#!/bin/bash
# pw-mute-active-window 0.3: 2025 Christian Birchinger <cbirchinger@netswarm.net>
#
# This script opens a rofi (dmenu) with available Pipewire Sinks for the currently
# active (X11) window.
#
# It uses "xdotool getactivewindow getwindowpid" to get the PID of the active window,
# obtains all child PIDs and then tries to find "Playback" stremas in PipeWire.
#
# So it not only works for GUI Players like DeaDBeeF, MPV, Fooyin but also players running
# in a terminal like openmpt123, Sidplay2, MPV (cli mode)
#
# Of course with such a hack, there are limits and restrictions. Some knowns are:
# - The player has to be activly playing something to be found.
# - Terminals that use one multiplexing main process for all windows


fail() {
	echo "ERROR: $*" >&2
	notify-send -i audio-speakers-symbolic "${0//*\/}" "<b>ERROR</b>: $*\n<i>(Playback must be active to be detected)</i>"
	exit 1
}

getchilds() {
	cpids=$(pgrep -P "$1" | xargs)
	for cpid in ${cpids}; do
		echo "$cpid"
		${FUNCNAME[0]} "${cpid}"
	done
}

get_objs_from_pids() {
	local p
	for p in "$@"; do
		jq -r ".[].info.props | select(.\"application.process.id\"==${p}) | .\"object.id\"" <<< "${pw_json}"
	done
}

get_pbs_from_objs() {
	local o
	for o in "$@"; do
		jq -r ".[].info.props | select(.\"media.class\"==\"Stream/Output/Audio\" and .\"client.id\"==${o} ) | .\"object.serial\"" <<< "${pw_json}"
	done
}

get_names_from_pbs() {
	local o
	local j
	local l=()
	for o in "$@"; do
		l+=( "$(jq -r ".[].info.props | select(.\"object.serial\"==${o}) | .\"application.name\"" <<< "${pw_json}")" )
	done
	printf -v j '%s,' "${l[@]}"
	echo "${j%,}"
}

get_sink_from_obj() {
	local o=$1
	local oid
	local sids=()
	oid=$(jq -r ".[] | select (.type==\"PipeWire:Interface:Node\") | .info.props | select(.\"media.class\"==\"Stream/Output/Audio\" and .\"client.id\"==${o} ) | .\"object.id\"" <<< "${pw_json}")
	readarray -t sids < <(jq -r ".[].info.props | select(.\"link.output.node\"==${oid}) | .\"link.input.node\"" <<< "${pw_json}")
	jq -r ".[].info.props | select(.\"object.id\"==${sids[0]}) | .\"node.description\"" <<< "${pw_json}"
}

wid=$(xdotool getwindowfocus)
wpid=$(xdotool getactivewindow getwindowpid)
[[ -z $wpid ]] && fail "Unable to get PID from active window"
readarray -t cpids <<< "$(getchilds "${wpid}")"
pids=( "${wpid}" )
[[ -n ${cpids[*]} ]] && pids+=( "${cpids[@]}" )

pw_json=$(pw-dump)
readarray -t objs < <(get_objs_from_pids "${pids[@]}")
[[ -z ${objs[*]} ]] && fail "Unable to get Pipewire objects from PIDs"
readarray -t pbs < <(get_pbs_from_objs "${objs[@]}")
[[ -z ${pbs[*]} ]] && fail "Unable to get Pipewire playbacks from PIDs"

current_sink=$(get_sink_from_obj "${objs[0]}")
players=$(get_names_from_pbs "${pbs[@]}")

sinks=$(jq -r '.[].info.props | select(."media.class"=="Audio/Sink") | "\(."node.description")\t\(."object.serial")"' <<< "${pw_json}")
[[ -z $sinks ]] && fail "Unable to get Pipewire sinks"

selected_sink=$(rofi -select "${current_sink}" -display-columns 1  -w "${wid}" -dmenu -i -p "Move ${players} to output device" <<< "${sinks}")
[[ -z $selected_sink ]] && exit
selected_sink=${selected_sink/*$'\t'}

for p in "${pbs[@]}"; do
	pactl move-sink-input "$p" "${selected_sink}"
done