#!/data/data/com.termux/files/usr/bin/bash
set -e -u

SCRIPTNAME=termux-sensor
show_usage () {
	echo "Usage: $SCRIPTNAME"
	echo "Get information about types of sensors as well as live data"
	echo "  -h, help           Show this help"
	echo "  -a, all            Listen to all sensors (WARNING! may have battery impact)"
	echo "  -c, cleanup        Perform cleanup (release sensor resources)"
	echo "  -l, list           Show list of available sensors"
	echo "  -s, sensors [,,,]  Sensors to listen to (can contain just partial name)"
	echo "  -d, delay [ms]     Delay time in milliseconds before receiving new sensor update"
	exit 0
}

# ensure we properly release resources if needed on ^C
trap handle_interrupt  SIGTERM SIGINT

if [ $# -eq 0 ]; then
	echo "No arguments supplied!"
	show_usage
	exit 1;
fi

SENSOR_FLAG=1
ALL_SENSORS_FLAG=2
LIST_FLAG=4
CLEANUP_FLAG=8
DELAY_FLAG=16
FLAGS=0

handle_interrupt () {
	echo "Caught interrupt.. Finishing..."
	cleanup
}

cleanup () {
	if [ $((FLAGS & (ALL_SENSORS_FLAG | SENSOR_FLAG))) != 0 ]; then
		echo "Performing sensor cleanup"
		call_api -a cleanup
	else
		echo "No cleanup necessary"
	fi
}

get_sensors () {
	if [ $# -gt 1 ]; then
		usage_error "Sensor arg should be a comma delimited string!"
	fi
}

get_delay () {
	if [ $# -gt 1 ]; then
		usage_error "Too many arguments for -d delay"
	elif ! [[ $1 =~ ^[0-9]+$ ]]; then
		usage_error "Illegal argument! -d delay arg should be a number!"
	fi
}

call_api () {
	/data/data/com.termux/files/usr/libexec/termux-api Sensor "$@"
}

set_flag () {
	FLAGS=$((FLAGS | $1));
}

usage_error () {
	echo "ERROR: $@"
	show_usage
	exit 1
}


PARAMS=()
while getopts :h,a,c,l,s:d: option
do
	case "$option" in
		h) show_usage ;;
		a) set_flag $ALL_SENSORS_FLAG; PARAMS+=(-a sensors --ez all true);;
		c) set_flag $CLEANUP_FLAG; PARAMS=(-a cleanup) ;;
		l) set_flag $LIST_FLAG; PARAMS=(-a list) ;;
		s) set_flag $SENSOR_FLAG; get_sensors "$OPTARG"; PARAMS+=(-a sensors --es sensors "$OPTARG") ;;
		d) set_flag $DELAY_FLAG; get_delay $OPTARG; PARAMS+=(--ei delay $OPTARG) ;;
		?) echo "$SCRIPTNAME: illegal option -$OPTARG"; exit 1;
	esac
done
shift $((OPTIND -1))

# Validate options were set properly

if [ $((FLAGS & CLEANUP_FLAG)) -ne 0 ] && [ $FLAGS -ne $CLEANUP_FLAG ]; then
	usage_error "No other options should be specified with -c cleanup!"
elif [ $((FLAGS & LIST_FLAG)) -ne 0 ] && [ $FLAGS -ne $LIST_FLAG ]; then
	usage_error "No other options should be specified with -l list!"
elif [ $((FLAGS & DELAY_FLAG)) -ne 0 ] && [ $((FLAGS & (ALL_SENSORS_FLAG | SENSOR_FLAG))) -eq 0 ]; then
	usage_error "Use -s <sensors> or -a option when using -d delay!"
elif [ $((FLAGS & ALL_SENSORS_FLAG)) -ne 0 ] && [ $((FLAGS & SENSOR_FLAG)) -ne 0 ]; then
	usage_error "Listed sensors will be ignored with -a all option!"
fi

call_api "${PARAMS[@]}"