(function (window, $, undefined) { 
	$.infinitescroll = function infscr(options, callback, element) { 
		this.element = $(element);
		this._create(options, callback); 
	}; 
	$.infinitescroll.defaults = {
		loading: {
			finished: undefined,
			finishedMsg: "<em>Congratulations, you've reached the end of the internet.</em>",
			img: "http://www.infinite-scroll.com/loading.gif",
			msg: null,
			msgText: "<em>Loading the next set of posts...</em>",
			selector: null,
			speed: 'fast',
			start: undefined
		},
		state: {
			isDuringAjax: false,
			isInvalidPage: false,
			isDestroyed: false,
			isDone: false, 	// For when it goes all the way through the archive.
			isPaused: false,
			currPage: 1
		},
		callback: undefined,
		debug: false,
		behavior: undefined,
		binder: $(window), // used to cache the selector
		nextSelector: "div.navigation a:first",
		navSelector: "div.navigation",
		contentSelector: null, // rename to pageFragment
		extraScrollPx: 150,
		itemSelector: "div.post",
		animate: false,
		pathParse: undefined,
		dataType: 'html',
		appendCallback: true,
		bufferPx: 40,
		errorCallback: function () { },
		infid: 0, //Instance ID
		pixelsFromNavToBottom: undefined,
		path: undefined
	};


    $.infinitescroll.prototype = {  
        _binding: function infscr_binding(binding) { 
            var instance = this,
				opts = instance.options; 
			if (!!opts.behavior && this['_binding_'+opts.behavior] !== undefined) {
				this['_binding_'+opts.behavior].call(this);
				return;
			} 
			if (binding !== 'bind' && binding !== 'unbind') {
                this._debug('Binding value  ' + binding + ' not valid')
                return false;
            } 
            if (binding == 'unbind') { 
                (this.options.binder).unbind('smartscroll.infscr.' + instance.options.infid); 
            } else { 
                (this.options.binder)[binding]('smartscroll.infscr.' + instance.options.infid, function () {
                    instance.scroll();
                }); 
            }; 
            this._debug('Binding', binding);

        }, 
		_create: function infscr_create(options, callback) { 
            if (!this._validate(options)) { 
				return false; 
			} 
            var opts = this.options = $.extend(true,  {},  $.infinitescroll.defaults,  options), 
				relurl = /(.*?\/\/).*?(\/.*)/, 
				path = $(opts.nextSelector).attr('href');  
				
            opts.contentSelector = opts.contentSelector || this.element; 
            opts.loading.selector = opts.loading.selector || opts.contentSelector;
            if(!path){ 
				this._debug('Navigation selector not found'); 
				return; 
			} 
            opts.path = this._determinepath(path); 
            opts.loading.msg = $('<div id="infscr-loading"><img alt="Loading..." src="' + opts.loading.img + '" /><div>' + opts.loading.msgText + '</div></div>'); 
            (new Image()).src = opts.loading.img; 
            opts.pixelsFromNavToBottom = $(document).height() - $(opts.navSelector).offset().top; 
            opts.loading.start = opts.loading.start || function() { 
				$(opts.navSelector).hide();
				opts.loading.msg
					.appendTo(opts.loading.selector)
					.show(opts.loading.speed, function () {
	                	beginAjax(opts);
	            });
			}; 
			opts.loading.finished = opts.loading.finished || function() {
				opts.loading.msg.fadeOut('normal');
			}; 
            opts.callback = function(instance,data) {
				if (!!opts.behavior && instance['_callback_'+opts.behavior] !== undefined) {
					instance['_callback_'+opts.behavior].call($(opts.contentSelector)[0], data);
				}
				if (callback) {
					callback.call($(opts.contentSelector)[0], data);
				}
			}; 
            this._setup(); 
        }, 
        _debug: function infscr_debug() { 
			if (this.options.debug) {
                return window.console && console.log.call(console, arguments);
            } 
        }, 
        _determinepath: function infscr_determinepath(path) { 
            var opts = this.options; 
			if (!!opts.behavior && this['_determinepath_'+opts.behavior] !== undefined) {
				this['_determinepath_'+opts.behavior].call(this,path);
				return;
			}  
            if (!!opts.pathParse) { 
                this._debug('pathParse manual');
                return opts.pathParse;
            } else if (path.match(/^(.*?)\b2\b(.*?$)/)) {
                path = path.match(/^(.*?)\b2\b(.*?$)/).slice(1); 
            } else if (path.match(/^(.*?)2(.*?$)/)) { 
                // http://www.infinite-scroll.com/changelog/comment-page-1/#comment-127
                if (path.match(/^(.*?page=)2(\/.*|$)/)) {
                    path = path.match(/^(.*?page=)2(\/.*|$)/).slice(1);
                    return path;
                } 
                path = path.match(/^(.*?)2(.*?$)/).slice(1); 
            } else { 
                // page= is used in drupal too but second page is page=1 not page=2: 
                if (path.match(/^(.*?page=)1(\/.*|$)/)) {
                    path = path.match(/^(.*?page=)1(\/.*|$)/).slice(1);
                    return path;
                } else {
                    this._debug('Sorry, we couldn\'t parse your Next (Previous Posts) URL. Verify your the css selector points to the correct A tag. If you still get this error: yell, scream, and kindly ask for help at infinite-scroll.com.'); 
                    opts.state.isInvalidPage = true;  // 阻止他运行
                }
            }
            this._debug('determinePath', path);
            return path; 
        },

