/**
 * Private methods
 */
module.exports = {

  _init: function() {

    var self = this;

    this._extend($.idealforms.extensions);

    this.$form = $(this.el);
    this.$fields = $();
    this.$inputs = $();

    this.$form.submit(function(e) {
      e.preventDefault();
      self.focusFirstInvalid();
      self.opts.onSubmit.call(self, self.getInvalid().length, e);
    });

    this._inject('_init');

    this.addRules(this.opts.rules || {});

    if (! this.opts.silentLoad) this.focusFirstInvalid();
  },

  _buildField: function(input) {

    var self = this
      , $field = this._getField(input)
      , $icon;

    $icon = $(this.opts.iconHtml, {
      class: this.opts.iconClass,
      click: function(){ $(input).focus() }
    });

    if (! this.$fields.filter($field).length) {
      this.$fields = this.$fields.add($field);
      if (this.opts.iconHtml) $field.append($icon);
      $field.addClass('idealforms-field idealforms-field-'+ input.type);
    }

    this._addEvents(input);

    this._inject('_buildField', input);
  },

  _addEvents: function(input) {

    var self = this
      , $field = this._getField(input);

    $(input)
      .on('change keyup', function(e) {

        var oldValue = $field.data('idealforms-value');

        if (e.which == 9 || e.which == 16) return;
        if (! $(this).is(':checkbox, :radio') && oldValue == this.value) return;

        $field.data('idealforms-value', this.value);

        self._validate(this, true, true);
      })
      .focus(function() {

        if (self.isValid(this.name)) return false;

        if (self._isRequired(this) || this.value) {
          $field.find(self.opts.error).show();
        }
      })
      .blur(function() {
        $field.find(self.opts.error).hide();
      });
  },

  _isRequired: function(input) {
    // We assume non-text inputs with rules are required
    if ($(input).is(':checkbox, :radio, select')) return true;
    return this.opts.rules[input.name].indexOf('required') > -1;
  },

  _getRelated: function(input) {
    return this._getField(input).find('[name="'+ input.name +'"]');
  },

  _getField: function(input) {
    return $(input).closest(this.opts.field);
  },

  _getFirstInvalid: function() {
    return this.getInvalid().first().find('input:first, textarea, select');
  },

  _handleError: function(input, error, valid) {
    valid = valid || this.isValid(input.name);
    var $error = this._getField(input).find(this.opts.error);
    this.$form.find(this.opts.error).hide();
    if (error) $error.text(error);
    $error.toggle(!valid);
  },

  _handleStyle: function(input, valid) {
    valid = valid || this.isValid(input.name);
    this._getField(input)
      .removeClass(this.opts.validClass +' '+ this.opts.invalidClass)
      .addClass(valid ? this.opts.validClass : this.opts.invalidClass)
      .find('.'+ this.opts.iconClass).show();
  },

  _fresh: function(input) {
    this._getField(input)
      .removeClass(this.opts.validClass +' '+ this.opts.invalidClass)
      .find(this.opts.error).hide()
      .end()
      .find('.'+ this.opts.iconClass).toggle(this._isRequired(input));
  },

  _validate: function(input, handleError, handleStyle) {

    var self = this
      , $field = this._getField(input)
      , userRules = this.opts.rules[input.name].split($.idealforms.ruleSeparator)
      , valid = true
      , rule;

    // Non-required input with empty value must pass validation
    if (! input.value && ! this._isRequired(input)) {
      $field.removeData('idealforms-valid');
      this._fresh(input);

    // Required inputs
    } else {

      $.each(userRules, function(i, userRule) {

        userRule = userRule.split($.idealforms.argSeparator);

        rule = userRule[0];

        var theRule = $.idealforms.rules[rule]
          , args = userRule.slice(1)
          , error;

        error = $.idealforms._format.apply(null, [
          $.idealforms._getKey('errors.'+ input.name +'.'+ rule, self.opts) ||
          $.idealforms.errors[rule]
        ].concat(args));

        valid = typeof theRule == 'function'
          ? theRule.apply(self, [input, input.value].concat(args))
          : theRule.test(input.value);

        $field.data('idealforms-valid', valid);

        if (handleError) self._handleError(input, error, valid);
        if (handleStyle) self._handleStyle(input, valid);

        self.opts.onValidate.call(self, input, rule, valid);

        return valid;
      });
    }

    this._inject('_validate', input, rule, valid);

    return valid;
  }

};