/*
 * SPDX-FileCopyrightText: Copyright (c) 2023-2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 * SPDX-License-Identifier: Apache-2.0
 *
 * 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 "cuda_hint.cuh"
#include "utils.cuh"
#include <cassert>
#include <cuda_fp16.h>
#include <filesystem>
#include <fstream>
#include <sstream>
#include <type_traits>

struct RefChecker
{
    half q[8][32][32];
    half k[8][4][64][32];
    float qk[4][32][64];
    float tileRowMax[4][32];
    half x[4][32][64];
    half v[8][4][32][64];
    float tileRowSum[4][32];
    float acc1PerStep[4][32][256];
    half out[32][256];

    void init()
    {
#define INIT_MEMBER(member) initMember(member, #member)
        INIT_MEMBER(q);
        INIT_MEMBER(k);
        INIT_MEMBER(qk);
        INIT_MEMBER(tileRowMax);
        INIT_MEMBER(x);
        INIT_MEMBER(v);
        INIT_MEMBER(tileRowSum);
        INIT_MEMBER(acc1PerStep);
        INIT_MEMBER(out);
#undef INIT_MEMBER
    }

private:
    template <typename T>
    void initMember(T& dst, char const* varName);
};

template <typename T, size_t d0, size_t d1, size_t d2, size_t d3>
std::enable_if_t<std::is_same_v<std::decay_t<T>, float> || std::is_same_v<std::decay_t<T>, half>, std::string>
makeFileName(T (&dst)[d0][d1][d2][d3], char const* varName)
{
    std::stringstream ss;
    ss << varName << '_' << d0 << 'x' << d1 << 'x' << d2 << 'x' << d3 << '_'
       << (std::is_same_v<std::decay_t<T>, float> ? "f32" : "f16") << ".bin";
    return ss.str();
}

template <typename T, size_t d0, size_t d1, size_t d2>
std::enable_if_t<std::is_same_v<std::decay_t<T>, float> || std::is_same_v<std::decay_t<T>, half>, std::string>
makeFileName(T (&dst)[d0][d1][d2], char const* varName)
{
    std::stringstream ss;
    ss << varName << '_' << d0 << 'x' << d1 << 'x' << d2 << '_'
       << (std::is_same_v<std::decay_t<T>, float> ? "f32" : "f16") << ".bin";
    return ss.str();
}

template <typename T, size_t d0, size_t d1>
std::enable_if_t<std::is_same_v<std::decay_t<T>, float> || std::is_same_v<std::decay_t<T>, half>, std::string>
makeFileName(T (&dst)[d0][d1], char const* varName)
{
    std::stringstream ss;
    ss << varName << '_' << d0 << 'x' << d1 << '_' << (std::is_same_v<std::decay_t<T>, float> ? "f32" : "f16")
       << ".bin";
    return ss.str();
}

template <typename T>
void RefChecker::initMember(T& dst, char const* varName)
{
    std::string const filename = makeFileName(dst, varName);
    printf("loading %s\n", filename.c_str());
    namespace fs = std::filesystem;
    assert(fs::exists(filename));
    assert(fs::file_size(filename) == sizeof(dst));
    std::ifstream fin(filename, std::ios::binary);
    fin.read(reinterpret_cast<char*>(&dst), sizeof(dst));
    assert(fin);
}