"sync"

	"github.com/minio/minio/internal/hash/sha256"
	xioutil "github.com/minio/minio/internal/ioutil"
	"github.com/tinylib/msgp/msgp"
)

//go:generate stringer -type=HandlerID -output=handlers_string.go -trimprefix=Handler msg.go $GOFILE

// HandlerID is a handler identifier.
// It is used to determine request routing on the server.
// Handlers can be registered with a static subroute.

func (i HandlerID) String() string {
	if i >= HandlerID(len(_HandlerID_index)-1) {
		return "HandlerID(" + strconv.FormatInt(int64(i), 10) + ")"
	}
	return _HandlerID_name[_HandlerID_index[i]:_HandlerID_index[i+1]]

	return
}

// DecodeMsg implements msgp.Decodable
func (z *HandlerID) DecodeMsg(dc *msgp.Reader) (err error) {
	{
		var zb0001 uint8
		zb0001, err = dc.ReadUint8()
		if err != nil {
			err = msgp.WrapError(err)
			return
		}
		(*z) = HandlerID(zb0001)
	}
	return
}

// EncodeMsg implements msgp.Encodable
func (z HandlerID) EncodeMsg(en *msgp.Writer) (err error) {
	err = en.WriteUint8(uint8(z))

//
//go:generate msgp -unexported -file=$GOFILE
//go:generate stringer -type=Op -output=msg_string.go -trimprefix=Op $GOFILE

// Op is operation type messages.
type Op uint8

// HandlerID is the ID for the handler of a specific type.
type HandlerID uint8

const (
	// OpConnect is a connect request.
	OpConnect Op = iota + 1

	// OpConnectResponse is a response to a connect request.
	OpConnectResponse

}

// RegisterSingleHandler will register a stateless handler that serves
// []byte -> ([]byte, error) requests.
// subroutes are joined with "/" to a single subroute.
func (m *Manager) RegisterSingleHandler(id HandlerID, h SingleHandlerFn, subroute ...string) error {
	if !id.valid() {
		return ErrUnknownHandler
	}
	s := strings.Join(subroute, "/")
	if debugPrint {

		LastPong:  time.Now().Unix(),
		BaseFlags: parent.baseFlags,
	}
}

// roundtrip performs a roundtrip, returning the first response.
// This cannot be used concurrently.
func (m *muxClient) roundtrip(h HandlerID, req []byte) ([]byte, error) {
	if m.init {
		return nil, errors.New("mux client already used")
	}
	m.init = true
	m.singleResp = true
	msg := message{
		Op:         OpRequest,
		MuxID:      m.MuxID,

// Request allows to do a single remote request.
// 'req' will not be used after the call and caller can reuse.
// If no deadline is set on ctx, a 1-minute deadline will be added.
func (c *Connection) Request(ctx context.Context, h HandlerID, req []byte) ([]byte, error) {
	if !h.valid() {
		return nil, ErrUnknownHandler
	}
	if c.State() != StateConnected {
		return nil, ErrDisconnected
	}
	// Create mux client and call.

From this connection individual requests can be made.

Each handler, with optional subroutes can be registered with the manager using 
`Manager.RegisterXHandler(handlerID, handler, subroutes...)`.

A `Handler()` function provides an HTTP handler, which should be hooked up to the appropriate route on the server.

	lockRPCUnlock      = newLockHandler(grid.HandlerLockUnlock)
	lockRPCRLock       = newLockHandler(grid.HandlerLockRLock)
	lockRPCRUnlock     = newLockHandler(grid.HandlerLockRUnlock)
)

func newLockHandler(h grid.HandlerID) *grid.SingleHandler[*dsync.LockArgs, *dsync.LockResp] {
	return grid.NewSingleHandler[*dsync.LockArgs, *dsync.LockResp](h, func() *dsync.LockArgs {
		return &dsync.LockArgs{}
	}, func() *dsync.LockResp {

	Local     string
	Remote    string
	Subroute  string
}

const (
	httpScheme  = "http://"
	httpsScheme = "https://"
)

func (c *muxClient) traceRoundtrip(ctx context.Context, t *tracer, h HandlerID, req []byte) ([]byte, error) {
	if t == nil || t.Publisher.NumSubscribers(t.TraceType) == 0 {
		return c.roundtrip(h, req)
	}

	// Following trimming is needed for consistency between outputs with other internode traces.