#!/bin/bash

# ==========================================
# Script: dns_check.sh
# Descripción: Consulta de registros DNS básica y completa
# Uso: ./dns_check.sh <dominio> [full]
# ==========================================

# Validar argumento de entrada
if [ -z "$1" ]; then
    echo -e "\e[0;31mError: Debes proporcionar un dominio.\e[0m"
    echo "Uso: $0 <dominio> [full]"
    exit 1
fi

DOMAIN=$1
MODE=${2:-basic} # Por defecto es "basic" si no se envía el segundo argumento

# Códigos de color
CYAN='\e[0;36m'
VERDE='\e[0;32m'
AMARILLO='\e[1;33m'
BLANCO_BOLD='\e[1;37m'
NC='\e[0m' # Sin color

# Servidores DNS (Fuentes de verdad)
DNS_GOOGLE="8.8.8.8"
DNS_EMPRESA="dns1.servidoraweb.net"

# ==========================================
# Función: Consulta Básica
# ==========================================
consultar_basico() {
    local server=$1
    local nombre_server=$2

    echo -e "${CYAN}====================================================${NC}"
    echo -e "${VERDE} 📡 Fuente de Verdad: ${nombre_server} (@${server})${NC}"
    echo -e "${CYAN}====================================================${NC}"

    # NS (DNS)
    echo -e "${AMARILLO}Registros DNS (NS):${NC}"
    dig @$server +short NS $DOMAIN | sed 's/^/  /' | grep . || echo "  (Sin respuesta)"
    
    # MX
    echo -e "${AMARILLO}Registros MX:${NC}"
    dig @$server +short MX $DOMAIN | sed 's/^/  /' | grep . || echo "  (Sin respuesta)"
    
    # Registro A (Principal)
    echo -e "${AMARILLO}Registro A (Dominio principal):${NC}"
    dig @$server +short A $DOMAIN | sed 's/^/  /' | grep . || echo "  (Sin respuesta)"
    
    # Registro www
    echo -e "${AMARILLO}Registro A (www):${NC}"
    dig @$server +short A www.$DOMAIN | sed 's/^/  /' | grep . || echo "  (Sin respuesta)"
    echo ""
}

# ==========================================
# Función: Consulta Full (Avanzada)
# ==========================================
consultar_full() {
    local server=$1
    local nombre_server=$2

    echo -e "${CYAN}====================================================${NC}"
    echo -e "${VERDE} 🔍 Análisis Completo (FULL) desde: ${nombre_server} (@${server})${NC}"
    echo -e "${CYAN}====================================================${NC}"

    # Matriz de registros estándar
    registros=("A" "AAAA" "NS" "MX" "TXT" "SOA" "CAA")
    
    for reg in "${registros[@]}"; do
        salida=$(dig @$server +short $reg $DOMAIN)
        if [ -n "$salida" ]; then
            echo -e "${AMARILLO}Registros ${reg}:${NC}"
            # Nota: El registro TXT contiene automáticamente el SPF
            echo "$salida" | sed 's/^/  /'
        fi
    done

    # DMARC (Requiere consultar el prefijo _dmarc)
    dmarc=$(dig @$server +short TXT _dmarc.$DOMAIN)
    if [ -n "$dmarc" ]; then
        echo -e "${AMARILLO}Registro DMARC:${NC}"
        echo "$dmarc" | sed 's/^/  /'
    fi

    # DKIM (Búsqueda predictiva del selector por defecto de cPanel)
    dkim=$(dig @$server +short TXT default._domainkey.$DOMAIN)
    if [ -n "$dkim" ]; then
        echo -e "${AMARILLO}Registro DKIM (Selector 'default'):${NC}"
        echo "$dkim" | sed 's/^/  /'
    fi
    
    # SRV Comunes (Ej. Autodiscover para correos)
    srv_auto=$(dig @$server +short SRV _autodiscover._tcp.$DOMAIN)
    if [ -n "$srv_auto" ]; then
        echo -e "${AMARILLO}Registro SRV (Autodiscover):${NC}"
        echo "$srv_auto" | sed 's/^/  /'
    fi
    echo ""
}

# ==========================================
# Ejecución Principal
# ==========================================
echo ""
echo -e "Iniciando diagnóstico DNS para: ${BLANCO_BOLD}${DOMAIN}${NC}"
echo ""

# Convertir el argumento de modo a minúsculas por si el usuario escribe "FULL"
MODE=$(echo "$MODE" | tr '[:upper:]' '[:lower:]')

if [ "$MODE" == "full" ]; then
    consultar_full $DNS_GOOGLE "Google DNS"
    consultar_full $DNS_EMPRESA "DNS ServidoraWeb"
else
    consultar_basico $DNS_GOOGLE "Google DNS"
    consultar_basico $DNS_EMPRESA "DNS ServidoraWeb"
fi

echo -e "${VERDE}✓ Consulta finalizada.${NC}"
echo ""