module GitHub::Markup

def can_render?(filename)
  !!renderer(filename)
end

def command(command, regexp, &block)
  if File.exists?(file = File.dirname(__FILE__) + "/commands/#{command}")
    command = file
  end
  markups << CommandImplementation.new(regexp, command, &block)
end

def markup(file, pattern, opts = {}, &block)
  markups << GemImplementation.new(pattern, file, &block)
end

def markups
  @@markups
end

def preload!
  markups.each do |markup|
    markup.load
  end
end

def render(filename, content = nil)
  content ||= File.read(filename)
  if impl = renderer(filename)
    impl.render(content)
  else
    content
  end
end

def renderer(filename)
  markups.find { |impl|
    impl.match?(filename)
  }
end