/**
 * Calculate the distances by using the numbers, strings and dates.
 * @param  {node} source
 * @param  {node} target
 * @param  {array} properties - the properties of the nodes.
 * @return {number}            the distance between source and target nodes.
 */
function calculateCosineSimilarity (source, target, properties, normArgs) {
  var numerator = 0.0;

  // console.log(properties);
  // Iterate through every column of data
  for (var i = 0; i < properties.length; i++) {
    property = properties[i];
    if (property.toLowerCase() !== 'class' && property.toLowerCase() !== 'app' && property.toLowerCase() !== 'user' && property.toLowerCase() !== 'weekday') {
      var s = source[property],
        t = target[property];

      numerator += s * t;
    }
  }

  let denominator = squareRooted(source, properties, normArgs) * squareRooted(target, properties, normArgs);

  // console.log(Math.abs(numerator / denominator));
  return Math.abs(numerator / denominator);
}

function squareRooted (node, properties, normArgs) {
  var sum = 0.0;

  for (var i = 0, s; i < properties.length; i++) {
    var s = node[properties[i]];

    sum += s * s;
  }

  return Math.sqrt(sum);
}