require 'mail'

module Glengarry
  class EmailValidator < ActiveModel::EachValidator
    def validate_each(record, attribute, value)
      unless valid_email?(value)
        msg = options[:message] 
        msg ||= I18n.t(:"validators.email.invalid", :default => "has invalid format")
        record.errors[attribute] << msg
      end
    end

    protected

    # Internal: Takes an email and returns whether is invalid or not.
    #
    # email - A String email address to be validated.
    #
    # Returns true if email is valid.
    def valid_email?(email)
      mail = Mail::Address.new(email)

      # We must check that value contains a domain and that value is 
      # an email address
      result = mail.domain && mail.address == email
      tree = mail.__send__(:tree)

      # We need to dig into treetop. A valid domain must have 
      # dot_atom_text elements size > 1. Addresses like user@localhost 
      # are excluded. Treetop must respond to domain.
      result && (tree.domain.dot_atom_text.elements.size > 1)
    rescue => e
      false
    end
  end
end