#!/bin/bash
################################################################################
# Copyright 2026 ModalAI Inc.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# 1. Redistributions of source code must retain the above copyright notice,
#    this list of conditions and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright notice,
#    this list of conditions and the following disclaimer in the documentation
#    and/or other materials provided with the distribution.
#
# 3. Neither the name of the copyright holder nor the names of its contributors
#    may be used to endorse or promote products derived from this software
#    without specific prior written permission.
#
# 4. The Software is used solely in conjunction with devices provided by
#    ModalAI Inc.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
################################################################################

NAME="mpld-0021x-kela"
SERVICE_FILE="${NAME}.service"
UDEV_RULE="99-${NAME}.rules"
UDEV_SRC="/usr/share/${NAME}/${UDEV_RULE}"
UDEV_DST="/etc/udev/rules.d/${UDEV_RULE}"
IOCONF="/etc/modalai/voxl-io-server.conf"
USER=$(whoami)


print_usage () {
	echo ""
	echo ""
	echo "The following args can be provided for headless scripted setup:"
	echo ""
	echo "voxl-configure-kela enable"
	echo "voxl-configure-kela disable"
	echo ""
	echo "enable:   installs the udev rule so ${NAME} is started when"
	echo "          the Kela ISAD USB link is plugged in and stopped on"
	echo "          unplug. Also disables voxl-io-server's payload_monitor"
	echo "          behavior so only one process talks to the Kela hardware."
	echo "disable:  removes the udev rule and stops the service if running."
	echo ""
	echo "show this help message:"
	echo "voxl-configure-kela help"
	echo ""
	exit 0
}


disable_and_exit () {
	echo "removing ${NAME} udev rule"
	rm -f ${UDEV_DST}
	udevadm control --reload-rules
	echo "stopping ${NAME} systemd service"
	systemctl stop ${SERVICE_FILE}
	echo "Done configuring ${NAME}"
	exit 0
}

enable_and_exit () {
	# voxl-io-server's payload_monitor behavior also talks to the Kela ISAD
	# munition (auto-detect by the same VID:PID over the same serial link) --
	# disable *only that behavior* so mpld-0021x-kela is the only process ever
	# talking to the hardware. voxl-io-server.conf can hold several other
	# unrelated behaviors (VTX failsafe, light bars, ESC passthrough, etc) in
	# the same "behaviors" array -- a blanket "enabled": true -> false replace
	# across the whole file would disable those too, so this is scoped to the
	# JSON object whose "mode" is "payload_monitor".
	if [ -f "${IOCONF}" ]; then
		echo "disabling voxl-io-server payload_monitor behavior"
		sed -i '/"mode":[[:space:]]*"payload_monitor"/,/}/ s/"enabled":\ttrue/"enabled":\tfalse/' "${IOCONF}"
		systemctl restart voxl-io-server.service 2>/dev/null
	fi

	echo "installing ${NAME} udev rule"
	cp ${UDEV_SRC} ${UDEV_DST}

	# mpld-0021x-kela is started/stopped by udev on USB plug/unplug, not
	# enabled at boot. Reload rules and re-trigger in case the USB device
	# is already plugged in.
	udevadm control --reload-rules
	udevadm trigger --action=add --subsystem-match=usb
	echo "Done configuring ${NAME}"
	exit 0
}



################################################################################
## actual start of execution, handle optional arguments first
################################################################################

## sanity checks
if [ "${USER}" != "root" ]; then
	echo "Please run this script as root"
	exit 1
fi


## convert argument to lower case for robustness
arg=$(echo "$1" | tr '[:upper:]' '[:lower:]')

## parse arguments
case ${arg} in
	"")
		echo "missing required argument"
		print_usage
		exit 1
		;;
	"h"|"-h"|"help"|"--help")
		print_usage
		exit 0
		;;
	"disable")
		disable_and_exit
		;;
	"enable")
		enable_and_exit
		;;
	*)
		echo "invalid option"
		print_usage
		exit 1
esac
