/*
===========================================================================
Copyright (C) 2000 - 2013, Raven Software, Inc.
Copyright (C) 2001 - 2013, Activision, Inc.
Copyright (C) 2013 - 2015, OpenJK contributors

This file is part of the OpenJK source code.

OpenJK is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License version 2 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/>.
===========================================================================
*/

#include "../server/exe_headers.h"

#ifndef __Q_SHARED_H
	#include "../qcommon/q_shared.h"
#endif

#if !defined(TR_LOCAL_H)
	#include "tr_local.h"
#endif

#if !defined(G2_H_INC)
	#include "../ghoul2/G2.h"
#endif

#define G2_MODEL_OK(g) ((g)&&(g)->mValid&&(g)->aHeader&&(g)->currentModel&&(g)->animModel)

class CQuickOverride
{
	int mOverride[512];
	int mAt[512];
	int mCurrentTouch;
public:
	CQuickOverride()
	{
		mCurrentTouch=1;
		int i;
		for (i=0;i<512;i++)
		{
			mOverride[i]=0;
		}
	}
	void Invalidate()
	{
		mCurrentTouch++;
	}
	void Set(int index,int pos)
	{
		if (index==10000)
		{
			return;
		}
		assert(index>=0&&index<512);
		mOverride[index]=mCurrentTouch;
		mAt[index]=pos;
	}
	int Test(int index)
	{
		assert(index>=0&&index<512);
		if (mOverride[index]!=mCurrentTouch)
		{
			return -1;
		}
		else
		{
			return mAt[index];
		}
	}
};

static CQuickOverride QuickOverride;


// find a particular surface in the surface override list
const surfaceInfo_t *G2_FindOverrideSurface(int surfaceNum,const surfaceInfo_v &surfaceList)
{

	if (surfaceNum<0)
	{
		// starting a new lookup
		QuickOverride.Invalidate();
		for(size_t i=0; i<surfaceList.size(); i++)
		{
			if (surfaceList[i].surface>=0)
			{
				QuickOverride.Set(surfaceList[i].surface,i);
			}
		}
		return NULL;
	}
	int idx=QuickOverride.Test(surfaceNum);
	if (idx<0)
	{
		if (surfaceNum==10000)
		{
			for(size_t i=0; i<surfaceList.size(); i++)
			{
				if (surfaceList[i].surface == surfaceNum)
				{
					return &surfaceList[i];
				}
			}
		}
#if _DEBUG
		// look through entire list
		size_t i;
		for(i=0; i<surfaceList.size(); i++)
		{
			if (surfaceList[i].surface == surfaceNum)
			{
				break;
			}
		}
		// didn't find it.
		assert(i==surfaceList.size()); // our quickoverride is not working right
#endif
		return NULL;
	}
	assert(idx>=0&&idx<(int)surfaceList.size());
	assert(surfaceList[idx].surface == surfaceNum);
	return &surfaceList[idx];
}


// given a surface name, lets see if it's legal in the model
int G2_IsSurfaceLegal(const model_s *mod_m, const char *surfaceName, uint32_t *flags)
{
	assert(mod_m);
	assert(mod_m->mdxm);
	// damn include file dependancies
	mdxmSurfHierarchy_t	*surf;
	surf = (mdxmSurfHierarchy_t *) ( (byte *)mod_m->mdxm + mod_m->mdxm->ofsSurfHierarchy );

	for ( int i = 0 ; i < mod_m->mdxm->numSurfaces ; i++)
	{
	 	if (!Q_stricmp(surfaceName, surf->name))
	 	{
			*flags = surf->flags;
			return i;
		}
		// find the next surface
  		surf = (mdxmSurfHierarchy_t *)( (byte *)surf + (intptr_t)( &((mdxmSurfHierarchy_t *)0)->childIndexes[ surf->numChildren ] ));
	}
	return -1;
}


