function StorageManager() 
{
	if (StorageManager.caller != StorageManager.getInstance) {
		if((navigator.userAgent.indexOf('Safari')==-1) && (navigator.userAgent.indexOf('Opera')==-1)) {
			throw new Error("There is no public constructor for StorageManager.");
		}
	}

	this.ondownloadFunctionArray = new Array();//SYNC
	this.onloadFunctionArray = new Array();
	this.failedStorageOptions = new Array();
	this.loadComplete = function()
	{
		// test the storage option availabe
		var haveGoodStorage = true;
		try
		{
			this.getStorage().put('validationTest','test');
			var value = this.getStorage().get('validationTest');
			if(value!='test') { haveGoodStorage = false;}
			this.getStorage().remove('validationTest');
		}catch(err)
		{
			 haveGoodStorage = false;
		}
	
		if(haveGoodStorage)
		{
			var loadFuncArr = this.onloadFunctionArray;
			for(var i=0;i<loadFuncArr.length;i++)
			{
				var funcObj = loadFuncArr[i];
				funcObj(StorageManager.getInstance().getStorage());
			}
		}
		else
		{
			this.reselectStorage();
		}
	
	}
	
	this.downloadComplete = function()//SYNC
	{
		this.loadComplete();
		var loadFuncArr = this.ondownloadFunctionArray;
		for(var i=0;i<loadFuncArr.length;i++)
		{
			var funcObj = loadFuncArr[i];
			funcObj(StorageManager.getInstance().getStorage());
		}
	
	}
	
	this.addOnLoad = function(loadFunc) { this.onloadFunctionArray.push(loadFunc);}
	this.addOnDownLoad = function(loadFunc) { 	//SYNC
		this.ondownloadFunctionArray.push(loadFunc);
	}
	this.availableStores = new Array();
	this.addStorageType = function (store) { this.availableStores.push(store);}
	this.currentStorageMechanism = false;
	this.getStorage = function()
	{
		if (this.currentStorageMechanism) 
		{
			return this.currentStorageMechanism;
		}
		for(var storCount=0;storCount<this.availableStores.length;storCount++)
		{
			var evalStorMec = this.availableStores[ storCount];
			if((evalStorMec.isSupported() ) && (!this.failedStorageOptions[ evalStorMec.name ] ))
			{
				this.currentStorageMechanism = evalStorMec;
				this.currentStorageMechanism.initialize();
				return this.currentStorageMechanism;
			}
		}
		return false;
	}
	this.reselectStorage = function() // Should only be called when we want to redo the selection of the storageMechanism
	{
		this.failedStorageOptions[ this.getStorage().name ]=1;
		this.currentStorageMechanism = false;
		this.getStorage();
	}
	
	//SYNC hereafter
	
	this.currentSync = false;
	this.setSyncMechanism = function ( syncObj )
	{
		this.currentSync = syncObj;
	}
	
	this.download = function()
	{
		this.getStorage().load();
		if(this.currentSync)
		{
			if(this.currentSync.hasUpdatedContent( this.currentStorageMechanism))
			{
				this.currentSync.getUpdatedContent(this.currentStorageMechanism);
			}
			else
			{
				this.downloadComplete();
			}
		}
	}
	
	this.mergeNewData = function(managedObjects)
	{
		var currentStorage = this.getStorage();
		var baseManagedKeys = this.currentSync.getBaseManagedKey();
		for(var i=0;i<managedObjects.length;i++)
		{
			var currentObject = managedObjects[ i ];
			currentStorage.put( currentObject.key, currentObject.value );
		}
		currentStorage.save(); 
		this.downloadComplete();
	}

	this.upload = function()
	{
		if(this.currentSync)
		{
			var currentStorage = this.getStorage();
			if(currentStorage)
			{
				var keyList = currentStorage.getAllKeys();
				var managedObjects = new Array();
				var baseManagedKeys = this.currentSync.getBaseManagedKey();
				for(var i=0;i<keyList.length;i++)
				{
					var keyOffset = keyList[i].indexOf(baseManagedKeys);
					if(keyOffset==0)
					{
						var mObj = new Object();
						mObj.key = keyList[i].substring( keyOffset );
						mObj.value = currentStorage.get( keyList[ i ]);
						
						managedObjects.push( mObj );
					}
				}
				this.currentSync.send( managedObjects );
			}			
		}
	}
	//SYNC end
	
