/**

 * vim: set ts=4 :

 * =============================================================================

 * SourceMod

 * Copyright (C) 2004-2008 AlliedModders LLC.  All rights reserved.

 * =============================================================================

 *

 * This program is free software; you can redistribute it and/or modify it under

 * the terms of the GNU General Public License, version 3.0, as published by the

 * Free Software Foundation.

 * 

 * 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/>.

 *

 * As a special exception, AlliedModders LLC gives you permission to link the

 * code of this program (as well as its derivative works) to "Half-Life 2," the

 * "Source Engine," the "SourcePawn JIT," and any Game MODs that run on software

 * by the Valve Corporation.  You must obey the GNU General Public License in

 * all respects for all other code used.  Additionally, AlliedModders LLC grants

 * this exception to all derivative works.  AlliedModders LLC defines further

 * exceptions, found in LICENSE.txt (as of this writing, version JULY-31-2007),

 * or <http://www.sourcemod.net/license.php>.

 *

 * Version: $Id$

 */

#include <time.h>

#include "TimerSys.h"

#include "ForwardSys.h"

#include "sourcemm_api.h"

#include "frame_hooks.h"

#include "ConVarManager.h"

#define TIMER_MIN_ACCURACY		0.1

TimerSystem g_Timers;

double g_fUniversalTime = 0.0f;

float g_fGameStartTime = 0.0f;	/* Game game start time, non-universal */

double g_fTimerThink = 0.0f;		/* Timer's next think time */

const double *g_pUniversalTime = &g_fUniversalTime;

ConVar *mp_timelimit = NULL;

int g_TimeLeftMode = 0;

ConVar sm_time_adjustment("sm_time_adjustment", "0", 0, "Adjusts the server time in seconds");

inline double GetSimulatedTime()

{

	return g_fUniversalTime;

}

time_t GetAdjustedTime(time_t *buf)

{

	time_t val = time(NULL) + sm_time_adjustment.GetInt();

	if (buf)

	{

		*buf = val;

	}

	return val;

}

class DefaultMapTimer : 

	public IMapTimer,

	public SMGlobalClass,

	public IConVarChangeListener

{

public:

	DefaultMapTimer()

	{

		m_bInUse = false;

	}

	void OnSourceModLevelChange(const char *mapName)

	{

		g_fGameStartTime = 0.0f;

	}

	int GetMapTimeLimit()

	{

		return mp_timelimit->GetInt();

	}

	void SetMapTimerStatus(bool enabled)

	{

		if (enabled && !m_bInUse)

		{

			Enable();

		} 

		else if (!enabled && m_bInUse)

		{

			Disable();

		}

		m_bInUse = enabled;

	}

	void ExtendMapTimeLimit(int extra_time)

	{

		if (extra_time == 0)

		{

			mp_timelimit->SetValue(0);

			return;

		}

		extra_time /= 60;

		mp_timelimit->SetValue(mp_timelimit->GetInt() + extra_time);

	}

	void OnConVarChanged(ConVar *pConVar, const char *oldValue, float flOldValue)

	{

		g_Timers.MapTimeLeftChanged();

	}

private:

	void Enable()

	{

		g_ConVarManager.AddConVarChangeListener("mp_timelimit", this);

	}

	void Disable()

	{

		g_ConVarManager.RemoveConVarChangeListener("mp_timelimit", this);

	}

private:

	bool m_bInUse;

} s_DefaultMapTimer;

/**

 * If the ticking process has run amok (should be impossible), we 

 * take care of this by "skipping" the in-between time, to prevent 

 * a bazillion times from firing on accident.  This has the result  

 * that a drastic jump in time will continue acting normally.  Users 

 * may not expect this, but... I think it is the best solution.

 */

inline double CalcNextThink(double last, float interval)

{

	if (g_fUniversalTime - last - interval <= TIMER_MIN_ACCURACY)

	{

		return last + interval;

	}

	else

	{

		return g_fUniversalTime + interval;

	}

}

void ITimer::Initialize(ITimedEvent *pCallbacks, float fInterval, float fToExec, void *pData, int flags)

{

	m_Listener = pCallbacks;

	m_Interval = fInterval;

	m_ToExec = fToExec;

	m_pData = pData;

	m_Flags = flags;

	m_InExec = false;

	m_KillMe = false;

}

TimerSystem::TimerSystem()

{

	m_pMapTimer = NULL;

	m_bHasMapTickedYet = false;

	m_bHasMapSimulatedYet = false;

	m_fLastTickedTime = 0.0f;

