jmdobry/reheat

var errorPrefix = 'Model#set(key[, value][, options][, cb]): ';

module.exports = function (Promise, utils, errors) {
  var IllegalArgumentError = errors.IllegalArgumentError;

  /**
   * @doc method
   * @id Model.instance_methods:set
   * @name set
   * @description
   * Set (asynchronously) the given values on this instance.
   *
   * ## Signature:
   * ```js
   * Model#set(key[, value][, options][, cb])
   * ```
   *
   * ## Examples:
   *
   * ### Promise-style:
   * ```js
   *  var contact = new Contact({
     *      address: {
     *          city: 'New York'
     *      }
     *  });
   *
   *  contact.set({
     *      firstName: 'John',
     *      lastName: 5
     *  }, { validate: true }).then(function (contact) {
     *      // Do something with contact
     *  })
   *  .catch(reheat.support.IllegalArgumentError, function (err) {
     *      res.send(400, err.errors);
     *  })
   *  .catch(reheat.support.ValidationError, function (err) {
     *      err.errors; // { lastName: { errors: ['type'] } }
     *      res.send(400, err.errors);
     *  })
   *  .error(function (err) {
     *      res.send(500, err.message);
     *  });
   * ```
   *
   * ### Node-style:
   * ```js
   *  var contact = new Contact({
     *      address: {
     *          city: 'New York'
     *      }
     *  });
   *
   *  contact.set({
     *      firstName: 'John',
     *      lastName: 5
     *  }, { validate: true }, function (err, contact) {
     *      err; // { lastName: { errors: ['type'] } }
     *
     *      contact.set('email', 'john.anderson@gmail.com', function (err, contact) {
     *          contact.get('email');   //  'john.anderson@gmail.com'
   *
   *          contact.set({ lastName:  'Anderson' }, function (err, contact) {
     *              contact.get('lastName');   //  'Anderson'
     *
     *              contact.toJSON();   //  {
     *                                  //      email: 'john.anderson@gmail.com',
   *                                  //      lastName: 'Anderson'
   *                                  //      address: {
     *                                  //          city: 'New York'
     *                                  //      }
   *                                  //  }
   *          });
   *      });
   *  });
   * ```
   *
   * ## Throws/Rejects with:
   *
   * - `{ValidationError}`
   * - `{IllegalArgumentError}`
   * - `{UnhandledError}`
   *
   * @param {string|object} key If a string, the key to be set to `value`. Supports nested keys, e.g. `"address.state"`.
   * If an object, the object will be merged into this instance's attributes.
   * @param {*} [value] The value to set. Used only if `key` is a string.
   * @param {boolean|object=} options Optional configuration. May be set to `true` as shorthand for
   * `{ validate: true }`. Properties:
   *
   * - `{boolean=false}` - `validate` - If `true` and the Model of this instance has a schema defined, ensure no schema
   * validation errors occur with the new attribute(s) before setting, otherwise abort with the
   * validation error.
   *
   * @param {function=} cb Optional callback function for Node-style usage. Signature: `cb(err, instance)`. Arguments:
   *
   * - `{ValidationError|UnhandledError}` - `err` - `null` if no error occurs. `ValidationError` if a validation error
   * occurs and `UnhandledError` for any other error.
   * - `{object}` - `instance` - If no error occurs, a reference to the instance on which
   * `set(key[, value][, options][, cb])` was called.
   * @returns {Promise} Promise.
   */
  function set(key, value, options, cb) {
    var _this = this;

    // Check pre-conditions
    if (utils.isFunction(value)) {
      cb = value;
      options = {};
    } else if (utils.isFunction(options)) {
      cb = options;
      if (utils.isObject(key)) {
        options = value;
      } else {
        options = {};
      }
    }
    options = options ? (options === true ? { validate: true } : options) : {};

    if (cb && !utils.isFunction(cb)) {
      throw new IllegalArgumentError(errorPrefix + 'cb: Must be a function!', { actual: typeof cb, expected: 'function' });
    }

    return Promise.resolve().then(function sanitize() {
      if (!utils.isObject(options)) {
        throw new IllegalArgumentError(errorPrefix + 'options: Must be an object', { actual: typeof options, expected: 'object' });
      } else if (!utils.isObject(key) && !utils.isString(key)) {
        throw new IllegalArgumentError(errorPrefix + 'key: Must be a string or an object!', { actual: typeof key, expected: 'string|object' });
      }

      if (options.validate && _this.constructor.schema) {
        var clone = utils.clone(_this.attributes),
          deferred = Promise.defer();

        if (utils.isObject(key)) {
          utils.deepMixIn(clone, key);
        } else {
          utils.set(clone, key, value);
        }

        _this.constructor.schema.validate(clone, function (err) {

          // Handle uncaught errors
          if (err) {
            _this.validationError = new errors.ValidationError(errorPrefix + 'key/value: Validation failed!', err);
            throw _this.validationError;
          } else {
            if (utils.isObject(key)) {
              utils.deepMixIn(_this.attributes, key);
            } else {
              utils.set(_this.attributes, key, value);
            }
            deferred.resolve(_this);
          }
        });

        return deferred.promise;
      } else {
        if (utils.isObject(key)) {
          utils.deepMixIn(_this.attributes, key);
        } else {
          utils.set(_this.attributes, key, value);
        }
        return _this;
      }
    }).nodeify(cb);
  }

  return set;
};