/***
    Copyright (C) 2021 J Reece Wilson (a/k/a "Reece"). All rights reserved.

    File: RamInfo.cpp
    Date: 2021-6-12
    Author: Reece
***/
#include <RuntimeInternal.hpp>
#include "HWInfo.hpp"
#include "RamInfo.hpp"


#if defined(AURORA_IS_BSD_DERIVED)
    #include <sys/sysctl.h>
    #include <sys/vmmeter.h>
    #include <sys/limits.h>
    #include <vm/vm_param.h>
#endif

#if defined(AURORA_IS_LINUX_DERIVED)
    #include <sys/sysinfo.h>
#endif

#if defined(AURORA_IS_MODERNNT_DERIVED)
    #include <psapi.h>
#endif

namespace Aurora::HWInfo
{
    static AuOptional<RamStat> gMemStartup;
    static AuOptional<RamStat> gMemSystem;

    AUKN_SYM AuOptional<RamStat> GetMemStatProcess()
    {
        auto max = GetMemStatSystem().value_or(RamStat {}).available;

    #if defined(AURORA_IS_MODERNNT_DERIVED)

        PROCESS_MEMORY_COUNTERS pmc;

        if (!GetProcessMemoryInfo(GetCurrentProcess(), &pmc, sizeof(PROCESS_MEMORY_COUNTERS)))
        {
            return {};
        }

        return RamStat {pmc.WorkingSetSize, max};

    #elif defined(AURORA_IS_POSIX_DERIVED)

        struct rusage usage;

        getrusage(RUSAGE_SELF, &usage);
        auto used = AuUInt64(usage.ru_maxrss) * 1024;
        return RamStat {used, max};

    #else

        return {};

    #endif
    }

#if defined(AURORA_IS_BSD_DERIVED)
    struct vmtotal GetVMInfo()
    {
        struct vmtotal info;
        int mib[2];

        mib[0] = CTL_VM;
        mib[1] = VM_TOTAL;

        size_t len = sizeof(info);
        sysctl(mib, 2, &info, &len, NULL, 0);

        return info;
    }
#endif

    AUKN_SYM AuOptional<RamStat> GetMemStatSystem()
    {
    #if defined(AURORA_IS_MODERNNT_DERIVED)

        MEMORYSTATUSEX statex;
        statex.dwLength = sizeof(statex);

        if (!GlobalMemoryStatusEx(&statex))
        {
            return {};
        }

        return RamStat {statex.ullTotalPhys - statex.ullAvailPhys, statex.ullTotalPhys};

    #elif defined(AURORA_IS_BSD_DERIVED)

        auto maxMem = QueryBsdHwStat(HW_PHYSMEM);
        auto vmInfo = GetVMInfo();
        auto freeMem = AuUInt64(vmInfo.t_free) * QueryBsdHwStat(HW_PAGESIZE).value_or(4096);

        return RamStat {maxMem.value_or(freeMem * 2) - freeMem, maxMem.value_or(0)};

    #elif defined(AURORA_IS_LINUX_DERIVED)

        struct sysinfo info;

        if (sysinfo(&info) != 0)
        {
            return {};
        }

        return RamStat {info.totalram - info.freeram, info.totalram}

    #else 

        return {};

    #endif
    }

    AUKN_SYM AuOptional<RamStat> GetMemStatStartup()
    {
        return gMemStartup;
    }

    void InitRamInfo()
    {
        gMemStartup = GetMemStatSystem();
    }
}