module InlineSvg::ActionView::Helpers

def backwards_compatible_html_escape(filename)
  # html_escape_once was introduced in newer versions of Rails.
  if ERB::Util.respond_to?(:html_escape_once)
    ERB::Util.html_escape_once(filename)
  else
    ERB::Util.html_escape(filename)
  end
end

def configured_asset_file
  InlineSvg.configuration.asset_file
end

def extension_hint(filename)
  filename.ends_with?(".svg") ? "" : "(Try adding .svg to your filename) "
end

def inline_svg(filename, transform_params={})
  render_inline_svg(filename, transform_params)
end

def inline_svg_pack_tag(filename, transform_params={})
  with_asset_finder(InlineSvg::WebpackAssetFinder) do
    render_inline_svg(filename, transform_params)
  end
end

def inline_svg_tag(filename, transform_params={})
  with_asset_finder(InlineSvg.configuration.asset_finder) do
    render_inline_svg(filename, transform_params)
  end
end

def placeholder(filename)
  css_class = InlineSvg.configuration.svg_not_found_css_class
  not_found_message = "'#{backwards_compatible_html_escape(filename)}' #{extension_hint(filename)}"
  if css_class.nil?
    return "<svg><!-- SVG file not found: #{not_found_message}--></svg>".html_safe
  else
    return "<svg class='#{css_class}'><!-- SVG file not found: #{not_found_message}--></svg>".html_safe
  end
end

def read_svg(filename)
  if InlineSvg::IOResource === filename
    InlineSvg::IOResource.read filename
  else
    configured_asset_file.named filename
  end
end

def render_inline_svg(filename, transform_params={})
  begin
    svg_file = read_svg(filename)
  rescue InlineSvg::AssetFile::FileNotFound => error
    raise error if InlineSvg.configuration.raise_on_file_not_found?
    return placeholder(filename) unless transform_params[:fallback].present?
    if transform_params[:fallback].present?
      begin
        svg_file = read_svg(transform_params[:fallback])
      rescue InlineSvg::AssetFile::FileNotFound
        placeholder(filename)
      end
    end
  end
  InlineSvg::TransformPipeline.generate_html_from(svg_file, transform_params).html_safe
end

def with_asset_finder(asset_finder)
  Thread.current[:inline_svg_asset_finder] = asset_finder
  output = yield
  Thread.current[:inline_svg_asset_finder] = nil
  output
end