// Copyright (c) 2026 Probo Inc <hello@probo.com>.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// 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()
}