change_volume

#!/bin/sh
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
# Copyright 2021 Jeremy Brubaker <jbru362@gmail.com>
#
# abstract: change volume
#
# Requires (wpctl | pactl) and dunst
#

# Arbitrary but unique message id for dunst
msg_id=chgvol-$0

if command -v wpctl >/dev/null; then

    case "$1" in
        mute)
            cmd=mute
            wpctl set-mute @DEFAULT_AUDIO_SINK@ toggle
            ;;
        +*|-*)
            cmd=adj
            sign=$(echo "$1" | cut -c1)
            amnt=$(echo "$1" | cut -c2-)

            wpctl set-volume -l 1.5 @DEFAULT_AUDIO_SINK@ "$amnt$sign"
            ;;
    esac
    current_volume=$(wpctl get-volume @DEFAULT_AUDIO_SINK@ |
        cut -d' ' -f2 | sed -e 's/^0\.//' -e 's/^0//')

    if wpctl get-volume @DEFAULT_AUDIO_SINK@ | grep -q MUTED; then
        is_muted=yes
    else
        is_muted=no
    fi

elif command -v pactl >/dev/null; then
    default_sink=$(LC_ALL=C pactl list sinks short | \
        grep "$(\
            pactl info | 
            grep "Default Sink" | 
            sed 's/[^:]*: //')" | 
            cut -f1)

    case "$@" in
        mute)
            pactl set-sink-mute @DEFAULT_SINK@ toggle
            ;;
        +*|-*)
            pactl set-sink-volume @DEFAULT_SINK@ "$@"
            ;;
        *) exit 1 ;;
    esac

    current_volume=$(LC_ALL=C pactl list sinks | \
        grep -A9 "Sink #$default_sink" | 
        grep Volume | 
        awk '{print $5}' | 
        tr -dc '[:digit:]')

    is_muted=$(LC_ALL=C pactl list sinks | \
        grep -A9 "Sink #$default_sink" | \
        grep Mute | \
        awk '{print $2}')
else
    printf '%s\n' 'Neither wpctl or pactl found' >&2
    exit 1
fi

if [ "$is_muted" = 'yes' ] || [ "$current_volume" = '0' ]; then
    icon=audio-volume-muted
else
    icon=audio-volume-high
fi

if [ "$cmd" = 'mute' ] && [ "$is_muted" = 'yes' ]; then
    dunstify -a "changeVolume" -u low -i "$icon" \
        -h "string:x-dunst-stack-tag:$msg_id" "Volume muted" 
else
    dunstify -a "changeVolume" -u low -i "$icon" \
        -h "string:x-dunst-stack-tag:$msg_id" \
        -h int:value:"$current_volume" "Volume: ${current_volume}%"
fi