class Shoulda::Matchers::ActiveModel::AllowMassAssignmentOfMatcher

def accessible_attributes
  @accessible_attributes ||= (@subject.class.accessible_attributes || [])
end

def active_model_less_than_3_1?
  ::ActiveModel::VERSION::STRING.to_f < 3.1
end

def as(role)
  if active_model_less_than_3_1?
    raise 'You can specify role only in Rails 3.1 or greater'
  end
  @options[:role] = role
  self
end

def attr_mass_assignable?
  !authorizer.deny?(@attribute)
end

def authorizer
  if active_model_less_than_3_1?
    @subject.class.active_authorizer
  else
    @subject.class.active_authorizer[role]
  end
end

def base_description
  "allow mass assignment of #{@attribute}"
end

def class_name
  @subject.class.name
end

def description
  [base_description, role_description].compact.join(' ')
end

def initialize(attribute)
  @attribute = attribute.to_s
  @options = {}
end

def matches?(subject)
  @subject = subject
  if attr_mass_assignable?
    if whitelisting?
      @failure_message_for_should_not = "#{@attribute} was made accessible"
    else
      if protected_attributes.empty?
        @failure_message_for_should_not = 'no attributes were protected'
      else
        @failure_message_for_should_not = "#{class_name} is protecting " <<
          "#{protected_attributes.to_a.to_sentence}, " <<
          "but not #{@attribute}."
      end
    end
    true
  else
    if whitelisting?
      @failure_message_for_should = "Expected #{@attribute} to be accessible"
    else
      @failure_message_for_should = "Did not expect #{@attribute} to be protected"
    end
    false
  end
end

def protected_attributes
  @protected_attributes ||= (@subject.class.protected_attributes || [])
end

def role
  @options[:role] || :default
end

def role_description
  if role != :default
    "as #{role}"
  end
end

def whitelisting?
  authorizer.kind_of?(::ActiveModel::MassAssignmentSecurity::WhiteList)
end