package peer

import (
	"context"
	"net"
	"net/http"
	"sync"

	"tailscale.com/client/local"
	"tailscale.com/client/tailscale/apitype"
)

type key struct{}

type peer struct {
	mu  sync.Mutex
	who *apitype.WhoIsResponse
}

func ConnContext(ctx context.Context, _ net.Conn) context.Context {
	return context.WithValue(ctx, key{}, &peer{})
}

func WhoIs(r *http.Request, lc *local.Client) (*apitype.WhoIsResponse, error) {
	p := r.Context().Value(key{}).(*peer)
	p.mu.Lock()
	defer p.mu.Unlock()
	if p.who != nil {
		return p.who, nil
	}
	who, err := lc.WhoIs(r.Context(), r.RemoteAddr)
	if err != nil {
		return nil, err
	}
	p.who = who
	return who, nil
}