/************************************************************************************************
 * G2_FindSurface
 *    find a surface in a ghoul2 surface override list based on it's name
 *
 * Input
 *    filename of model, surface list of model instance, name of surface, int to be filled in
 * with the index of this surface (defaults to NULL)
 *
 * Output
 *    pointer to surface if successful, false otherwise
 *
 ************************************************************************************************/
const mdxmSurface_t *G2_FindSurface(CGhoul2Info *ghlInfo, surfaceInfo_v &slist, const char *surfaceName,
							 int *surfIndex/*NULL*/)
{
	int						i = 0;
	// find the model we want
	assert(G2_MODEL_OK(ghlInfo));

	const mdxmHierarchyOffsets_t *surfIndexes = (mdxmHierarchyOffsets_t *)((byte *)ghlInfo->currentModel->mdxm + sizeof(mdxmHeader_t));

 	// first find if we already have this surface in the list
	for (i = slist.size() - 1; i >= 0; i--)
	{
		if ((slist[i].surface != 10000) && (slist[i].surface != -1))
		{
			const mdxmSurface_t	*surf = (mdxmSurface_t *)G2_FindSurface(ghlInfo->currentModel, slist[i].surface, 0);
			// back track and get the surfinfo struct for this surface
			const mdxmSurfHierarchy_t	*surfInfo = (mdxmSurfHierarchy_t *)((byte *)surfIndexes + surfIndexes->offsets[surf->thisSurfaceIndex]);

  			// are these the droids we're looking for?
			if (!Q_stricmp (surfInfo->name, surfaceName))
			{
				// yup
				if (surfIndex)
				{
					*surfIndex = i;
				}
				return surf;
			}
		}
	}
	// didn't find it
	if (surfIndex)
	{
		*surfIndex = -1;
	}
	return 0;
}

// set a named surface offFlags - if it doesn't find a surface with this name in the list then it will add one.
qboolean G2_SetSurfaceOnOff (CGhoul2Info *ghlInfo, const char *surfaceName, const int offFlags)
{
	int					surfIndex = -1;
	surfaceInfo_t		temp_slist_entry;

	// find the model we want
 	// first find if we already have this surface in the list
	const mdxmSurface_t *surf = G2_FindSurface(ghlInfo, ghlInfo->mSlist, surfaceName, &surfIndex);
	if (surf)
	{
		// set descendants value

		// slist[surfIndex].offFlags = offFlags;
		// seems to me that we shouldn't overwrite the other flags.
		// the only bit we really care about in the incoming flags is the off bit
		ghlInfo->mSlist[surfIndex].offFlags &= ~(G2SURFACEFLAG_OFF | G2SURFACEFLAG_NODESCENDANTS);
		ghlInfo->mSlist[surfIndex].offFlags |= offFlags & (G2SURFACEFLAG_OFF | G2SURFACEFLAG_NODESCENDANTS);
		return qtrue;
	}
	else
	{
		// ok, not in the list already - in that case, lets verify this surface exists in the model mesh
		uint32_t flags;
		int surfaceNum = G2_IsSurfaceLegal(ghlInfo->currentModel, surfaceName, &flags);
		if (surfaceNum != -1)
		{
			uint32_t newflags = flags;
			// the only bit we really care about in the incoming flags is the off bit
			newflags &= ~(G2SURFACEFLAG_OFF | G2SURFACEFLAG_NODESCENDANTS);
			newflags |= offFlags & (G2SURFACEFLAG_OFF | G2SURFACEFLAG_NODESCENDANTS);

			if (newflags != flags)
			{	// insert here then because it changed, no need to add an override otherwise
				temp_slist_entry.offFlags = newflags;
				temp_slist_entry.surface = surfaceNum;

				ghlInfo->mSlist.push_back(temp_slist_entry);
			}
			return qtrue;
		}
	}
	return qfalse;
}