}

TimerSystem::~TimerSystem()

{

	CStack<ITimer *>::iterator iter;

	for (iter=m_FreeTimers.begin(); iter!=m_FreeTimers.end(); iter++)

	{

		delete (*iter);

	}

	m_FreeTimers.popall();

}

void TimerSystem::OnSourceModAllInitialized()

{

	g_ShareSys.AddInterface(NULL, this);

	m_pOnGameFrame = g_Forwards.CreateForward("OnGameFrame", ET_Ignore, 0, NULL);

	m_pOnMapTimeLeftChanged = g_Forwards.CreateForward("OnMapTimeLeftChanged", ET_Ignore, 0, NULL);

}

void TimerSystem::OnSourceModGameInitialized()

{

	mp_timelimit = icvar->FindVar("mp_timelimit");

	if (m_pMapTimer == NULL && mp_timelimit != NULL)

	{

		SetMapTimer(&s_DefaultMapTimer);

	}

}

void TimerSystem::OnSourceModShutdown()

{

	SetMapTimer(NULL);

	g_Forwards.ReleaseForward(m_pOnGameFrame);

	g_Forwards.ReleaseForward(m_pOnMapTimeLeftChanged);

}

void TimerSystem::OnSourceModLevelEnd()

{

	m_bHasMapTickedYet = false;

	m_bHasMapSimulatedYet = false;

}

void TimerSystem::GameFrame(bool simulating)

{

	if (simulating && m_bHasMapTickedYet)

	{

		g_fUniversalTime += gpGlobals->curtime - m_fLastTickedTime;

		if (!m_bHasMapSimulatedYet)

		{

			m_bHasMapSimulatedYet = true;

			MapTimeLeftChanged();

		}

	}

	else 

	{

		g_fUniversalTime += gpGlobals->interval_per_tick;

	}

	m_fLastTickedTime = gpGlobals->curtime;

	m_bHasMapTickedYet = true;

	if (g_fUniversalTime >= g_fTimerThink)

	{

		RunFrame();

		g_fTimerThink = CalcNextThink(g_fTimerThink, TIMER_MIN_ACCURACY);

	}

	RunFrameHooks(simulating);

	if (m_pOnGameFrame->GetFunctionCount())

	{

		m_pOnGameFrame->Execute(NULL);

	}

}

void TimerSystem::RunFrame()

{

	ITimer *pTimer;

	TimerIter iter;

	double curtime = GetSimulatedTime();

	for (iter=m_SingleTimers.begin(); iter!=m_SingleTimers.end(); )

	{

		pTimer = (*iter);

		if (curtime >= pTimer->m_ToExec)

		{

			pTimer->m_InExec = true;

			pTimer->m_Listener->OnTimer(pTimer, pTimer->m_pData);

			pTimer->m_Listener->OnTimerEnd(pTimer, pTimer->m_pData);

			iter = m_SingleTimers.erase(iter);

			m_FreeTimers.push(pTimer);

		} 

		else 

		{

			break;

		}

	}

	ResultType res;

	for (iter=m_LoopTimers.begin(); iter!=m_LoopTimers.end(); )

	{

		pTimer = (*iter);

		if (curtime >= pTimer->m_ToExec)

		{

			pTimer->m_InExec = true;

			res = pTimer->m_Listener->OnTimer(pTimer, pTimer->m_pData);

			if (pTimer->m_KillMe || (res == Pl_Stop))

			{

				pTimer->m_Listener->OnTimerEnd(pTimer, pTimer->m_pData);

				iter = m_LoopTimers.erase(iter);

				m_FreeTimers.push(pTimer);

				continue;

			}

			pTimer->m_InExec = false;

			pTimer->m_ToExec = CalcNextThink(pTimer->m_ToExec, pTimer->m_Interval);

		}

		iter++;

	}

}

ITimer *TimerSystem::CreateTimer(ITimedEvent *pCallbacks, float fInterval, void *pData, int flags)

{

	ITimer *pTimer;

	TimerIter iter;

	float to_exec = GetSimulatedTime() + fInterval;

	if (m_FreeTimers.empty())

	{

		pTimer = new ITimer;

	} else {

		pTimer = m_FreeTimers.front();

		m_FreeTimers.pop();

	}

	pTimer->Initialize(pCallbacks, fInterval, to_exec, pData, flags);

	if (flags & TIMER_FLAG_REPEAT)

	{

		m_LoopTimers.push_back(pTimer);

		goto return_timer;