        // Custom error
        _error: function infscr_error(xhr) {

            var opts = this.options;

			// if behavior is defined and this function is extended, call that instead of default
			if (!!opts.behavior && this['_error_'+opts.behavior] !== undefined) {
				this['_error_'+opts.behavior].call(this,xhr);
				return;
			}

            if (xhr !== 'destroy' && xhr !== 'end') {
                xhr = 'unknown';
            }

            this._debug('Error', xhr);

            if (xhr == 'end') {
                this._showdonemsg();
            }

            opts.state.isDone = true;
            opts.state.currPage = 1; // if you need to go back to this instance
            opts.state.isPaused = false;
            this._binding('unbind');

        },

        // Load Callback
        _loadcallback: function infscr_loadcallback(box, data) { 
            var opts = this.options,
	    		callback = this.options.callback, // GLOBAL OBJECT FOR CALLBACK
	    		result = (opts.state.isDone) ? 'done' : (!opts.appendCallback) ? 'no-append' : 'append',
	    		frag;
	
			// if behavior is defined and this function is extended, call that instead of default
			if (!!opts.behavior && this['_loadcallback_'+opts.behavior] !== undefined) {
				this['_loadcallback_'+opts.behavior].call(this,box,data);
				return;
			} 
            switch (result) { 
                case 'done': 
                    this._showdonemsg();
                    return false; 
                    break; 
                case 'no-append': 
                    if (opts.dataType == 'html') {
                        data = '<div>' + data + '</div>';
                        data = $(data).find(opts.itemSelector);
                    }; 
                    break; 
                case 'append': 
                    var children = box.children(); 
                    // if it didn't return anything
                    if (children.length == 0) {
                        return this._error('end');
                    } 
                    // use a documentFragment because it works when content is going into a table or UL
                    frag = document.createDocumentFragment();
                    while (box[0].firstChild) {
                        frag.appendChild(box[0].firstChild);
                    } 
                    this._debug('contentSelector', $(opts.contentSelector)[0])
                    $(opts.contentSelector)[0].appendChild(frag);
                    // previously, we would pass in the new DOM element as context for the callback
                    // however we're now using a documentfragment, which doesnt havent parents or children,
                    // so the context is the contentContainer guy, and we pass in an array
                    //   of the elements collected as the first argument.

                    data = children.get(); 
                    break; 
            } 
            // loadingEnd function
			opts.loading.finished.call($(opts.contentSelector)[0],opts) 
            // smooth scroll to ease in the new content
            if (opts.animate) {
                var scrollTo = $(window).scrollTop() + $('#infscr-loading').height() + opts.extraScrollPx + 'px';
                $('html,body').animate({ scrollTop: scrollTo }, 800, function () { opts.state.isDuringAjax = false; });
            } 
            if (!opts.animate) opts.state.isDuringAjax = false; // once the call is done, we can allow it again. 
            callback(this,data); 
        },

        _nearbottom: function infscr_nearbottom(){ 
            var opts = this.options,
	        	pixelsFromWindowBottomToBottom = 0 + $(document).height() - (opts.binder.scrollTop()) - $(window).height();

            // if behavior is defined and this function is extended, call that instead of default
			if (!!opts.behavior && this['_nearbottom_'+opts.behavior] !== undefined) {
				this['_nearbottom_'+opts.behavior].call(this);
				return;
			} 
			this._debug('math:', pixelsFromWindowBottomToBottom, opts.pixelsFromNavToBottom); 
            // if distance remaining in the scroll (including buffer) is less than the orignal nav to bottom....
            return (pixelsFromWindowBottomToBottom - opts.bufferPx < opts.pixelsFromNavToBottom); 
        },

