require 'ruby-progressbar'
require 'simp/rake/build/constants'

module Simp; end
module Simp::Rake; end
module Simp::Rake::Build

  class Unpack < ::Rake::TaskLib
    include Simp::Rake::Build::Constants

    def initialize( base_dir )
      init_member_vars( base_dir )

      define_tasks
    end

    def define_tasks
      #!/usr/bin/rake -T

=begin
      desc "Unpack an ISO. Unpacks either a RHEL or CentOS ISO into
      <targetdir>/<RHEL|CentOS><version>-<arch>.
       * :iso_path - Full path to the ISO image to unpack.
       * :merge - If true, then automatically merge any existing
         directories. Defaults to prompting.
       * :targetdir - The parent directory for the to-be-created directory
         containing the unpacked ISO. Defaults to the current directory.
       * :isoinfo - The isoinfo executable to use to extract stuff from the ISO.
         Defaults to 'isoinfo'.
       * :version - optional override for the <version> number (e.g., '7.0' instead of '7')

      "
=end
      task :unpack,[:iso_path, :merge, :targetdir, :isoinfo, :version] do |t,args|
        args.with_defaults(
          :iso_path   => '',
          :isoinfo    => 'isoinfo',
          :targetdir  => Dir.pwd,
          :merge      => false,
          :version => false,
        )

        iso_path   = args.iso_path
        iso_info   = which(args.isoinfo)
        targetdir  = args.targetdir
        merge      = args.merge
        version = args.version

        # Checking for valid arguments
        File.exist?(args.iso_path) or
          fail "Error: You must provide the full path and filename of the ISO image."

        %x{file #{iso_path}}.split(":")[1..-1].to_s =~ /ISO/ or
          fail "Error: The file provided is not a valid ISO."

        pieces = File.basename(iso_path,'.iso').split('-')

        # Mappings of ISO name to target directory name.
        # This is a hash of hashes to provide room for growth.
        dvd_map = {
          # RHEL structure as provided from RHN:
          #   rhel-server-<version>-<arch>-<whatever>
          'rhel' => {
            'baseos'  => 'RHEL',
            'version' => version || pieces[2],
            'arch'    => pieces[3]
          },
          # CentOS structure as provided from the CentOS website:
          #   CentOS-<version>-<arch>-<whatever>
          'CentOS' => {
            'baseos'  => 'CentOS',
            'version' => version || pieces[1],
            'arch'    => pieces[2]
          }
        }

        # Determine the target directory
        map = dvd_map[pieces[0]]
        map.nil? and fail "Error: Could not find a mapping for '#{iso_path}'."
        out_dir = "#{File.expand_path(targetdir)}/#{map['baseos']}#{map['version']}-#{map['arch']}"

        # Attempt a merge
        if File.exist?(out_dir) and merge.to_s.strip == 'false'
          puts "Directory '#{out_dir}' already exists! Would you like to merge? [Yn]?"
          unless $stdin.gets.strip.match(/^(y.*|$)/i)
            puts "Skipping #{iso_path}"
            next
          end
        end

        puts "Target dir: #{out_dir}"
        mkdir_p(out_dir)

        # Unpack the ISO
        iso_toc = %x{#{iso_info} -Rf -i #{iso_path}}.split("\n")
        iso_toc.each do |iso_entry|
          iso_toc.delete(File.dirname(iso_entry))
        end

        progress = ProgressBar.create(:title => 'Unpacking', :total => iso_toc.size)

        iso_toc.each do |iso_entry|
          target = "#{out_dir}#{iso_entry}"
          unless File.exist?(target)
            FileUtils.mkdir_p(File.dirname(target))
            system("#{iso_info} -R -x #{iso_entry} -i #{iso_path} > #{target}")
          end
          if progress
            progress.increment
          else
            print "#"
          end
        end
      end
    end
  end
end