#!/usr/bin/env bash

# I frequently discover that there are crappy songs hidden in my music library.
# I ain't havin' none o' that! So I file them away in my 1-star.m3u playlist.
# This script reads that playlist, delete those songs, and cleans up any empty
# folders it leaves behind. It will also remove duplicates from all playlists.
#
# Usage: cleanup-music

set -e
shopt -s nullglob

music_dir=$(awk '/music_directory/ { print gensub(/"/, "", "g", $2); }' "$HOME/.config/mpd/mpd.conf")
music_dir="${music_dir/#\~/$HOME}"
playlist_dir=$(awk '/playlist_directory/ { print gensub(/"/, "", "g", $2); }' "$HOME/.config/mpd/mpd.conf")
playlist_dir="${playlist_dir/#\~/$HOME}"

playlist_file="${playlist_dir}/1-star.m3u"

# Delete designated songs
IFS=$'\n'
declare -a to_delete=()
while read -r song; do
  songpath="${music_dir}/${song}"
  [[ -f $songpath ]] && to_delete+=("$songpath")
done < "$playlist_file"

if (( ${#to_delete[@]} == 0 )); then
  echo "Nothing to delete"
  exit
fi

# List songs to delete and ask for confirmation
printf "Deleting %s songs:\n\n%s\n\nConfirm? (y/n) " \
  "${#to_delete[@]}" \
  "$(IFS=$'\n'; printf "%s" "${to_delete[*]}")"
read -r confirm
case $confirm in
  y|Y)
    echo "Deleting..."
    for file in "${to_delete[@]}"; do
      rm -fv "$file"
    done
    ;;
  n|N) echo "Aborted"; exit ;;
  *) echo "Invalid" ;;
esac
:>"$playlist_file"

# Remove duplicates across playlists
for playlist in ${playlist_dir}/*.m3u; do
  awk '!seen[$0]++' "${playlist}" > "${playlist}.tmp"
  if [[ -f "${playlist}.tmp" ]]; then
    rm -f "$playlist"
    mv "${playlist}.tmp" "$playlist"
  fi
done

# Remove empty directories
find "$music_dir" -type d -empty -delete