#pragma once

#include <cstdint>

#include "envoy/event/file_event.h"

#include "source/common/event/dispatcher_impl.h"

#include "source/common/event/event_impl_base.h"

namespace Envoy {

namespace Event {

/**

 * Implementation of FileEvent for libevent that uses persistent events and

 * assumes the user will read/write until EAGAIN is returned from the file.

 */

class FileEventImpl : public FileEvent, ImplBase {

public:

  FileEventImpl(DispatcherImpl& dispatcher, os_fd_t fd, FileReadyCb cb, FileTriggerType trigger,

                uint32_t events);

  // Event::FileEvent

  void activate(uint32_t events) override;

  void setEnabled(uint32_t events) override;

  void unregisterEventIfEmulatedEdge(uint32_t event) override;

  void registerEventIfEmulatedEdge(uint32_t event) override;

private:

  void assignEvents(uint32_t events, event_base* base);

  void mergeInjectedEventsAndRunCb(uint32_t events);

  void updateEvents(uint32_t events);

  Dispatcher& dispatcher_;

  FileReadyCb cb_;

  os_fd_t fd_;

  FileTriggerType trigger_;

  // Enabled events for this fd.

  uint32_t enabled_events_;

  // Injected FileReadyType events that were scheduled by recent calls to activate() and are pending

  // delivery.

  uint32_t injected_activation_events_{};

  // Used to schedule delayed event activation. Armed iff pending_activation_events_ != 0.

  SchedulableCallbackPtr activation_cb_;

};

} // namespace Event

} // namespace Envoy