/*
 * Copyright (C) 2005-2011 MaNGOS <http://getmangos.com/>
 * Copyright (C) 2009-2011 MaNGOSZero <https://github.com/mangos/zero>
 * Copyright (C) 2011-2016 Nostalrius <https://nostalrius.org>
 * Copyright (C) 2016-2017 Elysium Project <https://github.com/elysium-project>
 *
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include "Threading.h"
#include "Errors.h"
#include <ace/OS_NS_unistd.h>
#include <ace/Sched_Params.h>
#include <vector>
#include <chrono>

using namespace ACE_Based;

ThreadPriority::ThreadPriority()
{
 for (int i = Idle; i < MAXPRIORITYNUM; ++i)
 m_priority[i] = ACE_THR_PRI_OTHER_DEF;

 m_priority[Idle] = ACE_Sched_Params::priority_min(ACE_SCHED_OTHER);
 m_priority[Realtime] = ACE_Sched_Params::priority_max(ACE_SCHED_OTHER);

 std::vector<int> _tmp;

 ACE_Sched_Params::Policy _policy = ACE_SCHED_OTHER;
 ACE_Sched_Priority_Iterator pr_iter(_policy);

 while (pr_iter.more())
 {
 _tmp.push_back(pr_iter.priority());
 pr_iter.next();
 }

 //MANGOS_ASSERT (!_tmp.empty());

 if(_tmp.size() >= MAXPRIORITYNUM)
 {
 const size_t max_pos = _tmp.size();
 size_t min_pos = 1;
 size_t norm_pos = 0;
 for (size_t i = 0; i < max_pos; ++i)
 {
 if(_tmp[i] == ACE_THR_PRI_OTHER_DEF)
 {
 norm_pos = i + 1;
 break;
 }
 }

 //We have only 7(seven) values in enum Priority
 //and 3 we know already (Idle, Normal, Realtime) so
 //we need to split each list [Idle...Normal] and [Normal...Realtime]
 //into pieces
 const size_t _divider = 4;
 size_t _div = (norm_pos - min_pos) / _divider;
 if(_div == 0)
 _div = 1;

 min_pos = (norm_pos - 1);

 m_priority[Low] = _tmp[min_pos -= _div];
 m_priority[Lowest] = _tmp[min_pos -= _div ];

 _div = (max_pos - norm_pos) / _divider;
 if(_div == 0)
 _div = 1;

 min_pos = norm_pos - 1;

 m_priority[High] = _tmp[min_pos += _div];
 m_priority[Highest] = _tmp[min_pos += _div];
 }
}

int ThreadPriority::getPriority(Priority p) const
{
 if(p < Idle)
 p = Idle;

 if(p > Realtime)
 p = Realtime;

 return m_priority[p];
}

#ifndef __sun__
# define THREADFLAG (THR_NEW_LWP | THR_JOINABLE | THR_SCHED_DEFAULT)
#else
# define THREADFLAG (THR_NEW_LWP | THR_JOINABLE)
#endif

Thread::Thread() : m_iThreadId(0), m_hThreadHandle(0), m_task(0)
{

}

Thread::Thread(Runnable* instance) : m_iThreadId(0), m_hThreadHandle(0), m_task(instance)
{
 // register reference to m_task to prevent it deeltion until destructor
 if (m_task)
 m_task->incReference();

 bool _start = start();
 //MANGOS_ASSERT (_start);
}

Thread::~Thread()
{
 //Wait();

 // deleted runnable object (if no other references)
 if (m_task)
 m_task->decReference();
}

//initialize Thread's class static member
Thread::ThreadStorage Thread::m_ThreadStorage;
ThreadPriority Thread::m_TpEnum;

bool Thread::start()
{
 if (m_task == 0 || m_iThreadId != 0)
 return false;

 m_task->incReference();
 bool res = (ACE_Thread::spawn(&Thread::ThreadTask, (void*)m_task, THREADFLAG, &m_iThreadId, &m_hThreadHandle) == 0);
 if (!res)
 m_task->decReference();

 return res;
}

bool Thread::wait()
{
 if (!m_hThreadHandle || !m_task)
 return false;

 ACE_THR_FUNC_RETURN _value = ACE_THR_FUNC_RETURN(-1);
 int _res = ACE_Thread::join(m_hThreadHandle, &_value);

 m_iThreadId = 0;
 m_hThreadHandle = 0;

 return (_res == 0);
}

void Thread::destroy()
{
 if (!m_iThreadId || !m_task)
 return;

 if (ACE_Thread::kill(m_iThreadId, -1) != 0)
 return;

 m_iThreadId = 0;
 m_hThreadHandle = 0;

 // reference set at ACE_Thread::spawn
 Runnable* task = m_task;
 m_task = NULL;
 task->decReference(); // Prevent race conditions, because at this point, m_task may be deleted!
}

void Thread::suspend()
{
 ACE_Thread::suspend(m_hThreadHandle);
}

void Thread::resume()
{
 ACE_Thread::resume(m_hThreadHandle);
}

ACE_THR_FUNC_RETURN Thread::ThreadTask(void * param)
{
 unsigned int seed = std::chrono::high_resolution_clock::now().time_since_epoch().count();
 srand(seed);

 Runnable * _task = (Runnable*)param;
 _task->incReference();
 _task->run();

 // task execution complete, free referecne added at
 _task->decReference(); // for the last incReference
 _task->decReference(); // cf Thread::start

 return (ACE_THR_FUNC_RETURN)0;
}

ACE_thread_t Thread::currentId()
{
 return ACE_Thread::self();
}

ACE_hthread_t Thread::currentHandle()
{
 ACE_hthread_t _handle;
 ACE_Thread::self(_handle);

 return _handle;
}

Thread * Thread::current()
{
 Thread * _thread = m_ThreadStorage.ts_object();
 if(!_thread)
 {
 _thread = new Thread();
 _thread->m_iThreadId = Thread::currentId();
 _thread->m_hThreadHandle = Thread::currentHandle();

 Thread * _oldValue = m_ThreadStorage.ts_object(_thread);
 if(_oldValue)
 delete _oldValue;
 }

 return _thread;
}

void Thread::setPriority(Priority type)
{
#ifndef __sun__
 int _priority = m_TpEnum.getPriority(type);
 int _ok = ACE_Thread::setprio(m_hThreadHandle, _priority);
 //remove this ASSERT in case you don't want to know is thread priority change was successful or not
 //MANGOS_ASSERT (_ok == 0);
#endif
}

void Thread::Sleep(unsigned long msecs)
{
 ACE_OS::sleep(ACE_Time_Value(0, 1000 * msecs));
}