#!/bin/bash

# This little bash wrapper will just combine monitor and existing source from fender amplifier
# and create a virtual input that can be selected a default input for recording


f_log() {
   echo "[+] $0 -> $*"
}

function usage () {
cat << EOF

You need to call this script like this : $0 (-r) -i <input>
  -r : reset pulseaudio to default and so removes virtual input
  -i : external amplifier to combine with source monitor [required param, values: (guitar|bass)]

EOF
}

while getopts "hri:" option
do
  case ${option} in
    h)
      usage
      exit
      ;;
    r)
     action=reset
      ;;
    i)
     amplifier_model=${OPTARG}
     ;;
    ?)
      usage
      exit
      ;;
  esac
done

# Checking first if we just need to reset pulseaudio
if [ "${action}" == "reset" ] ; then
   f_log "Resetting pulseaudio to defaults ..."
   pactl unload-module module-loopback
   pactl unload-module module-null-sink
   sleep 2
   pulseaudio -k
   exit 
fi

# Parsing amplifier input to combine and exit if not specified
# One can use the following commands to know which sources are available
# pacmd list-sources | egrep '(^\s+name: .*)|(^\s+device.description = .*)'

if [ "${amplifier_model}" == "guitar" ] ; then
  f_log "Fender Mustang amplifier selected"
  source_device="alsa_input.usb-FMIC_Mustang_LT_25_00000000001A-02.analog-stereo"
  sink_name="monitor-and-amp"
  fake_input_name="mustang-combined"
elif [ "${amplifier_model}" == "bass" ] ; then 
  f_log "Fender Rumbler Amplifier selected"
  source_device="alsa_input.usb-FMIC_Fender_LT_USB_Audio_Streaming_00000000001A-00.analog-stereo"
  sink_name="monitor-and-bassamp"
  fake_input_name="rumble-combined"
else
  usage
  exit 1
fi

# Now let's do the real work
# Common
monitor_device="alsa_output.usb-Lenovo_ThinkPad_Thunderbolt_3_Dock_USB_Audio_000000000000-00.analog-stereo.monitor"

f_log "Adding new sink [${sink_name}]"
pactl load-module module-null-sink sink_name=${sink_name} sink_properties=device.description=Source-monitor-amp
sleep 5
f_log "Adding monitor device [${monitor_device}] to created sink [${sink_name}]"
pactl load-module module-loopback source=${monitor_device} sink_dont_move=true sink=${sink_name}
sleep 5
f_log "Adding external amplifier [${source_device}] to created sink [${sink_name}]"
pactl load-module module-loopback source=${source_device} sink_dont_move=true sink=${sink_name}

# Create fake input combining all sinks 
f_log "Creating now new virtual input [${fake_input_name}] to be used as input for recording"
sleep 5
pactl load-module module-remap-source source_name=${fake_input_name} master=${sink_name}.monitor source_properties=device.description=${fake_input_name}