#pragma once

#include "quiche/quic/core/quic_stream.h"

namespace Envoy {

namespace Quic {

// An interface for stream and connection to update send buffer watermark.

class SendBufferMonitor {

public:

  // A scoped object to update the send buffer size change of the given quic stream to

  // SendBufferMonitor during its life time. If the given send buffer monitor is already monitoring,

  // skip updating the monitor after it's out of scope because this updater is in the scope of

  // another one.

  class ScopedWatermarkBufferUpdater {

  public:

    ScopedWatermarkBufferUpdater(quic::QuicStream* quic_stream,

                                 SendBufferMonitor* send_buffer_monitor);

    ~ScopedWatermarkBufferUpdater();

  private:

    quic::QuicStream* quic_stream_{nullptr};

    uint64_t old_buffered_bytes_{0};

    SendBufferMonitor* send_buffer_monitor_{nullptr};

  };

protected:

  // Update the monitor with the new buffered bytes and check watermark threshold.

  virtual void updateBytesBuffered(uint64_t old_buffered_bytes, uint64_t new_buffered_bytes) = 0;

private:

  bool is_doing_watermark_accounting_{false};

};

} // namespace Quic

} // namespace Envoy