#!/bin/sh
# Minimal Hetzner DNS updater for pfSense/FreeBSD
# - Always updates on startup (no pre-check)
# - Then polls and only updates when IP changes
# - Keeps last IP only in memory (no files)

# --- CONFIG ---------------------------------------------------------------
API_TOKEN="$(cat /usr/local/etc/hetzner_auth)"
ZONE_ID="{{ hetzner_zone_id }}"
RECORD_ID="{{ hetzner_record_id }}"
RECORD_NAME=pursotin
RECORD_TYPE="A"
IFACE_CMD="ifconfig epw1b"

POLL_INTERVAL=60
API_BASE="https://dns.hetzner.com/api/v1"
TTL="300"
# --------------------------------------------------------------------------

get_ip() {
  # Expect FreeBSD-style ifconfig output; grab first IPv4 addr
  # Example: 'inet 192.0.2.3 ...'
  sh -c "$IFACE_CMD" 2>/dev/null | awk '/inet[[:space:]]/ {print $2; exit}'
}

update_record() {
  ip="$1"
  body=$(printf '{"type":"%s","name":"%s","value":"%s","zone_id":"%s","ttl":%s}' \
               "$RECORD_TYPE" "$RECORD_NAME" "$ip" "$ZONE_ID" "$TTL")

  http_code=$(
    curl -sS -o /dev/null -w "%{http_code}" -X PUT \
      -H "Content-Type: application/json" \
      -H "Auth-API-Token: ${API_TOKEN}" \
      --data "$body" \
      "${API_BASE}/records/${RECORD_ID}"
  )

  [ "$http_code" = "200" ] || {
    echo "$(date -u +"%F %T") update failed (HTTP $http_code)" >&2
    return 1
  }

  echo "$(date -u +"%F %T") updated ${RECORD_NAME} to ${ip}"
  return 0
}

# --- Startup: always update once (no check) --------------------------------
last_ip=""
ip="$(get_ip)"
if [ -n "$ip" ]; then
  update_record "$ip" && last_ip="$ip"
else
  echo "$(date -u +"%F %T") no IPv4 from: ${IFACE_CMD}; will retry..." >&2
fi

# --- Poll loop: update only on change --------------------------------------
while :; do
  ip="$(get_ip)"
  if [ -n "$ip" ] && [ "$ip" != "$last_ip" ]; then
    if update_record "$ip"; then
      last_ip="$ip"
    fi
  fi
  sleep "$POLL_INTERVAL"
done