/*
 * testUserDevice.js 1.3
 * Authored by Scott Jehl, Filament Group (filamentgroup.com)
 * Date: July 2007 (rev. March 2008)
 * Dual licensed under the MIT (filamentgroup.com/examples/mit-license.txt) and GPL (filamentgroup.com/examples/gpl-license.txt) licenses.
  
 * Notes: This script is used to test the capability of a browser before providing enhanced javascript and css functionality.
          The script waits until the document.body is ready and then performs the test.
          
          Upon successful completion of the test, the following steps occur to allow for easy separation of enhanced style:
               1. a class of "enhanced" is assigned to the body element to be used for optional css scoping (such as: body.enhanced {background: red;})
               2. Any links to alternate stylesheets that have a class of "enhanced" will be enabled.
               3. Any links to stylesheets that have a class of "basicNoCascade" will be disabled. This is optional depending on whether your enhanced stylesheets cascade or conflict with your basic sheets.
               4. Any scripting passed as an argument will be passed to the domReady event. This uses jQuery if available.
          	   5. A cookie is set as well to notify the script on future page loads that the browser has already passed and can receive an enhanced experience. 
          		  * The cookie is (enhanced = true) and can be used on the backend to speed things up even further!
          		  
 * Usage: To use this script, simply enclose any scripting within the following function:
		 enhancedDomReady(function(){
			 //put scripts here to be executed after the dom is ready and the browser has passed the test
		 });

 * Changes: 1.3: Script now checks to make sure body doesn't already have 'enhanced' class before applying.
 			1.2: class and cookie name has been changed to "enhanced". This may break backward compatibility with older implementations of this test.
 * Additional Info: For more information, visit filamentgroup.com/lab/delivering_the_right_experience_to_the_right_device/
*/

/* wait until body is ready, runs test, passes domReady events to preferred domReady function */
function enhancedDomReady(func){
	function bodyReady(){
		if(document.body){
			clearInterval(checkBody);
			if(testUserDevice()){
				enhanceDocument();
				//forward functions to domReady event with available library
				if(jQuery){J(function(){func();});}
				else indepDomReady(function(){func();});
			}
		}
	}
	var checkBody = setInterval(bodyReady, 10);
}

//this gets called after test is passed
function enhanceDocument(){
	//add class to body "enhanced" for css scoping (makes sure it's not already there)
	if (!/\benhanced\b/.exec(document.body.className)){
		document.body.className += ' enhanced';
	}
	//function to enable enhanced stylesheets (enables alt stylesheet links with class name "enhanced)
	var allLinks = document.getElementsByTagName('link');
	for(i=0; i<allLinks.length; i++){
		//if the link has a class of "basicNoCascade", disable it
		if (/\bbasicNoCascade\b/.exec(allLinks[i].className)){
			allLinks[i].disabled = true;
		}
		//if the link has a class of "enhanced", enable it
		if (/\benhanced\b/.exec(allLinks[i].className)){
			allLinks[i].disabled = true; //opera likes to have it toggled
			allLinks[i].disabled = false;
		}
	}
}

//test function - runs a variety of tests to weed out any unqualified browsers from enhanced functionality
var testUserDevice = function () {
	
	if(readCookie('enhanced')){
		enhanceDocument();
		return true;
	}
	if(document.getElementById && document.createElement){
		var newDiv = document.createElement('div');
		document.body.appendChild(newDiv);
		newDiv.style.visibility = 'hidden';
		newDiv.style.width = '20px';
		newDiv.style.padding = '10px';
		var divWidth = newDiv.offsetWidth;
		if(divWidth != 40) {document.body.removeChild(newDiv); return false;}
		newDiv.style.position = 'absolute';
		newDiv.style.left = '10px';
		var leftVal = newDiv.offsetLeft;
		if(leftVal != 10) { document.body.removeChild(newDiv); return false;}
		var newInnerDiv = document.createElement('div');
		newInnerDiv.style.width = '5px';
		newInnerDiv.style.cssFloat = 'left';
		newInnerDiv.style.styleFloat = 'left';
		newDiv.appendChild(newInnerDiv);
		var secondInnerDiv = newInnerDiv.cloneNode(true); 
		newDiv.appendChild(secondInnerDiv);
		var newInnerDivTop = newInnerDiv.offsetTop;
		var secondInnerDivTop = secondInnerDiv.offsetTop;
		if(newInnerDivTop != secondInnerDivTop) { document.body.removeChild(newDiv); return false;}
		newDiv.innerHTML = '<ul><li style="width: 5px; float: left;">test</li><li style="width: 5px; float: left;clear: left;">test</li></ul>';
		var top1 = newDiv.getElementsByTagName('li')[0].offsetTop;
		var top2 = newDiv.getElementsByTagName('li')[1].offsetTop;
		if(top1 == top2){return false;}
		newDiv.innerHTML = '<div style="height: 20px;"></div>';
		newDiv.style.padding = '0';
		newDiv.style.height = '10px';
		newDiv.style.overflow = 'auto';
		var newDivHeight = newDiv.offsetHeight;
		if(newDivHeight != 10){document.body.removeChild(newDiv); return false;}
		newDiv.innerHTML = '<div style="line-height: 2; font-size: 10px;">Te<br />st</div>';
		newDiv.style.padding = '0';
		newDiv.style.height = 'auto';
		newDiv.style.overflow = '';
		var newDivHeight = newDiv.offsetHeight;
		if(newDivHeight > 40){document.body.removeChild(newDiv); return false;}
		if(window.onresize == false){document.body.removeChild(newDiv); return false;}
		if(!window.print){ document.body.removeChild(newDiv); return false;}
		if(window.clientInformation && window.opera){document.body.removeChild(newDiv); return false;}
		document.body.removeChild(newDiv);
		enhanceDocument();
		createCookie('enhanced', 'true');
		return true;
	}
	else{return false; }
}

/*Utilities for this script*/


/* library-independent domReady script (used if jQuery is not available) Note: can't find script source.. tba */
function indepDomReady(func){
	if (!window.__load_events){
		var init = function (){
				if (arguments.callee.done) return;
				arguments.callee.done = true;
				if (window.__load_timer){
					clearInterval(window.__load_timer);
					window.__load_timer = null;
				}
				for (var i=0;i < window.__load_events.length;i++){
					window.__load_events[i]();
				}
				window.__load_events = null;
		};
		if (document.addEventListener){
			document.addEventListener("DOMContentLoaded", init, false);
		}
		if (/WebKit/i.test(navigator.userAgent)){
			window.__load_timer = setInterval(function(){
				if (/loaded|complete/.test(document.readyState)){
					init();
				}
			}
			, 10);
		}
	window.onload = init;
	window.__load_events = [];
	}
	window.__load_events.push(func);
}

//cookie functions from quirksmode
function createCookie(name,value,days) {
	if (days) {
		var date = new Date();
		date.setTime(date.getTime()+(days*24*60*60*1000));
		var expires = "; expires="+date.toGMTString();
	}
	else var expires = "";
	document.cookie = name+"="+value+expires+"; path=/";
}
function readCookie(name) {
	var nameEQ = name + "=";
	var ca = document.cookie.split(';');
	for(var i=0;i < ca.length;i++) {
		var c = ca[i];
		while (c.charAt(0)==' ') c = c.substring(1,c.length);
		if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
	}
	return null;
}

enhancedDomReady(function(){
	//put scripts here to be executed after the dom is ready and the browser has passed the test
});