module.exports = function quoted_printable_decode(str) {
  //       discuss at: https://locutus.io/php/quoted_printable_decode/
  //      original by: Ole Vrijenhoek
  //      bugfixed by: Brett Zamir (https://brett-zamir.me)
  //      bugfixed by: Theriault (https://github.com/Theriault)
  // reimplemented by: Theriault (https://github.com/Theriault)
  //      improved by: Brett Zamir (https://brett-zamir.me)
  //        example 1: quoted_printable_decode('a=3Db=3Dc')
  //        returns 1: 'a=b=c'
  //        example 2: quoted_printable_decode('abc  =20\r\n123  =20\r\n')
  //        returns 2: 'abc   \r\n123   \r\n'
  //        example 3: quoted_printable_decode('012345678901234567890123456789012345678901234567890123456789012345678901234=\r\n56789')
  //        returns 3: '01234567890123456789012345678901234567890123456789012345678901234567890123456789'
  //        example 4: quoted_printable_decode("Lorem ipsum dolor sit amet=23, consectetur adipisicing elit")
  //        returns 4: 'Lorem ipsum dolor sit amet#, consectetur adipisicing elit'

  // Decodes all equal signs followed by two hex digits
  const RFC2045Decode1 = /=\r\n/gm

  // the RFC states against decoding lower case encodings, but following apparent PHP behavior
  const RFC2045Decode2IN = /=([0-9A-F]{2})/gim
  // RFC2045Decode2IN = /=([0-9A-F]{2})/gm,

  const RFC2045Decode2OUT = function (sMatch, sHex) {
    return String.fromCharCode(parseInt(sHex, 16))
  }

  return str.replace(RFC2045Decode1, '').replace(RFC2045Decode2IN, RFC2045Decode2OUT)
}