Base32 Encoder/Decoder

"use strict";

const BASE32 = '0123456789abcdefghijklmnopqrstuv';
const BASE32_REVERSE = new Uint8Array(256);
for (let i = 0; i < BASE32.length; i++) {
    BASE32_REVERSE[BASE32.charCodeAt(i)] = i;
}

class cBase32EncoderDecoder{

    static fEncode = (aByteArray) => {
        let iLength = aByteArray.length;
        let sBase32 = '';

        for (let i = 0; i < iLength; i += 5) {
            sBase32 += BASE32[aByteArray[i] >> 3];
            sBase32 += BASE32[((aByteArray[i] & 7) << 2) | (aByteArray[i + 1] >> 6)];
            sBase32 += BASE32[((aByteArray[i + 1] & 63) >> 1)];
            sBase32 += BASE32[((aByteArray[i + 1] & 1) << 4 | (aByteArray[i + 2]) >> 4)];
            sBase32 += BASE32[((aByteArray[i + 2] & 15) << 1 | (aByteArray[i + 3]) >> 7)];
            sBase32 += BASE32[((aByteArray[i + 3] & 127) >> 2)];
            sBase32 += BASE32[((aByteArray[i + 3] & 3) << 3 | (aByteArray[i + 4]) >> 5)];
            sBase32 += BASE32[((aByteArray[i + 4] & 31))];
        }

        if (iLength % 5 === 4) {
            sBase32 = sBase32.substring(0, sBase32.length - 1);
        }
        else if (iLength % 5 === 3) {
            sBase32 = sBase32.substring(0, sBase32.length - 3);
        }
        else if (iLength % 5 === 2) {
            sBase32 = sBase32.substring(0, sBase32.length - 4);
        }
        else if (iLength % 5 === 1) {
            sBase32 = sBase32.substring(0, sBase32.length - 6);
        }

        return sBase32;
    };

    static fDecode = (sBase32) => {
        let iBufferLength = sBase32.length * 0.625;
        let iLength = sBase32.length;

        let iEncoded1;
        let iEncoded2;
        let iEncoded3;
        let iEncoded4;
        let iEncoded5;
        let iEncoded6;
        let iEncoded7;
        let iEncoded8;

        let aByteArray = new Uint8Array(iBufferLength);

        let p = 0;
        for (let i = 0; i < iLength; i += 8) {
            iEncoded1 = BASE32_REVERSE[sBase32.charCodeAt(i)];
            iEncoded2 = BASE32_REVERSE[sBase32.charCodeAt(i + 1)];
            iEncoded3 = BASE32_REVERSE[sBase32.charCodeAt(i + 2)];
            iEncoded4 = BASE32_REVERSE[sBase32.charCodeAt(i + 3)];
            iEncoded5 = BASE32_REVERSE[sBase32.charCodeAt(i + 4)];
            iEncoded6 = BASE32_REVERSE[sBase32.charCodeAt(i + 5)];
            iEncoded7 = BASE32_REVERSE[sBase32.charCodeAt(i + 6)];
            iEncoded8 = BASE32_REVERSE[sBase32.charCodeAt(i + 7)];

            aByteArray[p++] = (iEncoded1 << 3) | (iEncoded2 >> 2);
            aByteArray[p++] = ((iEncoded2 & 3) << 6) | (iEncoded3 << 1) | (iEncoded4 >> 4);
            aByteArray[p++] = ((iEncoded4 & 15) << 4) | (iEncoded5 >> 1);
            aByteArray[p++] = ((iEncoded5 & 1) << 7) | (iEncoded6 << 2) | (iEncoded7 >> 3);
            aByteArray[p++] = ((iEncoded7 & 7) << 5) | iEncoded8;
        }

        return aByteArray;
    };

}