#!/bin/bash
#
# Inspired by https://linuxappfinder.com/blog/auto_screen_rotation_in_ubuntu


# Output of "monitor-sensor --accel | grep 'orientation'":
#   === Has accelerometer (orientation: normal)
#   Accelerometer orientation changed: right-up

# Feed output of 'monitor-sensor' and stop after first match of 'orientation'
ORIENTATION_STR="$(grep -m 1 'orientation' <( monitor-sensor ))" || exit $?

case "${ORIENTATION_STR}" in
  *": normal"*)
    ORIENTATION="normal";
    ;;
  *": bottom-up"*)
    ORIENTATION="inverted";
    ;;
  *": right-up"*)
    ORIENTATION="right";
    ;;
  *": left-up"*)
    ORIENTATION="left";
    ;;
  *": undefined"*)
    echo "Reported orientation is 'undefined'. Please rotate the device a bit and try again." >&2;
    exit 1;
    ;;
  *)
    echo "Could not parse ORIENTATION_STR: ${ORIENTATION_STR}" >&2;
    exit 1;
esac

echo "${ORIENTATION}"