#!/usr/bin/env bash
set -euo pipefail

CIDR="${1:-}"

have() { command -v "$1" >/dev/null 2>&1; }

if ! have nmap; then
  echo "FEHLER: nmap fehlt. Install: brew install nmap"
  exit 1
fi

ip=""
if have ipconfig; then
  ip="$(ipconfig getifaddr en0 2>/dev/null || true)"
  if [ -z "$ip" ]; then ip="$(ipconfig getifaddr en1 2>/dev/null || true)"; fi
fi

if [ -z "$CIDR" ]; then
  if [ -n "$ip" ]; then
    base="$(echo "$ip" | awk -F. '{print $1"."$2"."$3".0"}')"
    CIDR="${base}/24"
  else
    CIDR="192.168.1.0/24"
  fi
fi

OUTDIR="$(cd "$(dirname "$0")" && pwd)/lan-scan-$(date +%F_%H-%M-%S)"
mkdir -p "$OUTDIR"

XML="$OUTDIR/scan.xml"
JSON="$OUTDIR/scan.json"
CSV="$OUTDIR/scan.csv"

echo "Scan läuft: $CIDR"
nmap -sn -n "$CIDR" -oX "$XML" >/dev/null

python3 - <<'PY' "$XML" "$CIDR" "$JSON" "$CSV"
import sys, json, xml.etree.ElementTree as ET, datetime, csv

xml_path, cidr, json_path, csv_path = sys.argv[1:5]
root = ET.parse(xml_path).getroot()

hosts = []
for h in root.findall("host"):
    st = h.find("status")
    if st is None or st.get("state") != "up":
        continue

    ip = ""
    mac = ""
    vendor = ""
    for a in h.findall("address"):
        if a.get("addrtype") == "ipv4":
            ip = a.get("addr","")
        if a.get("addrtype") == "mac":
            mac = a.get("addr","")
            vendor = a.get("vendor","")

    name = ""
    hn = h.find("hostnames")
    if hn is not None:
        first = hn.find("hostname")
        if first is not None:
            name = first.get("name","")

    hosts.append({"ip": ip, "name": name, "mac": mac, "vendor": vendor})

payload = {
    "ok": True,
    "cidr": cidr,
    "scanned_at": datetime.datetime.now().isoformat(timespec="seconds"),
    "count": len(hosts),
    "hosts": hosts
}

with open(json_path, "w", encoding="utf-8") as f:
    json.dump(payload, f, ensure_ascii=False, indent=2)

with open(csv_path, "w", encoding="utf-8", newline="") as f:
    w = csv.writer(f, delimiter=";")
    w.writerow(["IP","Hostname","MAC","Vendor"])
    for x in hosts:
        w.writerow([x["ip"], x["name"], x["mac"], x["vendor"]])

print("Fertig:")
print(" ", json_path)
print(" ", csv_path)
PY

echo "Done."