package guard

import "net/netip"

var blockedPrefixes = []netip.Prefix{
	netip.MustParsePrefix("0.0.0.0/8"),
	netip.MustParsePrefix("10.0.0.0/8"),
	netip.MustParsePrefix("100.64.0.0/10"),
	netip.MustParsePrefix("127.0.0.0/8"),
	netip.MustParsePrefix("169.254.0.0/16"),
	netip.MustParsePrefix("172.16.0.0/12"),
	netip.MustParsePrefix("192.0.0.0/24"),
	netip.MustParsePrefix("192.0.2.0/24"),
	netip.MustParsePrefix("192.88.99.0/24"),
	netip.MustParsePrefix("192.168.0.0/16"),
	netip.MustParsePrefix("198.18.0.0/15"),
	netip.MustParsePrefix("198.51.100.0/24"),
	netip.MustParsePrefix("203.0.113.0/24"),
	netip.MustParsePrefix("224.0.0.0/4"),
	netip.MustParsePrefix("240.0.0.0/4"),
	netip.MustParsePrefix("::/128"),
	netip.MustParsePrefix("::1/128"),
	netip.MustParsePrefix("::ffff:0:0/96"),
	netip.MustParsePrefix("64:ff9b::/96"),
	netip.MustParsePrefix("64:ff9b:1::/48"),
	netip.MustParsePrefix("100::/64"),
	netip.MustParsePrefix("2001::/32"),
	netip.MustParsePrefix("2001:db8::/32"),
	netip.MustParsePrefix("2002::/16"),
	netip.MustParsePrefix("fc00::/7"),
	netip.MustParsePrefix("fe80::/10"),
	netip.MustParsePrefix("fec0::/10"),
	netip.MustParsePrefix("ff00::/8"),
}

func IsPublicAddress(address netip.Addr) bool {
	address = address.Unmap().WithZone("")
	if !address.IsValid() ||
		!address.IsGlobalUnicast() ||
		address.IsPrivate() ||
		address.IsLoopback() ||
		address.IsLinkLocalUnicast() ||
		address.IsMulticast() ||
		address.IsUnspecified() {
		return false
	}

	for _, prefix := range blockedPrefixes {
		if prefix.Contains(address) {
			return false
		}
	}
	return true
}