text: var urljoin = require('url-join');
  
  var objectHelper = require('../helper/object');
  var assert = require('../helper/assert');
  var responseHandler = require('../helper/response-handler');
  
  function DBConnection(request, options) {
    this.baseOptions = options;
    this.request = request;
  }
  
  /**
   * @callback signUpCallback
   * @param {Error} [err] error returned by Auth0 with the reason why the signup failed
   * @param {Object} [result] result of the signup request
   * @param {Object} result.email user's email
   * @param {Object} result.emailVerified if the user's email was verified
   */
  
  /**
   * Creates a new user in a Auth0 Database connection
   *
   * @method signup
   * @param {Object} options
   * @param {String} options.email user email address
   * @param {String} options.password user password
   * @param {String} options.connection name of the connection where the user will be created
   * @param {signUpCallback} cb
   * @see   {@link https://auth0.com/docs/api/authentication#signup}
   */
  DBConnection.prototype.signup = function (options, cb) {
    var url;
    var body;
  
    assert.check(options, { type: 'object', message: 'options parameter is not valid' }, {
      connection: { type: 'string', message: 'connection option is required' },
      email: { type: 'string', message: 'email option is required' },
      password: { type: 'string', message: 'password option is required' }
    });
    assert.check(cb, { type: 'function', message: 'cb parameter is not valid' });
  
    url = urljoin(this.baseOptions.rootUrl, 'dbconnections', 'signup');
  
    body = objectHelper.merge(this.baseOptions, ['clientID'])
                  .with(options);
  
    body = objectHelper.blacklist(body, ['scope']);
  
    body = objectHelper.toSnakeCase(body, ['auth0Client']);
  
    return this.request
      .post(url)
      .send(body)
      .end(responseHandler(cb));
  };
  
  /**
   * @callback changePasswordCallback
   * @param {Error} [err] error returned by Auth0 with the reason why the request failed
   */
  
  /**
   * Request an email with instruction to change a user's password
   *
   * @method changePassword
   * @param {Object} options
   * @param {String} options.email address where the user will recieve the change password email. It should match the user's email in Auth0
   * @param {String} options.connection name of the connection where the user was created
   * @param {changePasswordCallback} cb
   * @see   {@link https://auth0.com/docs/api/authentication#change-password}
   */
  DBConnection.prototype.changePassword = function (options, cb) {
    var url;
    var body;
  
    assert.check(options, { type: 'object', message: 'options parameter is not valid' }, {
      connection: { type: 'string', message: 'connection option is required' },
      email: { type: 'string', message: 'email option is required' }
    });
    assert.check(cb, { type: 'function', message: 'cb parameter is not valid' });
  
    url = urljoin(this.baseOptions.rootUrl, 'dbconnections', 'change_password');
  
    body = objectHelper.merge(this.baseOptions, ['clientID'])
                  .with(options, ['email', 'connection']);
  
    body = objectHelper.toSnakeCase(body, ['auth0Client']);
  
    return this.request
      .post(url)
      .send(body)
      .end(responseHandler(cb));
  };
  
  module.exports = DBConnection;
  