#!/bin/bash
# Use bash not ash for >32bit arithmetic

touch /run/openslx || exit 1
full=false
[ "$1" = "--full" ] && full=true

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

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

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

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

USED=0
Name=

# detect if we need '--no-legend' or not...
LEGEND=
loginctl --help 2>&1 | grep -q -- '--no-legend' && LEGEND="--no-legend"
for SESSION in $(loginctl $LEGEND | awk '{print $1}'); do
	unset Display Remote State Class
	eval "$(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 # keeps $Name set!
	fi
	unset Name
done

. "$( which slx-tools )"

# Also report usage of /tmp and swap
TMP="$( fs_path_space /tmp )"
TMP_FREE="${TMP% *}"
TMP_SIZE="${TMP#* }"
PERSISTENT_SIZE=0
PERSISTENT_FREE=0
if fs_path_ismountpoint /opt/openslx/persistent; then
	TMP="$( fs_path_space /opt/openslx/persistent )"
	ID45_FREE="${TMP% *}"
	ID45_SIZE="${TMP#* }"
fi

SWAP_SIZE=$( awk '{if ($1 == "SwapTotal:") { print $2; exit; }}' /proc/meminfo )
SWAP_FREE=$( awk '{if ($1 == "SwapFree:") { print $2; exit; }}' /proc/meminfo )
MEM_SIZE=$( awk '{if ($1 == "MemTotal:") { print $2; exit; }}' /proc/meminfo )
MEM_FREE=$( awk '{if ($1 == "MemAvailable:") { print $2; exit; }}' /proc/meminfo )
if [ -z "$MEM_FREE" ]; then
	MEM_FREE=$( awk 'BEGIN{n=0}{if ($1 == "MemFree:" || $1 == "Buffers:" || $1 == "Cached:") n += $2}END{print n}' /proc/meminfo )
fi
# CPU temp and load
set --
if $full; then
	current="$( awk '$1 == "cpu" {printf "%.0f %.0f", ($5+$6), ($2+$3+$4+$5+$6+$7+$8)}' /proc/stat )"
	c_count=${current#* }
	write=false
	if [ -s "/run/openslx/usage.state" ]; then
		old="$( cat "/run/openslx/usage.state" )"
		l_count="${old#* }"
		# sloppy way to prevent rapid updates; counter speed varies depending on HZ and core count
		if [ "$(( c_count - l_count ))" -gt 12000 ]; then
			write=true
			set -- "$@" "--data-urlencode" "cpuload=$( echo "$current $old" | awk '{ print (100 - ($1 - $3)/($2 - $4) * 100) }' )"
		fi
	else
		write=true
	fi
	if $write; then
		echo "$current" > "/run/openslx/usage.state"
	fi
	if command -v sensors > /dev/null; then
		# TODO JSON support arrived recently, port after base system is updated from 18.04
		# Try to get the package id reading, use core temps as fallback
		set -- "$@" "--data-urlencode" "cputemp=$( sensors | tr 'A-Z' 'a-z' \
			| awk 'BEGIN{p=0;pc=0;c=0;cc=0;tctl=0} {
					if ($1 == "package" && substr($4, 1, 1) == "+") {
						gsub("[^0-9.]", "", $4);
						p += $4;
						pc++;
					} else if ($1 ~ /^core/ && substr($3, 1, 1) == "+") {
						gsub("[^0-9.]", "", $3);
						c += $3;
						cc++;
					} else if ($1 ~ /^tctl:/ && substr($2, 1, 1) == "+") {
						gsub("[^0-9.]", "", $2);
						tctl = $2;
					}
			} END {
				if (pc > 0) print (p / pc);
				else if (cc > 0) print (c / cc);
				else if (tctl > 0) print (tctl);
			}' )"
	fi
fi

# Bail out if we already sent the shutdown event to server
# or if the cron-job hasn't been set up yet.
# Do this right before the curl call to minimize odds for a race condition
if [ -e "/etc/cron.d/usage_stats" ] && ! [ -e "/run/openslx/shutdown.mutex" ]; then
	curl --retry 3 --retry-connrefused --connect-timeout 3 --max-time 15 --retry-max-time 20 -sS \
		--data-urlencode "type=~runstate" --data-urlencode "uuid=$UUID" \
		--data-urlencode "used=$USED" \
		--data-urlencode "user=$Name" --data-urlencode "tmpsize=$TMP_SIZE" --data-urlencode "tmpfree=$TMP_FREE" \
		--data-urlencode "id45size=$ID45_SIZE" --data-urlencode "id45free=$ID45_FREE" \
		--data-urlencode "swapsize=$SWAP_SIZE" --data-urlencode "swapfree=$SWAP_FREE" \
		--data-urlencode "memsize=$MEM_SIZE" --data-urlencode "memfree=$MEM_FREE" \
		"$@" \
		"$SLX_REMOTE_LOG" | grep -v 'RESULT=0'
fi

# Warn user if tmp or swap usage is high; system might crash soon

# ..but not if flag to shut up is present
[ -e "/run/openslx/no-ram-warning" ] && exit 0

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."
	idle-daemon --send "warn $WARN"
fi

exit 0