class HTMLProofer::Check::Images

def alt_all_spaces?
  !missing_alt_tag? && @img.node["alt"].split.all?(" ")
end

def empty_alt_tag?
  !missing_alt_tag? && @img.node["alt"].empty?
end

def empty_whitespace_alt_tag?
  !missing_alt_tag? && @img.node["alt"].strip.empty?
end

def ignore_element?
  @img.url.ignore? || @img.aria_hidden?
end

def ignore_empty_alt?
  @runner.options[:ignore_empty_alt]
end

def ignore_missing_alt?
  @runner.options[:ignore_missing_alt]
end

def missing_alt_tag?
  @img.node["alt"].nil?
end

def missing_src?
  blank?(@img.url.to_s)
end

def run
  @html.css("img, source").each do |node|
    @img = create_element(node)
    next if @img.ignore?
    # screenshot filenames should return because of terrible names
    add_failure(
      "image has a terrible filename (#{@img.url.raw_attribute})",
      element: @img,
    ) if terrible_filename?
    # does the image exist?
    if missing_src?
      add_failure("image has no src or srcset attribute", element: @img)
    elsif @img.multiple_srcsets? || @img.multiple_sizes?
      @img.srcsets_wo_sizes.each do |srcset|
        srcset_url = HTMLProofer::Attribute::Url.new(@runner, srcset, base_url: @img.base_url, source: @img.url.source, filename: @img.url.filename, extract_size: true)
        if srcset_url.protocol_relative?
          add_failure(
            "image link #{srcset_url.url} is a protocol-relative URL, use explicit https:// instead",
            element: @img,
          )
        elsif srcset_url.remote?
          add_to_external_urls(srcset_url.url, @img.line)
        elsif !srcset_url.exists?
          add_failure("internal image #{srcset} does not exist", element: @img)
        end
      end
    elsif @img.url.protocol_relative?
      add_failure(
        "image link #{@img.url} is a protocol-relative URL, use explicit https:// instead",
        element: @img,
      )
    elsif @img.url.remote?
      add_to_external_urls(@img.url, @img.line)
    elsif !@img.url.exists? && !@img.multiple_srcsets? && !@img.multiple_sizes?
      add_failure(
        "internal image #{@img.url.raw_attribute} does not exist",
        element: @img,
      )
    end
    # if this is an img element, check that the alt attribute is present
    if @img.img_tag? && !ignore_element?
      if missing_alt_tag? && !ignore_missing_alt?
        add_failure(
          "image #{@img.url.raw_attribute} does not have an alt attribute",
          element: @img,
        )
      elsif (empty_alt_tag? || alt_all_spaces?) && !ignore_empty_alt?
        add_failure(
          "image #{@img.url.raw_attribute} has an alt attribute, but no content",
          element: @img,
        )
      end
    end
    add_failure(
      "image #{@img.url.raw_attribute} uses the http scheme",
      element: @img,
    ) if @runner.enforce_https? && @img.url.http?
  end
  external_urls
end

def terrible_filename?
  @img.url.to_s =~ SCREEN_SHOT_REGEX
end