#include "global.h"
#include "GameLoop.h"
#include "RageLog.h"
#include "RageTextureManager.h"
#include "RageSoundManager.h"
#include "PrefsManager.h"
#include "RageDisplay.h"

#include "arch/ArchHooks/ArchHooks.h"

#include "GameSoundManager.h"
#include "ThemeManager.h"
#include "SongManager.h"
#include "GameState.h"
#include "MemoryCardManager.h"
#include "ScreenManager.h"
#include "InputFilter.h"
#include "InputMapper.h"
#include "RageFileManager.h"
#include "LightsManager.h"
#include "NetworkSyncManager.h"
#include "RageTimer.h"
#include "RageInput.h"

static RageTimer g_GameplayTimer;

static Preference<bool> g_bNeverBoostAppPriority( "NeverBoostAppPriority", false );

/* experimental: force a specific update rate.  This prevents big 
 * animation jumps on frame skips.  0 to disable. */
static Preference<float> g_fConstantUpdateDeltaSeconds( "ConstantUpdateDeltaSeconds", 0 );

void HandleInputEvents( float fDeltaTime );

static float g_fUpdateRate = 1;
void GameLoop::SetUpdateRate( float fUpdateRate )
{
	g_fUpdateRate = fUpdateRate;
}

static void CheckGameLoopTimerSkips( float fDeltaTime )
{
	if( !PREFSMAN->m_bLogSkips )
		return;

	static int iLastFPS = 0;
	int iThisFPS = DISPLAY->GetFPS();

	/* If vsync is on, and we have a solid framerate (vsync == refresh and we've sustained this
	 * for at least one second), we expect the amount of time for the last frame to be 1/FPS. */
	if( iThisFPS != DISPLAY->GetActualVideoModeParams().rate || iThisFPS != iLastFPS )
	{
		iLastFPS = iThisFPS;
		return;
	}

	const float fExpectedTime = 1.0f / iThisFPS;
	const float fDifference = fDeltaTime - fExpectedTime;
	if( fabsf(fDifference) > 0.002f && fabsf(fDifference) < 0.100f )
		LOG->Trace( "GameLoop timer skip: %i FPS, expected %.3f, got %.3f (%.3f difference)",
			iThisFPS, fExpectedTime, fDeltaTime, fDifference );
}

static bool ChangeAppPri()
{
	if( g_bNeverBoostAppPriority.Get() )
		return false;

	// if using NTPAD don't boost or else input is laggy
#if defined(_WINDOWS)
	{
		vector<InputDeviceInfo> vDevices;

		// This can get called before INPUTMAN is constructed.
		if( INPUTMAN )
		{
			INPUTMAN->GetDevicesAndDescriptions(vDevices);
			FOREACH_CONST( InputDeviceInfo, vDevices, d )
			{
				if( d->sDesc.find("NTPAD") != string::npos )
				{
					LOG->Trace( "Using NTPAD.  Don't boost priority." );
					return false;
				}
			}
		}
	}
#endif

	/* If this is a debug build, don't.  It makes the VC debugger sluggish. */
#if defined(WIN32) && defined(DEBUG)
	return false;
#else
	return true;
#endif
}

static void CheckFocus()
{
	if( !HOOKS->AppFocusChanged() )
		return;

	/* If we lose focus, we may lose input events, especially key releases. */
	INPUTFILTER->Reset();

	if( ChangeAppPri() )
	{
		if( HOOKS->AppHasFocus() )
			HOOKS->BoostPriority();
		else
			HOOKS->UnBoostPriority();
	}
}

/* On the next update, change themes, and load sNewScreen. */
static RString g_sNewTheme;
static RString g_sNewScreen;
void GameLoop::ChangeTheme( const RString &sNewTheme, const RString &sNewScreen )
{
	g_sNewTheme = sNewTheme;
	g_sNewScreen = sNewScreen;
}

#include "StepMania.h" // XXX
namespace
{
	void DoChangeTheme()
	{
		SAFE_DELETE( SCREENMAN );
		TEXTUREMAN->DoDelayedDelete();

		/* Clear theme metrics, so ThemeMetric<apActorCommand>s are cleared. */
		THEME->ClearSubscribers();

		/* In case the previous theme overloaded class bindings, reinitialize them. */
		LUA->RegisterTypes();

		THEME->SwitchThemeAndLanguage( g_sNewTheme, THEME->GetCurLanguage(), PREFSMAN->m_bPseudoLocalize );
		PREFSMAN->m_sTheme.Set( g_sNewTheme );

		/* Apply the new window title, icon and aspect ratio. */
		StepMania::ApplyGraphicOptions();

		SCREENMAN = new ScreenManager();

		StepMania::ResetGame();
		SCREENMAN->ThemeChanged();
		SCREENMAN->SetNewScreen( g_sNewScreen );

		g_sNewTheme = RString();
		g_sNewScreen = RString();
	}

}

void GameLoop::RunGameLoop()
{
	/* People may want to do something else while songs are loading, so do
	 * this after loading songs. */
	if( ChangeAppPri() )
		HOOKS->BoostPriority();

	while( !ArchHooks::UserQuit() )
	{
		if( !g_sNewTheme.empty() )
			DoChangeTheme();

		/*
		 * Update
		 */
		float fDeltaTime = g_GameplayTimer.GetDeltaTime();

		if( g_fConstantUpdateDeltaSeconds > 0 )
			fDeltaTime = g_fConstantUpdateDeltaSeconds;
		
		CheckGameLoopTimerSkips( fDeltaTime );

		fDeltaTime *= g_fUpdateRate;

		CheckFocus();

