"golang.org/x/tools/internal/aliases"
)

// ReceiverNamed returns the named type (if any) associated with the
// type of recv, which may be of the form N or *N, or aliases thereof.
// It also reports whether a Pointer was present.
func ReceiverNamed(recv *types.Var) (isPtr bool, named *types.Named) {
	t := recv.Type()
	if ptr, ok := aliases.Unalias(t).(*types.Pointer); ok {
		isPtr = true
		t = ptr.Elem()
	}

	"istio.io/istio/pkg/log"
	"istio.io/istio/pkg/sleep"
)

type slowClientStream struct {
	grpc.ClientStream
	recv, send time.Duration
}

func (w *slowClientStream) RecvMsg(m any) error {
	if w.recv > 0 {
		sleep.UntilContext(w.Context(), w.recv)
		log.Infof("delayed recv for %v", w.recv)
	}
	return w.ClientStream.RecvMsg(m)
}

func (w *slowClientStream) SendMsg(m any) error {
	if w.send > 0 {

				}
				if cause != "" {
					check.errorf(recv, InvalidRecv, "invalid receiver type %s (%s)", rtyp, cause)
				}
			case *Basic:
				check.errorf(recv, InvalidRecv, "cannot define new methods on non-local type %s", rtyp)
			default:
				check.errorf(recv, InvalidRecv, "invalid receiver type %s", recv.typ)
			}
		}).describef(recv, "validate receiver %s", recv)
	}

	sig.params = NewTuple(params...)

				}
				if cause != "" {
					check.errorf(recv, InvalidRecv, "invalid receiver type %s (%s)", rtyp, cause)
				}
			case *Basic:
				check.errorf(recv, InvalidRecv, "cannot define new methods on non-local type %s", rtyp)
			default:
				check.errorf(recv, InvalidRecv, "invalid receiver type %s", recv.typ)
			}
		}).describef(recv, "validate receiver %s", recv)
	}

	sig.params = NewTuple(params...)

//
// Example: "(*Buffer).Grow" -> (true, "Buffer", "Grow")
func (sym *Symbol) SplitMethod() (ptr bool, recv, name string) {
	if sym.Kind != Method {
		panic("not a method")
	}
	recv, name, _ = strings.Cut(sym.Name, ".")
	recv = recv[len("(") : len(recv)-len(")")]
	ptr = recv[0] == '*'
	if ptr {
		recv = recv[len("*"):]
	}
	return

func (s *Selection) Type() Type {
	switch s.kind {
	case MethodVal:
		// The type of x.f is a method with its receiver type set
		// to the type of x.
		sig := *s.obj.(*Func).typ.(*Signature)
		recv := *sig.recv
		recv.typ = s.recv
		sig.recv = &recv
		return &sig

	case MethodExpr:
		// The type of x.f is a function (without receiver)
		// and an additional first argument with the same type as x.

func (s *Selection) Type() Type {
	switch s.kind {
	case MethodVal:
		// The type of x.f is a method with its receiver type set
		// to the type of x.
		sig := *s.obj.(*Func).typ.(*Signature)
		recv := *sig.recv
		recv.typ = s.recv
		sig.recv = &recv
		return &sig

	case MethodExpr:
		// The type of x.f is a function (without receiver)
		// and an additional first argument with the same type as x.

func NewMethodType(sig *types.Type, recv *types.Type) *types.Type {
	nrecvs := 0
	if recv != nil {
		nrecvs++
	}

	// TODO(mdempsky): Move this function to types.
	// TODO(mdempsky): Preserve positions, names, and package from sig+recv.

	params := make([]*types.Field, nrecvs+sig.NumParams())
	if recv != nil {
		params[0] = types.NewField(base.Pos, nil, recv)
	}
	for i, param := range sig.Params() {

		argidx := -1

		recv := fn.Type().(*types.Signature).Recv()
		if fn.Name() == "Unmarshal" && recv == nil {
			// "encoding/json".Unmarshal
			// "encoding/xml".Unmarshal
			// "encoding/asn1".Unmarshal
			switch fn.Pkg().Path() {
			case "encoding/json", "encoding/xml", "encoding/asn1":
				argidx = 1 // func([]byte, interface{})
			}
		} else if fn.Name() == "Decode" && recv != nil {

func fsend[T any](chan<- T) {}

func _() {
	var both chan int
	var recv <-chan int
	var send chan<-int

	fboth(both)
	fboth(recv /* ERROR "cannot use" */ )
	fboth(send /* ERROR "cannot use" */ )

	frecv(both)
	frecv(recv)
	frecv(send /* ERROR "cannot use" */ )

	fsend(both)
	fsend(recv /* ERROR "cannot use" */)
	fsend(send)
}

func ffboth[T any](func(chan T)) {}