#!/usr/bin/env bash
# rice-audio - audio state for the eww panel, and the actions it runs.
#
#   rice-audio watch                    JSON on every change (eww deflisten)
#   rice-audio sink <name>              default output; playing streams move with it
#   rice-audio source <name>            default input
#   rice-audio app-volume <index> <pct> volume of one playing app
#   rice-audio app-mute <index>
#   rice-audio mic <pct> | mic-mute
set -uo pipefail

snapshot() {
  jq -cn \
    --arg dsink "$(pactl get-default-sink 2>/dev/null)" \
    --arg dsrc "$(pactl get-default-source 2>/dev/null)" \
    --argjson sinks "$(pactl -f json list sinks 2>/dev/null || echo '[]')" \
    --argjson sources "$(pactl -f json list sources 2>/dev/null || echo '[]')" \
    --argjson apps "$(pactl -f json list sink-inputs 2>/dev/null || echo '[]')" '
    def pct: [.volume[]?.value_percent | rtrimstr("%") | tonumber] | if length > 0 then (add / length | round) else 0 end;
    def level: {name: (.description // ""), vol: pct, muted: (.mute // false)};
    {
      sink:    (($sinks   | map(select(.name == $dsink)) | .[0]) // {} | level),
      source:  (($sources | map(select(.name == $dsrc))  | .[0]) // {} | level),
      sinks:   [ $sinks[]   | {index, name, desc: .description, default: (.name == $dsink)} ],
      sources: [ $sources[] | select(.name | endswith(".monitor") | not)
                            | {index, name, desc: .description, default: (.name == $dsrc)} ],
      apps:    [ $apps[] | {id: .index,
                            name: (.properties["application.name"] // .properties["media.name"] // "app"),
                            vol: pct, muted: .mute} ]
    }'
}

watch() {
  snapshot
  pactl subscribe 2>/dev/null |
    grep --line-buffered -E "'(change|new|remove)' on (sink|source|sink-input|server)" |
    while read -r _; do
      # A slider drag fires dozens of events; wait for the burst to end.
      while read -r -t 0.08 _; do :; done
      snapshot
    done
}

# Panel buttons pass numeric indexes, never device names, so nothing a
# device reports about itself ends up inside a shell command.
num() { [[ ${1:-} =~ ^[0-9]+$ ]] || { echo "rice-audio: expected a number, got '${1:-}'" >&2; exit 2; }; }

case "${1:-}" in
  watch) watch ;;
  sink)
    num "${2:-}"
    pactl set-default-sink "$2"
    pactl -f json list sink-inputs | jq -r '.[].index' | while read -r i; do pactl move-sink-input "$i" "$2"; done
    ;;
  source)     num "${2:-}"; pactl set-default-source "$2" ;;
  app-volume) num "${2:-}"; num "${3:-}"; pactl set-sink-input-volume "$2" "$3%" ;;
  app-mute)   num "${2:-}"; pactl set-sink-input-mute "$2" toggle ;;
  mic)        num "${2:-}"; wpctl set-volume -l 1.0 @DEFAULT_AUDIO_SOURCE@ "$2%" ;;
  mic-mute)   rice-volume mic-mute ;;
  *) sed -n '2,10p' "$0" | sed 's/^# \{0,1\}//'; exit 2 ;;
esac