		/* Update SOUNDMAN early (before any RageSound::GetPosition calls), to flush position data. */
		SOUNDMAN->Update();

		/* Update song beat information -before- calling update on all the classes that
		 * depend on it.  If you don't do this first, the classes are all acting on old 
		 * information and will lag.  (but no longer fatally, due to timestamping -glenn) */
		SOUND->Update( fDeltaTime );
		TEXTUREMAN->Update( fDeltaTime );
		GAMESTATE->Update( fDeltaTime );
		SCREENMAN->Update( fDeltaTime );
		MEMCARDMAN->Update( fDeltaTime );
		NSMAN->Update( fDeltaTime );

		/* Important:  Process input AFTER updating game logic, or input will be acting on song beat from last frame */
		HandleInputEvents( fDeltaTime );

		if( INPUTMAN->DevicesChanged() )
		{
			INPUTFILTER->Reset();	// fix "buttons stuck" if button held while unplugged
			INPUTMAN->LoadDrivers();
			RString sMessage;
			if( INPUTMAPPER->CheckForChangedInputDevicesAndRemap(sMessage) )
				SCREENMAN->SystemMessage( sMessage );
		}

		LIGHTSMAN->Update( fDeltaTime );

		/*
		 * Render
		 */
		SCREENMAN->Draw();
	}

	/* If we ended mid-game, finish up. */
	GAMESTATE->EndGame();

	if( ChangeAppPri() )
		HOOKS->UnBoostPriority();
}

class ConcurrentRenderer
{
public:
	ConcurrentRenderer();
	~ConcurrentRenderer();

	void Start();
	void Stop();

private:
	RageThread m_Thread;
	RageEvent m_Event;
	bool m_bShutdown;
	void RenderThread();
	static int StartRenderThread( void *p );

	enum State { RENDERING_IDLE, RENDERING_START, RENDERING_ACTIVE, RENDERING_END };
	State m_State;
};
static ConcurrentRenderer *g_pConcurrentRenderer = NULL;

ConcurrentRenderer::ConcurrentRenderer():
	m_Event("ConcurrentRenderer")
{
	m_bShutdown = false;
	m_State = RENDERING_IDLE;

	m_Thread.SetName( "ConcurrentRenderer" );
	m_Thread.Create( StartRenderThread, this );
}

ConcurrentRenderer::~ConcurrentRenderer()
{
	ASSERT( m_State == RENDERING_IDLE );
	m_bShutdown = true;
	m_Thread.Wait();
}

void ConcurrentRenderer::Start()
{
	DISPLAY->BeginConcurrentRenderingMainThread();

	m_Event.Lock();
	ASSERT( m_State == RENDERING_IDLE );
	m_State = RENDERING_START;
	m_Event.Signal();
	while( m_State != RENDERING_ACTIVE )
		m_Event.Wait();
	m_Event.Unlock();
}

void ConcurrentRenderer::Stop()
{
	m_Event.Lock();
	ASSERT( m_State == RENDERING_ACTIVE );
	m_State = RENDERING_END;
	m_Event.Signal();
	while( m_State != RENDERING_IDLE )
		m_Event.Wait();
	m_Event.Unlock();

	DISPLAY->EndConcurrentRenderingMainThread();
}

void ConcurrentRenderer::RenderThread()
{
	ASSERT( SCREENMAN != NULL );

	while( !m_bShutdown )
	{
		m_Event.Lock();
		while( m_State == RENDERING_IDLE && !m_bShutdown )
			m_Event.Wait();
		m_Event.Unlock();

		if( m_State == RENDERING_START )
		{
			/* We're starting to render.  Set up, and then kick the event to wake
			 * up the calling thread. */
			DISPLAY->BeginConcurrentRendering();
			HOOKS->SetupConcurrentRenderingThread();

			LOG->Trace( "ConcurrentRenderer::RenderThread start" );

			m_Event.Lock();
			m_State = RENDERING_ACTIVE;
			m_Event.Signal();
			m_Event.Unlock();
		}

		/* This is started during Update().  The next thing the game loop
		 * will do is Draw, so shift operations around to put Draw at the
		 * top.  This makes sure updates are seamless. */
		if( m_State == RENDERING_ACTIVE )
		{
			SCREENMAN->Draw();

			float fDeltaTime = g_GameplayTimer.GetDeltaTime();
			SCREENMAN->Update( fDeltaTime );
		}

		if( m_State == RENDERING_END )
		{
			LOG->Trace( "ConcurrentRenderer::RenderThread done" );

			DISPLAY->EndConcurrentRendering();

			m_Event.Lock();
			m_State = RENDERING_IDLE;
			m_Event.Signal();
			m_Event.Unlock();
		}
	}
}

int ConcurrentRenderer::StartRenderThread( void *p )
{
	((ConcurrentRenderer *) p)->RenderThread();
	return 0;
}

void GameLoop::StartConcurrentRendering()
{
	if( g_pConcurrentRenderer == NULL )
		g_pConcurrentRenderer = new ConcurrentRenderer;
	g_pConcurrentRenderer->Start();
}

void GameLoop::FinishConcurrentRendering()
{
	g_pConcurrentRenderer->Stop();
}

/*
 * (c) 2001-2005 Chris Danford, Glenn Maynard
 * All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, and/or sell copies of the Software, and to permit persons to
 * whom the Software is furnished to do so, provided that the above
 * copyright notice(s) and this permission notice appear in all copies of
 * the Software and that both the above copyright notice(s) and this
 * permission notice appear in supporting documentation.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF
 * THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS
 * INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL INDIRECT
 * OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
 * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */
