#!/bin/sh -e
# Play given files on mpd, enabling playing of external files through symlinking and recursively resolving playlists
# depends: xargs mpc realpath
# env: MUSIC
links="$MUSIC/links"
test "$1" = "-r" || next=true
{ for arg;
do path="$(test -e "$MUSIC/$arg" && echo "$MUSIC/$arg" || realpath "$arg")"
  test -n "$path" || continue
  if file "$path" | grep -i ' playlist' || expr "$path" : ".*\.m3u8\?$" >/dev/null
  then pushd "$(dirname "$path")" >/dev/null && cat "$path" | xargs --delim='\n' play -r && popd >/dev/null
  else
    find "$path" -name "*.flac" -o -name "*.mp3" | while read file
      do case "$path" in
        ($MUSIC/*) echo "${file/$MUSIC\/}";;
        (*) mkdir -p "$links" && ln -fs "$file" "$links/$(basename "$file")" && echo "links/$(basename "$file")";;
      esac done
  fi
done && mpc update --wait -q; } | xargs --delim='\n' mpc insert
test "$next" && test "$(mpc status | wc -l)" -gt 1 || mpc play -q && mpc next