#!/bin/bash

t="/tmp/remote-access-$DISPLAY"
mkdir -p "$t"
modmap="$t/modmap.want"
tmpmap="$t/modmap.have"
(
	sleep 1
	setxkbmap de
	xmodmap -e "keycode 92 ="
	xmodmap -e "keycode 187 ="
	xmodmap -e "keycode 188 ="
	xmodmap -e "keycode 26 = e E e E U20AC U20AC U20AC"
	xmodmap -pke > "$modmap"
) &
. /opt/openslx/config
# TODO If we support multiple parallel sessions in the future, we need dedicated
# ports for each session for both, the VNC and the RPC port.
vnc_port="${SLX_REMOTE_VNC_PORT:-5900}"
if ! [ "$vnc_port" -gt 0 ] || ! [ "$vnc_port" -lt 65535 ]; then
	vnc_port=5900
fi
srchost="$SLX_REMOTE_HOST_ACCESS"
if [ -n "$srchost" ]; then
	# IPTABLES
	rule="/opt/openslx/iptables/rules.d/80-remote-access"
	if ! [ -e "$rule" ]; then
		(
			echo "#!/bin/sh"
			echo "iptables -A INPUT -s "'"'"$srchost"'"'" -p tcp --dport $vnc_port -j ACCEPT"
			echo "iptables -A INPUT -s "'"'"$srchost"'"'" -p tcp --dport 7551 -j ACCEPT"
			echo "iptables -A INPUT -p tcp --dport $vnc_port -j DROP"
			echo "iptables -A INPUT -p tcp --dport 7551 -j DROP"
		) > "$rule"
		chmod +x "$rule"
	fi
fi
#set -x
#exec &> /tmp/fooooooooooooo
# dd since busybox head doesn't know -c
passwd="$( < /dev/urandom  tr -c -d 'a-zA-Z0-9#&/=()[]{}' | dd bs=8 count=1 status=none )"
printf "%s" "$passwd" > "$t/vnc-passwd"
[ "$SLX_REMOTE_VNC" = "x11vnc" ] && chmod 0600 "$t/vnc-passwd"
(
	# Make a copy of xauth, so if the xserver restarts, we'll use the old one and fail to connect
	if [ -n "$XAUTHORITY" ]; then
		copy="$( mktemp )"
		cat "$XAUTHORITY" > "$copy"
		export XAUTHORITY="$copy"
		trap 'exit 1' INT TERM
		trap 'rm -f -- "$copy"' EXIT
	fi
	< "$t/vnc-passwd"  tigervncpasswd -f  > "$t/tigervnc-passwd"
	fails=0
	while true; do
		s="$( date +%s )"
		x0vncserver -fg -SecurityTypes VncAuth,TLSvnc -rfbauth "$t/tigervnc-passwd" -rfbport "$vnc_port" -localhost no -Log "*:stdout:100" \
			-AlwaysShared=true -DisconnectClients=false -MaxConnectionTime=0 -MaxDisconnectionTime=0 -MaxIdleTime=0
		e="$( date +%s )"
		d="$(( e - s ))"
		if [ "$d" -gt 5 ]; then
			fails=0
		else
			fails="$(( fails + 1 ))"
			[ "$fails" -gt 10 ] && break
			[ "$fails" -gt 3 ] && usleep 333333
		fi
	done
) &> "$t/x11vnc-log-$$" &
vncpid=$!
# Delay this a bit until x11vnc is ready, and since we might potentially have had a race
# with the ~poweron event, which would reset the password in the database.
(
	if [ -n "$SLX_REMOTE_LOG" ]; then
		url="${SLX_REMOTE_LOG//=clientlog/=remoteaccess}"
	elif [ -n "$SLX_PVS_CONFIG_URL" ]; then
		url="${SLX_PVS_CONFIG_URL//=roomplanner/=remoteaccess}"
	else
		url="http://${SLX_PXE_SERVER_IP}/slx-admin/api.php?do=remoteaccess"
	fi
	for _ in {1..20}; do
		sleep 1
		[ -e "/etc/cron.d/usage_stats" ] && break
	done
	[ -d "/proc/${vncpid}" ] || exit 1 # Something is wrong, bail
	curl -s -S -L --retry 4 --retry-connrefused --max-time 3 --retry-max-time 10 \
		--data-urlencode "password=$passwd" \
		--data-urlencode "vncport=$vnc_port" \
		"$url" > /dev/null
) &
gotone=false
vmvnc=false
idle=0
stepcount=0
# In case of stale entry
# TODO: This sucks anyways performance-wise for VMware, maybe remove?
iptables -t nat -D PREROUTING -p tcp --dport "$vnc_port" -j REDIRECT --to-ports 5901
while [ -d "/proc/${vncpid}" ]; do
	sleep 5
	if netstat -tn | awk 'BEGIN{ e=1 } { if ($4 ~ /:('"$vnc_port"'|5901)$/) e=0 } END{ exit e }'; then
		gotone=true
		idle=0
	else
		idle=$(( idle + 1 ))
	fi
	if $gotone; then
		# As soon as someone is connected, "blank" the screen by setting brightness to zero.
		# This doesn't seem to affect the framebuffer, luckily
		# Let's see how well this works in practice. :-(
		if (( stepcount == 0 )); then
			declare -a args
			args=()
			for o in $( xrandr | grep -E '^[A-Z0-9-]+ connected.*[0-9]+x[0-9]+' | awk '{print $1}' ); do
				args+=( "--output" "$o" "--brightness" "0" )
			done
			xrandr "${args[@]}"
		fi
		if (( stepcount++ > 3 )); then
			stepcount=0
		fi
	fi
	if $gotone && [ "$idle" -gt 120 ]; then # 120 * 5 = 10 mins
		kill "$vncpid"
		break
	fi
	# In case we access vmplayer via x11vnc; vmplayer won't leave the keymap alone >:(
	xmodmap -pke > "$tmpmap"
	if ! cmp -s "$tmpmap" "$modmap"; then
		echo "$( date ) Reloading modmap" >> "$t/reload-log"
		xmodmap "$modmap"
	fi

	# Check if we should redirect to vmware
	if [ "$SLX_REMOTE_VNC" != 'x11vnc' ]; then
		if netstat -tnl | awk 'BEGIN{ e=1 } { if ($4 ~ /:5901$/) e=0 } END{ exit e }'; then
			#enable
			if ! $vmvnc; then
				killall x0vncserver
				usleep 10000
				iptables -t nat -I PREROUTING 1 -p tcp --dport "$vnc_port" -j REDIRECT --to-ports 5901
			fi
			vmvnc=true
		else
			# disable
			if $vmvnc; then
				iptables -t nat -D PREROUTING -p tcp --dport "$vnc_port" -j REDIRECT --to-ports 5901
			fi
			vmvnc=false
		fi
	fi
done
systemctl restart lightdm