package allowsources

import (
	"encoding/binary"

	"golang.org/x/sys/unix"

	"github.com/projectcalico/calico/felix/bpf/maps"
	"github.com/projectcalico/calico/felix/ip"
)

const AllowSourcesEntryV6Size = 24

type AllowSourcesEntryV6 [AllowSourcesEntryV6Size]byte

var MapV6Parameters = maps.MapParameters{
	Type:       "lpm_trie",
	KeySize:    AllowSourcesEntryV6Size,
	ValueSize:  4,
	MaxEntries: 1024 * 1024,
	Name:       "cali_v6_sprefix",
	Flags:      unix.BPF_F_NO_PREALLOC,
}

func MapV6() maps.Map {
	return maps.NewPinnedMap(MapV6Parameters)
}

func (e AllowSourcesEntryV6) Addr() ip.Addr {
	var addr ip.V6Addr
	copy(addr[:], e[8:24])
	return addr
}

func (e AllowSourcesEntryV6) PrefixLen() int {
	return int(binary.LittleEndian.Uint32(e[:4]))
}

func (e AllowSourcesEntryV6) IfIndex() int {
	return int(binary.LittleEndian.Uint32(e[4:8]))
}

func (e AllowSourcesEntryV6) AsBytes() []byte {
	return e[:]
}

func NewKeyV6(cidr ip.CIDR, ifindex int) AllowSourcesEntryV6 {
	var entry AllowSourcesEntryV6
	prefixLen := cidr.Prefix() + 32

	ipv6 := cidr.Addr().(ip.V6Addr)
	binary.LittleEndian.PutUint32(entry[:4], uint32(prefixLen))
	binary.LittleEndian.PutUint32(entry[4:8], uint32(ifindex))
	copy(entry[8:24], ipv6[:])
	return entry
}