require 'rdiscount'
require 'nokogiri'
require 'coderay'

module Falcon
  class Content
    # Return a summary if a delimiter is found, otherwise
    # return the full body.
    def self.summary_of(text, delimiter = "~\n")
      summary = if text =~ /#{delimiter}/i
        text.split(/#{delimiter}/i).first.strip
      else
        text
      end
    end

    # Return the full body, excluding any delimiter
    # that may be present
    def self.body_of(text, delimiter = "~\n")
      text.gsub(/#{delimiter}/i, '')
    end

    # Apply markdown and CodeRay syntax highlighting,
    def self.htmlify(text)
      # Mardown => HTML
      html = RDiscount.new(text).to_html

      # Syntax highlighting with Coderay
      doc = Nokogiri::HTML::fragment(html, 'UTF-8')
      nodes = doc.search("pre>code")
      highlighter = :coderay
      nodes.each do |node|
        s = node.inner_html || "[++where is the code?++]"
        node.parent.swap(send(highlighter, s))
      end

      doc.to_html
    end

    private
    def self.coderay(string, pattern = /\A:::(\w+)\s*(\n|
)/i)
      lang = 'unknown'
      refs = pattern.match(string)  # extract language name
      if refs
        lang = refs[1]
        str = unescape_html(string.sub(pattern, ""))
        "<pre class='CodeRay'>#{::CodeRay.encoder(:html).encode str, lang}</pre>"
      else
        "<pre class='CodeRay'>#{string}</pre>"
      end
    end

    private
    def self.unescape_html(string)
      string.to_s.gsub(/&#x000A;/i, "\n").gsub("<", '<').gsub(">", '>').gsub("&", '&')
    end
  end
end