Thumbnailer = ->

  Thumbnailer = this
  
  fs = require "fs"

  cp = require "child_process"

  path = require "path"

  exec = cp.exec

  enctype = "binary"

  ###
   doc_to_image opts, cb
   
   opts = 
     file_path: "/location/of/file/to/convert" #required
     write_path
  ###

  @doc_to_image: (opts, cb) ->

    filename = opts.file_path.replace path.extname opts.file_path, ".#{opts.convert_to}"

    is_pdf = path.extname opts.file_path is "pdf"

    commands = 
      un: "unoconv --stdout #{opts.file_path} | "
      gs: "gs -q -dNOPAUSE -dBATCH \
           -dPDFFitPage -sDEVICE=#{opts.convert_to} \
           -r144 -sOutputFile=%stdout \
           #{if is_pdf then opts.file_path else '-_'}"
      
    writable = fs.createWriteStream path.resolve(opts.write_to, filename),
      flags: "w"
      encoding: enctype
      mode: 0o0777
    
    child_process = exec "#{commands.un}#{commands.gs}",
      encoding: enctype
      maxBuffer: 5000 * 1024

      writable.on "close", -> cb null, filename, writable

      child_process.stdout.on "data", (chunk) -> writable.write chunk, enctype

      child_process.stdout.on "close", -> writable.close()

      child_process.stderr.on "data", (d) -> console.log d

module.exports = new Thumbnailer()