		// Pause / temporarily disable plugin from firing
        _pausing: function infscr_pausing(pause) { 
            var opts = this.options; 
            // if behavior is defined and this function is extended, call that instead of default
			if (!!opts.behavior && this['_pausing_'+opts.behavior] !== undefined) {
				this['_pausing_'+opts.behavior].call(this,pause);
				return;
			} 
			// If pause is not 'pause' or 'resume', toggle it's value
            if (pause !== 'pause' && pause !== 'resume' && pause !== null) {
                this._debug('Invalid argument. Toggling pause value instead');
            }; 
            pause = (pause && (pause == 'pause' || pause == 'resume')) ? pause : 'toggle';

            switch (pause) {
                case 'pause':
                    opts.state.isPaused = true;
                    break;

                case 'resume':
                    opts.state.isPaused = false;
                    break;

                case 'toggle':
                    opts.state.isPaused = !opts.state.isPaused;
                    break;
            } 
            this._debug('Paused', opts.state.isPaused);
            return false;

        },

		// Behavior is determined
		// If the behavior option is undefined, it will set to default and bind to scroll
		_setup: function infscr_setup() { 
			var opts = this.options; 
			// if behavior is defined and this function is extended, call that instead of default
			if (!!opts.behavior && this['_setup_'+opts.behavior] !== undefined) {
				this['_setup_'+opts.behavior].call(this);
				return;
			} 
			this._binding('bind'); 
			return false; 
		},

        // Show done message
        _showdonemsg: function infscr_showdonemsg() { 
            var opts = this.options; 
			// if behavior is defined and this function is extended, call that instead of default
			if (!!opts.behavior && this['_showdonemsg_'+opts.behavior] !== undefined) {
				this['_showdonemsg_'+opts.behavior].call(this);
				return;
			} 
            opts.loading.msg.find('img').hide().parent().find('div').html(opts.loading.finishedMsg).animate({ opacity: 1 }, 2000, function () {
	    		    $(this).parent().fadeOut('normal');
	    	}); 
            // user provided callback when done    
            opts.errorCallback.call($(opts.contentSelector)[0],'done'); 
        },

		// grab each selector option and see if any fail
        _validate: function infscr_validate(opts) { 
            for (var key in opts) {
                if (key.indexOf && key.indexOf('Selector') > -1 && $(opts[key]).length === 0) {
                    this._debug('Your ' + key + ' found no elements.');
                    return false;
                }
                return true;
            } 
        },

        /*	
        ----------------------------
        Public methods
        ----------------------------
        */

		// Bind to scroll
		bind: function infscr_bind() {
			this._binding('bind');
		}, 
        // Destroy current instance of plugin
        destroy: function infscr_destroy() {
            this.options.state.isDestroyed = true;
            return this._error('destroy');

        }, 
		// Set pause value to false
		pause: function infscr_pause() {
			this._pausing('pause');
		}, 
		// Set pause value to false
		resume: function infscr_resume() {
			this._pausing('resume');
		}, 
        // Retrieve next set of content items
        retrieve: function infscr_retrieve(pageNum) { 
            var instance = this,
				opts = instance.options,
				path = opts.path,
				box, frag, desturl, method, condition,
	    		pageNum = pageNum || null,
				getPage = (!!pageNum) ? pageNum : opts.state.currPage;
				beginAjax = function infscr_ajax(opts) { 
					// increment the URL bit. e.g. /page/3/
	                opts.state.currPage++; 
	                instance._debug('heading into ajax', path); 
	                // if we're dealing with a table we can't use DIVs
	                box = $(opts.contentSelector).is('table') ? $('<tbody/>') : $('<div/>'); 
	                desturl = path.join(opts.state.currPage); 
	                method = (opts.dataType == 'html' || opts.dataType == 'json') ? opts.dataType : 'html+callback';
	                if (opts.appendCallback && opts.dataType == 'html') method += '+callback' 
	                switch (method) { 
	                    case 'html+callback': 
	                        instance._debug('Using HTML via .load() method');
	                        box.load(desturl + ' ' + opts.itemSelector, null, function infscr_ajax_callback(responseText) {
	                            instance._loadcallback(box, responseText);
	                        }); 
	                        break; 
	                    case 'html':
	                    case 'json': 
	                        instance._debug('Using ' + (method.toUpperCase()) + ' via $.ajax() method');
	                        $.ajax({
	                            // params
	                            url: desturl,
	                            dataType: opts.dataType,
	                            complete: function infscr_ajax_callback(jqXHR, textStatus) {
	                                condition = (typeof (jqXHR.isResolved) !== 'undefined') ? (jqXHR.isResolved()) : (textStatus === "success" || textStatus === "notmodified");
	                                (condition) ? instance._loadcallback(box, jqXHR.responseText) : instance._error('end');
	                            }
	                        }); 
	                        break;
	                }
				}; 
			// if behavior is defined and this function is extended, call that instead of default
			if (!!opts.behavior && this['retrieve_'+opts.behavior] !== undefined) {
				this['retrieve_'+opts.behavior].call(this,pageNum);
				return;
			} 
			// for manual triggers, if destroyed, get out of here
			if (opts.state.isDestroyed) {
                this._debug('Instance is destroyed');
                return false;
            };