	}

	if (m_SingleTimers.size() >= 1)

	{

		iter = --m_SingleTimers.end();

		if ((*iter)->m_ToExec <= to_exec)

		{

			goto normal_insert_end;

		}

	}

	for (iter=m_SingleTimers.begin(); iter!=m_SingleTimers.end(); iter++)

	{

		if ((*iter)->m_ToExec >= to_exec)

		{

			m_SingleTimers.insert(iter, pTimer);

			goto return_timer;

		}

	}

normal_insert_end:

	m_SingleTimers.push_back(pTimer);

return_timer:

	return pTimer;

}

void TimerSystem::FireTimerOnce(ITimer *pTimer, bool delayExec)

{

	ResultType res;

	if (pTimer->m_InExec)

	{

		return;

	}

	pTimer->m_InExec = true;

	res = pTimer->m_Listener->OnTimer(pTimer, pTimer->m_pData);

	if (!(pTimer->m_Flags & TIMER_FLAG_REPEAT))

	{

		pTimer->m_Listener->OnTimerEnd(pTimer, pTimer->m_pData);

		m_SingleTimers.remove(pTimer);

		m_FreeTimers.push(pTimer);

	} 

	else 

	{

		if ((res != Pl_Stop) && !pTimer->m_KillMe)

		{

			if (delayExec)

			{

				pTimer->m_ToExec = GetSimulatedTime() + pTimer->m_Interval;

			}

			pTimer->m_InExec = false;

			return;

		}

		pTimer->m_Listener->OnTimerEnd(pTimer, pTimer->m_pData);

		m_LoopTimers.remove(pTimer);

		m_FreeTimers.push(pTimer);

	}

}

void TimerSystem::KillTimer(ITimer *pTimer)

{

	if (pTimer->m_KillMe)

	{

		return;

	}

	if (pTimer->m_InExec)

	{

		pTimer->m_KillMe = true;

		return;

	}

	pTimer->m_InExec = true; /* The timer it's not really executed but this check needs to be done */

	pTimer->m_Listener->OnTimerEnd(pTimer, pTimer->m_pData);

	if (pTimer->m_Flags & TIMER_FLAG_REPEAT)

	{

		m_LoopTimers.remove(pTimer);

	} else {

		m_SingleTimers.remove(pTimer);

	}

	m_FreeTimers.push(pTimer);

}

CStack<ITimer *> s_tokill;

void TimerSystem::RemoveMapChangeTimers()

{

	ITimer *pTimer;

	TimerIter iter;

	for (iter=m_SingleTimers.begin(); iter!=m_SingleTimers.end(); iter++)

	{

		pTimer = (*iter);

		if (pTimer->m_Flags & TIMER_FLAG_NO_MAPCHANGE)

		{

			s_tokill.push(pTimer);

		}

	}

	for (iter=m_LoopTimers.begin(); iter!=m_LoopTimers.end(); iter++)

	{

		pTimer = (*iter);

		if (pTimer->m_Flags & TIMER_FLAG_NO_MAPCHANGE)

		{

			s_tokill.push(pTimer);

		}

	}

	while (!s_tokill.empty())

	{

		KillTimer(s_tokill.front());

		s_tokill.pop();

	}

}

IMapTimer *TimerSystem::SetMapTimer(IMapTimer *pTimer)

{

	IMapTimer *old = m_pMapTimer;

	m_pMapTimer = pTimer;

	if (m_pMapTimer)

	{

		m_pMapTimer->SetMapTimerStatus(true);

	}

	if (old)

	{

		old->SetMapTimerStatus(false);

	}

	return old;

}

IMapTimer *TimerSystem::GetMapTimer()

{

	return m_pMapTimer;

}

void TimerSystem::MapTimeLeftChanged()

{

	m_pOnMapTimeLeftChanged->Execute(NULL);

}

void TimerSystem::NotifyOfGameStart(float offset)

{

	g_fGameStartTime = gpGlobals->curtime + offset;

}

float TimerSystem::GetTickedTime()

{

	return g_fUniversalTime;

}

bool TimerSystem::GetMapTimeLeft(float *time_left)

{

	if (!m_pMapTimer)

	{

		return false;

	}

	int time_limit;

	if (!m_bHasMapSimulatedYet || (time_limit = m_pMapTimer->GetMapTimeLimit()) < 1)

	{

		*time_left = -1.0f;

	}

	else

	{

		*time_left = (g_fGameStartTime + time_limit * 60.0f) - gpGlobals->curtime;

	}

	return true;

}