const charTable=[
'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', '2', '3', '4', '5', '6', '7',
'='
],allowedPeddingCount=[6,4,3,1,0];
function str_split(str,length){
if(typeof str !== 'string')return [];
let a=[],i=0;
length||(length=1);
do{
a.push(str.substr(i,length));
i+=length;
}while(i<str.length);
return a;
}
const Base32={
encode:function(str,padding){
if(!str)return '';
let binaryString='';
for (let i = 0;i<str.length;i++) {
let bin=str.charCodeAt(i).toString(2);
binaryString+=('0'.repeat(8-bin.length)+bin);
}
let fiveBitBinaryArray=str_split(binaryString,5),base32='';
for(let i=0;i<fiveBitBinaryArray.length;i++){
let bin=fiveBitBinaryArray[i];
base32+=charTable[parseInt(bin+'0'.repeat(5-bin.length),2)];
}
let x=binaryString.length%40;
if (padding && x != 0) {
if (x == 8)base32+=charTable[32].repeat(6);
else if(x===16)base32+=charTable[32].repeat(4);
else if(x===24)base32+=charTable[32].repeat(3);
else if(x===32)base32+=charTable[32];
}
return base32;
},
decode:function(str){
if(!str)return '';
let paddingMatch=str.match(/\=+$/),
paddingCharCount=paddingMatch?paddingMatch[0].length:0;
if(allowedPeddingCount.indexOf(paddingCharCount)<0)return false;
for (let i=0;i<4;i++){
if (paddingCharCount===allowedPeddingCount[i]
&& str.substr(-(allowedPeddingCount[i]))!=charTable[32].repeat(allowedPeddingCount[i]))
return false;
}
str=str.replace(/\=+$/,'');
let binaryString = "";
for (let i=0;i<str.length;i+=8) {
let x='';
if (charTable.indexOf(str[i])<0)return false;
for (let j=0;j<8;j++) {
let bin=charTable.indexOf(str[i+j]).toString(2);
x+='0'.repeat(5-bin.length)+bin;
}
let eightBits=str_split(x,8);
for (let z = 0; z < eightBits.length; z++) {
let y,cd=parseInt(eightBits[z],2,10);
binaryString+=((y=String.fromCharCode(cd))||cd==48)?y:"";
}
}
return binaryString;
}
}