            // we dont want to fire the ajax multiple times
            opts.state.isDuringAjax = true; 
            opts.loading.start.call($(opts.contentSelector)[0],opts); 
        },

        // Check to see next page is needed
        scroll: function infscr_scroll() { 
            var opts = this.options, state = opts.state; 
            // if behavior is defined and this function is extended, call that instead of default
			if (!!opts.behavior && this['scroll_'+opts.behavior] !== undefined) {
				this['scroll_'+opts.behavior].call(this);
				return;
			} 
			if (state.isDuringAjax || state.isInvalidPage || state.isDone || state.isDestroyed || state.isPaused) return; 
            if (!this._nearbottom()) return; 
            this.retrieve(); 
        }, 
		// Toggle pause value
		toggle: function infscr_toggle() {
			this._pausing();
		}, 
		// Unbind from scroll
		unbind: function infscr_unbind() {
			this._binding('unbind');
		},
		// update options
		update: function infscr_options(key) {
			if ($.isPlainObject(key)) {
				this.options = $.extend(true,this.options,key);
			}
		}

    }
 
    /*	
    ----------------------------
    Infinite Scroll function
    ----------------------------
	
    Borrowed logic from the following...
	
    jQuery UI
    - https://github.com/jquery/jquery-ui/blob/master/ui/jquery.ui.widget.js
	
    jCarousel
    - https://github.com/jsor/jcarousel/blob/master/lib/jquery.jcarousel.js
	
    Masonry
    - https://github.com/desandro/masonry/blob/master/jquery.masonry.js		
	
    */ 
    $.fn.infinitescroll = function infscr_init(options, callback) { 
        var thisCall = typeof options; 
        switch (thisCall) { 
            // method 
            case 'string': 
                var args = Array.prototype.slice.call(arguments, 1); 
                this.each(function () { 
                    var instance = $.data(this, 'infinitescroll'); 
                    if (!instance) { 
                        // return $.error('Method ' + options + ' cannot be called until Infinite Scroll is setup');
						return false;
                    }
                    if (!$.isFunction(instance[options]) || options.charAt(0) === "_") {
                        // return $.error('No such method ' + options + ' for Infinite Scroll');
						return false;
                    }

                    // no errors!
                    instance[options].apply(instance, args);

                });

                break;

            // creation 
            case 'object': 
                this.each(function () { 
                    var instance = $.data(this, 'infinitescroll'); 
                    if (instance) {  
                        instance.update(options); 
                    } else { 
                        $.data(this, 'infinitescroll', new $.infinitescroll(options, callback, this)); 
                    } 
                }); 
                break; 
        } 
        return this; 
    }; 
    var event = $.event,scrollTimeout; 
    event.special.smartscroll = {
        setup: function () {
            $(this).bind("scroll", event.special.smartscroll.handler);
        },
        teardown: function () {
            $(this).unbind("scroll", event.special.smartscroll.handler);
        },
        handler: function (event, execAsap) {
            // Save the context
            var context = this, args = arguments;
 
            event.type = "smartscroll";

            if (scrollTimeout) { 
				clearTimeout(scrollTimeout); 
			}
            scrollTimeout = setTimeout(function () {
                $.event.handle.apply(context, args);
            }, execAsap === "execAsap" ? 0 : 100);
        }
    };

    $.fn.smartscroll = function (fn) {
        return fn ? this.bind("smartscroll", fn) : this.trigger("smartscroll", ["execAsap"]);
    }; 

})(window, jQuery);