#!/bin/bash

set -o errexit
set -o pipefail
set -o nounset

DNS_SERVER="{{ dns_server }}"
DNS_ZONE="{{ dns_zone }}"
API_TOKEN="{{ api_token }}"

HOSTNAME=$(hostname)
IP_ADDRESS=$(hostname -I | awk '{print $1}')
DOMAIN="$HOSTNAME.$DNS_ZONE"

LOGFILE="/var/log/update-dns.log"
DEBUG=true   # bei Bedarf auf false setzen

log() {
  echo "$(date '+%Y-%m-%d %H:%M:%S') | $1" | tee -a "$LOGFILE"
}

debug() {
  if [ "$DEBUG" = true ]; then
    log "DEBUG: $1"
  fi
}

log "🔄 Starte DNS-Update für $DOMAIN ($IP_ADDRESS)"

# --- CURL REQUEST -------------------------------------------------------------

API_URL="http://$DNS_SERVER:5380/api/zones/records/add"
QUERY="domain=$DOMAIN&zone=$DNS_ZONE&type=A&overwrite=true&IPAddress=$IP_ADDRESS&token=$API_TOKEN"

debug "API-URL: $API_URL?$QUERY"

response=$(curl \
  --silent \
  --show-error \
  --write-out "%{http_code}" \
  --output /tmp/dns_api_response.txt \
  --max-time 10 \
  "$API_URL?$QUERY" 2>/tmp/dns_api_error.txt || true)

curl_exit=$?

debug "Curl Exit-Code: $curl_exit"
debug "HTTP-Code: $response"
debug "Curl stderr: $(cat /tmp/dns_api_error.txt || true)"

if [ "$curl_exit" -ne 0 ]; then
  log "❌ Curl-Fehler beim DNS-Update (Exit-Code $curl_exit)"
  log "    → $(cat /tmp/dns_api_error.txt || echo 'kein Fehlertext')"
  exit 10
fi

if [ "$response" -ne 200 ]; then
  log "❌ DNS-Server antwortete mit HTTP $response"
  log "    API Response: $(cat /tmp/dns_api_response.txt || echo 'keine Antwort')"
  exit 11
fi

log "✅ DNS-Eintrag erfolgreich gesetzt."

# --- DNS CHECK ---------------------------------------------------------------

log "🔍 Prüfe DNS-Eintrag mit dig..."

max_retries=5
retry_delay=2
success=false

for i in $(seq 1 "$max_retries"); do
  dns_check=$(dig +time=2 +tries=1 +short "$DOMAIN" 2>/tmp/dns_dig_error.txt || true)

  if [ -s /tmp/dns_dig_error.txt ]; then
    debug "dig error: $(cat /tmp/dns_dig_error.txt)"
  fi

  if [ -n "$dns_check" ]; then
    log "🟢 DNS-Eintrag gefunden: $dns_check"
    success=true
    break
  else
    log "🔁 Versuch $i/$max_retries: DNS-Eintrag noch nicht sichtbar"
    sleep "$retry_delay"
  fi
done

if [ "$success" = false ]; then
  log "🔴 Kein DNS-Eintrag gefunden nach $max_retries Versuchen."
  exit 12
fi

log "🎉 DNS-Update abgeschlossen."
exit 0