dotfiles/mixer

#!/usr/bin/env sh

###########################################
# Displays audio sinks and control volume #
###########################################

sink="$HOME/.cache/mixer/sink"
save="$HOME/.cache/mixer/save"

# list options
help() {
    echo "Usage:
      listen             [monitor events and display current sink volume]
      update {+,-}1%     [update current sink volume]
      switch             [switch to the next sink]
      restore            [restore saved configuration]
      help, --help       [this help page]
    懶 toggle             [toggle between play and pause]
    玲 prev               [play previous song]
    怜 next               [play next song]
    栗 stop               [stop playing]
    "
}

# return selected color generated by pywal
get_color() {
    grep -o "$1.*" "$HOME/.cache/wal/colors.sh" | sed "s/$1='\(.*\)'.*/\1/"
}

# display volume icon
# @param: volume between 1 and 100, normalized_volume otherwise
volume_icon() {
    volume=${1:-$(normalized_volume)}
    len_icons=$(echo "$volume_icons" | wc -l)
    for i in $(seq 1 "$len_icons"); do
        if [ "$(echo "$i * (100/$len_icons) + 1" | bc -l | xargs printf "%0.f\n" )" -ge "${volume}" ]; then
            echo "$volume_icons" | sed "$i!d"
            break
        fi
    done
}

# return current volume associated with current sink
current_volume() {
    sndioctl "$(current_sink).level" | sed '/device/d' | cut -f 2 -d '='
}

# print current sink
current_sink() {
    cat "$sink"
}

# return volume between 0 and 100%
# @param: volume between 0 and 1.0, current_volume otherwise
normalized_volume() {
    volume=${1:-$(current_volume)}
    echo "${volume} * 100" | bc | xargs printf "%0.f\n"
}

# save sinks with volumes
save() {
    aucatctl | tr '\n' ' ' > "$save"
}

# update volume with increment of value
# value between 0..100
# increment +n or -n
update() {
    operand=$(echo "$1" | grep -o '+\|-')
    value=$(echo "$1" | grep -o '[[:digit:]]*')
    volume=$(normalized_volume)
    { [ "$volume" -eq 0 ] && [ "$operand" = "-" ]; } || { [ "$volume" -eq 100 ] && [ "$operand" = "+" ]; } && return
    sndioctl "$(current_sink).level=$operand$(echo "scale=2;$value/100" | bc -l)"
    save
}

# automatically set current sink to last modified
auto_switch_sink() {
    new_sink="$(echo "$1" | sed '/device/d' | cut -f 1 -d '.')"
    [ "$new_sink" = '' ] && return
    [ "$new_sink" = "$(current_sink)" ] || echo "$new_sink" > "$sink"
}

mpris() {
    while true; do
        player_status=$(playerctl status 2> /dev/null)
        if [ "$player_status" = "Playing" ]; then
            volume=$(playerctl status --format '{{volume}}')
            player=$(playerctl status --format '{{playerName}}')
            normalized_volume=$(normalized_volume "$volume")
            echo "$player  %{F$color}$(volume_icon "$normalized_volume")%{F-} ${normalized_volume}%"
            sleep 1
        fi
    done
}

# listen on sndiod new events and sink change
listen() {
    # on separated thread listen to sndiod events
    {
        sndioctl -m | while read -r MSG; do
            auto_switch_sink "$MSG"
            display
            save
        done
    } &
    # watch for current sink value stored in file change
    while inotifywait -q -q -e close_write "$sink"; do
        display
    done
}

# display sink and associated volume in polybar
display() {
    echo "$(current_sink)  %{F$color}$(volume_icon)%{F-} $(normalized_volume)%"
}

# switch to the next available sink
switch() {
    sinks=$(sndioctl | sed '/device/d')
    max_index=$(echo "$sinks" | wc -l)
    current_index=$(echo "$sinks" | grep -n "$(current_sink)" | cut -f 1 -d ':')
    next_index=$(echo "$current_index%$max_index + 1" | bc)
    echo "$sinks" | sed "$next_index!d" | cut -f 1 -d '=' | sed 's/.level//' > "$sink"
}

# restore last saved volume per sink
restore() {
    [ -f "$save" ] && aucatctl "$(cat "$save")"
}

is_mpd_sink() {
    [ "$(current_sink | grep -o 'mpd')" = "mpd" ] && echo "true" || echo "false"
}

toggle() {
    [ "$(is_mpd_sink)" = "true" ] && mpc toggle || playerctl play-pause
}

prev() {
    [ "$(is_mpd_sink)" = "true" ] && mpc prev || playerctl previous
}

next() {
    [ "$(is_mpd_sink)" = "true" ] && mpc next || playerctl next
}

stop() {
    [ "$(is_mpd_sink)" = "true" ] && mpc stop || playerctl stop
}

main() {
    [ ! -f "$sink" ] && mkdir -p "$HOME/.cache/mixer" && echo "output" > "$sink"
    color=$(get_color 'color2')
    volume_icons="奄\n奔\n墳\n"
    case "$1" in
        listen)
            case "$2" in
                --color=?*)
                    case "$3" in
                        --volume-icons=?*)
                            volume_icons=$(echo "${3#*=}" | tr ',' '\n')
                    esac
                    color=$(get_color "${2#*=}");;
            esac
            listen;;
        mpris)
            mpris;;
        update)
            shift;
            update "$@";;
        switch)
            switch;;
        restore)
            restore;;
        prev)
            prev;;
        next)
            next;;
        toggle)
            toggle;;
        stop)
            stop;;
        --help|-h|*)
            help;;
    esac
}

main "$@"