#!/usr/bin/env sh
# vim: set noet sw=2 ts=2 sts=2:

help() {
  [ 0 -lt $# ] && >&2 echo "$*"
  >&2 cat <<EOF
Usage: $0 [*options] command [*args]

Options:
  -h
  -t TO       default: your login-user
  -f FROM     default: your login-user
  -s SUBJECT  default: "timer: [command *args]"
  -e          send email only on error (command exit-code != 0)
  -o          send email only if command writes something to syslog (default)
              In Services, stdout and stderr are logged to syslog.
  -a          send always email
EOF
  exit 42
}

if [ -z "$INVOCATION_ID" ]
then
	>&2 echo 'No INVOCATION_ID set, not running systemd?'
fi

subject=
on=
to=
from=

eval set -- "$(getopt -n "$0" "ht:f:s:aev" "$@")"
while [ 0 -lt $# ]
do
	case "$1" in
	-h) help ;;
	-s) shift ; subject="$1" ;;
	-t) shift ; to="$1" ;;
	-f) shift ; from="$1" ;;
	-e) on=error ;;
	-o) on=output ;;
	-a) on=always ;;
	--) shift ; break ;;
	*) help "Unknown option: $1" ;;
	esac
	shift
done

subject="${subject:-timer: $*}"
on=${on:-output}
to="${to:-${LOGNAME:-$USER}}"
from="${from:-${LOGNAME:-$USER}}"

"$@"
r=$?

# should a mail be sent?
mm=false
case "$on" in
always) mm=true ;;
error)	[ 0 -lt $r ] && mm=true ;;
output) journalctl -n1 _SYSTEMD_INVOCATION_ID="$INVOCATION_ID" | grep -sqm1 "\S" && mm=true ;;
esac

if $mm
then
  journalctl _SYSTEMD_INVOCATION_ID="$INVOCATION_ID" + INVOCATION_ID="$INVOCATION_ID" + USER_INVOCATION_ID="$INVOCATION_ID"  |  \
		mail -s "$subject" -r "$from" -- "$to"  ||  exit 97
fi

exit $r