#include "Pomme.h"
#include "PommeFiles.h"
#include "QD3D.h"
#include "3DMFInternal.h"

#define EDGE_PADDING_REPEAT 8

static void Assert(bool condition, const char* message)
{
	if (!condition)
	{
		throw std::runtime_error(message);
	}
}

TQ3MetaFile* Q3MetaFile_Load3DMF(const FSSpec* spec)
{
	short refNum;
	OSErr err;

	err = FSpOpenDF(spec, fsRdPerm, &refNum);
	if (err != noErr)
		return nullptr;

	TQ3MetaFile* metaFile = __Q3Alloc<TQ3MetaFile>(1, '3DMF');

	auto& fileStream = Pomme::Files::GetStream(refNum);
	Q3MetaFileParser(fileStream, *metaFile).Parse3DMF();
	FSClose(refNum);

	return metaFile;
}

void Q3MetaFile_Dispose(TQ3MetaFile* metaFile)
{
	__Q3GetCookie(metaFile, '3DMF');

	for (int i = 0; i < metaFile->numTextures; i++)
		Q3Pixmap_Dispose(metaFile->textures[i].pixmap);

	for (int i = 0; i < metaFile->numMeshes; i++)
		Q3TriMeshData_Dispose(metaFile->meshes[i]);

	for (int i = 0; i < metaFile->numTopLevelGroups; i++)
		__Q3Dispose(metaFile->topLevelGroups[i].meshes, 'GMSH');

	__Q3Dispose(metaFile->textures,				'TXSU');
	__Q3Dispose(metaFile->meshes,				'MLST');
	__Q3Dispose(metaFile->topLevelGroups,		'GLST');
	__Q3Dispose(metaFile,						'3DMF');
}

#pragma mark -


template<typename T>
static void _EdgePadding(
		T* const pixelData,
		const int width,
		const int height,
		const int rowBytes,
		const T alphaMask)
{
	Assert(rowBytes % sizeof(T) == 0, "EdgePadding: rowBytes is not a multiple of pixel bytesize");
	const int rowAdvance = rowBytes / sizeof(T);

	T* const firstRow = pixelData;
	T* const lastRow = firstRow + (height-1) * rowAdvance;

	for (int i = 0; i < EDGE_PADDING_REPEAT; i++)
	{
		// Dilate horizontally, row by row
		for (T* row = firstRow; row <= lastRow; row += rowAdvance)
		{
			// Expand east
			for (int x = 0; x < width-1; x++)
				if (!row[x])
					row[x] = row[x+1] & ~alphaMask;

			// Expand west
			for (int x = width-1; x > 0; x--)
				if (!row[x])
					row[x] = row[x-1] & ~alphaMask;
		}

		// Dilate vertically, column by column
		for (int x = 0; x < width; x++)
		{
			// Expand south
			for (T* row = firstRow; row < lastRow; row += rowAdvance)
				if (!row[x])
					row[x] = row[x + rowAdvance] & ~alphaMask;

			// Expand north
			for (T* row = lastRow; row > firstRow; row -= rowAdvance)
				if (!row[x])
					row[x] = row[x - rowAdvance] & ~alphaMask;
		}
	}
}

void Q3Pixmap_ApplyEdgePadding(TQ3Pixmap* pm)
{
	switch (pm->pixelType)
	{
		case kQ3PixelTypeARGB16:
			Assert(pm->rowBytes >= pm->width * 2, "EdgePadding ARGB16: incorrect rowBytes");
			_EdgePadding<uint16_t>(
					(uint16_t *) pm->image,
					pm->width,
					pm->height,
					pm->rowBytes,
					pm->byteOrder==kQ3EndianNative? 0x8000: 0x0080);
			break;

		case kQ3PixelTypeARGB32:
			Assert(pm->rowBytes >= pm->width * 4, "EdgePadding ARGB32: incorrect rowBytes");
			_EdgePadding<uint32_t>(
					(uint32_t *) pm->image,
					pm->width,
					pm->height,
					pm->rowBytes,
					pm->byteOrder==kQ3EndianNative? 0xFF000000: 0x000000FF);
			break;

		case kQ3PixelTypeRGBA32:
			Assert(pm->rowBytes >= pm->width * 4, "EdgePadding RGBA32: incorrect rowBytes");
			_EdgePadding<uint32_t>(
					(uint32_t *) pm->image,
					pm->width,
					pm->height,
					pm->rowBytes,
					pm->byteOrder==kQ3EndianNative? 0x000000FF: 0xFF000000);
			break;

		case kQ3PixelTypeRGB16:
		case kQ3PixelTypeRGB16_565:
		case kQ3PixelTypeRGB24:
		case kQ3PixelTypeRGB32:
			// Unnecessary to apply edge padding here because there's no alpha channel
			break;

		default:
			Assert(false, "EdgePadding: pixel type unsupported");
			break;
	}
}

void Q3Pixmap_Dispose(TQ3Pixmap* pixmap)
{
	__Q3Dispose(pixmap->image,					'IMAG');
	__Q3Dispose(pixmap,							'PXMP');
}

