#!/usr/bin/ruby -w

# Rip an entire CD into a collection of FLAC files.
# Input is an album description text file.  Example:
#   Genre=Classical
#   Artist=Prokofiev
#   Album=Violin Sonata No. 1 in F minor / Gidon Kremer & Martha Argerich
#   Date=1992
#   track_01.flac=1. Andante assai
#   track_02.flac=2. Allegro brusco
#   track_03.flac=3. Andante
#   track_04.flac=4. Allegrissimo - Andante assai, come prima

require 'fileutils'
require 'getoptlong'

# Option values
$dryrun = false
$debug = false
$temperature = nil
$force = false
$eject = false
$movealbum = false
$flac_track = 1
$cd_track = 1

tags = {}
files = []
titles = {}

def usage
   puts "usage: ripalbum [options] album.txt"
   puts "-v        Enable debug messages"
   puts "-n        Dry run, don't run commands"
   puts "-f        Force overwrite of existing files"
   puts "-e        Eject CD after ripping"
   puts "-m        Move album file to rip directory after ripping"
   puts "-t temp   Wait for CPU temperature to drop to this level before each file"
   puts "-f n      Initial FLAC track number"
   puts "-c n      Initial CD track number"
   exit 1
end

opts = GetoptLong.new(
   [ "--verbose",     "-v", GetoptLong::NO_ARGUMENT ],
   [ "--dryrun",      "-n", GetoptLong::NO_ARGUMENT ],
   [ "--force",       "-f", GetoptLong::NO_ARGUMENT ],
   [ "--eject",       "-e", GetoptLong::NO_ARGUMENT ],
   [ "--movealbum",   "-m", GetoptLong::NO_ARGUMENT ],
   [ "--temperature", "-t", GetoptLong::REQUIRED_ARGUMENT ],
   [ "--flactrack",   "-i", GetoptLong::REQUIRED_ARGUMENT ],
   [ "--cdtrack",     "-c", GetoptLong::REQUIRED_ARGUMENT ]
)

opts.each do |opt, arg|
   case opt
   when '--verbose'
      $debug = true
   when '--dryrun'
      $dryrun = true
   when '--force'
      $force = true
   when '--eject'
      $eject = true
   when '--movealbum'
      $movealbum = true
   when '--temperature'
      $temperature = arg
   when '--flactrack'
      $flac_track = arg.to_i
   when '--cdtrack'
      $cd_track = arg.to_i
   end
end

usage if ARGV.length != 1


# Put out a string if debugging is enabled.

def dputs(string)
   puts(string) if $debug
end

# Escape quote characters in filename, and surround the result in
# quotes, so that it can be embedded in a shell command.

def escape(str)
  '"' + str.gsub('"', '\"') + '"'
end

# check_status --
#
#	Check the most recent child program status, and if it
#	was aborted with control-C, exit.

def check_status
   if $?.signaled?
      signum = $?.termsig
      if Signal.list['INT'] == signum
	 puts "\nChild process aborted by Control-C.  Exiting."
	 exit 1
      end
   end
end

# Read the album file.  Lines that are of the form "file.flac=title"
# define the association between files and track titles. And other lines
# of the form "tag=value" are tags that will be applied to every file.

albumfile = ARGV[0]
track = $flac_track
IO.foreach(albumfile) do |line|
   line.rstrip!
   case line
   when /^(.+\.flac)=(.+)$/
      files.push($1)
      titles[$1] = $2
      track += 1
   when /^(\w+)=(.+)$/
      tags[$1] = $2
   else
      # Assume it's a track title.  Construct a filename by prepending
      # the track number and appending a file extension.
      title = sprintf("%02d - %s", track, line)
      filename = title + ".flac"
      files.push(filename)
      titles[filename] = title
      track += 1
   end
end

# Make sure the required tags are present
bad = false
['Artist', 'Genre', 'Date', 'Album'].each do |key|
   if !tags[key]
      puts "#{key} not defined in album file!"
      bad = true
   end
end
exit 1 if bad

# Rip each track and pipe the data to the FLAC encoder.
# Set the tags for each file, and also set the track numbers in ascending
# order.
track = $flac_track
flacdir = nil
files.each do |file|
   dputs "Ripping #{file}"
   flacfile = tags['Artist'] + '/' + tags['Album'] + '/' + file

   # Create output directory if it doesn't exist.
   flacdir = File.dirname(flacfile)
   unless File.directory?(flacdir)
      dputs "Creating directory #{flacdir}"
      if $dryrun
	 puts("mkdir -p #{flacdir}")
      else
	 FileUtils.mkdir_p(flacdir)
      end
   end

   if File.exist?(flacfile)
      # Don't rip the track if the FLAC file already exists.
      puts "File #{flacfile} already exists.  Skipping."
   else
      # Construct the pipe command that will rip the track and encode it.
      tracktag = sprintf("%02d", track)
      cdtrack = track - $flac_track + $cd_track
      cmd = "cdparanoia -q #{cdtrack}-#{cdtrack} - |" +
	    "flac --best -o " + escape(flacfile) +
	    " --tag=Title=" + escape(titles[file]) +
	    " --tag=Tracknumber=#{tracktag}"
      ['Artist', 'Genre', 'Date', 'Album'].each do |key|
	 cmd += " --tag=#{key}=" + escape(tags[key])
      end
      cmd += ' -f' if $force
      cmd += ' -'

      if $dryrun
	 puts("waittemp #{$temperature}") if $temperature
	 puts(cmd)
      else
	 if $temperature
	    system("waittemp", $temperature)
	    check_status
	 end
	 system(cmd)
	 check_status
      end
   end

   track += 1
end

if ($dryrun)
   puts("mv #{albumfile} #{flacdir}") if $movealbum
   puts("eject /dev/cdrom") if $eject
else
   FileUtils.mv(albumfile, flacdir, :verbose => $debug) if $movealbum
   system("eject /dev/cdrom") if $eject
end