#!/usr/bin/env ruby
# encoding: utf-8
Version = '0.01'
Myname = File.basename($0)

Help=
<<'DOC'
= apecue - unpack ape, mpc, flac audio files,
reencode into separate ogg or mp3 tracks
= Synopsis
apecue [options] inputfile [cuefile]	

= Options
-v,--verbose		report what's going on
-k,--keep		keep input and intermediate files
-c,--composer=STRING	set composer for this album
-q,--quality=INT	set quality for encoding (default 3)
-m,--mp3		convert to mp3 instead of the default ogg
-h			print this help and exit
-H, --help		show full documentation via less and exit

= Description
apecue is a Ruby version of a bash script by Rafael Ponieman - Buenos
Aires, Argentina, with some added flexibility and options. apecue is
intended to convert ape (Monkeys Audio Files), mcp (Musepack) or flac
(Free Lossless Audio Codec) + cue files to ogg vorbis or mp3 files,
setting the tags, obtained from the cue file, to the correct value.

The simplest use is just:
   apecue name
which looks for an input file |name.ape|, |name.mpc|, or |name.flac|,
whichever it finds first. A file |name.cue| should then be present, too,
and the input file is converted to Ogg Vorbis tracks, with
tag-information taken from the |.cue| file.

The file extensions and the name of the cue files can also be stated
explicitly, thus overriding the defaults.

The |-m| option can be used to obtain mp3 instead of ogg tracks. 
On exit, input (|flac|, |ape|, |cue|) files and intermediate files are
removed, unless the |-k| option is used.

== Examples:
In a directory containing Vol1.ape and Vol1.cue:
   apecue Vol1        # convert Vol1.ape + Vol1.cue into ogg tracks
   apecue Vol1 file   # convert Vol1.ape + file.cue into ogg tracks
   apecue -m Vol1     # convert Vol1.ape + Vol1.cue into mp3 tracks

In a directory containing Vol1.mpc and Vol1.mpc.cue:
   apecue -kv Vol1    # convert Vol1.ape + Vol1.mpc.cue into ogg tracks,
                      # with verbose output, keep both Vol1.mpc and Vol1.mpc.cue.

= Requirements
- Oggenc installed (it comes with vorbis-tools) if you want to encode into Ogg Vorbis.
- lame installed if you want to encode into mp3
- mac to decode ape files (Monkey's Audio); I used |APE_3.96b8_Binary_Linux.zip|
- flac to decode flac files.
- mp3splt to split ogg and mp3 in tracks. Use a recent version, I use:
     libmad-0.15.1b.tar.gz
     libmp3splt-0.4_rc1.tar.gz
     mp3splt-2.2_rc1.tar.gz

= Author
[Wybo Dekker](wybo@dekkerdocumenten.nl)

= Copyright
Released under the [GNU General Public License](www.gnu.org/copyleft/gpl.html)
DOC

begin
  require 'scriptingutils'
rescue LoadError
  raise LoadError,<<EOF,['scriptingutils.rb']
\n    You probably did not install scriptingutils.rb. 
    This gem is included in #{File.basename($0)}'s distribution
    Install with: sudo gem install scriptingutils-x.y.z.gem
EOF
end

require 'tempfile'
require 'fileutils'
include FileUtils
require 'pp'

KNOWN_EXTENSIONS = %w{.ape .mpc .flac}

class TrackTags
  attr_accessor :composer, :artist, :tracknumber, :title
  def initialize(tnum)
    @tracknumber = tnum
  end
end

# Create an object containing tags, read from a .cue file
class AlbumTags
  attr_accessor :composer, :artist, :album, :genre, :trackcount, :tracks
  def initialize(cuefile)
    @genre = 'Classical'
    @tracks = []
    c = open(cuefile) or quit("Failed to open #{cuefile}")
    tnum = nil
    lasttime = 0
    c.readlines.each do |l|
      l.encode!('UTF-8','ISO-8859-1') unless l.valid_encoding?
      tag, rest = l.strip.split(/\s+/,2)
      next unless tag && rest
      rest.tr!('"','')
      case tag
        when 'TITLE'
          if tnum 
            @tracks[tnum].title = rest.sub(/^[ 0-9.-]+/,'')
          else
            @album = rest
          end
        when 'PERFORMER'
          if tnum 
            @tracks[tnum].artist = rest
          else
            @artist = rest
          end
        when 'COMPOSER'
          if tnum 
            @tracks[tnum].composer = rest
          else
            @composer = rest
          end
        when 'TRACK'
          tnum = rest.split[0].to_i
          @tracks[tnum] = TrackTags.new(tnum)
      end
    end
    @tracks.shift
    @trackcount = @tracks.size
    c.close
  end
end

