onlyurei/knockout-spa

define(['sugar'], function () {

  var stringRegEx = /(.*?)(?:--|$|\/)/i;
  var invalidStringRegExTest = /[^a-z0-9_\-\s\.]/i;
  var invalidStringRegExReplace = /[^a-z0-9_\-\s\.]/gi;
  var hexStringRegEx = /^\-[0-9A-Fa-f]+$/;

  function stringToHex(string) {
    var hexString = '';
    string = string.encodeBase64();
    for (var i = 0; i < string.length; i++) {
      hexString += string.charCodeAt(i).toString(16);
    }
    return hexString;
  }

  function hexToString(hexString) {
    var string = '';
    if (hexString.length % 2) {
      hexString = '0' + hexString;
    }
    for (var i = 0; i < hexString.length; i += 2) {
      string += String.fromCharCode(parseInt(hexString.substr(i, 2), 16));
    }
    return string.decodeBase64();
  }

  function normalize(urlString, escapeToHex) {
    urlString = urlString.compact();
    if (invalidStringRegExTest.test(urlString)) {
      urlString = (escapeToHex === true) ? ('-' + stringToHex(urlString)) : urlString.replace(invalidStringRegExReplace, '');
    }
    return urlString;
  }

  function fromUrl(urlString) {
    if (hexStringRegEx.test(urlString)) {
      urlString = hexToString(urlString.from(1));
    }
    return urlString.replace(/\-/gi, ' ');
  }

  function toUrl(urlString, escapeToHex) {
    return normalize(urlString, escapeToHex).replace(/\s/gi, '-') || '-';
  }

  return {
    regEx: stringRegEx,
    normalize: normalize,
    fromUrl: fromUrl,
    toUrl: toUrl
  };

});