module GOVUKDesignSystemFormBuilder
  module Traits
    module Input
      def initialize(builder, object_name, attribute_name, hint_text:, label:, caption:, width:, **extra_args, &block)
        super(builder, object_name, attribute_name, &block)

        @width          = width
        @extra_args     = extra_args
        @label          = label
        @caption        = caption
        @hint_text      = hint_text
      end

      def html
        Containers::FormGroup.new(@builder, @object_name, @attribute_name).html do
          safe_join(
            [
              label_element.html,
              supplemental_content.html,
              hint_element.html,
              error_element.html,
              @builder.send(
                builder_method,
                @attribute_name,
                id: field_id(link_errors: true),
                class: input_classes,
                aria: {
                  describedby: described_by(
                    hint_id,
                    error_id,
                    supplemental_id
                  )
                },
                **@extra_args
              )
            ]
          )
        end
      end

    private

      def input_classes
        [%(#{brand}-input)].push(width_classes, error_classes).compact
      end

      def error_classes
        %(#{brand}-input--error) if has_errors?
      end

      def width_classes
        return if @width.blank?

        case @width

          # fixed (character) widths
        when 20 then %(#{brand}-input--width-20)
        when 10 then %(#{brand}-input--width-10)
        when 5  then %(#{brand}-input--width-5)
        when 4  then %(#{brand}-input--width-4)
        when 3  then %(#{brand}-input--width-3)
        when 2  then %(#{brand}-input--width-2)

          # fluid widths
        when 'full'           then %(#{brand}-!-width-full)
        when 'three-quarters' then %(#{brand}-!-width-three-quarters)
        when 'two-thirds'     then %(#{brand}-!-width-two-thirds)
        when 'one-half'       then %(#{brand}-!-width-one-half)
        when 'one-third'      then %(#{brand}-!-width-one-third)
        when 'one-quarter'    then %(#{brand}-!-width-one-quarter)

        else fail(ArgumentError, "invalid width '#{@width}'")
        end
      end
    end
  end
end