// Copyright (c) 2024 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.

#include <stdio.h>
#include <string.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#include <sys/types.h>
#include "paddle/extension.h"

#ifndef PD_BUILD_STATIC_OP
#define PD_BUILD_STATIC_OP(name) PD_BUILD_OP(static_op_##name)
#endif

#define MAX_BSZ 256
#define MAX_DRAFT_TOKENS 6

struct msgdata {
    int64_t mtype;
    int mtext[MAX_BSZ * MAX_DRAFT_TOKENS + MAX_BSZ +
              2];  // stop_flag, bsz, accept_num*bsz, tokens...
};

void SpeculateGetOutput(const paddle::Tensor& x,
                        int64_t rank_id,
                        bool wait_flag,
                        int msg_queue_id,
                        bool get_each_rank) {
    if (!get_each_rank && rank_id > 0) {
        return;
    }

    if (const char* inference_msg_queue_id_env_p =
            std::getenv("INFERENCE_MSG_QUEUE_ID")) {
        std::string inference_msg_queue_id_env_str(
            inference_msg_queue_id_env_p);
        int inference_msg_queue_id_from_env =
            std::stoi(inference_msg_queue_id_env_str);
#ifdef GET_OUTPUT_DEBUG
        std::cout << "Your INFERENCE_MSG_QUEUE_ID is: "
                  << inference_msg_queue_id_from_env << std::endl;
#endif
        msg_queue_id = inference_msg_queue_id_from_env;
    }

    static struct msgdata msg_rcv;

    static key_t key = ftok("./", msg_queue_id);

    static int msgid = msgget(key, IPC_CREAT | 0666);

    int64_t* out_data = const_cast<int64_t*>(x.data<int64_t>());
    int ret = -1;
    if (!wait_flag) {
        ret = msgrcv(msgid,
                     &msg_rcv,
                     (MAX_BSZ * MAX_DRAFT_TOKENS + MAX_BSZ + 2) * 4,
                     0,
                     IPC_NOWAIT);
    } else {
        ret = msgrcv(msgid,
                     &msg_rcv,
                     (MAX_BSZ * MAX_DRAFT_TOKENS + MAX_BSZ + 2) * 4,
                     0,
                     0);
    }
    if (ret == -1) {
        out_data[0] = -2;
        out_data[1] = 0;
        return;
    }
    int bsz = msg_rcv.mtext[1];

    for (int64_t i = 0; i < MAX_BSZ * MAX_DRAFT_TOKENS + MAX_BSZ + 2; i++) {
        out_data[i] = (int64_t)msg_rcv.mtext[i];
    }
    return;
}

void SpeculateGetOutputStatic(const paddle::Tensor& x,
                              int64_t rank_id,
                              bool wait_flag,
                              bool get_each_rank) {
    SpeculateGetOutput(x, rank_id, wait_flag, 1, get_each_rank);
}

void SpeculateGetOutputDynamic(const paddle::Tensor& x,
                               int64_t rank_id,
                               bool wait_flag,
                               int msg_queue_id,
                               bool get_each_rank) {
    SpeculateGetOutput(x, rank_id, wait_flag, msg_queue_id, get_each_rank);
}

PD_BUILD_STATIC_OP(speculate_get_output)
    .Inputs({"x"})
    .Attrs({"rank_id: int64_t", "wait_flag: bool", "get_each_rank: bool"})
    .Outputs({"x_out"})
    .SetInplaceMap({{"x", "x_out"}})
    .SetKernelFn(PD_KERNEL(SpeculateGetOutputStatic));

PD_BUILD_STATIC_OP(speculate_get_output_dynamic)
    .Inputs({"x"})
    .Attrs({"rank_id: int64_t", "wait_flag: bool", "msg_queue_id: int", "get_each_rank: bool"})
    .Outputs({"x_out"})
    .SetInplaceMap({{"x", "x_out"}})
    .SetKernelFn(PD_KERNEL(SpeculateGetOutputDynamic));
