require 'rubygems/package'
require 'zlib'
require 'fileutils'
 
# SOURCE: https://gist.github.com/sinisterchipmunk/1335041
# Adapted for Rbbt 

module Misc
  # Creates a tar file in memory recursively
  # from the given path.
  #
  # Returns a StringIO whose underlying String
  # is the contents of the tar file.
  def self.tar(path, tarfile = nil)
    tarfile ||= StringIO.new("")

    Gem::Package::TarWriter.new(tarfile) do |tar|
      Dir[File.join(path, "**/*")].each do |file|
        mode = File.stat(file).mode
        relative_file = file.sub /^#{Regexp::escape path}\/?/, ''

        if File.directory?(file)
          tar.mkdir relative_file, mode
        else
          tar.add_file relative_file, mode do |tf|
            File.open(file, "rb") { |f| tf.write f.read }
          end
        end
      end
    end

    tarfile.rewind

    tarfile
  end

  def self.tarize(path, gz = nil)
    gz ||= StringIO.new('wb')

    tar =  Misc.in_dir(path) do self.tar('.') end

    tar.rewind

    string = tar.string

    z = Zlib::GzipWriter.new(gz)
    z.write string
    z.close

    gz.reopen('read')
    gz.rewind


    gz
  end

  def self.tarize(path)
    Misc.in_dir(path) do
      CMD.cmd("tar cvfz - '.'", :pipe => true)
    end
  end

  # gzips the underlying string in the given StringIO,
  # returning a new StringIO representing the 
  # compressed file.
  def self.gzip(tarfile)
    gz = StringIO.new("")
    z = Zlib::GzipWriter.new(gz)
    z.write tarfile.string
    z.close # this is necessary!

    # z was closed to write the gzip footer, so
    # now we need a new StringIO
    StringIO.new gz.string
  end

  # un-gzips the given IO, returning the
  # decompressed version as a StringIO
  def ungzip(tarfile)
    z = Zlib::GzipReader.new(tarfile)
    unzipped = StringIO.new(z.read)
    z.close
    unzipped
  end

  # untars the given IO into the specified
  # directory
  def untar(io, destination)
    Gem::Package::TarReader.new io do |tar|
      tar.each do |tarfile|
        destination_file = File.join destination, tarfile.full_name

        if tarfile.directory?
          FileUtils.mkdir_p destination_file
        else
          destination_directory = File.dirname(destination_file)
          FileUtils.mkdir_p destination_directory unless File.directory?(destination_directory)
          File.open destination_file, "wb" do |f|
            f.print tarfile.read
          end
        end
      end
    end
  end
end


### Usage Example: ###
#
# include Util::Tar
# 
# io = tar("./Desktop")   # io is a TAR of files
# gz = gzip(io)           # gz is a TGZ
# 
# io = ungzip(gz)         # io is a TAR
# untar(io, "./untarred") # files are untarred
#