var templateUrlRegex = /templateUrl\s*:(\s*['"`](.*?)['"`]\s*([,}]))/gm;
var stylesRegex = /styleUrls *:(\s*\[[^\]]*?\])/g;
var stringRegex = /(['`"])((?:[^\\]\\\1|.)*?)\1/g;

function replaceStringsWithRequires(string) {
  return string.replace(stringRegex, function (match, quote, url) {
    if (url.charAt(0) !== ".") {
      url = "./" + url;
    }
    return "require('" + url + "')";
  });
}

module.exports = function(source, sourcemap) {
  // Not cacheable during unit tests;
  this.cacheable && this.cacheable();

  var newSource = source.replace(templateUrlRegex, function (match, url) {
    return "template:" + replaceStringsWithRequires(url);
  }).replace(stylesRegex, function (match, urls) {
    return "styles:" + replaceStringsWithRequires(urls);
  });

  // Support for tests
  if (this.callback) {
    this.callback(null, newSource, sourcemap)
  } else {
    return newSource;
  }
};