// Copyright (c) 2026 Probo Inc <hello@getprobo.com>.
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
// AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
// OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
// PERFORMANCE OF THIS SOFTWARE.

package cookiebanner

import "net"

// AnonymizeIP truncates an IP address for GDPR compliance.
// IPv4: zeroes the last octet (e.g. 192.168.1.123 -> 192.168.1.0).
// IPv6: zeroes the last 80 bits (/48 mask, e.g. 2001:db8:1:2:3:4:5:6 -> 2001:db8:1::).
func AnonymizeIP(raw string) string {
	ip := net.ParseIP(raw)
	if ip == nil {
		return raw
	}

	if v4 := ip.To4(); v4 != nil {
		v4[3] = 0
		return v4.String()
	}

	mask := net.CIDRMask(48, 128)

	return ip.Mask(mask).String()
}