module Kramdown::Converter::MathEngine::Mathjax

def self.call(converter, el, opts)
  type = el.options[:category]
  text = (el.value =~ /<|&/ ? "% <![CDATA[\n#{el.value} %]]>" : el.value).dup
  text.gsub!(/<\/?script>?/, '')
  preview = preview_string(converter, el, opts).dup
  attr = {type: "math/tex#{type == :block ? '; mode=display' : ''}"}
  preview << if type == :block
               converter.format_as_block_html('script', attr, text, opts[:indent])
             else
               converter.format_as_span_html('script', attr, text)
             end
end

def self.preview_string(converter, el, opts)
  preview = converter.options[:math_engine_opts][:preview]
  return '' unless preview
  preview = (preview == true ? converter.escape_html(el.value) : preview.to_s)
  preview_as_code = converter.options[:math_engine_opts][:preview_as_code]
  if el.options[:category] == :block
    if preview_as_code
      converter.format_as_block_html('pre', {'class' => 'MathJax_Preview'},
                                     converter.format_as_span_html('code', {}, preview),
                                     opts[:indent])
    else
      converter.format_as_block_html('div', {'class' => 'MathJax_Preview'}, preview,
                                     opts[:indent])
    end
  else
    converter.format_as_span_html(preview_as_code ? 'code' : 'span',
                                  {'class' => 'MathJax_Preview'}, preview)
  end
end