class Jekyll::Tags::HighlightBlock

def add_code_tags(code, lang)
  # Add nested <code> tags to code blocks
  code = code.sub(/<pre>/,'<pre><code class="' + lang.to_s.gsub("+", "-") + '">')
  code = code.sub(/<\/pre>/,"</code></pre>")
end

def initialize(tag_name, markup, tokens)
  super
  if markup.strip =~ SYNTAX
    @lang = $1.downcase
    @options = {}
    if defined?($2) && $2 != ''
      $2.split.each do |opt|
        key, value = opt.split('=')
        if value.nil?
          if key == 'linenos'
            value = 'inline'
          else
            value = true
          end
        end
        @options[key] = value
      end
    end
  else
    raise SyntaxError.new <<-eos
 Error in tag 'highlight' while parsing the following markup:
rkup}
syntax: highlight <lang> [linenos]
  end
end

def render(context)
  case context.registers[:site].highlighter
  when 'pygments'
    render_pygments(context, super)
  when 'rouge'
    render_rouge(context, super)
  else
    render_codehighlighter(context, super)
  end
end

def render_codehighlighter(context, code)
  #The div is required because RDiscount blows ass
  <<-HTML
>
re><code class='#{@lang.to_s.gsub("+", "-")}'>#{h(code).strip}</code></pre>
v>
  HTML
end

def render_pygments(context, code)
  require 'pygments'
  @options[:encoding] = 'utf-8'
  highlighted_code = Pygments.highlight(code, :lexer => @lang, :options => @options)
  if highlighted_code.nil?
    Jekyll.logger.error "There was an error highlighting your code:"
    puts
    Jekyll.logger.error code
    puts
    Jekyll.logger.error "While attempting to convert the above code, Pygments.rb" +
      " returned an unacceptable value."
    Jekyll.logger.error "This is usually a timeout problem solved by running `jekyll build` again."
    raise ArgumentError.new("Pygments.rb returned an unacceptable value when attempting to highlight some code.")
  end
  output = add_code_tags(highlighted_code, @lang)
  output = context["highlighter_prefix"] + output if context["highlighter_prefix"]
  output << context["highlighter_suffix"] if context["highlighter_suffix"]
  return output
end

def render_rouge(context, code)
  require 'rouge'
  linenos = @options.keys.include?('linenos')
  lexer = Rouge::Lexer.find_fancy(@lang, code) || Rouge::Lexers::PlainText
  formatter = Rouge::Formatters::HTML.new(line_numbers: linenos, wrap: false)
  pre = "<pre>#{formatter.format(lexer.lex(code))}</pre>"
  output = context["highlighter_prefix"] || ""
  output << "<div class=\"highlight\">"
  output << add_code_tags(pre, @lang)
  output << "</div>"
  output << context["highlighter_suffix"] if context["highlighter_suffix"]
  return output
end