# defaults
@mp3 = false
@verbose = false
@quality = 3
@keep = false
@composer = ''

def handle_options
  ARGV.options do |opt|
    opt.banner =  "#{Myname} - convert ape, mcp or flac + cue files to ogg or mp3 files\n"
    opt.banner << "            setting the tags as obtained from the cue file.\n\n"
    opt.banner << "Usage: #{Myname} [options] <ape or flac file> [<cue file>]\n"
    opt.banner << "       extension of file names are optional in the call, but\n"
    opt.banner << "       only file with the correct extensions can be handled.\n"
    opt.banner << "       In file names, no whitespace is allowed."
    opt.separator ""
    opt.on('-v','--verbose',"report what's going on") do
      @verbose = true
    end
    opt.on('-k','--keep',"keep input and intermediate files") do
      @keep = true
    end
    opt.on('-c','--composer=STRING',String,'set composer for this album') do |v|
      @composer = v
    end
    opt.on('-q','--quality=INT',Integer,'set quality for encoding (default 3)') do |v|
      @quality = v
    end
    opt.on('-m','--mp3','convert to mp3 instead of the default ogg') do
      @mp3 = true
    end
    opt.on('-h','print this help and exit') do
      puts opt.help
      exit
    end
    opt.on('-H','--help','show full documentation via less and exit') do
       help
       exit
    end
    opt.on('-V','--version', 'print version and exit') do
      puts Version
      exit
    end
    opt.parse!
    opt.help 
  end or quit("Error parsing options")
end

def syst(command)
  puts "Running:",command.yellow if @verbose
  system(command) or exit 1
end

def help
  system("echo \"#{Help}\" | less -P#{Myname}-#{Version.tr('.','·')}")
end

h = init(%w{mac mppdec mp3splt},:handle_options)

infile = ARGV.shift or quit(h,0)
infile =~ /\s/ && quit("input filename has whitespace - not allowed")
unless infile =~ /\.(ape|flac)/
  %w{ape flac}.each { |e| f = infile+'.'+e; infile = f if File.exist?(f) }
  quit("No .ape or .flac file for #{infile}") unless infile =~ /\.(ape|flac)/
end
ext = File.extname(infile)

if cuefile = ARGV.shift
  cuefile = File.basename(cuefile,'.cue') + '.cue'
  File.exist?(cuefile) or quit("#{cuefile} not found")
else
  nocue = true
  [infile,infile.sub(/\.(ape|flac)$/,'')].each do |f|
    cuefile = f + '.cue'
    if File.exist?(cuefile)
      nocue = false
      break
    end
  end
  puts "No cue file found" if nocue
end
puts "archive: #{infile}"
puts "cue:     #{cuefile}" unless nocue

cueinfo = AlbumTags.new(cuefile) unless nocue

executable(@mp3 ? 'lame' : 'oggenc',true)

if @verbose
  puts "Cueape 0.2"
  puts "Starting decompression of '#{infile}'".green.bold
end

# use temporary files 
wav = "temp#{$$}.wav"
out = "temp#{$$}.#{@mp3 ? 'mp3' : 'ogg'}"

# decompress
case ext
when '.flac'
  h = sys("flac #{@verbose ? '' : '-s'} -f -d '#{infile}' -o #{wav} >/dev/null")
when '.ape'
  h = sys("mac \'#{infile}\' #{wav} -d >/dev/null")
when '.mpc'
  h = sys("mppdec #{@verbose ? '' : '--silent'} '#{infile}' #{wav}")
end
quit(h.error) unless h.success

if @verbose
  puts "Decompression finished"
  puts "Starting reencoding"
end

# reencode
base = File.basename(infile,".*")
if @mp3
  h = sys("lame #{@verbose ? '' : '--quiet'} -q #{@quality} --preset standard #{wav} #{out} >/dev/null")
else
  h = sys("oggenc #{@verbose ? '' : '-Q'} -q #{@quality} -o #{out} #{wav} >/dev/null")
end
quit(h.error) unless h.success

puts "Reencoding finished"

if nocue
  newname = infile.sub(ext,@mp3 ? '.mp3' : '.ogg')
  puts "Can't split - no cuefile; saving as #{newname}"
  cp(out,newname)
else
  puts "Splitting".green.bold if @verbose
  info=AlbumTags.new(cuefile)
  if @mp3
    h = sys("mp3splt #{@verbose ? '' : '-q'} -f -c '#{cuefile}' -o '@n' #{out} >/dev/null")
    # insert mp3 tags here
  else
    h = sys("mp3splt #{@verbose ? '' : '-q'} -c '#{cuefile}' -o '@n' #{out} >/dev/null")
    # insert ogg tags
    cueinfo.tracks.each do |t|
      n = t.tracknumber
      # mp3splt splits into 1 2 3.. if <= 9 tracks, 01, 02, 03 if > 9 tracks
      f = "%00#{info.trackcount.to_s.size}d.ogg" % [n]
      open("|vorbiscomment --raw -w #{f}",'w') do |v|
        v.print "" + (<<-EOF).gsub(/^\s+/,'')
        album=#{cueinfo.album}
        artist=#{t.artist}
        composer=#{t.composer || @composer}
        genre=#{cueinfo.genre}
        tracks=#{cueinfo.trackcount}
        tracknumber=#{n}
        title=#{t.title}
        EOF
      end
      # rename to 0001.ogg 0002.ogg ... overbodig??
      ##File.rename(f,f.rjust(8,'0')) unless f.size == 8
    end
  end
  quit(h.error) unless h.success
  puts "Processing finished successfully" if @verbose
end
exit 0 if @keep
[infile,cuefile,wav,out].each { |f|
  next unless File.exist?(f)
  puts "Deleting #{f}"
  File.delete(f) or puts "Failed deleting #{f}"
}