#!/bin/bash
#
# Das Skript ist ein Wrapper für loudgain, um im angegebenen Verzeichnis
# und allen darunter liegenden Verzeichnissen die REPLAYGAIN-Tags für Track
# und Album zu berechnen. Um zeitaufwändige mehrfache Berechnungen zu verhindern,
# wird je Verzeichnis das letzte Berechnungsdatum protokolliert.
# Weiters ist es möglich, die Berechnung von Album-Tags je Verzeichnis zu verhindern.
#
# Vieles von skript `rgbpm` aus dem Paket `loudgain`übernommen, vieles auch
# gelöscht und aus meinen eigenen mp3gain-Skripten übernommen.

# define me
me=`basename "$0"`
version="0.13"
MUSICDIR="/home/musik/INCOMING"

# wenn eine solche Datei im Verzeichnis liegt, dann nichts tun (z.B. bei Compilations):
RG_NOALBUM=.replaygain_noalbum
# hier wird reingeschrieben, wann die Dateien im Verzeichnis das letzte Mal geprüft wurden:
RG_TAGGED=.replaygain_tagged

# option handling
usage() {
cat <<EOF
Usage: ${me} [OPTIONS] FOLDER ...

$me assumes one music album per folder, all tracks of the same file type.
It will then traverse from (and including) the starting folder(s) to all
folders below and add the recommended replay gain track & album tags to
audio files.

If using 'loudgain', $me currently supports files of type:
  *.flac, *.ogg, *.mp2, *.mp3, *.m4a, *.opus, *.asf, *.wma, *.wav, *.wv, *.aiff, *.ape
EOF
cat <<EOF

Options:
  -h  Show this help.
  -v  Show version number of this script.
EOF
}

while getopts "hv" option ; do
  case "${option}" in
    v)
      echo "$me $version"
      exit 0;
      ;;
    h)
      usage
      exit 0;
      ;;
    *)
      exit 1;
      ;;
  esac
done
shift $((OPTIND-1))

# default to MUSICDIR if no path(s) given
if [ "$1" = "" ] ; then
  # (re-)set arguments
  set -- "${@}" "$MUSICDIR"
fi

if [ -z "$1" ] ; then
  usage
  exit 1;
fi

# go process each path
while [ "$1" != '' ] ; do

   # build an array with all folders within $1
   # need to change IFS (internal field separator), otherwise content would be split by space, tab, newline
   IFS=$'\n'
   FOLDERLIST=( $(find "$1" -depth -type d -print0 | xargs -0 -I{} echo {}) )
   unset $IFS
   echo "${#FOLDERLIST[@]} Verzeichnisse in $1 gefunden"

   for FOLDER in ${FOLDERLIST[@]} ; do
      echo ""
      echo "Bearbeite Verzeichnis $FOLDER ..."

      if [ -f "$FOLDER/$RG_TAGGED" ]; then
         echo "   übersprungen, da eine Datei namens $RG_TAGGED existiert."
      else
         ALBUMMODE="-a"
         if [ -f "$FOLDER/$RG_NOALBUM" ]; then
            echo "   Albummodus ausgeschaltet, da eine Datei namens $RG_NOALBUM existiert."
            ALBUMMODE=""
         fi

         # calculate replay gain for all MP3 in this folder
         #find "$FOLDER" -maxdepth 1 -iname "*.mp3" -type f -exec loudgain -I3 -S -L -a -k -s e {} +
         # ich will stattdessen ID3v2.4 (-I4) und kein Löschen von ID3v1 (-S):
         find "$FOLDER" -maxdepth 1 -iname "*.mp3" -type f -exec loudgain -I4 -L $ALBUMMODE -k -s e {} +

         # calculate replay gain for all FLAC in this folder
         find "$FOLDER" -maxdepth 1 -iname "*.flac" -type f -exec loudgain $ALBUMMODE -k -s e {} +
         # calculate replay gain for all Ogg Vorbis in this folder
         find "$FOLDER" -maxdepth 1 -iname "*.ogg" -type f -exec loudgain $ALBUMMODE -k -s e {} +
         # calculate replay gain for all Ogg FLAC in this folder
         find "$FOLDER" -maxdepth 1 -iname "*.oga" -type f -exec loudgain $ALBUMMODE -k -s e {} +
         # calculate replay gain for all Ogg Speex in this folder
         find "$FOLDER" -maxdepth 1 -iname "*.spx" -type f -exec loudgain $ALBUMMODE -k -s e {} +
         # calculate replay gain for all Ogg Opus in this folder
         find "$FOLDER" -maxdepth 1 -iname "*.opus" -type f -exec loudgain $ALBUMMODE -k -s e {} +
         # calculate replay gain for all MP2 in this folder
         find "$FOLDER" -maxdepth 1 -iname "*.mp2" -type f -exec loudgain -I3 -S -L $ALBUMMODE -k -s e {} +
         # calculate replay gain for all M4A in this folder
         find "$FOLDER" -maxdepth 1 -iname "*.m4a" -type f -exec loudgain -L $ALBUMMODE -k -s e {} +
         # calculate replay gain for all WMA in this folder
         find "$FOLDER" -maxdepth 1 -iname "*.wma" -type f -exec loudgain -L $ALBUMMODE -k -s e {} +
         # calculate replay gain for all ASF in this folder
         find "$FOLDER" -maxdepth 1 -iname "*.asf" -type f -exec loudgain -L $ALBUMMODE -k -s e {} +
         # calculate replay gain for all WAV in this folder
         find "$FOLDER" -maxdepth 1 -iname "*.wav" -type f -exec loudgain -I3 -L $ALBUMMODE -k -s e {} +
         # calculate replay gain for all AIFF in this folder
         find "$FOLDER" -maxdepth 1 -iname "*.aiff" -type f -exec loudgain -I3 -L $ALBUMMODE -k -s e {} +
         # calculate replay gain for all AIF in this folder
         find "$FOLDER" -maxdepth 1 -iname "*.aif" -type f -exec loudgain -I3 -L $ALBUMMODE -k -s e {} +
         # calculate replay gain for all WavPack in this folder
         find "$FOLDER" -maxdepth 1 -iname "*.wv" -type f -exec loudgain -S $ALBUMMODE -k -s e {} +
         # calculate replay gain for all APE in this folder
         find "$FOLDER" -maxdepth 1 -iname "*.ape" -type f -exec loudgain -S $ALBUMMODE -k -s e {} +

         # vermerken, dass wir schon da waren:
         date > "$FOLDER/$RG_TAGGED"
      fi
   done

   shift
done