#!/usr/bin/env bash

# Rate the currently playing song in mpd.
#
# Under the hood, this simply appends the playing song to the
# $playlist_directory/$N-star.m3u playlist.
#
# If rating = 0,
#     then clear it from all playlists
# Else if 1 <= rating <= 5,
#     then clear it from all playlists,
#     and add it to ${rating}-star.m3u
# Else
#     display the current rating of the playing song
#
# Usage: rate [N]

playlist_dir=$(awk '/playlist_directory/ { print gensub(/"/, "", "g", $2); }' "$HOME/.config/mpd/mpd.conf")
playlist_dir="${playlist_dir/#\~/$HOME}"
song_file=$(mpc current -f '%file%')
song_title=$(mpc current)
if [[ -z "$song_file" ]]; then
  >&2 echo 'Nothing is playing!'
  exit 1
fi

#
_clear_playlists() {
  # Remove the song from other playlists
  for playlist in "${playlist_dir}/"*-star.m3u; do
    if grep "^$1$" "$playlist" >/dev/null; then
      sed -i "\#^$1\$#d" "$playlist"
    fi
  done
}

_display_stars() {
  # Display new rating
  stars=""
  star_filled_icon='\033[0;32m*\033[0m'
  star_empty_icon='\033[0;30m*\033[0m'
  for ((i=1;i<=5;i++)); do
    if (( "$1" >= "$i" )); then
      stars="${stars}${star_filled_icon}"
    else
      stars="${stars}${star_empty_icon}"
    fi
  done
  echo -e "$stars"
}


#
if (( $# != 1 )); then
  for ((i=1;i<=5;i++)); do
    if grep "^${song_file}$" "${playlist_dir}/"${i}-star.m3u >/dev/null; then
      echo "($(_display_stars $i)) $song_title"
      exit 1
    fi
  done
  echo "($(_display_stars 0)) $song_title"
  exit 1
fi

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

if (( rating == 0 )); then
  _clear_playlists "$song_file"
  echo "Rating cleared"
elif [[ ! -f "$target" ]]; then
  >&2 echo "Not a valid rating, must be between 0-5!"
  exit 2
elif ! grep "^${song_file}$" "$target" >/dev/null; then
  _clear_playlists "$song_file"
  echo "$song_file" >> "$target"
fi

# Display new rating
echo "($(_display_stars $rating)) $song_title"