#!/usr/bin/env nix-shell
#!nix-shell -i bash -p coreutils -p gnugrep -p gnused -p wireplumber

set -e

debug() {
  printf "$@" >&2
  printf "\n" >&2
}
verbose() {
  if [ "$WOB_VERBOSE" = "1" ]; then
    debug "$@"
  fi
}

volget() {
  # returns audio volume, as an integer (0 - 100)
  volLine="$(wpctl get-volume @DEFAULT_AUDIO_SINK@)"
  if echo "$volLine" | grep -q '\[MUTED\]'; then
    verbose "muted"
    echo "0"
  else
    vol="$(echo "$vol" | cut -d' ' -f2)"
    echo "$(( $vol * 100 ))"
  fi
}

notify_volume_change() {
  verbose "notify_volume_change"
  vol="$(volget)"
  verbose "got volume: %d -> %d" "$lastvol" "$vol"
  if [ "$vol" != "$lastvol" ]; then
    debug "notify wob: %d -> %d" "$lastvol" "$vol"
    printf "%s\n" "$vol" > "$XDG_RUNTIME_DIR/$WOBSOCK_NAME"
  fi
  lastvol="$vol"
}

pactl subscribe | while read -r line; do
  verbose "pactl says: %s" "$line"
  case "$line" in
    "Event 'change' on sink "*)
      notify_volume_change
      ;;
    "Event 'change' on source "*)
      # microphone volume changed. ignore.
      ;;
  esac
done