// Run Live Queries when the Document is ready
$(function() { $.livequery.play(); });


// Save a reference to the original init method
var init = $.prototype.init;

// Create a new init method that exposes two new properties: selector and context
$.prototype.init = function(a,c) {
  // Call the original init and save the result
  var r = init.apply(this, arguments);

  // Copy over properties if they exist already
  if (a && a.selector)
  {
    r.context = a.context;
    r.selector = a.selector;
  }

  // Set properties
  if ( typeof a === 'string' )
  {
    r.context = c || document;
    r.selector = a;
  }

  // Return the result
  return r;
};

// Give the init function the jQuery prototype for later instantiation (needed after Rev 4091)
$.prototype.init.prototype = $.prototype;

})(jQuery);