/* [toyo-keizai.co.jp]
 * Summary: script for "korean lesson" page
 * LastModified: 2009-03-26
 * This script requires prototype.js
 */

/*----------------------------------------------------------------------------
 global object
----------------------------------------------------------------------------*/
if (!TK) TK = {};

/*----------------------------------------------------------------------------
 press page navigation
----------------------------------------------------------------------------*/
TK.klNav = {
	crIndex: 0,
	
	init: function() {
		var nav = $("pagenav");
		if(!nav) return;
		
		// Hightlight Current Link --------------------------
		var links = nav.getElementsByTagName("a");
		var url = window.location.href;
		
		if (url.charAt(url.length - 1) == "/") {
			links[0].className = "cr";
		} else {
			for (var i = 0, l = links.length; i < l; i ++) {
				var href = links[i].getAttribute("href");
				if(url.indexOf(href) != -1) {
					links[i].className = "cr";
				}
			}
		}
		
		// Split Navigation ---------------------------------
		var wrap = $("pagenav-list");
		var ul = nav.getElementsByTagName("ul")[0];
		var li = ul.getElementsByTagName("li");
		var liGroupLength = Math.ceil(li.length / 10);
		var liGroup = [], ulGroup = [];
		for (var i = 0; i < liGroupLength; i ++) {
			var tempI = i + 1;
			//liGroup[i] = [];
			ulGroup[i] = document.createElement("ul");
			
			for (var i2 = i * 10; i2 < tempI * 10; i2 ++) {
				ulGroup[i].appendChild(li[i2].cloneNode(true));
			}
			wrap.appendChild(ulGroup[i]);
		}
		// Remove Original List
		ul.parentNode.removeChild(ul);
		
		// Set Current Group Number
		var splurl = url.split(".");
		var tempurl = splurl[splurl.length - 2];
		var crGroupNum = tempurl.substring((tempurl.length - 2), (tempurl.length - 1));
		crGroupNum -= 0;
		if (isNaN(crGroupNum)) crGroupNum = 0;
		
		if (tempurl.substring((tempurl.length - 1), tempurl.length) == "0") crGroupNum --;
		this.crIndex = crGroupNum;
		
		// Toggle Navigaion Display -------------------------
		var splitUL = wrap.getElementsByTagName("ul");
		
		this.setup(splitUL, this.crIndex, liGroupLength);
		
		// previous link/next link  -------------------------
		var prevNav = $("pagenav_prev");
		var nextNav = $("pagenav_next");
		
		function initNavs(maxlength) {
			var index = TK.klNav.crIndex;
			if (index == 0) {
				prevNav.style.display = "none";
			} else if (index == maxlength - 1) {
				nextNav.style.display = "none";
			} else {
				prevNav.style.display = "block";
				nextNav.style.display = "block";
			}
		}
		initNavs(liGroupLength);
		
		$("pagenav_prev").getElementsByTagName("a")[0].onclick = function() {
			TK.klNav.crIndex --;
			TK.klNav.setup(splitUL, TK.klNav.crIndex, liGroupLength);
			initNavs(liGroupLength);
			return false;
		};
		$("pagenav_next").getElementsByTagName("a")[0].onclick = function() {
			TK.klNav.crIndex ++;
			TK.klNav.setup(splitUL, TK.klNav.crIndex, liGroupLength);
			initNavs(liGroupLength);
			return false;
		};
		
		wrap.style.display = "block";
	},
	
	setup: function(nodeList, index, maxlength) {
		for (var i = 0; i < maxlength; i ++) {
			if (i == index) nodeList[i].style.display = "block";
			else nodeList[i].style.display = "none";
		}
	}
};

/*----------------------------------------------------------------------------
 onload event function
----------------------------------------------------------------------------*/
Event.observe(window, "load", function () {
	TK.klNav.init();
});