#!/usr/bin/env sh

# xwin-tabletd v0.1
# rotates display and digitizer input based on accelerometer

# detect primary display
dpy="$(xrandr | grep '[^dis]connected' | tr -s ' ' '\t' | cut -f1)"

# detect digitizer devices
dpy_digitizer="$(xinput list --name-only | grep -i wacom)"
[ ! -z "$dpy_digitizer" ] || exit 0

# workaround: repeatedly poke at iio-sensor-proxy on a timer to avoid
# aggressive battery optimization
while :; do
	cat /sys/bus/iio/devices/iio:device0/in_accel_x_raw > /dev/null
	sleep 5
done &

monitor-sensor | while read -r line; do
	state="${line##* }"
	unset rot mat
	case "$state" in
		normal)    rot='normal';   mat='1 0 0 0 1 0 0 0 1';;
		right-up)  rot='right';    mat='0 1 0 -1 0 1 0 0 1';;
		left-up)   rot='left';     mat='0 -1 1 1 0 0 0 0 1';;
		bottom-up) rot='inverted'; mat='-1 0 1 0 -1 1 0 0 1';;
	esac
	if [ ! -z "$rot" ] && [ ! -z "$mat" ]; then
		echo "[${0##*/}]: Rotating display: $rot" | notify-send -t 2
		xrandr --output "$dpy" --rotate "$rot"
		echo "$dpy_digitizer" | while read -r f; do
			xinput set-prop "$f" 'Coordinate Transformation Matrix' $mat
		done
	fi
done