/*
 * Copyright (C) 2008-2017 TrinityCore <http://www.trinitycore.org/>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.
 *
 * This program is distributed in the hope that 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/>.
 */

#ifndef _PROCESSPRIO_H
#define _PROCESSPRIO_H

#include "Configuration/Config.h"

#ifdef __linux__
#include <sched.h>
#include <sys/resource.h>
#define PROCESS_HIGH_PRIORITY -15 // [-20, 19], default is 0
#endif

void SetProcessPriority(const std::string& logChannel)
{
#if defined(_WIN32) || defined(__linux__)

    ///- Handle affinity for multiple processors and process priority
    uint32 affinity = sConfigMgr->GetIntDefault("UseProcessors", 0);
    bool highPriority = sConfigMgr->GetBoolDefault("ProcessPriority", false);

#ifdef _WIN32 // Windows

    HANDLE hProcess = GetCurrentProcess();
    if (affinity > 0)
    {
        ULONG_PTR appAff;
        ULONG_PTR sysAff;

        if (GetProcessAffinityMask(hProcess, &appAff, &sysAff))
        {
            // remove non accessible processors
            ULONG_PTR currentAffinity = affinity & appAff;

            if (!currentAffinity)
                TC_LOG_ERROR(logChannel, "Processors marked in UseProcessors bitmask (hex) %x are not accessible. Accessible processors bitmask (hex): %x", affinity, appAff);
            else if (SetProcessAffinityMask(hProcess, currentAffinity))
                TC_LOG_INFO(logChannel, "Using processors (bitmask, hex): %x", currentAffinity);
            else
                TC_LOG_ERROR(logChannel, "Can't set used processors (hex): %x", currentAffinity);
        }
    }

    if (highPriority)
    {
        if (SetPriorityClass(hProcess, HIGH_PRIORITY_CLASS))
            TC_LOG_INFO(logChannel, "Process priority class set to HIGH");
        else
            TC_LOG_ERROR(logChannel, "Can't set process priority class.");
    }

#else // Linux

    if (affinity > 0)
    {
        cpu_set_t mask;
        CPU_ZERO(&mask);

        for (unsigned int i = 0; i < sizeof(affinity) * 8; ++i)
            if (affinity & (1 << i))
                CPU_SET(i, &mask);

        if (sched_setaffinity(0, sizeof(mask), &mask))
            TC_LOG_ERROR(logChannel, "Can't set used processors (hex): %x, error: %s", affinity, strerror(errno));
        else
        {
            CPU_ZERO(&mask);
            sched_getaffinity(0, sizeof(mask), &mask);
            TC_LOG_INFO(logChannel, "Using processors (bitmask, hex): %lx", *(__cpu_mask*)(&mask));
        }
    }

    if (highPriority)
    {
        if (setpriority(PRIO_PROCESS, 0, PROCESS_HIGH_PRIORITY))
            TC_LOG_ERROR(logChannel, "Can't set process priority class, error: %s", strerror(errno));
        else
            TC_LOG_INFO(logChannel, "Process priority class set to %i", getpriority(PRIO_PROCESS, 0));
    }

#endif
#else
    // Suppresses unused argument warning for all other platforms
    (void)logChannel;
#endif
}

#endif