helm/shell/+mpd/bin/rate

#!/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="★"
    star_empty_icon="☆"
    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 "$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"