package internal

import (
	log "github.com/sirupsen/logrus"
	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"

	"github.com/netbirdio/netbird/client/internal/pqkem"
)

// pqPresharedKeySetter is the subset of the WireGuard interface the ML-KEM callback
// needs: programming a peer's preshared key. *iface.WGIface satisfies it.
type pqPresharedKeySetter interface {
	SetPresharedKey(peerKey string, psk wgtypes.Key, updateOnly bool) error
}

// pqCallbackHandler programs the derived PQ PSK onto the WireGuard peer. It is the
// engine-side implementation of pqkem.CallbackHandler.
type pqCallbackHandler struct {
	wg pqPresharedKeySetter
}

// OnNewPSKReady programs the freshly derived PSK for the peer (updateOnly: a no-op
// if the peer is not present, mirroring Rosenpass). remoteID is the peer's WG pubkey.
func (h pqCallbackHandler) OnNewPSKReady(remoteID string, psk pqkem.PSK) error {
	return h.wg.SetPresharedKey(remoteID, wgtypes.Key(psk), true)
}

// OnRekeyFailed reports a failed PQ (re)key convergence.
// TODO(NET-1406): tear the peer connection down / trigger ICE reconnect.
func (h pqCallbackHandler) OnRekeyFailed(remoteID string) error {
	log.Warnf("pqkem: post-quantum rekey failed for peer %s", remoteID)
	return nil
}

// noopPQTransport is a placeholder data-path transport for the ML-KEM manager.
// TODO(NET-1406): replace with the real dedicated UDP transport bound on the WG
// overlay IPv4 (send over the data path, feed inbound to Manager.OnDataPathMessage),
// analogue of go-rosenpass's Conn.
type noopPQTransport struct{}

func (noopPQTransport) SendDataPath(remoteID string, msg []byte) error { return nil }