// Copyright (c) 2019 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef QUICHE_QUIC_CORE_STREAM_DELEGATE_INTERFACE_H_
#define QUICHE_QUIC_CORE_STREAM_DELEGATE_INTERFACE_H_

#include <cstddef>
#include <optional>

#include "quiche/quic/core/quic_stream_priority.h"
#include "quiche/quic/core/quic_types.h"

namespace quic {

class QuicStream;

// Pure virtual class to get notified when particular QuicStream events
// occurred.
class QUICHE_EXPORT StreamDelegateInterface {
 public:
  virtual ~StreamDelegateInterface() {}

  // Called when the stream has encountered errors that it can't handle.
  virtual void OnStreamError(QuicErrorCode error_code,
                             std::string error_details) = 0;
  // Called when the stream has encountered errors that it can't handle,
  // specifying the wire error code |ietf_error| explicitly.
  virtual void OnStreamError(QuicErrorCode error_code,
                             QuicIetfTransportErrorCodes ietf_error,
                             std::string error_details) = 0;
  // Called when the stream needs to write data at specified |level| and
  // transmission |type|.
  virtual QuicConsumedData WritevData(QuicStreamId id, size_t write_length,
                                      QuicStreamOffset offset,
                                      StreamSendingState state,
                                      TransmissionType type,
                                      EncryptionLevel level) = 0;
  // Called to write crypto data.
  virtual size_t SendCryptoData(EncryptionLevel level, size_t write_length,
                                QuicStreamOffset offset,
                                TransmissionType type) = 0;
  // Called on stream creation.
  virtual void RegisterStreamPriority(QuicStreamId id, bool is_static,
                                      const QuicStreamPriority& priority) = 0;
  // Called on stream destruction to clear priority.
  virtual void UnregisterStreamPriority(QuicStreamId id) = 0;
  // Called by the stream on SetPriority to update priority.
  virtual void UpdateStreamPriority(QuicStreamId id,
                                    const QuicStreamPriority& new_priority) = 0;
};

}  // namespace quic

#endif  // QUICHE_QUIC_CORE_STREAM_DELEGATE_INTERFACE_H_