void G2_FindRecursiveSurface(const model_t *currentModel, int surfaceNum, surfaceInfo_v &rootList, int *activeSurfaces)
{
	assert(currentModel);
	assert(currentModel->mdxm);
	int							i;
 	const mdxmSurface_t			*surface = (mdxmSurface_t *)G2_FindSurface(currentModel, surfaceNum, 0);
	const mdxmHierarchyOffsets_t	*surfIndexes = (mdxmHierarchyOffsets_t *)((byte *)currentModel->mdxm + sizeof(mdxmHeader_t));
	const mdxmSurfHierarchy_t		*surfInfo = (mdxmSurfHierarchy_t *)((byte *)surfIndexes + surfIndexes->offsets[surface->thisSurfaceIndex]);

	// see if we have an override surface in the surface list
	const surfaceInfo_t	*surfOverride = G2_FindOverrideSurface(surfaceNum, rootList);

	// really, we should use the default flags for this surface unless it's been overriden
	int offFlags = surfInfo->flags;

	// set the off flags if we have some
	if (surfOverride)
	{
		offFlags = surfOverride->offFlags;
	}

	// if this surface is not off, indicate as such in the active surface list
	if (!(offFlags & G2SURFACEFLAG_OFF))
	{
		activeSurfaces[surfaceNum] = 1;
	}
 	else
	// if we are turning off all descendants, then stop this recursion now
	if (offFlags & G2SURFACEFLAG_NODESCENDANTS)
	{
		return;
	}

	// now recursively call for the children
	for (i=0; i< surfInfo->numChildren; i++)
	{
		surfaceNum = surfInfo->childIndexes[i];
		G2_FindRecursiveSurface(currentModel, surfaceNum, rootList, activeSurfaces);
	}

}

qboolean G2_SetRootSurface( CGhoul2Info_v &ghoul2, const int modelIndex, const char *surfaceName)
{
	int					surf;
	uint32_t			flags;
	assert(modelIndex>=0&&modelIndex<ghoul2.size());
	assert(ghoul2[modelIndex].currentModel);
	assert(ghoul2[modelIndex].currentModel->mdxm);
 	// first find if we already have this surface in the list
	surf = G2_IsSurfaceLegal(ghoul2[modelIndex].currentModel, surfaceName, &flags);
	if (surf != -1)
	{
		ghoul2[modelIndex].mSurfaceRoot = surf;
		return qtrue;
	}
	assert(0);
	return qfalse;
}


extern int			G2_DecideTraceLod(CGhoul2Info &ghoul2, int useLod);
int G2_AddSurface(CGhoul2Info *ghoul2, int surfaceNumber, int polyNumber, float BarycentricI, float BarycentricJ, int lod )
{
	lod = G2_DecideTraceLod(*ghoul2, lod);

	// first up, see if we have a free one already set up  - look only from the end of the constant surfaces onwards
	size_t i;
	for (i=0; i<ghoul2->mSlist.size(); i++)
	{
		// is the surface count -1? That would indicate it's free
		if (ghoul2->mSlist[i].surface == -1)
		{
			break;
		}
	}
	if (i==ghoul2->mSlist.size())
	{
		ghoul2->mSlist.push_back(surfaceInfo_t());
	}
	ghoul2->mSlist[i].offFlags = G2SURFACEFLAG_GENERATED;
	ghoul2->mSlist[i].surface = 10000;		// no model will ever have 10000 surfaces
	ghoul2->mSlist[i].genBarycentricI = BarycentricI;
	ghoul2->mSlist[i].genBarycentricJ = BarycentricJ;
	ghoul2->mSlist[i].genPolySurfaceIndex = ((polyNumber & 0xffff) << 16) | (surfaceNumber & 0xffff);
	ghoul2->mSlist[i].genLod = lod;
	return i;
}

qboolean G2_RemoveSurface(surfaceInfo_v &slist, const int index)
{
	if (index != -1)
	{
		slist[index].surface = -1;
		return qtrue;
	}
	assert(0);
	return qfalse;
}


int G2_GetParentSurface(CGhoul2Info *ghlInfo, const int index)
{
	assert(ghlInfo->currentModel);
	assert(ghlInfo->currentModel->mdxm);
	const mdxmHierarchyOffsets_t	*surfIndexes = (mdxmHierarchyOffsets_t *)((byte *)ghlInfo->currentModel->mdxm + sizeof(mdxmHeader_t));