}

StorageManager.__instance__ = null; // static property

StorageManager.getInstance = function ()
{
	if (this.__instance__ == null) {
		this.__instance__ = new StorageManager();
	}
	return this.__instance__;
}

function AbstractStorageMechanism() {
	this.name = 'AbstractStorage';
	this.dataObjects;
	this.keysExpireDates;
	this.maxCapacity = Number.MAX_VALUE;
	this.singleEntrymaxCapacity = Number.MAX_VALUE;
	this.allKeys;
	this.isSupported = function() { return false;}
	this.initialize = function() 
	{
		this.dataObjects = new Array();
		this.allKeys = new Array();
		this.keysExpireDates = new Array();
	}
	this.setOnload = function(func) 
	{ 
		StorageManager.getInstance().addOnLoad( func );
	}
	this.put = function(key, obj, expirationDate) 
	{
		try
		{
			if(this.dataObjects[key] === undefined || this.dataObjects[key] === false) {
		
				if(!expirationDate) { expirationDate=new Date(new Date().getTime() + 7*24*3600000 ); } // setting default to expire in 7 days
				this.keysExpireDates[ key ] = expirationDate;
				this.allKeys.push(key);
			}
			this.dataObjects[key] = obj;
			return true;
		}catch(e) { return false;}
	}
	this.get = function(key) {
		return this.dataObjects[key];
	}
	this.remove = function(key) {
		if(this.contains( key )) {
			var newArray = new Array();
			for(var i=0;i<this.allKeys.length;i++) {
				if(this.allKeys[i]!=key) {
					newArray.push(this.allKeys[i]);
				}
			}
			this.allKeys = newArray;
			this.dataObjects[key] = false;
		}
	}
	this.contains =function(key) {
		if(this.dataObjects[key]) { return true;} else { return false;}
	}
	this.getAllKeys = function(key) {
		return this.allKeys;
	}
	this.save = function() {}
	this.load = function()
	{
		StorageManager.getInstance().loadComplete();
	}	
	this.clear = function() {}
}

function CookieStorageMechanism() {
	this.name = 'CookieStorage';
	this.maxCapacity = 20480; // 20k
	this.path = '/';
	this.domain = '';
	this.secure = false;	
	this.createCookie = function(key,value,expiration) {
			document.cookie = key + '=' + value + ((expiration)?(';expires=' + expiration):'') + ((this.path)?';path=' + this.path:'') + ((this.domain)?';domain=' + this.domain:'') + ((this.secure && (this.secure == true))?'; secure':'');
	}
	this.isSupported = function()
	{
		return (document.cookie || document.cookie=='');
	}
	this.save = function() {
		this.clear();
		var allKeys = this.getAllKeys();
		var lengthCount = 0;
		for(var i=0;i<allKeys.length;i++) {
			var currentKey = allKeys[i];
			var value = this.get(currentKey);
			var newObject = new Object();
			newObject.value = value;
			newObject.expireDate = (this.keysExpireDates[currentKey]).getTime();
			dataString = escape(JSON.stringify(newObject));
			if ((lengthCount + dataString.length) > this.maxCapacity)
				return false;
			else {
				lengthCount += dataString.length;
				this.createCookie('js_'+currentKey,dataString,(this.keysExpireDates[currentKey]).toGMTString());
			}
		}	
		return true;
	}
	this.load = function() {
		if ( document.cookie != '' ) {
			var cookieArr = document.cookie.split('; ');
			for(var i=0;i<cookieArr.length;i++) {
				var key = cookieArr[i].substring(0,cookieArr[i].indexOf('='));
				if(key.indexOf('js_')==0) {
					storedObject = eval('('+(unescape(cookieArr[i].substring(cookieArr[i].indexOf('=')+1)))+')');
					key = key.substring(3);
					this.put(key, storedObject.value, new Date(storedObject.expireDate) );
				}
			}
		}
		StorageManager.getInstance().loadComplete();
	}
	this.clear = function() {
		if (document.cookie != '') {
			var cookieArr = document.cookie.split('; ');
			for (var i = 0; i < cookieArr.length; i++) {
				var key = cookieArr[i].substring(0,cookieArr[i].indexOf('='));
				if (key.indexOf('js_') == 0) {
					toExpireDateString = (new Date((new Date()).getTime() - (24*60*60*60*1000))).toGMTString();
					this.createCookie(key,'clear this',toExpireDateString);
				}
			}
		}
	}
}

