#!/bin/bash

# Vérifie si une IP est fournie
if [ -z "$1" ]; then
    echo "Usage: $0 <IP>"
    exit 1
fi

IP="$1"

echo "🔍 Recherche du nom d'hôte pour l'IP : $IP"

# Fonction pour vérifier si une commande est disponible
command_exists() {
    command -v "$1" &> /dev/null
}

# 1️⃣ Test LLMNR (Link-Local Multicast Name Resolution)
if command_exists resolvectl; then
    HOSTNAME_LLMNR=$(resolvectl query "$IP" 2>/dev/null | grep -oP '(?<=Name:\s).*' | head -n1)
    if [ ! -z "$HOSTNAME_LLMNR" ]; then
        echo "✅ LLMNR: $HOSTNAME_LLMNR"
        exit 0
    fi
else
    echo "⚠ LLMNR non disponible (resolvectl absent)"
fi

# 2️⃣ Test mDNS (Multicast DNS / Avahi)
if command_exists avahi-resolve; then
    HOSTNAME_MDNS=$(avahi-resolve -a "$IP" 2>/dev/null | awk '{print $2}')
    if [ ! -z "$HOSTNAME_MDNS" ]; then
        echo "✅ mDNS (Avahi): $HOSTNAME_MDNS"
        exit 0
    fi
else
    echo "⚠ mDNS non disponible (avahi-resolve absent)"
fi

# 3️⃣ Vérification du cache ARP
if command_exists arp; then
    HOSTNAME_ARP=$(arp -a | grep "$IP" | awk '{print $1}')
    if [ ! -z "$HOSTNAME_ARP" ]; then
        echo "✅ ARP: $HOSTNAME_ARP"
        exit 0
    fi
else
    echo "⚠ ARP non disponible"
fi

# 4️⃣ Vérification via NetBIOS (Windows/Samba)
if command_exists nmblookup; then
    HOSTNAME_NETBIOS=$(nmblookup -A "$IP" 2>/dev/null | grep -m1 '<00>' | awk '{print $1}')
    if [ ! -z "$HOSTNAME_NETBIOS" ]; then
        echo "✅ NetBIOS: $HOSTNAME_NETBIOS"
        exit 0
    fi
else
    echo "⚠ NetBIOS non disponible (nmblookup absent)"
fi

# 5️⃣ Scan réseau avec Nmap pour identifier l'hôte
if command_exists nmap; then
    HOSTNAME_NMAP=$(nmap -sP "$IP" 2>/dev/null | grep "Nmap scan report" | awk '{print $5}')
    if [ ! -z "$HOSTNAME_NMAP" ]; then
        echo "✅ Nmap: $HOSTNAME_NMAP"
        exit 0
    fi
else
    echo "⚠ Nmap non disponible"
fi

echo "❌ Aucune correspondance trouvée."
exit 1