#pragma mark -

TQ3TriMeshData* Q3TriMeshData_New(int numTriangles,	int numPoints, int featureFlags)
{
	TQ3TriMeshData* mesh	= __Q3Alloc<TQ3TriMeshData>(1, 'MESH');

	mesh->numTriangles		= numTriangles;
	mesh->numPoints			= numPoints;
	mesh->points			= __Q3Alloc<TQ3Point3D>(numPoints, 'TMpt');
	mesh->triangles			= __Q3Alloc<TQ3TriMeshTriangleData>(numTriangles, 'TMtr');
	mesh->diffuseColor		= {1, 1, 1, 1};
	mesh->texturingMode		= kQ3TexturingModeOff;
	mesh->internalTextureID	= -1;
	mesh->bBox				= {{0,0,0}, {0,0,0}, kQ3True};	// empty

	if (featureFlags & kQ3TriMeshDataFeatureVertexUVs)
	{
		mesh->vertexUVs = __Q3Alloc<TQ3Param2D>(numPoints, 'TMuv');
		for (int i = 0; i < numPoints; i++)
			mesh->vertexUVs[i] = {.5f, .5f};
	}
	else
	{
		mesh->vertexUVs = nullptr;
	}

	if (featureFlags & kQ3TriMeshDataFeatureVertexNormals)
	{
		mesh->hasVertexNormals = true;
		mesh->vertexNormals = __Q3Alloc<TQ3Vector3D>(numPoints, 'TMvn');
		for (int i = 0; i < numPoints; i++)
			mesh->vertexNormals[i] = {0, 1, 0};
	}
	else
	{
		mesh->vertexNormals = nullptr;
		mesh->hasVertexNormals = false;
	}

	if (featureFlags & kQ3TriMeshDataFeatureVertexColors)
	{
		mesh->hasVertexColors = true;
		mesh->vertexColors = __Q3Alloc<TQ3ColorRGBA>(numPoints, 'TMvc');
		for (int i = 0; i < numPoints; i++)
			mesh->vertexColors[i] = {1, 1, 1, 1};
	}
	else
	{
		mesh->vertexColors = nullptr;
		mesh->hasVertexColors = false;
	}

	return mesh;
}

TQ3TriMeshData* Q3TriMeshData_Duplicate(const TQ3TriMeshData* source)
{
	TQ3TriMeshData* mesh	= __Q3Copy(source, 'MESH');
	mesh->points			= __Q3Copy(source->points,			'TMpt');
	mesh->triangles			= __Q3Copy(source->triangles,		'TMtr');
	mesh->vertexNormals		= __Q3Copy(source->vertexNormals,	'TMvn');
	mesh->vertexColors		= __Q3Copy(source->vertexColors,	'TMvc');
	mesh->vertexUVs			= __Q3Copy(source->vertexUVs,		'TMuv');
	return mesh;
}

void Q3TriMeshData_Dispose(TQ3TriMeshData* mesh)
{
	__Q3DisposeArray(&mesh->points,				'TMpt');
	__Q3DisposeArray(&mesh->triangles,			'TMtr');
	__Q3DisposeArray(&mesh->vertexNormals,		'TMvn');
	__Q3DisposeArray(&mesh->vertexColors,		'TMvc');
	__Q3DisposeArray(&mesh->vertexUVs,			'TMuv');
	__Q3Dispose(mesh, 'MESH');
}

void Q3TriMeshData_SubdivideTriangles(TQ3TriMeshData* mesh)
{
	struct Edge
	{
		uint32_t a;
		uint32_t b;
		uint32_t midpoint;
	};

	std::map<uint32_t, Edge> edges;

	const int oldNumTriangles	= mesh->numTriangles;
	const int oldNumPoints		= mesh->numPoints;

	auto triangleEdges = new Edge*[oldNumTriangles * 3];
	int numDistinctEdges = 0;

	//-------------------------------------------------------------------------
	// Prep edge records (so we have edge count too)

	for (int t = 0; t < mesh->numTriangles; t++)
	{
		auto& triangle = mesh->triangles[t];

		for (int e = 0; e < 3; e++)
		{
			uint32_t edgeP0 = triangle.pointIndices[e];
			uint32_t edgeP1 = triangle.pointIndices[(e+1) % 3];
			if (edgeP0 > edgeP1)
			{
				int swap = edgeP0;
				edgeP0 = edgeP1;
				edgeP1 = swap;
			}
			uint32_t edgeHash = (edgeP0 << 16) | edgeP1;

			auto foundEdge = edges.find(edgeHash);
			if (foundEdge != edges.end())
			{
				triangleEdges[t*3 + e] = &foundEdge->second;
			}
			else
			{
				edges[edgeHash] = { edgeP0, edgeP1, (uint32_t) -1 };
				triangleEdges[t*3 + e] = &edges[edgeHash];
				numDistinctEdges++;
			}
		}
	}