	// walk each surface and see if this index is listed in it's children
	const mdxmSurface_t				*surf = (mdxmSurface_t *)G2_FindSurface(ghlInfo->currentModel, index, 0);
	const mdxmSurfHierarchy_t		*surfInfo = (mdxmSurfHierarchy_t *)((byte *)surfIndexes + surfIndexes->offsets[surf->thisSurfaceIndex]);

	return surfInfo->parentIndex;

}

int G2_GetSurfaceIndex(CGhoul2Info *ghlInfo, const char *surfaceName)
{
	uint32_t			flags;
	assert(ghlInfo->currentModel);
	return G2_IsSurfaceLegal(ghlInfo->currentModel, surfaceName, &flags);
}

int G2_IsSurfaceRendered(CGhoul2Info *ghlInfo, const char *surfaceName, surfaceInfo_v &slist)
{
	uint32_t				flags = 0u;//, surfFlags = 0;
	int						surfIndex = 0;
	assert(ghlInfo->currentModel);
	assert(ghlInfo->currentModel->mdxm);
	if (!ghlInfo->currentModel->mdxm)
	{
		return -1;
	}

	// now travel up the skeleton to see if any of it's ancestors have a 'no descendants' turned on

	// find the original surface in the surface list
	int surfNum = G2_IsSurfaceLegal(ghlInfo->currentModel, surfaceName, &flags);
	if ( surfNum != -1 )
	{//must be legal
		const mdxmHierarchyOffsets_t	*surfIndexes = (mdxmHierarchyOffsets_t *)((byte *)ghlInfo->currentModel->mdxm + sizeof(mdxmHeader_t));
		const mdxmSurfHierarchy_t *surfInfo = (mdxmSurfHierarchy_t *)((byte *)surfIndexes + surfIndexes->offsets[surfNum]);
		surfNum = surfInfo->parentIndex;
		// walk the surface hierarchy up until we hit the root
		while (surfNum != -1)
		{
			const mdxmSurface_t *parentSurf;
			uint32_t parentFlags = 0u;
			const mdxmSurfHierarchy_t *parentSurfInfo;

			parentSurfInfo = (mdxmSurfHierarchy_t *)((byte *)surfIndexes + surfIndexes->offsets[surfNum]);

			// find the original surface in the surface list
			//G2 was bug, above comment was accurate, but we don't want the original flags, we want the parent flags
			G2_IsSurfaceLegal(ghlInfo->currentModel, parentSurfInfo->name, &parentFlags);

			// now see if we already have overriden this surface in the slist
			parentSurf = G2_FindSurface(ghlInfo, slist, parentSurfInfo->name, &surfIndex);
			if (parentSurf)
			{
				// set descendants value
				parentFlags = slist[surfIndex].offFlags;
			}
			// now we have the parent flags, lets see if any have the 'no descendants' flag set
			if (parentFlags & G2SURFACEFLAG_NODESCENDANTS)
			{
				flags |= G2SURFACEFLAG_OFF;
				break;
			}
			// set up scan of next parent
			surfNum = parentSurfInfo->parentIndex;
		}
	}
	else
	{
		return -1;
	}
	if ( flags == 0 )
	{//it's not being overridden by a parent
		// now see if we already have overriden this surface in the slist
		const mdxmSurface_t *surf = G2_FindSurface(ghlInfo, slist, surfaceName, &surfIndex);
		if (surf)
		{
			// set descendants value
			flags = slist[surfIndex].offFlags;
		}
	  	// ok, at this point in flags we have what this surface is set to, and the index of the surface itself
	}
	return flags;

}