/** @copyright The code was taken from the portal http://www.webtoolkit.info/javascript-base64.html */

const base64Sequence = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';

const utf8Encode = (value: string) => {
  value = value.replace(/\r\n/g, '\n');

  let utftext = '';

  for (let n = 0; n < value.length; n++) {
    const c = value.charCodeAt(n);

    if (c < 128) {
      utftext += String.fromCharCode(c);
    } else if (c > 127 && c < 2048) {
      utftext += String.fromCharCode((c >> 6) | 192);

      utftext += String.fromCharCode((c & 63) | 128);
    } else {
      utftext += String.fromCharCode((c >> 12) | 224);

      utftext += String.fromCharCode(((c >> 6) & 63) | 128);

      utftext += String.fromCharCode((c & 63) | 128);
    }
  }

  return utftext;
};

export const encode = (input: string) => {
  let output = '';
  let chr1;
  let chr2;
  let chr3;
  let enc1;
  let enc2;
  let enc3;
  let enc4;
  let i = 0;

  input = utf8Encode(input);

  while (i < input.length) {
    chr1 = input.charCodeAt(i++);
    chr2 = input.charCodeAt(i++);
    chr3 = input.charCodeAt(i++);

    enc1 = chr1 >> 2;
    enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
    enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
    enc4 = chr3 & 63;

    if (isNaN(chr2)) {
      enc3 = enc4 = 64;
    } else if (isNaN(chr3)) {
      enc4 = 64;
    }

    output += `${base64Sequence.charAt(enc1)}${base64Sequence.charAt(enc2)}${base64Sequence.charAt(
      enc3,
    )}${base64Sequence.charAt(enc4)}`;
  }

  return output;
};