#!/bin/ash

[ -r "/run/system-uuid" ] || exit 0

. /opt/openslx/config
[ -z "$SLX_REMOTE_LOG" ] && exit 0

UUID=$(cat "/run/system-uuid")

[ -z "$UUID" ] && exit 1

USED=0
Name=

for SESSION in $(loginctl | awk '{print $1}'); do
	unset Display Remote State
	eval $(loginctl -p Display -p Remote -p State -p Class -p Name show-session "$SESSION")
	if [ "$Display" = ":0" ] && [ "$Remote" = "no" ] && [ "$State" = "active" -o "$State" = "online" ] && [ "$Class" = "user" ]; then
		USED=1 # We only consider sessions on the primary display, which should always be the case
		break
	fi
done

# Also report usage of /tmp and swap
TMP=$(df -P /tmp | grep -m1 ' /tmp$')
TMP_SIZE=$(echo $TMP | awk '{print $2}')
TMP_FREE=$(echo $TMP | awk '{print $4}')
SWAP_FREE=$(grep -m1 ^SwapFree: /proc/meminfo | awk '{print $2}')

curl -s --data-urlencode "type=~runstate" --data-urlencode "uuid=$UUID" --data-urlencode "used=$USED" \
	--data-urlencode "user=$Name" --data-urlencode "tmpsize=$TMP_SIZE" --data-urlencode "tmpfree=$TMP_FREE" \
	--data-urlencode "swapfree=$SWAP_FREE" "$SLX_REMOTE_LOG" > /dev/null 2>&1

# Warn user if tmp or swap usage is high; system might crash soon
WARN=
if [ "$SWAP_FREE" -gt 0 ] && [ "$SWAP_FREE" -lt 500000 ]; then # less than 500MB swap
	WARN="$WARN
Der Arbeitsspeicher des Computers ist fast voll.
The computer is running out of RAM."
fi
if [ -n "$TMP_FREE" ] && [ "$TMP_FREE" -lt 500000 ]; then
	WARN="$WARN
Es verbleibt wenig temporärer Speicher für die Arbeitsdaten der laufenden VM.
Little temporary storage is left for the current VM."
fi

if [ -n "$WARN" ]; then
	WARN="$WARN

Bitte sichern Sie Ihre Arbeit und starten Sie den PC neu.
Please save your work and reboot this machine.

Sie können einen bwLehrpool-Admin bitten, eine größere ID-44-Partition einzurichten.
You could ask a bwLehrpool administrator to create a larger ID-44 partition."
		for d in $(who | awk '{print $2}' | sort -u); do
			if [ "${d:0:1}" = ":" ]; then
				# X11
				export DISPLAY=$d
				export XAUTHORITY=$(ps a | grep " $DISPLAY " | grep -o -- '-auth.*$' | grep -m1 -v grep | awk '{print $2}')
				notify-send -u critical "System instabil" "$WARN"
				unset DISPLAY XAUTHORITY
			elif [ "${d:0:3}" = "tty" ]; then
				# Regular tty
				cat > "/dev/$d" <<EOF
				*
				***************************
				$WARN
				***************************
				*
EOF
			elif [ "${d:0:3}" = "pts" ]; then
				# pts - xterm or ssh session
				cat > "/dev/pts/${d:3}" <<EOF
				*
				***************************
				$WARN
				***************************
				*
EOF
			fi
		done
fi

exit 0