#!/usr/bin/env ruby
# Author : Emad Elsaid (https://github.com/blazeeboy)
require 'pygmentize' # gem install pygmentize
require 'redcarpet' # gem install redcarpet

# consecutive lines of code
# should be highlighted using pygmentize
# and converter to markdown block simply
# using the markdown syntax for code
# used by github flavored markdown
class CodeBlock < Array

  def to_html
    Pygmentize.process join, :ruby
  end

  def to_md
    "```ruby\n#{join}\n```"
  end
  alias_method :to_markdown, :to_md
end

# set of consecutive lines of comments
class CommentBlock < Array

  # will use this Redcarpet renderer to convert 
  # markdown to html
  @@renderer = Redcarpet::Markdown.new(Redcarpet::Render::HTML, 
                            fenced_code_blocks: true,
                            disable_indented_code_blocks: true,
                            strikethrough: true,
                            superscript: true,
                            underline: true,
                            autolink: true )

  # use the renderer on the content
  def to_html
    @@renderer.render join("\n")
  end

  # convert the block to markdown format
  # and also give it a full name alias
  def to_md
    join("\n")
  end
  alias_method :to_markdown, :to_md

end 

# container class will have multiple blocks of 
# comments and code
class CodeConverter < Array

  # you should pass code when
  # initializing new instance
  # in order to parse it
  def initialize( code )
    parse code
  end

  # add new line of code to the class
  # it start new code block if the last block is
  # not code block then adds the line of code
  # to the last block
  def add_code( line )
    self << CodeBlock.new unless last.is_a? CodeBlock
    last << line
  end

  # add new comment line to the class
  # it adds new comment block if the last block is not 
  # comments block then add the comment line to the block
  def add_comment( line )
    self << CommentBlock.new unless last.is_a? CommentBlock
    last << line
  end

  # parse code and put result to this class
  # first insert a comment block then
  # parse each line and add it according 
  # to the line type
  def parse(code)
    replace [CommentBlock.new]

    code.lines.each do |line|
      case
        when line.strip.start_with?('# ')
          add_comment line.strip[2..-1]

        when line.strip.start_with?('#!')
          add_code line

        when line.strip.start_with?('#')
          add_comment line.strip[1..-1]

        else
          add_code line
      end
    end

  end

  # convert each block to html
  # and wrap it in a styled page
  # if a file path passed it'll write output to it
  # in all cases it'll return the output
  def to_html(file = nil)
    code = map.with_index do |block, i| 
          # each cell in resulted table 
          # will have a class same as the 
          # class name of teh block downcased
          klass = block.class.to_s.downcase
          # start table row or end it
          # according to the current block index
          prefix = i.even? ? '<tr>' : ''
          suffix = i.odd? ? '</tr>' : ''
          # produced block html
          "#{prefix}<td class=\"section #{klass}\">#{block.to_html}</td>#{suffix}" 
        end

    # add a closing cell if the code 
    # ends with comments lines
    code << "<td></td></tr>" if last.is_a? CommentBlock

    # here is the full page with embeded style
    # i had to add the css here to make sure script stay as 
    # one file not multiple dependent files.
    html = <<-EOT
<html>
<head>
<style>
body { background: #29281e; padding:0px; margin:0px; font-family: verdana, tahoma; font-size: 13px; }
.content{ border-collapse: collapse; }
.section{ padding: 5px; border-top: 1px solid #333; } 
.commentblock{ width: 40%;text-align: right; vertical-align: top; font-size: 13px; color: #ddd; text-shadow: 1px 1px 0px black; }
.codeblock{ width: 60%; background: #29281e; border-left: 1px solid #333; padding-left: 10px; }
.commentblock a{ color: #fff; }
.codeblock pre{ white-space: pre-wrap; margin: 0px; }
.highlight { padding: 0px; font-size: 13px; }
div.highlight, div.highlight code, div.highlight pre  { padding: 0px; }div.highlight code { padding: 0; }div.highlight .c { color: #75715e }div.highlight .err { color: #960050; background-color: #1e0010 }div.highlight .k { color: #66d9ef }div.highlight .l { color: #ae81ff }div.highlight .n { color: #f8f8f2 }div.highlight .o { color: #f92672 }div.highlight .p { color: #f8f8f2 }div.highlight .cm { color: #75715e }div.highlight .cp { color: #75715e }div.highlight .c1 { color: #75715e }div.highlight .cs { color: #75715e }div.highlight .ge { font-style: italic }div.highlight .gs { font-weight: bold }div.highlight .kc { color: #66d9ef }div.highlight .kd { color: #66d9ef }div.highlight .kn { color: #f92672 }div.highlight .kp { color: #66d9ef }div.highlight .kr { color: #66d9ef }div.highlight .kt { color: #66d9ef }div.highlight .ld { color: #e6db74 }div.highlight .m { color: #ae81ff }div.highlight .s { color: #e6db74 }div.highlight .na { color: #a6e22e }div.highlight .nb { color: #f8f8f2 }div.highlight .nc { color: #a6e22e }div.highlight .no { color: #66d9ef }div.highlight .nd { color: #a6e22e }div.highlight .ni { color: #f8f8f2 }div.highlight .ne { color: #a6e22e }div.highlight .nf { color: #a6e22e }div.highlight .nl { color: #f8f8f2 }div.highlight .nn { color: #f8f8f2 }div.highlight .nx { color: #a6e22e }div.highlight .py { color: #f8f8f2 }div.highlight .nt { color: #f92672 }div.highlight .nv { color: #f8f8f2 }div.highlight .ow { color: #f92672 }div.highlight .w { color: #f8f8f2 }div.highlight .mf { color: #ae81ff }div.highlight .mh { color: #ae81ff }div.highlight .mi { color: #ae81ff }div.highlight .mo { color: #ae81ff }div.highlight .sb { color: #e6db74 }div.highlight .sc { color: #e6db74 }div.highlight .sd { color: #e6db74 }div.highlight .s2 { color: #e6db74 }div.highlight .se { color: #ae81ff }div.highlight .sh { color: #e6db74 }div.highlight .si { color: #e6db74 }div.highlight .sx { color: #e6db74 }div.highlight .sr { color: #e6db74 }div.highlight .s1 { color: #e6db74 }div.highlight .ss { color: #e6db74 }div.highlight .bp { color: #f8f8f2 }div.highlight .vc { color: #f8f8f2 }div.highlight .vg { color: #f8f8f2 }div.highlight .vi { color: #f8f8f2 }div.highlight .il { color: #ae81ff }
</style>
</head>
<body>
<table class="content">#{code.join}</table>
</body>
</html>
EOT
  
    # write output to file if a path is passed
    # and return html
    File.write file, html unless file.nil?
    html
  end

  # Convert the analyzed code into Markdown
  # this is easier than HTML as you'll need
  # to convert each block to markdown and
  # join them with new line
  # write output to file if a path is passed
  def to_md(file=nil)
    
    md = map {|b| b.to_md }.join "\n"
    
    File.write file, md unless file.nil?
    md
  end
  alias_method :to_markdown, :to_md

end

# ## How to use ?
# create new Code Converter class with code
blocks = CodeConverter.new( File.read('/path/to/code/file.rb') )
# and convert to html and markdown and save it to this file path
blocks.to_html '/path/to/html/code.html'
blocks.to_md '/path/to/md/markdown.md'