/**
 * Fix base64 encode for javascript
 */
const base64_encode = (param) => {
    const convert_binary_str = (str) => {
        if (str.length < 1) {
            return '';
        }
        let ord = str[0].charCodeAt(0);
        if (ord < 0) {
            ord = 0xFFFFFFFF + ord + 1;
        }
        let tmp = ord.toString(2);
        tmp = "0".repeat(8 - tmp.length) + tmp;
        return tmp + convert_binary_str(str.substring(1));
    };
    param = convert_binary_str(param);
    let final = "";
    let start = 0;
    let tmp;
    while (start < param.length) {
        if (param.substring(start).length < 6) {
            param += "0".repeat(6 - param.substring(start).length);
        }
        let bin = param.slice(start, start + 6);
        tmp = parseInt(bin.replace(/[^01]/gi, ''), 2);
        if (tmp < 26) {
            final += String.fromCharCode(tmp + 65);
        }
        else if (tmp > 25 && tmp < 52) {
            final += String.fromCharCode(tmp + 71);
        }
        else if (tmp === 62) {
            final += "+";
        }
        else if (tmp === 63) {
            final += "/";
        }
        else if (!tmp) {
            final += "A";
        }
        else {
            final += String.fromCharCode(tmp - 4);
        }
        start += 6;
    }
    if ((final.length % 4) > 0) {
        final += "=".repeat(4 - final.length % 4);
    }
    return final;
};