function DOMStorageMechanism() {
	this.name = 'DOMStorage';
	this.maxCapacity = 3145728; // 3M
	
	this.isSupported = function()
	{
	 	return (window.globalStorage && (window.globalStorage!=null));
	}

	this.save = function() {
		var allKeys = this.getAllKeys();
		var storedObject = new Array();
		for(var i=0;i<allKeys.length;i++) {
			var currentKey = allKeys[i];
			var value = this.get(currentKey);
			var newObject = new Object();
			newObject.key = currentKey;
			newObject.value = value;
			newObject.expireDate = (this.keysExpireDates[currentKey]).toGMTString();
			storedObject.push(newObject);
		}	
		dataString = JSON.stringify(storedObject);
		if (dataString.length > this.maxCapacity)
			return false;
		else
			window.globalStorage[document.domain].storage = dataString;
		return true;
	}
	this.load = function() {
		var storedDataObjectsStr = window.globalStorage[document.domain].storage+'';
		if(storedDataObjectsStr)
		{
			storedDataObjects = eval('('+storedDataObjectsStr+')');
			if(storedDataObjects && storedDataObjects!='')
			{
				for(var i=0;i<storedDataObjects.length;i++) 
				{
					var storedObject = storedDataObjects[i];
					if ((new Date(storedObject.expireDate)).getTime() > (new Date().getTime())) 
					{
						this.put(storedObject.key, storedObject.value, new Date(storedObject.expireDate));
					}					
				}
			}
		}
		StorageManager.getInstance().loadComplete();
	}
	this.clear = function() {
		window.globalStorage[document.domain].storage = JSON.stringify(new Object());
	}	
}

function LocalStorageMechanism() {
	this.name = 'localStorage';
	this.maxCapacity = 5000000; // 3M

	this.key = 'undefined';
	this.isSupported = function()
	{
	 	return (window.localStorage && (window.localStorage!=null));
	}

	this.save = function() {
		
		var allKeys = this.getAllKeys();
		var currentSize = 0;
		for(var i=0;i<allKeys.length;i++) {
			var currentKey = allKeys[i];
			var value = this.get(currentKey);
			var newObject = new Object();
			newObject.key = currentKey;
			newObject.value = value;
			newObject.expireDate = (this.keysExpireDates[currentKey]).toGMTString();
			dataString = JSON.stringify(newObject);
			currentSize += dataString.length;
			if (currentSize > this.maxCapacity){
				return false;
			}
			else{
				window.localStorage.setItem(currentKey, dataString);
			}
		}	
		return true;
	}
	this.load = function() {
	
	
		if(window.localStorage){
			var localStorage = window.localStorage;
			
			for (j=0; j<=localStorage.length-1; j++) {
			
				var key = localStorage.key(j);
				var storedDataString = localStorage.getItem(key);
				storedDataObject = eval('('+storedDataString+')');
				if(storedDataObject && storedDataObject!=''){
					if ((new Date(storedDataObject.expireDate)).getTime() > (new Date().getTime())) 
					{
						this.put(storedDataObject.key, storedDataObject.value, new Date(storedDataObject.expireDate));
					}	
				}
			}
		}
		
