validate TRON address (簡易版)

validate.js

const ADDRESS_SIZE = 34;
const ADDRESS_PREFIX_BYTE = 0x41;
const ALPHABET_MAP = {};
const BASE = 58
const ALPHABET = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz';


function decode58(string) {
    if (string.length === 0)
        return [];

    let i;
    let j;

    const bytes = [0];

    for (i = 0; i < string.length; i++) {
        const c = string[i];

        if (!(c in ALPHABET_MAP))
            throw new Error('Non-base58 character');

        for (j = 0; j < bytes.length; j++)
            bytes[j] *= BASE;

        bytes[0] += ALPHABET_MAP[c];
        let carry = 0;

        for (j = 0; j < bytes.length; ++j) {
            bytes[j] += carry;
            carry = bytes[j] >> 8;
            bytes[j] &= 0xff;
        }

        while (carry) {
            bytes.push(carry & 0xff);
            carry >>= 8;
        }
    }

    for (i = 0; string[i] === '1' && i < string.length - 1; i++)
        bytes.push(0);

    return bytes.reverse();
}

function isAddressValid(base58Str) {
    if (typeof (base58Str) !== 'string')
        return false;

    if (base58Str.length !== ADDRESS_SIZE)
        return false;

    let address = decode58(base58Str);

    if (address.length !== 25)
        return false;

    if (address[0] !== ADDRESS_PREFIX_BYTE)
        return false;

    return true
    
    // const checkSum = address.slice(21);
    // address = address.slice(0, 21);

    // const hash0 = SHA256(address);
    // const hash1 = SHA256(hash0);
    // const checkSum1 = hash1.slice(0, 4);

    // if (checkSum[0] == checkSum1[0] && checkSum[1] == checkSum1[1] && checkSum[2] ==
    //    checkSum1[2] && checkSum[3] == checkSum1[3]
    //) {
    //    return true
    //}

    //return false;
}