if defined?(ActiveRecord)
  module Huberry
    module AttrEncrypted
      module Adapters
        module ActiveRecord
          def self.extended(base)
            base.eigenclass_eval { alias_method_chain :method_missing, :attr_encrypted }
          end
        
          protected
        
            # Calls attr_encrypted with the options <tt>:encode</tt> and <tt>:marshal</tt> set to true
            # unless they've already been specified
            #
            # Also defines the attribute methods for db fields if they don't exist yet
            def attr_encrypted(*attrs)
              define_attribute_methods
              options = { :encode => true, :marshal => true }.merge(attrs.last.is_a?(Hash) ? attrs.pop : {})
              super *(attrs << options)
            end
          
            # Allows you to use dynamic methods like <tt>find_by_email</tt> or <tt>scoped_by_email</tt> for 
            # encrypted attributes
            #
            # NOTE: This only works when the <tt>:key</tt> option is specified as a string (see the README)
            #
            # This is useful for encrypting fields like email addresses. Your user's email addresses 
            # are encrypted in the database, but you can still look up a user by email for logging in
            #
            # Example
            #
            #   class User < ActiveRecord::Base
            #     attr_encrypted :email, :key => 'secret key'
            #   end
            #
            #   User.find_by_email_and_password('test@example.com', 'testing')
            #   # results in a call to
            #   User.find_by_encrypted_email_and_password('the_encrypted_version_of_test@example.com', 'testing')
            def method_missing_with_attr_encrypted(method, *args, &block)
              if match = /^(find|scoped)_(all_by|by)_([_a-zA-Z]\w*)$/.match(method.to_s)
                attribute_names = match.captures.last.split('_and_')
                attribute_names.each_with_index do |attribute, index|
                  if attr_encrypted?(attribute)
                    args[index] = send("encrypt_#{attribute}", args[index])
                    attribute_names[index] = encrypted_attributes[attribute]
                  end
                end
                method = "#{match.captures[0]}_#{match.captures[1]}_#{attribute_names.join('_and_')}".to_sym
              end
              method_missing_without_attr_encrypted(method, *args, &block)
            end
        end
      end
    end
  end
  
  ActiveRecord::Base.extend Huberry::AttrEncrypted::Adapters::ActiveRecord
end