/**
 * Copyright 2019-2020 Huawei Technologies Co., Ltd
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/**
 * @file hcom.h
 * @brief HCOM API
 */

#ifndef HCOM_H_
#define HCOM_H_

#include <hccl/base.h>
#include <hccl/hccl_types.h>
#include <functional>
#include <vector>

#ifdef __cplusplus
extern "C" {
#endif // __cplusplus



/**
 * @brief Get the rank number in the group.
 *
 * @param group A string identifying the group name.
 * @param rankSize A pointer identifying the rank number.
 * @return HcclResult 
 */
HcclResult HcomGetRankSize(const char *group, u32 *rankSize);

/**
 * @brief Get the rank number of this rank's server within the group.
 *
 * @param group A string identifying the group name.
 * @param localRankSize A pointer identifying the rank number.
 * @return HcclResult 
 */
HcclResult HcomGetLocalRankSize(const char *group, u32 *localRankSize);

/**
 * @brief Get the rank id of this rank.
 *
 * @param group A string identifying the group name.
 * @param rankId A pointer identifying the rank id.
 * @return HcclResult 
 */
HcclResult HcomGetRankId(const char *group, u32 *rankId);

/**
 * @brief Get the local rank id of this rank's server within the group.
 *
 * @param group A string identifying the group name.
 * @param localRankId A pointer identifying the local rank id.
 * @return HcclResult 
 */
HcclResult HcomGetLocalRankId(const char *group, u32 *localRankId);

/**
 * @brief Get the world rank id according to the group rank id.
 *
 * @param group A string identifying the group name.
 * @param groupRank An integer(u32) identifying the group rank id.
 * @param worldRank A pointer identifying the world rank id.
 * @return HcclResult 
 */
HcclResult HcomGetWorldRankFromGroupRank(const char *group, u32 groupRank, u32 *worldRank);

/**
 * @brief Get the group rank id according to the world rank id.
 *
 * @param worldRank An integer(u32) identifying the world rank id.
 * @param group A string identifying the group name.
 * @param groupRank A pointer identifying the group rank id.
 * @return HcclResult 
 */
HcclResult HcomGetGroupRankFromWorldRank(u32 worldRank, const char *group, u32 *groupRank);

/**
 * @brief Create group.
 *
 * @param group A string identifying the group name.
 * @param rankNum An integer(u32) identifying the number of ranks in the group.
 * @param rankIds A list identifying the ranks in the group.
 * @return HcclResult 
 */
HcclResult HcomCreateGroup(const char *group, u32 rankNum, u32 *rankIds);

/**
 * @brief Destroy group
 *
 * @param group A string identifying the group name.
 * @return HcclResult 
 */
HcclResult HcomDestroyGroup(const char *group);

/**
 * @brief Set the gradient split strategy with in the group, according to gradient index.
 *
 * @param group A string identifying the group name.
 * @param segmentNum An integer(u32) identifying the segments number of gradients.
 * @param IdxList A list identifying the index of end gradient in each segment.
 * @return HcclResult
 */
extern HcclResult HcomSetGradFusionByIndex(const char *group, u32 segmentNum, const u32 *IdxList);

/**
 * @brief Set the gradient split strategy with in the group, according to gradient data size.
 *
 * @param group A string identifying the group name.
 * @param segmentNum An integer(u32) identifying the segments number of gradients.
 * @param sizeList A list identifying the percent of each segment.
 * @return HcclResult
 */
extern HcclResult HcomSetGradFusionBySize(const char *group, u32 segmentNum, const float *sizeList);

/**
 * @brief Initialize hcom executor.
 *
 * @param void
 * @return HcclResult
 */
HcclResult HcomExecInitialize();

/**
 * @brief Finalize hcom executor.
 *
 * @param void
 * @return HcclResult
 */
HcclResult HcomExecFinalize();

/**
 * @brief Put collective communication operation into hcom executor.
 *
 * @param opInfo information about collective communication operation.
 * @param callback callback after collective communication operation.
 * @return HcclResult
 */
HcclResult HcomExecEnqueueOperation(HcomOperation opInfo, std::function<void(HcclResult status)> callback);

/**
 * @brief Put remote access operation into hcom executor.
 *
 * @param remoteAccessType operation type (read or write).
 * @param addrInfos address information about collective communication operation.
 * @param callback callback after collective communication operation.
 * @return HcclResult
 */
HcclResult HcomExecEnqueueRemoteAccess(const std::string& remoteAccessType,
                                       const std::vector<HcomRemoteAccessAddrInfo>& addrInfos,
                                       std::function<void(HcclResult status)> callback);

/**
 * @brief Register memories and init resources for remote access.
 *
 * @param addrList memory addresses for remote access.
 * @param count number of remote memory addresses.
 * @return HcclResult
 */
extern HcclResult HcomRegRemoteAccessMem(const MemRegisterAddr* addrList, u32 count);

#ifdef __cplusplus
}
#endif // __cplusplus
#endif // HCOM_H_