ip.go

package kit

import (
	"net"
	"strings"
)

// AnonymizeIP drops the last octet of the IPv4 and IPv6 address to anonymize it
func AnonymizeIP(ip string) string {
	if ip == "" {
		return ""
	}
	parsedIP := net.ParseIP(ip)
	if parsedIP == nil {
		return ip // not an ip
	}

	// IPv4
	if parsedIP.To4() != nil {
		ipParts := strings.Split(parsedIP.String(), ".")
		if len(ipParts) == 4 {
			ipParts[3] = "0"
			return strings.Join(ipParts, ".")
		}
	}

	// IPv6
	ipParts := strings.Split(parsedIP.String(), ":")
	ipParts[len(ipParts)-1] = "0"
	return strings.Join(ipParts, ":")
}

// IsValidIP checks if the given string is a valid IPv4 or IPv6 address by:
// - ensuring the format is correct
// - ensuring the IP is not an unspecified, loopback, private, multicast, or link-local address
func IsValidIP(ipStr string) bool {
	ip := net.ParseIP(ipStr)
	if ip == nil {
		return false
	}

	return !ip.IsUnspecified() && !ip.IsPrivate() && !ip.IsLoopback() && !ip.IsMulticast() && !ip.IsLinkLocalUnicast() && !ip.IsLinkLocalMulticast()
}