		StorageManager.getInstance().loadComplete();
	}
	this.clear = function() {
	 	window.localStorage.clear();
		//window.globalStorage[document.domain].storage = JSON.stringify(new Object());
	}	
}

function IEStorageMechanism() {
	this.name = 'IEStorage';
	this.maxCapacity = 65536;
	this.isSupported = function()
	{
		return (navigator.userAgent.indexOf('MSIE')!=-1)
	}

	this.initialize = function() 
	{
		this.dataObjects = new Array();
		this.allKeys = new Array();
		this.keysExpireDates = new Array();
		this.dataHook = false;
		var newIframeNode = document.createElement('iframe');
		newIframeNode.setAttribute('src','/.element/js/3.0/scripts/IEPersistence.html');
		newIframeNode.setAttribute('name','IEPersistence');
		newIframeNode.setAttribute('width','10');
		newIframeNode.setAttribute('height','10');
		newIframeNode.setAttribute('style','visibility:hidden;position:absolute;top:0px;left:-100px;');
		newIframeNode.style.top='0px';
		newIframeNode.style.left='-100px';
		newIframeNode.style.position='absolute';
		document.documentElement.appendChild(newIframeNode);
	}
	this.load = function() {}
	this.save = function () {
		var allKeys = this.getAllKeys();
		var storedObject = new Array();
		for(var i=0;i<allKeys.length;i++) {
			var currentKey = allKeys[i];
			var value = this.get(currentKey);
			var newObject = new Object();
			newObject.key = currentKey;
			newObject.value = value;
			newObject.expireDate = (this.keysExpireDates[currentKey]).toGMTString();
			storedObject.push(newObject);
		}	
		dataString = JSON.stringify(storedObject);
		if (dataString.length > this.maxCapacity){
			return false;
		}
		else{
			if(this.dataHook && this.dataHook.saveData)
			{
				this.dataHook.saveData(JSON.stringify( storedObject ));
			}
		}
		return true;
	}
	this.clear = function () {
		this.dataHook.saveData('');
	}
}

CookieStorageMechanism.prototype = new AbstractStorageMechanism;
DOMStorageMechanism.prototype = new AbstractStorageMechanism;
LocalStorageMechanism.prototype = new AbstractStorageMechanism;
IEStorageMechanism.prototype = new AbstractStorageMechanism;

StorageManager.getInstance().addStorageType( new LocalStorageMechanism() );
StorageManager.getInstance().addStorageType( new DOMStorageMechanism() );
StorageManager.getInstance().addStorageType( new IEStorageMechanism() );
StorageManager.getInstance().addStorageType( new CookieStorageMechanism() );

/*
Copyright (c) 2005 JSON.org

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The Software shall be used for Good, not Evil.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

Array.prototype.______array = '______array';

var JSON = {
    org: 'http://www.JSON.org',
    copyright: '(c)2005 JSON.org',
    license: 'http://www.crockford.com/JSON/license.html',

    stringify: function (arg, namedValue) {
        var c, i, l, s = '', v;

        switch (typeof arg) {
        case 'object':
            if (arg) {
                if (arg.______array == '______array') {
                    for (i = 0; i < arg.length; ++i) {
                        v = this.stringify(arg[i]);
                        if (s) {
                            s += ',';
                        }
                        s += v;
                    }
                    return '[' + s + ']';
                } else if (typeof arg.toString != 'undefined') {
                    for (i in arg) {
                        v = arg[i];
                        if (typeof v != 'undefined' && typeof v != 'function') {
                            v = this.stringify(v);
                            if (s) {
                                s += ',';
                            }
                            s += this.stringify(i, true) + ':' + v;
                        }
                    }
                    return '{' + s + '}';
                }
            }
            return 'null';
        case 'number':
            return isFinite(arg) ? String(arg) : 'null';
        case 'string':
            l = arg.length;
			if(!namedValue)
			{
	            s = '"';
			}
            for (i = 0; i < l; i += 1) {
                c = arg.charAt(i);
                if (c >= ' ') {
                    if (c == '\\' || c == '"') {
                        s += '\\';
                    }
                    s += c;
                } else {
                    switch (c) {
                        case '\b':
                            s += '\\b';
                            break;
                        case '\f':
                            s += '\\f';
                            break;
                        case '\n':
                            s += '\\n';
                            break;
                        case '\r':
                            s += '\\r';
                            break;
                        case '\t':
                            s += '\\t';
                            break;
                        default:
                            c = c.charCodeAt();
                            s += '\\u00' + Math.floor(c / 16).toString(16) +
                                (c % 16).toString(16);
                    }
                }
            }
			if(!namedValue)
			{
	            return s + '"';
			}
			else
			{
            return s;
			}
        case 'boolean':
            return String(arg);
        default:
            return 'null';
        }
    },
    parse: function (text) {
        var at = 0;
        var ch = ' ';

