package main

import (
	"context"
	"net"

	E "github.com/sagernet/sing/common/exceptions"

	"google.golang.org/grpc/credentials"
	"google.golang.org/grpc/peer"
)

type peerIdentity struct {
	UserID    string
	ProcessID uint32
	SessionID uint32
}

type peerAuthInfo struct {
	credentials.CommonAuthInfo
	identity peerIdentity
}

func (i *peerAuthInfo) AuthType() string {
	return "local-process"
}

func peerIdentityFromContext(ctx context.Context) (peerIdentity, error) {
	peerInfo, loaded := peer.FromContext(ctx)
	if !loaded || peerInfo.AuthInfo == nil {
		return platformFallbackPeerIdentity(ctx)
	}
	authInfo, loaded := peerInfo.AuthInfo.(*peerAuthInfo)
	if !loaded {
		return peerIdentity{}, E.New("unexpected peer authentication type")
	}
	return authInfo.identity, nil
}

var _ credentials.AuthInfo = (*peerAuthInfo)(nil)

type peerConnection interface {
	net.Conn
	peerConnectionIdentity() peerIdentity
}