/*

 * jQuery history plugin

 * 

 * sample page: http://www.serpere.info/jquery-history-plugin/samples/

 *

 * Copyright (c) 2006-2009 Taku Sano (Mikage Sawatari)

 * Copyright (c) 2010 Takayuki Miwa

 * Licensed under the MIT License:

 *   http://www.opensource.org/licenses/mit-license.php

 *

 * Modified by Lincoln Cooper to add Safari support and only call the callback once during initialization

 * for msie when no initial hash supplied.

 */



(function($) {

    var locationWrapper = {

        put: function(hash, win) {

            (win || window).location.hash = encodeURIComponent(hash);

        },

        get: function(win) {

            var hash = ((win || window).location.hash).replace(/^#/, '');

            return $.browser.fx ? hash : decodeURIComponent(hash);

        }

    };



    var iframeWrapper = {

        id: "__jQuery_history",

        init: function() {

            var html = '<iframe id="'+ this.id +'" style="display:none" src="javascript:false;" />';

            $("body").prepend(html);

            return this;

        },

        _document: function() {

            return $("#"+ this.id)[0].contentWindow.document;

        },

        put: function(hash) {

            var doc = this._document();

            doc.open();

            doc.close();

            locationWrapper.put(hash, doc);

        },

        get: function() {

            return locationWrapper.get(this._document());

        }

    };



    // public base interface

    var _ = {

        appState: undefined,

        callback: undefined,

        init:  function(callback) {},

        check: function() {},

        load:  function(hash) {}

    };

    $.history = _;



    var SimpleImpl = {

        init: function(callback) {

            _.callback = callback;

            var current_hash = locationWrapper.get();

            _.appState = current_hash;

            _.callback(current_hash);

            setInterval(_.check, 100);

        },

        check: function() {

            var current_hash = locationWrapper.get();

            if(current_hash != _.appState) {

                _.appState = current_hash;

                _.callback(current_hash);

            }

        },

        load: function(hash) {

            if(hash != _.appState) {

                locationWrapper.put(hash);

                _.appState = hash;

                _.callback(hash);

            }

        }

    };



    var IframeImpl = {

        init: function(callback) {

            _.callback = callback;

            var current_hash = locationWrapper.get();

            _.appState = current_hash;

            iframeWrapper.init().put(current_hash);

            _.callback(current_hash);

            setInterval(_.check, 100);

        },

        check: function() {

            var current_hash = iframeWrapper.get();

            if(current_hash != _.appState) {

                locationWrapper.put(current_hash);

                _.appState = current_hash;

                _.callback(current_hash);

            }

        },

        load: function(hash) {

            if(hash != _.appState) {

                locationWrapper.put(hash);

                iframeWrapper.put(hash);

                _.appState = hash;

                _.callback(hash);

            }

        }

    };



    if($.browser.msie && ($.browser.version < 8 || document.documentMode < 8)) {

        $.extend(_, IframeImpl);

    } else {

        $.extend(_, SimpleImpl);

    }

})(jQuery);