#!/usr/bin/env bash
# check-backup-freshness — alert if the newest backup is older than 26h.
#
# Exit 0 = fresh (or no backups ever made and NONE expected yet)
# Exit 1 = stale: last backup dir older than MAX_HOURS, or no dir at all
#          while the age recipient is configured (backups should exist).
#
# Wire it anywhere you like (cron, another timer, or run manually from the
# Mac after the daily pull). Not attached to any timer by itself — the only
# authorized timer in Tanda B is cayce-backup.timer.
set -euo pipefail

BACKUP_ROOT="/var/backups/cayce"
MAX_HOURS=26
RECIPIENT_FILE="/etc/cayce-backup/age-recipient.pub"

newest="$(find "$BACKUP_ROOT" -mindepth 1 -maxdepth 1 -type d -name "2*-*-*" 2>/dev/null | sort | tail -1 || true)"

if [[ -z "$newest" ]]; then
  if [[ -f "$RECIPIENT_FILE" ]]; then
    echo "ALERT: no backups exist although the age recipient is configured" >&2
    exit 1
  fi
  echo "INFO: no backups yet (age recipient not configured) — nothing to alert"
  exit 0
fi

hours=$(( ( $(date +%s) - $(stat -c %Y "$newest") ) / 3600 ))
if (( hours > MAX_HOURS )); then
  echo "ALERT: last backup ($newest) is ${hours}h old (max ${MAX_HOURS}h)" >&2
  exit 1
fi
echo "OK: last backup ($newest) is ${hours}h old"