var _ = require('underscore');

exports.updateDocument = function(doc, SchemaTarget, data) {
  for (var field in SchemaTarget.schema.paths) {
    if ((field !== '_id') && (field !== '__v')) {
      var newValue = getObjValue(field, data);
      if (newValue !== undefined) {
        setObjValue(field, doc, newValue);
      }
    }
  }
  return doc;
};

function getObjValue(field, data) {
  return _.reduce(field.split("."), function(obj, f) {
    if(obj) return obj[f];
  }, data);
}

function setObjValue(field, data, value) {
  var fieldArr = field.split('.');
  return _.reduce(fieldArr, function(o, f, i) {
    if(i == fieldArr.length-1) {
      o[f] = value;
    } else {
      if(!o[f]) o[f] = {};
    }
    return o[f];
  }, data);
}