#!/usr/bin/env bash

# usage
usage() {
USAGE=$(cat <<EOF
Usage: systemd_failure_notify [CONFIG_FILE (absolute path)] <service>

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

set -e;

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

SYSTEMD_FAILURE_NOTFY_HOSTNAME=$(hostname)
SYSTEMD_FAILURE_NOTFY_USER=$(whoami)

SYSTEMD_FAILURE_NOTIFY_MAIL_ENABLED="true";
SYSTEMD_FAILURE_NOTIFY_MAIL_ADDRESS="";

SYSTEMD_FAILURE_NOTIFY_GOTIFY_ENABLED="false";

# 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() {
	local mailEnabled=$1;
	local gotifyEnabled=$2;

	if [[ "${mailEnabled}" == "true" ]]; then
		type mailx &> /dev/null || echo "Requiring 'mailx' but it's not installed"; exit 1
	fi

	if [[ "${gotifyEnabled}" == "true" ]]; then
		type gotify &> /dev/null || echo "Requiring 'gotify' but it's not installed"; exit 1
	fi
}

source_config() {
  local config=$1;
  local configFallback=$2;
  local configGlobalFallback=$3;

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

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

  if [[ -f "$configGlobalFallback" ]]; then
    apply_config "$configGlobalFallback";
    return;
  fi
}
source_config "$2" "$HOME/.systemd_failure_notify.conf" "/etc/systemd_failure_notify.conf"
check_requirements "$SYSTEMD_FAILURE_NOTIFY_MAIL_ENABLED" "$SYSTEMD_FAILURE_NOTIFY_GOTIFY_ENABLED"

SUBJECT="[systemd $SYSTEMD_FAILURE_NOTFY_HOSTNAME for $SYSTEMD_FAILURE_NOTFY_USER] $SYSTEMD_FAILURE_NOTFY_SERVICE RUN FAILED"
MESSAGE="$SYSTEMD_FAILURE_NOTFY_SERVICE run failed"

if [[ "${SYSTEMD_FAILURE_NOTIFY_MAIL_ENABLED}" == "true" ]]; then
  echo "$MESSAGE"|mailx -Ssendwait -s "$SUBJECT" "$SYSTEMD_FAILURE_NOTIFY_MAIL_ADDRESS";
  echo "Sent notifiction via mail"
else
  echo "Sending notifictions via mail is disabled"
fi

if [[ "${SYSTEMD_FAILURE_NOTIFY_GOTIFY_ENABLED}" == "true" ]]; then

  if [[ ! -f "${HOME}/.config/gotify/cli.json" && ! -f "${HOME}/gotify/cli.json" && ! -f "./cli.json" && ! -f "/etc/gotify/cli.json" ]]; then
    echo "Cannot find a valid cli.json, please run 'gotify init' before using this"
    exit 1;
  fi

  echo "$MESSAGE"|gotify push --quiet --title "${SUBJECT}";
  echo "Sent message via gotify"
else
  echo "Sending notifictions via gotify is disabled"
fi