	//-------------------------------------------------------------------------
	// Reallocate mesh

	int numPointsWritten		= oldNumPoints;
	int numTrianglesWritten		= oldNumTriangles;

	mesh->numTriangles *= 4;
	mesh->numPoints += numDistinctEdges;

	mesh->points			= __Q3Realloc(mesh->points,			mesh->numPoints, 'TMpt');
	mesh->vertexUVs			= __Q3Realloc(mesh->vertexUVs,		mesh->numPoints, 'TMuv');
	mesh->vertexNormals		= __Q3Realloc(mesh->vertexNormals,	mesh->numPoints, 'TMvn');
	if (mesh->vertexColors)
		mesh->vertexColors	= __Q3Realloc(mesh->vertexColors,	mesh->numPoints, 'TMvc');

	mesh->triangles			= __Q3Realloc(mesh->triangles,		mesh->numTriangles, 'TMtr');

	//-------------------------------------------------------------------------
	// Create edge midpoints

	for (auto& edgeKV: edges)
	{
		auto& edge = edgeKV.second;

		edge.midpoint = numPointsWritten;
		numPointsWritten++;

		uint32_t M = edge.midpoint;
		uint32_t A = edge.a;
		uint32_t B = edge.b;

		mesh->points[M].x = (mesh->points[A].x + mesh->points[B].x) / 2.0f;
		mesh->points[M].y = (mesh->points[A].y + mesh->points[B].y) / 2.0f;
		mesh->points[M].z = (mesh->points[A].z + mesh->points[B].z) / 2.0f;

		mesh->vertexNormals[M].x = (mesh->vertexNormals[A].x + mesh->vertexNormals[B].x) / 2.0f;
		mesh->vertexNormals[M].y = (mesh->vertexNormals[A].y + mesh->vertexNormals[B].y) / 2.0f;
		mesh->vertexNormals[M].z = (mesh->vertexNormals[A].z + mesh->vertexNormals[B].z) / 2.0f;

		mesh->vertexUVs[M].u = (mesh->vertexUVs[A].u + mesh->vertexUVs[B].u) / 2.0f;
		mesh->vertexUVs[M].v = (mesh->vertexUVs[A].v + mesh->vertexUVs[B].v) / 2.0f;

		if (mesh->vertexColors)
		{
			mesh->vertexColors[M].r = (mesh->vertexColors[A].r + mesh->vertexColors[B].r) / 2.0f;
			mesh->vertexColors[M].g = (mesh->vertexColors[A].g + mesh->vertexColors[B].g) / 2.0f;
			mesh->vertexColors[M].b = (mesh->vertexColors[A].b + mesh->vertexColors[B].b) / 2.0f;
			mesh->vertexColors[M].a = (mesh->vertexColors[A].a + mesh->vertexColors[B].a) / 2.0f;
		}
	}

	//-------------------------------------------------------------------------
	// Create new triangles

	for (int t = 0; t < oldNumTriangles; t++)
	{
		auto& triangle = mesh->triangles[t];

		/*
		Original triangle: ABC.
		Create 4 new triangles.

		            B
		            +
		           / \
		          /   \
		         /     \
		       >+ . . . +<
		       / .     . \
		      /   .   .   \
		     /     . .     \
		    +-------+-------+
		   A        ^        C
		*/

		uint32_t A		= triangle.pointIndices[0];
		uint32_t B		= triangle.pointIndices[1];
		uint32_t C		= triangle.pointIndices[2];
		uint32_t A2B	= triangleEdges[t*3 + 0]->midpoint;
		uint32_t B2C	= triangleEdges[t*3 + 1]->midpoint;
		uint32_t C2A	= triangleEdges[t*3 + 2]->midpoint;

		mesh->triangles[numTrianglesWritten++]	= {{A2B, B, B2C} };
		mesh->triangles[numTrianglesWritten++]	= {{B2C, C, C2A} };
		mesh->triangles[numTrianglesWritten++]	= {{C2A, A, A2B} };
		mesh->triangles[t]						= {{A2B, B2C, C2A} };	// replace original triangle
	}

	//-------------------------------------------------------------------------
	// Make sure we didn't break the mesh

	delete[] triangleEdges;

	Assert(numTrianglesWritten == 4*oldNumTriangles, "unexpected number of triangles written");
	Assert(numPointsWritten == oldNumPoints + (int)edges.size(), "unexpected number of points written");
}