AAXtoMP3/interactiveAAXtoMP3

#!/usr/bin/env bash

# ===Note for contributors========================================================================================================================

# This script interactively asks the user for the options to call AAXtoMP3 with. This first version does not include all options of AAXtoMP3
# since I tried to keep the dialog short, but I added an --advanced option, which is unused right now, but might be used in the future to add
# more options which only show up if explicitely wanted.
# If you want to add functionality please consider, whether the functionality you add might belong to the advanced options.

# ===Variables====================================================================================================================================

# Help message
help=$'\nUsage: interactiveAAXtoMP3 [--advanced] [--help]\n
--advanced	More options
--help		Print this message\n'
summary=""         # This will contain a summary of the options allready set.
call="./AAXtoMP3"  # This will contain the call for AAXtoMP3.
advanced=0         # Toggles advanced options on or off.

# ===Options======================================================================================================================================

while true; do
  case "$1" in
                     # Advanced options.
    -a | --advanced  ) advanced=1;      shift ;;
                     # Command synopsis.
    -h | --help      ) echo -e "$help"; exit ;;
                     # Anything else stops command line processing.
    *                )                  break ;;
  esac
done

# ===Cross platform compatible use grep and sed===================================================================================================

# ===Detect which annoying version of grep we have===
GREP=$(grep --version | grep -q GNU && echo "grep" || echo "ggrep")
if ! [[ $(type -P "$GREP") ]]; then
  echo "$GREP (GNU grep) is not in your PATH"
  echo "Without it, this script will break."
  echo "On macOS, you may want to try: brew install grep"
  exit 1
fi

# ===Detect which annoying version of sed we have===
SED=$(sed --version 2>&1 | $GREP -q GNU && echo "sed" || echo "gsed")
if ! [[ $(type -P "$SED") ]]; then
  echo "$SED (GNU sed) is not in your PATH"
  echo "Without it, this script will break."
  echo "On macOS, you may want to try: brew install gnu-sed"
  exit 1
fi

# ===Get options from last time===================================================================================================================

# ===Set default values===
lastcodec="mp3"
lastcompression="4"
lastchapters="yes"
lastauthcode=""
lastloglevel="1"

# ===Get Values from last time===
if [ -f ".interactivesave" ]; then
  for ((i=1;i<=$(wc -l .interactivesave | cut -d " " -f 1);i++)) do
    line=$(head -$i .interactivesave | tail -1)
    case $(echo $line | cut -d " " -f 1 | $SED 's/.$//') in
      codec        ) lastcodec="$(echo $line | cut -d " " -f 2)";;
      compression  ) lastcompression="$(echo $line | cut -d " " -f 2)";;
      chapters     ) lastchapters="$(echo $line | cut -d " " -f 2)";;
      authcode     ) lastauthcode="$(echo $line | cut -d " " -f 2)";;
      loglevel     ) lastloglevel="$(echo $line | cut -d " " -f 2)";;
      *            ) rm .interactivesave; exit 1;;
    esac
  done
fi

# ===Get options for AAXtoMP3=====================================================================================================================

# ===Codec===
while true; do
  clear;
  read -e -p "codec (mp3/m4a/m4b/flac/aac/opus): " -i "$lastcodec" codec
  case "$codec" in
    mp3   ) summary="$summary""codec: $codec"; call="$call -e:mp3"; break;;
    m4a   ) summary="$summary""codec: $codec"; call="$call -e:m4a"; break;;
    m4b   ) summary="$summary""codec: $codec"; call="$call -e:m4b"; break;;
    flac  ) summary="$summary""codec: $codec"; call="$call --flac"; break;;
    aac   ) summary="$summary""codec: $codec"; call="$call --aac";  break;;
    opus  ) summary="$summary""codec: $codec"; call="$call --opus"; break;;
  esac
done

# ===Compression===
while true; do
  clear; echo -e "$summary"
  case "$codec" in
    mp3   ) maxlevel=9;;
    flac  ) maxlevel=12;;
    opus  ) maxlevel=10;;
    *     ) break;;
  esac
  read -e -p "compression level (0-$maxlevel): " -i "$lastcompression" compression
  if [[ $compression =~ ^[0-9]+$ ]] && [[ "$compression" -ge "0" ]] && [[ "$compression" -le "$maxlevel" ]]; then
    summary="$summary""\ncompression level: $compression"
    call="$call --level $compression"
    break
  fi
done

# ===Chapters===
while true; do
  clear; echo -e "$summary"
  read -e -p "chapters (yes/no/chapternumber to continue with): " -i "$lastchapters" chapters
  case "$chapters" in
    ^[0-9]+$  ) summary="$summary""\nchapters: $chapters"; call="$call -c --continue ${chapters}"; break;;
    yes       ) summary="$summary""\nchapters: $chapters"; call="$call -c"; break;;
    no        ) summary="$summary""\nchapters: $chapters"; call="$call -s"; break;;
  esac
done

# ===Authcode===
if ! [ -r .authcode ] || [ -r ~/.authcode ]; then
  clear; echo -e "$summary"
  read -e -p "Authcode: " -i "$lastauthcode" authcode
  summary="$summary""\nauthcode: $authcode"
  call="$call -A $authcode"
fi

# ===Loglevel===
while true; do
  clear; echo -e "$summary"
  read -e -p "loglevel (0/1/2/3): " -i "$lastloglevel" loglevel
  if [[ $loglevel =~ ^[0-9]+$ ]] && [[ "$loglevel" -ge "0" ]] && [[ "$loglevel" -le "3" ]]; then
    summary="$summary""\nloglevel: $loglevel"
    call="$call -l $loglevel"
    break
  fi
done

# ===File===
clear; echo -e "$summary"
read -p "aax-file: " file
file="${file%\'}" #remove suffix ' if file is given via drag'n'drop
file="${file#\'}" #remove prefix ' if file is given via drag'n'drop
savefile="$summary"
summary="$summary""\naax-file: $file"
call="$call $(echo $file | $SED "s;~;$HOME;")"

# ===Summerize chosen options and call AAXtoMP3===================================================================================================

# ===Summary===
clear; echo -e "$summary\n"
echo -e "$call\n"

# ===Save chosen options===
echo -e $savefile | $SED "s;\ level:;:;" > .interactivesave

# ===Call AAXtoMP3===
$call