// Copyright (c) 2025 PaddlePaddle Authors. All Rights Reserved.
//
// 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.

#pragma once

#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#include <unistd.h>

#include "driver_types.h"
#include "paddle/extension.h"
#include "paddle/phi/core/allocator.h"
#include "paddle/phi/core/dense_tensor.h"
#include "msg_utils.h"

struct RemoteCacheKvIpc {
    struct save_cache_kv_complete_signal_layerwise_meta_data{
        int32_t layer_id=-1;
        void * shm_ptr=nullptr;
        int shm_fd=-1;
        save_cache_kv_complete_signal_layerwise_meta_data(){}
        save_cache_kv_complete_signal_layerwise_meta_data(int32_t layer_id_,
                                                            void* shm_ptr_,
                                                            int shm_fd_)
            :layer_id(layer_id_), shm_ptr(shm_ptr_), shm_fd(shm_fd_){
        }
    };

    struct save_cache_kv_complete_signal_layerwise_meta_data_per_query{
        int layer_id_;
        int num_layers_;
        bool inited = false;
        struct msgdatakv msg_sed;
        int msgid;

        save_cache_kv_complete_signal_layerwise_meta_data_per_query(){}

        void init(const int *seq_lens_encoder,
                  const int *seq_lens_decoder,
                  const int rank,
                  const int num_layers,
                  const int real_bsz) {
            layer_id_ = 0;
            num_layers_ = num_layers;
            msg_sed.mtype = 1;
            int encoder_count = 0;
            for (int i = 0; i < real_bsz; i++) {
                if (seq_lens_encoder[i] > 0) {
                    encoder_count++;
                    msg_sed.mtext[2 * i + 2] = i;
                    msg_sed.mtext[2 * i + 3] = seq_lens_decoder[i];
                }
            }
            msg_sed.mtext[0] = encoder_count;
            
            if (!inited) {
                // just init once
                const int msg_id = 1024 + rank;
                key_t key = ftok("/opt/", msg_id);
                msgid = msgget(key, IPC_CREAT | 0666);
                inited = true;
            }
        }

        void CUDART_CB send_signal() {
            msg_sed.mtext[1] = layer_id_;
            if ((msgsnd(msgid, &msg_sed, (MAX_BSZ * 2 + 2) * 4, 0)) == -1) {
                printf("kv signal full msg buffer\n");
            }
            layer_id_ = (layer_id_ + 1);
            assert(layer_id_ <= num_layers_);
        }
    };
    
    static RemoteCacheKvIpc::save_cache_kv_complete_signal_layerwise_meta_data kv_complete_signal_meta_data;
    static RemoteCacheKvIpc::save_cache_kv_complete_signal_layerwise_meta_data_per_query kv_complete_signal_meta_data_per_query;
    static void* kv_complete_signal_identity_ptr;
    static bool kv_complete_signal_shmem_opened;

    static RemoteCacheKvIpc::save_cache_kv_complete_signal_layerwise_meta_data open_shm_and_get_complete_signal_meta_data(
        const int rank_id,
        const int device_id,
        const bool keep_pd_step_flag);
    static void CUDART_CB save_cache_kv_complete_signal_layerwise(void* meta_data);
    static void CUDART_CB save_cache_kv_complete_signal_layerwise_per_query(void* meta_data);
};