#!/bin/bash

set -e

# Source debconf library.
. /usr/share/debconf/confmodule

REGEXP_IPV4_ADDR='^([01]?[0-9][0-9]?|2[0-4][0-9]|25[0-5])\.([01]?[0-9][0-9]?|2[0-4][0-9]|25[0-5])\.([01]?[0-9][0-9]?|2[0-4][0-9]|25[0-5])\.([01]?[0-9][0-9]?|2[0-4][0-9]|25[0-5])$'
REGEXP_IPV6_ADDR='^(([0-9a-fA-F]{0,4}:){2,7}[0-9a-fA-F]{0,4})$'

is_ip_v4() {
	if [[ "${1}" =~ ${REGEXP_IPV4_ADDR} ]]; then
		return 0
	fi
	return 1
}

is_ip_v6() {
	# our REGEXP_IPV6_ADDR is not 100% perfect, so...
	if [[ "${1}" =~ ${REGEXP_IPV6_ADDR} ]] && ! [[ "${1}" =~ ::: ]]; then
		return 0
	fi
	return 1
}

is_net_v4() {
	NET=`echo "$1" | cut -d/ -f1`
	MASK=`echo "$1" | cut -d/ -f2`
	is_ip_v4 "$MASK" && is_ip_v4 "$NET" && return 0
	echo "$MASK"|egrep -q '^([0-2]?[0-9]?|3[0-2])$' && is_ip_v4 "$NET" && return 0
	return 1
}

is_net_v6() {
	NET=`echo "$1" | cut -d/ -f1`
	MASK=`echo "$1" | cut -d/ -f2`
	is_ip_v6 "$MASK" && is_ip_v6 "$NET" && return 0
	[[ "${MASK}" =~ ^[0-9]+$ ]] && [ ${MASK} -ge 32 ] && [ ${MASK} -le 128 ] && is_ip_v6 "$NET" && return 0
	return 1
}

is_host_v4() {
	LANG=C host "$1" 2> /dev/null | grep "address" | grep -v "IPv6" | cut -d" " -f4
}

is_host_v6() {
	LANG=C host "$1" 2> /dev/null | grep "IPv6 address" | cut -d" " -f4
}

is_host_v4_and_v6() {
	is_host=1
	[ -n "$(is_host_v4 "$1")" ] && [ -n "$(is_host_v6 "$1")" ] && is_host=0
	return ${is_host}
}

while true; do
	# Chooser for conf_method
	db_input high uif/conf_method || true
	db_go

	# Check their answer.
	db_get uif/conf_method

	case "$RET" in
		workstation)
			# show message
			db_input high uif/really-setup-workstation || true
			db_go

			# safety net question, jump back to asking for uif/conf_mode again
			# if not ACK'ed here.
			db_get uif/really-setup-workstation || true
			if [ "${RET}" = "false" ]; then
				continue
			fi

			# configure ping / traceroutes
			db_input high uif/pings || true
			db_go

			db_input high uif/traceroute || true
			db_go

			# configure trusted hostnames
			while true; do
				db_input high uif/trusted-hostnames || true
				db_go
				db_get uif/trusted-hostnames

				if [ -n "$RET" ]; then
					for i in $RET; do
						WORKS=0
						is_host_v4_and_v6 "$i" && WORKS=1
						if [ $WORKS -eq 0 ]; then
							db_input high uif/error || true
							db_go
							break
						fi
					done
					[ $WORKS -eq 0 ] && continue
				fi
				break
			done

			# configure trusted IPv4 hosts
			while true; do
				db_input high uif/trusted || true
				db_go
				db_get uif/trusted

				if [ -n "$RET" ]; then
					for i in $RET; do
						WORKS=0
						is_ip_v4 "$i" && WORKS=1
						[ $WORKS -eq "0" ] && is_net_v4 "$i" && WORKS=1
						[ $WORKS -eq "0" ] && HOST=`is_host_v4 "$i"`
						[ -n "$HOST" ] && WORKS=1
						if [ $WORKS -eq 0 ]; then
							db_input high uif/error || true
							db_go
							break
						fi
					done
					[ $WORKS -eq 0 ] && continue
				fi
				break
			done

			# configure trusted IPv6 hosts
			while true; do
				db_input high uif/trusted-v6 || true
				db_go
				db_get uif/trusted-v6

				if [ -n "$RET" ]; then
					for i in $RET; do
						WORKS=0
						is_ip_v6 "$i" && WORKS=1
						[ $WORKS -eq "0" ] && is_net_v6 "$i" && WORKS=1
						[ $WORKS -eq "0" ] && HOST=`is_host_v6 "$i"`
						[ -n "$HOST" ] && WORKS=1
						if [ $WORKS -eq 0 ]; then
							db_input high uif/error || true
							db_go
							break
						fi
					done
					[ $WORKS -eq 0 ] && continue
				fi
				break
			done

			# if we reach here, we can simply leave the outer while loop
			break

			;;

		debian-edu-router)
			# show message
			db_input high uif/really-setup-debianedurouter || true
			db_go

			# safety net question, jump back to asking for uif/conf_mode again
			# if not ACK'ed here.
			db_get uif/really-setup-debianedurouter || true
			if [ "${RET}" = "false" ]; then
				continue
			fi

			# configure ping / traceroutes
			db_input high uif/pings || true
			db_go

			db_input high uif/traceroute || true
			db_go

			# if we reach here, we can simply leave the outer while loop
			break
			;;

		*)
			break
			;;
	esac

done

exit 0