//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
//  This source code is licensed under both the GPLv2 (found in the
//  COPYING file in the root directory) and Apache 2.0 License
//  (found in the LICENSE.Apache file in the root directory).
//
// This file implements the callback "bridge" between Java and C++ for
// ROCKSDB_NAMESPACE::EventListener.

#ifndef JAVA_ROCKSJNI_EVENT_LISTENER_JNICALLBACK_H_
#define JAVA_ROCKSJNI_EVENT_LISTENER_JNICALLBACK_H_

#include <jni.h>

#include <memory>
#include <set>

#include "rocksdb/listener.h"
#include "rocksjni/jnicallback.h"

namespace ROCKSDB_NAMESPACE {

enum EnabledEventCallback {
  ON_FLUSH_COMPLETED = 0x0,
  ON_FLUSH_BEGIN = 0x1,
  ON_TABLE_FILE_DELETED = 0x2,
  ON_COMPACTION_BEGIN = 0x3,
  ON_COMPACTION_COMPLETED = 0x4,
  ON_TABLE_FILE_CREATED = 0x5,
  ON_TABLE_FILE_CREATION_STARTED = 0x6,
  ON_MEMTABLE_SEALED = 0x7,
  ON_COLUMN_FAMILY_HANDLE_DELETION_STARTED = 0x8,
  ON_EXTERNAL_FILE_INGESTED = 0x9,
  ON_BACKGROUND_ERROR = 0xA,
  ON_STALL_CONDITIONS_CHANGED = 0xB,
  ON_FILE_READ_FINISH = 0xC,
  ON_FILE_WRITE_FINISH = 0xD,
  ON_FILE_FLUSH_FINISH = 0xE,
  ON_FILE_SYNC_FINISH = 0xF,
  ON_FILE_RANGE_SYNC_FINISH = 0x10,
  ON_FILE_TRUNCATE_FINISH = 0x11,
  ON_FILE_CLOSE_FINISH = 0x12,
  SHOULD_BE_NOTIFIED_ON_FILE_IO = 0x13,
  ON_ERROR_RECOVERY_BEGIN = 0x14,
  ON_ERROR_RECOVERY_COMPLETED = 0x15,

  NUM_ENABLED_EVENT_CALLBACK = 0x16,
};

class EventListenerJniCallback : public JniCallback, public EventListener {
 public:
  EventListenerJniCallback(
      JNIEnv* env, jobject jevent_listener,
      const std::set<EnabledEventCallback>& enabled_event_callbacks);
  virtual ~EventListenerJniCallback();
  virtual void OnFlushCompleted(DB* db, const FlushJobInfo& flush_job_info);
  virtual void OnFlushBegin(DB* db, const FlushJobInfo& flush_job_info);
  virtual void OnTableFileDeleted(const TableFileDeletionInfo& info);
  virtual void OnCompactionBegin(DB* db, const CompactionJobInfo& ci);
  virtual void OnCompactionCompleted(DB* db, const CompactionJobInfo& ci);
  virtual void OnTableFileCreated(const TableFileCreationInfo& info);
  virtual void OnTableFileCreationStarted(
      const TableFileCreationBriefInfo& info);
  virtual void OnMemTableSealed(const MemTableInfo& info);
  virtual void OnColumnFamilyHandleDeletionStarted(ColumnFamilyHandle* handle);
  virtual void OnExternalFileIngested(DB* db,
                                      const ExternalFileIngestionInfo& info);
  virtual void OnBackgroundError(BackgroundErrorReason reason,
                                 Status* bg_error);
  virtual void OnStallConditionsChanged(const WriteStallInfo& info);
  virtual void OnFileReadFinish(const FileOperationInfo& info);
  virtual void OnFileWriteFinish(const FileOperationInfo& info);
  virtual void OnFileFlushFinish(const FileOperationInfo& info);
  virtual void OnFileSyncFinish(const FileOperationInfo& info);
  virtual void OnFileRangeSyncFinish(const FileOperationInfo& info);
  virtual void OnFileTruncateFinish(const FileOperationInfo& info);
  virtual void OnFileCloseFinish(const FileOperationInfo& info);
  virtual bool ShouldBeNotifiedOnFileIO();
  virtual void OnErrorRecoveryBegin(BackgroundErrorReason reason,
                                    Status bg_error, bool* auto_recovery);
  virtual void OnErrorRecoveryCompleted(Status old_bg_error);

 private:
  inline void InitCallbackMethodId(jmethodID& mid, EnabledEventCallback eec,
                                   JNIEnv* env,
                                   jmethodID (*get_id)(JNIEnv* env));
  template <class T>
  inline jobject SetupCallbackInvocation(
      JNIEnv*& env, jboolean& attached_thread, const T& cpp_obj,
      jobject (*convert)(JNIEnv* env, const T* cpp_obj));
  inline void CleanupCallbackInvocation(JNIEnv* env, jboolean attached_thread,
                                        std::initializer_list<jobject*> refs);
  inline void OnFileOperation(const jmethodID& mid,
                              const FileOperationInfo& info);

  const std::set<EnabledEventCallback> m_enabled_event_callbacks;
  jmethodID m_on_flush_completed_proxy_mid;
  jmethodID m_on_flush_begin_proxy_mid;
  jmethodID m_on_table_file_deleted_mid;
  jmethodID m_on_compaction_begin_proxy_mid;
  jmethodID m_on_compaction_completed_proxy_mid;
  jmethodID m_on_table_file_created_mid;
  jmethodID m_on_table_file_creation_started_mid;
  jmethodID m_on_mem_table_sealed_mid;
  jmethodID m_on_column_family_handle_deletion_started_mid;
  jmethodID m_on_external_file_ingested_proxy_mid;
  jmethodID m_on_background_error_proxy_mid;
  jmethodID m_on_stall_conditions_changed_mid;
  jmethodID m_on_file_read_finish_mid;
  jmethodID m_on_file_write_finish_mid;
  jmethodID m_on_file_flush_finish_mid;
  jmethodID m_on_file_sync_finish_mid;
  jmethodID m_on_file_range_sync_finish_mid;
  jmethodID m_on_file_truncate_finish_mid;
  jmethodID m_on_file_close_finish_mid;
  jmethodID m_should_be_notified_on_file_io;
  jmethodID m_on_error_recovery_begin_proxy_mid;
  jmethodID m_on_error_recovery_completed_mid;
};

}  // namespace ROCKSDB_NAMESPACE

#endif  // JAVA_ROCKSJNI_EVENT_LISTENER_JNICALLBACK_H_