#pragma once

#include <cstdint>

#include <string>

#include "envoy/common/platform.h"

#include "source/common/buffer/buffer_impl.h"

#include "source/common/common/byte_order.h"

#include "source/common/common/logger.h"

namespace Envoy {

namespace Extensions {

namespace NetworkFilters {

namespace ZooKeeperProxy {

/**

 * Helper for extracting ZooKeeper data from a buffer.

 *

 * If at any point a peek is tried beyond max_len, an EnvoyException

 * will be thrown. This is important to protect Envoy against malformed

 * requests (e.g.: when the declared and actual length don't match).

 *

 * Note: ZooKeeper's protocol uses network byte ordering (big-endian).

 */

class BufferHelper : public Logger::Loggable<Logger::Id::filter> {

public:

  BufferHelper(uint32_t max_len) : max_len_(max_len) {}

  int32_t peekInt32(Buffer::Instance& buffer, uint64_t& offset);

  int64_t peekInt64(Buffer::Instance& buffer, uint64_t& offset);

  std::string peekString(Buffer::Instance& buffer, uint64_t& offset);

  bool peekBool(Buffer::Instance& buffer, uint64_t& offset);

  void skip(uint32_t len, uint64_t& offset);

  void reset() { current_ = 0; }

private:

  void ensureMaxLen(uint32_t size);

  const uint32_t max_len_;

  uint32_t current_{};

};

} // namespace ZooKeeperProxy

} // namespace NetworkFilters

} // namespace Extensions

} // namespace Envoy