#!/usr/bin/env bash

# usage
usage() {
USAGE=$(cat <<EOF
Usage: systemd_failure_notify [SERVICE]

Sends out notifications for failed services. Please see man systemd_failure_notify.
EOF
)
	echo "$USAGE";
}

set -e;

SYSTEMD_FAILURE_NOTIFY_SERVICE=$1
if [ -z "$SYSTEMD_FAILURE_NOTIFY_SERVICE" ]; then
	echo "No service given";
	echo "";
	usage;
	exit 1;
fi

# check for config file
apply_config() {
  local config=$1;

  if [[ ! -f "$config" ]]; then
      echo "No config file specified";
      echo "";
      usage;
      exit 1;
  fi

  set -a;
  # shellcheck disable=SC1090
  source "$config";
  set +a;
}

check_requirements() {
  type whoami &> /dev/null || { echo "Requiring 'whoami' but it's not installed"; exit 1; }
}

source_config() {
  local configFallback=$1;
  local configGlobalFallback=$2;

  if [[ -f "$configFallback" ]]; then
    apply_config "$configFallback";
    return;
  fi

  if [[ -f "$configGlobalFallback" ]]; then
    apply_config "$configGlobalFallback";
    return;
  fi
}
source_config "$HOME/.systemd_failure_notify.conf" "/etc/systemd_failure_notify.conf"
check_requirements

SYSTEMD_FAILURE_NOTIFY_HOSTNAME=$(hostname)
SYSTEMD_FAILURE_NOTIFY_USER=$(whoami)

SUBJECT="[systemd $SYSTEMD_FAILURE_NOTIFY_HOSTNAME for $SYSTEMD_FAILURE_NOTIFY_USER] $SYSTEMD_FAILURE_NOTIFY_USER RUN FAILED"
MESSAGE="$SYSTEMD_FAILURE_NOTIFY_SERVICE run failed"

notifier "${SUBJECT}" "${MESSAGE}"