(function ($, Drupal) {

  Drupal.BootstrapPassword = function (element) {
    var self = this;
    var $element = $(element);
    this.settings = Drupal.settings.password;
    this.$wrapper = $element.parent().parent();
    this.$row = $('<div class="row">').prependTo(this.$wrapper);

    // The password object.
    this.password = {
      $input: $element,
      $label: $element.parent().find('label'),
      $wrapper: $element.parent().addClass('col-sm-6 col-md-4 has-feedback').appendTo(self.$row)
    };
    this.password.$icon = $('<span class="glyphicon form-control-feedback"></span>').appendTo(this.password.$wrapper);

    // Strength meter.
    this.strength = {
      $label: $('<div class="label" aria-live="assertive"></div>').appendTo(this.password.$label),
      $progress: $('<div class="progress"><div class="progress-bar" role="progressbar" aria-valuenow="0" aria-valuemin="0" aria-valuemax="100"></div></div>').appendTo(this.password.$wrapper)
    };
    this.strength.$bar = this.strength.$progress.find('.progress-bar');

    // The confirmation object.
    this.confirm = {
      $input: this.$wrapper.find('input.password-confirm')
    };
    this.confirm.$wrapper = this.confirm.$input.parent().addClass('col-sm-6 col-md-4 has-feedback').appendTo(self.$row);
    this.confirm.$icon = $('<span class="glyphicon form-control-feedback"></span>').appendTo(this.confirm.$wrapper);

    // Bind events.
    this.password.$input.on('keyup focus blur', function () {
      self.validateStrength();
    });
    this.confirm.$input.on('keyup blur', function () {
      self.validateMatch();
    });

    // Add password help at the of row.
    this.$helpBlock = $('<div class="help-block password-help"></div>').appendTo(this.$row);

    return this;
  };

  /**
   * Helper method to switch classes on elements based on status.
   *
   * @param {jQuery} $element
   *   The jQuery element to modify.
   * @param {string} type
   *   The name of the class to switch to. Can be one of: "danger", "info",
   *   "success" or "warning".
   * @param {string} prefix
   *   The prefix to use. Typically this would be something like "label" or
   *   "progress-bar".
   */
  Drupal.BootstrapPassword.prototype.switchClass = function ($element, type, prefix) {
    prefix = prefix + '-' || '';
    var types = prefix === 'has-' ? ['error', 'warning', 'success'] : ['danger', 'info', 'success', 'warning'];
    if (type) {
      type = types.splice($.inArray(type, types), 1).shift();
      $element.addClass(prefix + type);
    }
    $element.removeClass(prefix + types.join(' ' + prefix));
  };

  /**
   * Validates the strength of a password.
   */
  Drupal.BootstrapPassword.prototype.validateStrength = function () {
    var result = Drupal.evaluatePasswordStrength(this.password.$input.val(), Drupal.settings.password);

    // Ensure visibility.
    this.$helpBlock.show();
    this.strength.$label.show();
    this.strength.$bar.show();

    // Update the suggestions for how to improve the password.
    this.$helpBlock.html(result.message);

    // Only show the description box if there is a weakness in the password.
    this.$helpBlock[result.strength === 100 ? 'hide' : 'show']();

    // Update the strength indication text.
    this.strength.$label.html(result.indicatorText);

    // Adjust the length of the strength indicator.
    this.strength.$bar.attr('aria-valuenow', result.strength);
    this.strength.$bar.css('width', result.strength + '%');

    // Change the classes (color) of the strength meter based on result level.
    switch (result.indicatorText) {
      case this.settings.weak:
        this.switchClass(this.password.$wrapper, 'error', 'has');
        this.switchClass(this.strength.$label, 'danger', 'label');
        this.switchClass(this.strength.$bar, 'danger', 'progress-bar');
        this.password.$icon.addClass('glyphicon-remove').removeClass('glyphicon-warning-sign glyphicon-ok');
        break;

      case this.settings.fair:
      case this.settings.good:
        this.switchClass(this.password.$wrapper, 'warning', 'has');
        this.switchClass(this.strength.$label, 'warning', 'label');
        this.switchClass(this.strength.$bar, 'warning', 'progress-bar');
        this.password.$icon.addClass('glyphicon-warning-sign').removeClass('glyphicon-remove glyphicon-ok');
        break;

      case this.settings.strong:
        this.switchClass(this.password.$wrapper, 'success', 'has');
        this.switchClass(this.strength.$label, 'success', 'label');
        this.switchClass(this.strength.$bar, 'success', 'progress-bar');
        this.password.$icon.addClass('glyphicon-ok').removeClass('glyphicon-warning-sign glyphicon-remove');
        break;
    }
    this.validateMatch();
  };

  /**
   * Validates both original and confirmation passwords to ensure they match.
   */
  Drupal.BootstrapPassword.prototype.validateMatch = function () {
    var password = this.password.$input.val();

    // Passwords match.
    if (password && password === this.confirm.$input.val()) {
      this.switchClass(this.password.$wrapper, 'success', 'has');
      this.switchClass(this.confirm.$wrapper, 'success', 'has');
      this.$helpBlock.hide();
      this.strength.$label.hide();
      this.strength.$bar.hide();
      this.password.$icon.addClass('glyphicon-ok').removeClass('glyphicon-warning-sign glyphicon-remove');
      this.confirm.$icon.addClass('glyphicon-ok').removeClass('glyphicon-remove');
    }
    // Passwords do not match.
    else if (password) {
      this.switchClass(this.confirm.$wrapper, 'error', 'has');
      this.confirm.$icon.addClass('glyphicon-remove').removeClass('glyphicon-ok');
    }
    // No password.
    else {
      this.confirm.$icon.removeClass('glyphicon-ok glyphicon-remove');
      this.confirm.$input.val('');
      this.switchClass(this.confirm.$wrapper, '', 'has');
    }
  };

  /**
   * Overrides core JS for password strength and confirmation.
   *
   * Attach handlers to evaluate the strength of any password fields and to check
   * that its confirmation is correct.
   */
  Drupal.behaviors.password = {
    attach: function (context) {
      $('input.password-field', context).once('password', function () {
        new Drupal.BootstrapPassword(this);
      });
    }
  };

})(jQuery, window.Drupal);