class HexaPDF::Type::AcroForm::ButtonField

def allowed_values
  (each_widget.with_object([]) do |widget, result|
     keys = widget.appearance_dict&.normal_appearance&.value&.keys
     result.concat(keys) if keys
   end - [:Off]).uniq
end

def check_box?
  !push_button? && !flagged?(:radio)
end

def concrete_field_type
  if push_button?
    :push_button
  elsif radio_button?
    :radio_button
  else
    :check_box
  end
end

def create_appearances(force: false)
  appearance_generator_class = document.config.constantize('acro_form.appearance_generator')
  each_widget do |widget|
    normal_appearance = widget.appearance_dict&.normal_appearance
    next if !force && normal_appearance &&
      ((!push_button? && normal_appearance.value.length == 2 &&
        normal_appearance.each.all? {|_, v| v.kind_of?(HexaPDF::Stream) }) ||
       (push_button? && normal_appearance.kind_of?(HexaPDF::Stream)))
    if check_box?
      appearance_generator_class.new(widget).create_check_box_appearances
    elsif radio_button?
      appearance_generator_class.new(widget).create_radio_button_appearances
    else
      appearance_generator_class.new(widget).create_push_button_appearances
    end
  end
end

def create_widget(page, defaults: true, value: nil, **values)
  super(page, allow_embedded: !radio_button?, **values).tap do |widget|
    value = :Yes if check_box? && value.nil?
    if radio_button? || check_box?
      unless value.respond_to?(:to_sym)
        raise ArgumentError, "Argument 'value' has to be provided for radio buttons " \
          "and needs to respond to #to_sym"
      end
      widget[:AP] = {N: {value.to_sym => nil, Off: nil}}
    end
    next unless defaults
    widget.border_style(color: 0, width: 1, style: (push_button? ? :beveled : :solid))
    widget.background_color(push_button? ? 0.5 : 255)
    widget.marker_style(style: check_box? ? :check : :circle) unless push_button?
  end
end

def default_field_value
  normalized_field_value(:DV)
end

def default_field_value=(value)
  normalized_field_value_set(:DV, value)
end

def field_value
  normalized_field_value(:V)
end

def field_value=(value)
  normalized_field_value_set(:V, value)
end

def initialize_as_check_box
  self[:V] = :Off
  unflag(:push_button)
  unflag(:radio)
end

def initialize_as_push_button
  self[:V] = nil
  flag(:push_button)
  unflag(:radio)
end

def initialize_as_radio_button
  self[:V] = :Off
  unflag(:push_button)
  flag(:radio)
end

def normalized_field_value(key)
  if push_button?
    nil
  else
    self[key] == :Off ? nil : self[key]
  end
end

def normalized_field_value_set(key, value)
  return if push_button?
  av = allowed_values
  self[key] = if value.nil? || value == :Off
                :Off
              elsif check_box?
                if value == false
                  :Off
                elsif value == true && av.size == 1
                  av[0]
                elsif av.include?(value.to_sym)
                  value.to_sym
                else
                  @document.config['acro_form.on_invalid_value'].call(self, value)
                end
              elsif av.include?(value.to_sym)
                value.to_sym
              else
                @document.config['acro_form.on_invalid_value'].call(self, value)
              end
  update_widgets
end

def perform_validation #:nodoc:
  if field_type != :Btn
    yield("Field /FT of AcroForm button field has to be :Btn", true)
    self[:FT] = :Btn
  end
  super
  unless key?(:V)
    yield("Button field has no value set, defaulting to :Off", true)
    self[:V] = :Off
  end
end

def push_button?
  flagged?(:push_button)
end

def radio_button?
  !push_button? && flagged?(:radio)
end

def update_widgets
  return if push_button?
  create_appearances
  value = self[:V]
  each_widget do |widget|
    widget[:AS] = (widget.appearance_dict&.normal_appearance&.key?(value) ? value : :Off)
  end
end