        function error(m) {
            throw {
                name: 'JSONError',
                message: m,
                at: at - 1,
                text: text
            };
        }

        function next() {
            ch = text.charAt(at);
            at += 1;
            return ch;
        }

        function white() {
            while (ch != '' && ch <= ' ') {
                next();
            }
        }

        function str() {
            var i, s = '', t, u;

            if (ch == '"') {
outer:          while (next()) {
                    if (ch == '"') {
                        next();
                        return s;
                    } else if (ch == '\\') {
                        switch (next()) {
                        case 'b':
                            s += '\b';
                            break;
                        case 'f':
                            s += '\f';
                            break;
                        case 'n':
                            s += '\n';
                            break;
                        case 'r':
                            s += '\r';
                            break;
                        case 't':
                            s += '\t';
                            break;
                        case 'u':
                            u = 0;
                            for (i = 0; i < 4; i += 1) {
                                t = parseInt(next(), 16);
                                if (!isFinite(t)) {
                                    break outer;
                                }
                                u = u * 16 + t;
                            }
                            s += String.fromCharCode(u);
                            break;
                        default:
                            s += ch;
                        }
                    } else {
                        s += ch;
                    }
                }
            }
            error("Bad string");
        }

        function arr() {
            var a = [];

            if (ch == '[') {
                next();
                white();
                if (ch == ']') {
                    next();
                    return a;
                }
                while (ch) {
                    a.push(val());
                    white();
                    if (ch == ']') {
                        next();
                        return a;
                    } else if (ch != ',') {
                        break;
                    }
                    next();
                    white();
                }
            }
            error("Bad array");
        }

        function obj() {
            var k, o = {};

            if (ch == '{') {
                next();
                white();
                if (ch == '}') {
                    next();
                    return o;
                }
                while (ch) {
                    k = str();
                    white();
                    if (ch != ':') {
                        break;
                    }
                    next();
                    o[k] = val();
                    white();
                    if (ch == '}') {
                        next();
                        return o;
                    } else if (ch != ',') {
                        break;
                    }
                    next();
                    white();
                }
            }
            error("Bad object");
        }

        function num() {
            var n = '', v;
            if (ch == '-') {
                n = '-';
                next();
            }
            while (ch >= '0' && ch <= '9') {
                n += ch;
                next();
            }
            if (ch == '.') {
                n += '.';
                while (next() && ch >= '0' && ch <= '9') {
                    n += ch;
                }
            }
            if (ch == 'e' || ch == 'E') {
                n += 'e';
                next();
                if (ch == '-' || ch == '+') {
                    n += ch;
                    next();
                }
                while (ch >= '0' && ch <= '9') {
                    n += ch;
                    next();
                }
            }
            v = +n;
            if (!isFinite(v)) {
                error("Bad number");
            } else {
                return v;
            }
        }

        function word() {
            switch (ch) {
                case 't':
                    if (next() == 'r' && next() == 'u' && next() == 'e') {
                        next();
                        return true;
                    }
                    break;
                case 'f':
                    if (next() == 'a' && next() == 'l' && next() == 's' &&
                            next() == 'e') {
                        next();
                        return false;
                    }
                    break;
                case 'n':
                    if (next() == 'u' && next() == 'l' && next() == 'l') {
                        next();
                        return null;
                    }
                    break;
            }
            error("Syntax error");
        }

        function val() {
            white();
            switch (ch) {
                case '{':
                    return obj();
                case '[':
                    return arr();
                case '"':
                    return str();
                case '-':
                    return num();
                default:
                    return ch >= '0' && ch <= '9' ? num() : word();
            }
        }

        return val();
    }
};