/*
 * Copyright (c) Souldbminer, Lightos_ and Horizon OC Contributors
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

/* --------------------------------------------------------------------------
 * "THE BEER-WARE LICENSE" (Revision 42):
 * <p-sam@d3vs.net>, <natinusala@gmail.com>, <m4x@m4xw.net>
 * wrote this file. As long as you retain this notice you can do whatever you
 * want with this stuff. If you meet any of us some day, and you think this
 * stuff is worth it, you can buy us a beer in return.  - The sys-clk authors
 * --------------------------------------------------------------------------
 */

#include <switch.h>
#include <sysclk.h>
#include <nxExt.h>
#include <algorithm>
#include <math.h>
#include <numeric>
#include "board_misc.hpp"

namespace board {

    Thread gpuThread;
    LEvent threadexit;
    Thread cpuCore0Thread;
    Thread cpuCore1Thread;
    Thread cpuCore2Thread;

    u32 gpuLoad;
    u32 _fd;

    u64 idletick0 = 0;
    u64 idletick1 = 0;
    u64 idletick2 = 0;

    constexpr u64 CpuTimeOutNs = 500'000'000;
    constexpr double Systemtickfrequency = 19200000.0 * (static_cast<double>(CpuTimeOutNs) / 1'000'000'000.0);

    void GpuLoadThread(void *nvCheckPtr) {
        Result nvCheck = *static_cast<Result *>(nvCheckPtr);
        constexpr u32 GpuSamples = 8;
        u32 gpu_load_array[GpuSamples] = {};
        size_t i = 0;
        constexpr u32 NVGPU_GPU_IOCTL_PMU_GET_GPU_LOAD  = 0x80044715;

        if (R_SUCCEEDED(nvCheck)) do {
            u32 temp;
            if (R_SUCCEEDED(nvIoctl(_fd, NVGPU_GPU_IOCTL_PMU_GET_GPU_LOAD, &temp))) {
                gpu_load_array[i++ % gpu_samples_average] = temp;
                gpuLoad = std::accumulate(&gpu_load_array[0], &gpu_load_array[gpu_samples_average], 0) / gpu_samples_average;
            }
            svcSleepThread(16'666'000); // wait a bit (this is the perfect amount of time to keep the reading accurate)
        } while(true);
    }

    void CheckCore(void *idletickPtr) {
        u64* idletick = static_cast<u64 *>(idletickPtr);
        while(true) {
            u64 idletickA;
            u64 idletickB;
            svcGetInfo(&idletickB, InfoType_IdleTickCount, INVALID_HANDLE, -1);
            svcWaitForAddress(&threadexit, ArbitrationType_WaitIfEqual, 0, CpuTimeOutNs);
            svcGetInfo(&idletickA, InfoType_IdleTickCount, INVALID_HANDLE, -1);
            *idletick = idletickA - idletickB;
        }
    }

    void StartLoad() {
        _fd = fd;
        threadCreate(&gpuThread, GpuLoadThread, &nvCheck, NULL, 0x1000, 0x3F, -2);
        threadStart(&gpuThread)

        leventClear(&threadexit);
        threadCreate(&cpuCore0Thread, CheckCore, &idletick0, NULL, 0x1000, 0x10, 0);
        threadCreate(&cpuCore1Thread, CheckCore, &idletick1, NULL, 0x1000, 0x10, 1);
        threadCreate(&cpuCore2Thread, CheckCore, &idletick2, NULL, 0x1000, 0x10, 2);

        threadStart(&cpuCore0Thread);
        threadStart(&cpuCore1Thread);
        threadStart(&cpuCore2Thread);
    }

    u32 GetMaxCpuLoad() {
        float cpuUsage0 = std::clamp(((Systemtickfrequency - idletick0) / static_cast<double>(Systemtickfrequency)) * 1000.0, 0.0, 1000.0);
        float cpuUsage1 = std::clamp(((Systemtickfrequency - idletick1) / static_cast<double>(Systemtickfrequency)) * 1000.0, 0.0, 1000.0);
        float cpuUsage2 = std::clamp(((Systemtickfrequency - idletick2) / static_cast<double>(Systemtickfrequency)) * 1000.0, 0.0, 1000.0);
        return std::round(std::max({cpuUsage0, cpuUsage1, cpuUsage2}));
    }

    u32 GetPartLoad(SysClkPartLoad loadSource) {
        switch(loadSource) {
            case SysClkPartLoad_EMC:
                return t210EmcLoadAll();
            case SysClkPartLoad_EMCCpu:
                return t210EmcLoadCpu();
            case HocClkPartLoad_GPU:
                return gpuLoad;
            case HocClkPartLoad_CPUMax:
                return GetMaxCpuLoad();
            case HocClkPartLoad_BAT:
                BatteryChargeInfo info;
                batteryInfoGetChargeInfo(&info);
                return info.RawBatteryCharge;
            case HocClkPartLoad_FAN:
                return GetFanLevel();
            default:
                ASSERT_ENUM_VALID(SysClkPartLoad, loadSource);
        }
        return 0;
    }

    void ExitLoad() {
        threadClose(&gpuThread);
        threadClose(&cpuCore0Thread);
        threadClose(&cpuCore1Thread);
        threadClose(&cpuCore2Thread);
    }

}