#!/bin/bash

# Source config
. ../config.txt

check_eula () {
	if [ ! -f eula_accepted ]; then
		echo "======================================================"
		echo "${bold}TUYA-CONVERT${normal}"
		echo
		echo "https://github.com/ct-Open-Source/tuya-convert"
		echo "TUYA-CONVERT was developed by Michael Steigerwald from the IT security company VTRUST (https://www.vtrust.de/) in collaboration with the techjournalists Merlin Schumacher, Pina Merkert, Andrijan Moecker and Jan Mahn at c't Magazine. (https://www.ct.de/)"
		echo 
		echo 
		echo "======================================================"
		echo "${bold}PLEASE READ THIS CAREFULLY!${normal}"
		echo "======================================================"
		echo "TUYA-CONVERT creates a fake update server environment for ESP8266/85 based tuya devices. It enables you to backup your devices firmware and upload an alternative one (e.g. ESPEasy, Tasmota, Espurna) without the need to open the device and solder a serial connection (OTA, Over-the-air)."
		echo "Please make sure that you understand the consequences of flashing an alternative firmware, since you might lose functionality!"
		echo
		echo "Flashing an alternative firmware can cause unexpected device behavior and/or render the device unusable. Be aware that you do use this software at YOUR OWN RISK! Please acknowledge that VTRUST and c't Magazine (or Heise Medien GmbH & Co. KG) CAN NOT be held accountable for ANY DAMAGE or LOSS OF FUNCTIONALITY by typing ${bold}yes + Enter${normal}"
		echo 
		read
		if [ "$REPLY" != "yes" ]; then
			exit
		fi
		touch eula_accepted
	fi
}

check_config () {
	if ! iw list | grep -q "* AP"; then
		echo "AP mode not supported!"
		echo "Please attach a WiFi card that supports AP mode."
		exit 1
	fi

	echo -n "Checking for network interface $WLAN... "
	if [ -e /sys/class/net/$WLAN ]; then
		echo "Found."
	else
		echo "Not found!"
		echo -n "Please edit WLAN in config.txt to one of: "
		ls -m /sys/class/net
		exit 1
	fi
}

check_port () {
	protocol="$1"
	port="$2"
	reason="$3"
	echo -n "Checking ${protocol^^} port $port... "
	process_pid=$(sudo ss -Hlnp -A "$protocol" "sport = :$port" | grep -Po "(?<=pid=)(\d+)" | head -n1)
	if [ -n "$process_pid" ]; then
		process_name=$(ps -p "$process_pid" -o comm=)
		echo "Occupied by $process_name with PID $process_pid."
		echo "Port $port is needed to $reason"
		read -p "Do you wish to terminate $process_name? [y/N] " -n 1 -r
		echo
		if [[ ! $REPLY =~ ^[Yy]$ ]]; then
			echo "Aborting due to occupied port"
			exit 1
		else
			service=$(ps -p "$process_pid" -o unit=)
			if [ -n "$service" ]; then
				echo "Attempting to stop $service"
				sudo systemctl stop "$service"
			else
				echo "Attempting to terminate $process_name with PID $process_pid"
				sudo kill -9 "$process_pid"
				sudo tail --pid="$process_pid" -f /dev/null
			fi
			sleep 1
		fi
	else
		echo "Available."
	fi
}

check_eula
check_config
check_port udp 53 "resolve DNS queries"
check_port udp 67 "offer DHCP leases"
check_port tcp 80 "answer HTTP requests"
check_port tcp 443 "answer HTTPS requests"
check_port udp 6666 "detect unencrypted Tuya firmware"
check_port udp 6667 "detect encrypted Tuya firmware"
check_port tcp 1883 "run MQTT"
check_port tcp 8886 "run MQTTS"