function setActiveStyleSheet(title) {
	var i, a, main;
	for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
		if(a.getAttribute("rel").indexOf("style") != -1 && a.getAttribute("title")) {
            if (compare_excrusive(title, a.getAttribute("title"))){
                a.disabled = true;
            }
//            a.disabled = true;
			if(a.getAttribute("title") == title) a.disabled = false;
		}
	}
}

/**
 *getActiveStyleSheet
 *
 * @param kind kind スタイル設定種類 global, fontsize
 * @access public
 * @return void
 */
function getActiveStyleSheet(kind) {
	var i, a, match;
    var kind_pattern = new RegExp('^(' + kind + ')-');
	for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
        var match = kind_pattern.exec(a.getAttribute("title"));
		if(a.getAttribute("rel").indexOf("style") != -1 && a.getAttribute("title") && !a.disabled && match) return a.getAttribute("title");
	}
	return null;
}

function getPreferredStyleSheet() {
	var i, a;
	for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
		if(a.getAttribute("rel").indexOf("style") != -1
			 && a.getAttribute("rel").indexOf("alt") == -1
			 && a.getAttribute("title")
			 ) return a.getAttribute("title");
	}
	return null;
}

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 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;
}

var style_load = function() {
    var kind = ['global', 'fontsize'];
    setActiveStyleSheet('global-style');
    setActiveStyleSheet('fontsize-medium');
    for (var i=0; i < kind.length; i++) {
        var cookie = readCookie(kind[i] + "-style");
        var title = cookie ? cookie : getPreferredStyleSheet();
        setActiveStyleSheet(title);
    }
}

window.onunload = function(e) {
    var kind = ['global', 'fontsize'];
    for (var i=0; i < kind.length; i++) {
        var title = getActiveStyleSheet(kind[i]);
        createCookie(kind[i] +"-style", title, 365);
    }
}

function  compare_excrusive (target1, target2) {
    if (target1 == null || target2 == null) { return false; }
    return target1.slice(0, target1.indexOf('-')) ==
           target2.slice(0, target2.indexOf('-'));
}

style_load();