(function (ns) {
  ns.Form = qs.createObject();

  ns.Form.prototype = {
    initialize: function (options) {
      this.options = options;
      this.className = 'app.user.form';
      this.namespace = 'userForm';
      if (this.initElements()) {
        this.initEvents();
      }
      return this;
    },

    initElements: function () {
      this.form = $('#' + this.options.formId);
      if (!$(this.form).size()) {
        this.showError('Form "' + this.options.formId + '" not found.');
        return false;
      }

      this.element = {};

      for (var name in {'firstName': '', 'lastName': '', 'email': ''}) {
        this.element[name] = $('[name=' + name + ']', this.form);
        if (!$(this.form).size()) {
          this.showError('Element "' + name + '" not found');
          return false;
        }
      }
      return true;
    },

    initEvents: function () {
      this.element.firstName.bind('blur.' + this.namespace, _.bind(this.onBlur, this, 'firstName'));
      this.element.lastName.bind('blur.' + this.namespace, _.bind(this.onBlur, this, 'lastName'));
      this.element.email.bind('blur.' + this.namespace, _.bind(this.onBlur, this, 'email'));

      for (var i = 0; i < this.options.addressTypes.length; i++) {
        var type = this.options.addressTypes[i];
        var asBilling = $('[name="' + type + '[asBilling]"]', this.form);
        if (asBilling.size()) {
          asBilling.bind('change.' + this.namespace, _.bind(this.onAsBillingClick, this, asBilling, type));
          this.onAsBillingClick(asBilling, type);
        }
      }

      return this;
    },

    onAsBillingClick: function (asBilling, type, event) {
      for (var i = 0; i < this.options.addressFields.length; i++) {
        var name = this.options.addressFields[i];
        var idTpl = type + '-' + name + '-';
        var selector = '#' + idTpl + 'label, #' + idTpl + 'element';
        if ($(asBilling).is(':checked')) {
          $(selector).addClass('hidden');
        } else {
          $(selector).removeClass('hidden');
          if (undefined != event && 'change' == event.type && !this.getElementValue(type, name)) {
            this.setElementValue(type, name, this.getElementValue(this.options.inheritedAddress, name));
          }
        }
      }
      return true;
    },

    onBlur: function (name) {
      var value = $(this.element[name]).val();
      if (value && !this.getElementValue(this.options.inheritedAddress, name)) {
        this.setElementValue(this.options.inheritedAddress, name, value);
      }

      return this;
    },

    getElementValue: function (type, name) {
      return $('#' + type + '-' + name, this.form).val();
    },

    setElementValue: function (type, name, value) {
      $('#' + type + '-' + name, this.form).val(value);
    },

    showError: function (error) {
      alert(this.className + ' can not be initialized. ' + error);
      return this;
    }
  };
})(qs.defineNS('app.user'));