/*----------------------------------------*\
* 使用 javascript HTML DOM 高亮显示页面特定字词 By shawl.qiu
* 参数说明:
* o: 对象, 要进行高亮显示的对象.
* flag: 字符串, 要进行高亮的词或多个词, 使用 竖杠(|) 分隔多个词 .
* rndColor: 布尔值, 是否随机显示文字背景色与文字颜色, true 表示随机显示.
* url: URI, 是否对高亮的词添加链接.
\*----------------------------------------*/
function Light(o, flag, rndColor, url) {
	var bgCor = fgCor = '';
	if(rndColor){
		bgCor = fRndCor(10, 20);
		fgCor = fRndCor(230, 255);
	}
	else {
		bgCor = 'yellow';
		fgCor = 'red';
	}
	var re = new RegExp(flag, 'i');
	for(var i = 0; i < o.childNodes.length; i++) {
		var o_ = o.childNodes[i];
		var o_p = o_.parentNode;
		if(o_.nodeType == 1) {
			Light(o_, flag, rndColor, url);
		}
		else if (o_.nodeType == 3) {
			if(!(o_p.nodeName == 'A')){
				if(o_.data.search(re) ==  -1) continue;
				var temp = fEleA(o_.data, flag);
				o_p.replaceChild(temp, o_);
			}
		}
	}

	function fEleA(text, flag) {
		var style = ' style="background-color:' + bgCor + ';color:' + fgCor + ';" '
		var o = document.createElement('span');
		var str = '';
		var re = new RegExp('(' + flag + ')', 'gi');
		if(url) {
			str = text.replace(re, '<a href="' + url + '$1"' + style + '>$1</a>');
		}
		else {
			str = text.replace(re, '<span ' + style + '>$1</span>');
		}
		o.innerHTML = str;
		return o;
	}

	function fRndCor(under, over){
		if(arguments.length == 1){
			var over = under;
			under = 0;
		}
		else if(arguments.length == 0) {
			var under = 0;
			var over = 255;
		}
		var r = fRandomBy(under, over).toString(16);
		r = padNum(r, r, 2);
		var g = fRandomBy(under, over).toString(16);
		g = padNum(g, g, 2);
		var b = fRandomBy(under, over).toString(16);
		b = padNum(b, b, 2);

		return '#' + r + g + b;

		function fRandomBy(under, over) {
			switch(arguments.length){
				case 1: return parseInt(Math.random() * under + 1);
				case 2: return parseInt(Math.random()*(over - under + 1) + under);
				default: return 0;
			}
		}
		function padNum(str, num, len) {
			var temp = ''
			for(var i = 0; i < len;temp+=num, i++);
			return temp = (temp += str).substr(temp.length - len);
		}
	}
}