#pragma once

#ifndef _WIN32
#include <aio.h>
using SizeReturn = ssize_t;
#else
#include <windows.h>
using SizeReturn = DWORD;
#endif

#include "Util.hpp"
#include <vector>

namespace kabufuda {

class AsyncIO {
#ifndef _WIN32
  int m_fd = -1;
  std::vector<std::pair<struct aiocb, SizeReturn>> m_queue;
#else
  HANDLE m_fh = INVALID_HANDLE_VALUE;
  std::vector<std::pair<OVERLAPPED, SizeReturn>> m_queue;
#endif
  void _waitForOperation(size_t qIdx) const;
  size_t m_maxBlock = 0;

public:
  AsyncIO() = default;
  AsyncIO(SystemStringView filename, bool truncate = false);
  ~AsyncIO();
  AsyncIO(AsyncIO&& other);
  AsyncIO& operator=(AsyncIO&& other);
  AsyncIO(const AsyncIO* other) = delete;
  AsyncIO& operator=(const AsyncIO& other) = delete;
  void resizeQueue(size_t queueSz) { m_queue.resize(queueSz); }
  bool asyncRead(size_t qIdx, void* buf, size_t length, off_t offset);
  bool asyncWrite(size_t qIdx, const void* buf, size_t length, off_t offset);
  ECardResult pollStatus(size_t qIdx, SizeReturn* szRet = nullptr) const;
  ECardResult pollStatus() const;
  void waitForCompletion() const;
#ifndef _WIN32
  operator bool() const { return m_fd != -1; }
#else
  operator bool() const { return m_fh != INVALID_HANDLE_VALUE; }
#endif
};

} // namespace kabufuda