var END_OF_INPUT = -1;
var base64Chars = new Array(
	'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P',
	'Q','R','S','T','U','V','W','X','Y','Z','a','b','c','d','e','f',
	'g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v',
	'w','x','y','z','0','1','2','3','4','5','6','7','8','9','+','/'
);
var reverseBase64Chars = new Array();

for (var i=0; i < base64Chars.length; i++){
    reverseBase64Chars[base64Chars[i]] = i;
}
var base64Str;
var base64Count;

function setBase64Str(str){
	base64Str = str;
	base64Count = 0;
}

function readReverseBase64(){   
	if (!base64Str) return END_OF_INPUT;
	while (true){	  
		if (base64Count >= base64Str.length) return END_OF_INPUT;
		var nextCharacter = base64Str.charAt(base64Count);
		base64Count++;
		if (reverseBase64Chars[nextCharacter]){
			return reverseBase64Chars[nextCharacter];
		}
		if (nextCharacter == 'A') return 0;
	}
	return END_OF_INPUT;
}

function ntos(n){
	n=n.toString(16);
	if (n.length == 1) n="0"+n;
	return unescape("%"+n);
}

function decodeBase64(str){
	setBase64Str(str);
	var result = "";
	var inBuffer = new Array(4);
	var done = false;
	while (!done && (inBuffer[0] = readReverseBase64()) != END_OF_INPUT
		&& (inBuffer[1] = readReverseBase64()) != END_OF_INPUT){
		inBuffer[2] = readReverseBase64();
		inBuffer[3] = readReverseBase64();
		result += ntos((((inBuffer[0] << 2) & 0xff)| inBuffer[1] >> 4));
		if (inBuffer[2] != END_OF_INPUT){
			result +=  ntos((((inBuffer[1] << 4) & 0xff)| inBuffer[2] >> 2));
			if (inBuffer[3] != END_OF_INPUT){
				result +=  ntos((((inBuffer[2] << 6)  & 0xff) | inBuffer[3]));
			} else {
				done = true;
			}
		} else {
			done = true;
		}
	}
	return result;
}

function setMailtos() {
	this.setAttribute('href', decodeBase64('bWFpbHRvOg==') + decodeBase64(this.id));
}

function unsetMailtos() {
	this.setAttribute('href', '#');
}

function processB64() {
	processAnchors();
	processSpans();
}

function processSpans() {
	var spans = document.getElementsByTagName('span');
	for (var i=0, span; span = spans[i]; i++) {
		if (span.className == 'b64text') {
			span.innerHTML = decodeBase64(span.id);
		}
	}
}

function processAnchors() {
	var anchors = document.getElementsByTagName('a');
	for (var i=0, anchor; anchor = anchors[i]; i++) {
		if (anchor.className == 'b64email') {
			// mouse navigation
			anchor.onmouseover = setMailtos;
			anchor.onmouseout = unsetMailtos;
			// keyboard navigation (status bar doesn't work)
			anchor.onfocus = setMailtos;
			anchor.onblur = unsetMailtos;
		}
	}
}

window.onload = processB64;