/*
	--------------------------------
	infinite scroll
	--------------------------------
	+ https://github.com/paulirish/infinite-scroll
	+ version 2.0b2.111027
	+ copyright 2011 paul irish & luke shumard
	+ licensed under the mit license
	
	+ documentation: http://infinite-scroll.com/
	
*/

(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 = {

        /*	
        ----------------------------
        private methods
        ----------------------------
        */

        // bind or unbind from scroll
        _binding: function infscr_binding(binding) {

            var instance = this,
            opts = instance.options;
				
            opts.v = '2.0b2.111027';

            // if behavior is defined and this function is extended, call that instead of default
            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);

        },

        // fundamental aspects of the plugin are initialized
        _create: function infscr_create(options, callback) {

            // if selectors from options aren't valid, return false
            if (!this._validate(options)) {
                return false;
            }
            // define options and shorthand
            var opts = this.options = $.extend(true, {}, $.infinitescroll.defaults, options),
            // get the relative url - everything past the domain name.
            relurl = /(.*?\/\/).*?(\/.*)/,
            path = $(opts.nextselector).attr('href');

            // contentselector is 'page fragment' option for .load() / .ajax() calls
            opts.contentselector = opts.contentselector || this.element;

            // loading.selector - if we want to place the load message in a specific selector, defaulted to the contentselector
            opts.loading.selector = opts.loading.selector || opts.contentselector;

            // if there's not path, return
            if (!path) {
                this._debug('navigation selector not found');
                return;
            }

            // set the path to be a relative url from root.
            opts.path = this._determinepath(path);

            // define loading.msg
            opts.loading.msg = $('<div id="infscr-loading"><img alt="loading..." src="' + opts.loading.img + '" /><div>' + opts.loading.msgtext + '</div></div>');

            // preload loading.img
            (new image()).src = opts.loading.img;

            // distance from nav links to bottom
            // computed as: height of the document + top offset of container - top offset of nav link
            opts.pixelsfromnavtobottom = $(document).height() - $(opts.navselector).offset().top;

            // determine loading.start actions
            opts.loading.start = opts.loading.start || function() {
				
                $(opts.navselector).hide();
                opts.loading.msg
                .appendto(opts.loading.selector)
                .show(opts.loading.speed, function () {
                    beginajax(opts);
                });
            };
			
            // determine loading.finished actions
            opts.loading.finished = opts.loading.finished || function() {
                opts.loading.msg.fadeout('normal');
            };

            // callback loading
            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, opts);
                }
            };

            this._setup();

        },

        // console log wrapper
        _debug: function infscr_debug() {

            if (this.options && this.options.debug) {
                return window.console && console.log.call(console, arguments);
            }

        },

        // find the number to increment in the path.
        _determinepath: function infscr_determinepath(path) {

            var opts = this.options;

            // if behavior is defined and this function is extended, call that instead of default
            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(path, this.options.state.currpage+1);

            } else if (path.match(/^(.*?)\b2\b(.*?$)/)) {
                path = path.match(/^(.*?)\b2\b(.*?$)/).slice(1);

            // if there is any 2 in the url at all.    
            } else if (path.match(/^(.*?)2(.*?$)/)) {

                // page= is used in django:
                // 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:
                // thx jerod fritz, vladikoff
                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.');
                    // get rid of isinvalidpage to allow permalink to state
                    opts.state.isinvalidpage = true;  //prevent it from running on this page.
                }
            }
            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) {
                return this['_nearbottom_'+opts.behavior].call(this);
            }

            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) {
                        // not setup yet
                        // 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) {

                        // update options of current instance
                        instance.update(options);

                    } else {

                        // initialize new instance
                        $.data(this, 'infinitescroll', new $.infinitescroll(options, callback, this));

                    }

                });

                break;

        }

        return this;

    };



    /* 
    * smartscroll: debounced scroll event for jquery *
    * https://github.com/lukeshumard/smartscroll
    * based on smartresize by @louis_remi: https://github.com/lrbabe/jquery.smartresize.js *
    * copyright 2011 louis-remi & luke shumard * licensed under the mit license. *
    */

    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;

            // set correct event type
            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"]);
    };

/* 閰风珯浠ｇ爜鏁寸悊 http://www.5icool.org */
})(window, jquery);