Personal PulseAudio microphone script which also creates a loopback from host to VM guest, giving me great flexibility

pa-toggle-mic.sh

#!/bin/bash 
# Personal PulseAudio microphone toggle script
# Allows me to mute/unmute mic as well as send/stop sending microphone output to a virtual machine for 
# maximum flexibility (e.g simultaneously using discord on linux, game voice chat on windows) and only needing to configure one mic ever
source_microphone="alsa_input.usb-Blue_Microphones_Yeti_Stereo_Microphone_REV8-00.analog-stereo" # Main microphone 
source_we_wanna_send_to_vm="PulseEffects_mic.monitor" # This is PulseEffects mic output (since it improves the quality of the Main microphone)
sink_wired_to_vm_sound="alsa_output.usb-C-Media_Electronics_Inc._USB_Audio_Device-00.analog-stereo" # A soundcard that is quite literally wired to another soundcard which is passed in a Virtual Machine. Lmao. Hey, it works..
pid_file="/tmp/pa_mic_loopback.pid" # Where the last pactl module ID will be saved to.

# Arguments
enable_mic=0
force_mic=0
disable_mic=0
toggle_mic=0
is_mic_muted()
{
    if [[ $(pactl get-source-mute "$source_microphone" | grep "Mute: yes") ]]; then 
        echo 1
    else 
        echo 0
    fi 
}

while [ $# -gt 0 ]; do
    case $1 in
        --enable)
            enable_mic=1
        ;;
        --force)
            force_mic=1
        ;;
        --disable)
            disable_mic=1    
        ;;
        --toggle)
            toggle_mic=1
        ;;
        --muted) # just prints whether or not mic is muted. Can be useful for GUI buttons and stuff.. \o/
            is_mic_muted
            exit 
        ;;
    esac
    shift 
done 

unload_vm_loopback()
{
    if [ -s "$pid_file" ]; then 
        pactl unload-module $(cat $pid_file)
    fi 
}

# My wacky setup uses 2 identical USB soundcards, which unfortunately means pulseaudio gets confused and we need to tell it to pick whatever is available on the host (not passed in a VM) 
choose_vm_sink()
{
    sound_cards=$(pactl list sinks short | grep "$sink_wired_to_vm_sound")
    
    if [ "$force_mic" -ne 1 ] && [ $(echo "$sound_cards" | wc -l) -gt 1 ]; then 
        unload_vm_loopback
        echo "More than 1 sound card is present. Is a VM running? Did you pass one to it?"
        exit 1
    fi
    
    sink_wired_to_vm_sound=$(echo "$sound_cards" | awk 'NR==1 { print $2 }')
    echo "Found soundcard wired to VM sink: $sink_wired_to_vm_sound"
}

load_vm_loopback()
{
    choose_vm_sink
    pactl load-module module-loopback source="$source_we_wanna_send_to_vm" sink="$sink_wired_to_vm_sound" source_dont_move="true" sink_dont_move="true" > "$pid_file"
}

mute_mic()
{
    pactl set-source-mute "$source_microphone" 1
}

unmute_mic()
{
    pactl set-source-mute "$source_microphone" 0
}

enable_mic()
{
    unmute_mic 
    
    # so we don't accidentally start several identical loopback streams 
    unload_vm_loopback
    load_vm_loopback    
}

disable_mic()
{
    unload_vm_loopback
    mute_mic 
}

if [[ "$enable_mic" -eq 0 && "$disable_mic" -eq 0 && "$toggle_mic" -eq 0 ]]; then
    echo "You need to pass --enable, --disable, or --toggle"
    exit 1
fi 

if [[ "$enable_mic" -eq 1 && "$disable_mic" -eq 1 ]]; then 
    echo "You can only enable or disable, not both."
    exit 1
fi 

if [[ ! $(pidof pulseeffects) ]]; then 
    unload_module
    echo "PulseEffects is not running."
    exit 1
fi 

if [ "$enable_mic" -eq 1 ]; then  
    enable_mic 
fi 

if [ "$disable_mic" -eq 1 ]; then 
    disable_mic 
fi 

if [ "$toggle_mic" -eq 1 ]; then 
    if [[ $(is_mic_muted) -eq 1 ]]; then
        enable_mic
    else 
        disable_mic 
    fi 
fi