#ifndef PlantManager_h__
#define PlantManager_h__

#include "Globals.h"
#include "Terrain.h"
#include <vector>
#include "math/LifeMath.h"
#include <stdlib.h>
#include <BoundingBox3D.h>

struct GRASS_INSTANCE_INFO
{
	LifeMath::float4 info;
};
class GrassCacheBlock
{
public:
	LifeCore::BoundingBox3D bbox;
	std::vector<LifeGraphics::IVertexBuffer*> buffers;
	int bw;
	int cr;
	int counters[4];

	GrassCacheBlock(int blockWidth, int coverageResolution, int grassLayersCount)
	{
		bw = blockWidth;
		cr = coverageResolution;

		int subBlocksStride = blockWidth / coverageResolution;
		int subBlockCnt = subBlocksStride * subBlocksStride;

		int instanceCnt = subBlockCnt * 3;

		for(int i = 0; i<grassLayersCount; i++)
			buffers.push_back(LifeGraphics::CG::me()->GetRenderer()->CreateVertexBufferDynamic(instanceCnt * sizeof(GRASS_INSTANCE_INFO), sizeof(GRASS_INSTANCE_INFO)));
	}
	void UpdateBuffer(int plantId, GRASS_INSTANCE_INFO* tmpBuffer, int count)
	{
		counters[plantId] = count;
		LifeGraphics::IVertexBuffer* vb = buffers[plantId];
		LifeCore::IDataStream* ds = vb->Map(0, LifeGraphics::LF_Discard);
		ds->Write(tmpBuffer, count * sizeof(GRASS_INSTANCE_INFO));
		vb->Unmap();
	}
	~GrassCacheBlock()
	{
		for(size_t i = 0; i < buffers.size(); i++)
			delete buffers[i];
	}
};
class GridCell
{
public:
	LifeGraphics::Rectangle2D rect;
	float minHeight;
	float maxHeight;
    std::vector<GRASS_INSTANCE_INFO> instances;
	int instanceCount;
	GridCell()
		:instanceCount(0)
	{
	}
	~GridCell()
	{
		instances.clear();
	}
	void pushInstance(const GRASS_INSTANCE_INFO& instance)
	{
		instances.push_back(instance);
		instanceCount++;
	}
};

class PlantGrid
{
public:
	GridCell* cells;
	int gridSize;
	int cellSize;
	int cellStride;
	std::vector<GridCell*> visibleCells;

	void pushInstance(const GRASS_INSTANCE_INFO& info)
	{
		int id = getCellId(info.info);
		getCell(id)->pushInstance(info);
	}
	int getCellId(const LifeMath::float3& position)
	{
		int pX = static_cast<int>(floorf(position.X / static_cast<float>(cellSize)));
		int pY = static_cast<int>(floorf(-position.Z / static_cast<float>(cellSize)));

		if(pX < 0 || pY < 0) return -1;
		if(pX >= cellStride || pY >= cellStride) return -1;

		return pY * cellStride + pX;
	}
	int getCellId(const LifeMath::float4& position)
	{
		int pX = static_cast<int>(floor(position.X / static_cast<float>(cellSize)));
		int pY = static_cast<int>(floor(-position.Z / static_cast<float>(cellSize)));

		if(pX < 0 || pY < 0) return -1;
		if(pX >= cellStride || pY >= cellStride) return -1;

		return pY * cellStride + pX;
	}

	GridCell* getCell(int id)
	{
		return cells + id;
	}

	PlantGrid(int _gridSize, int _cellSize)
	{
		gridSize = _gridSize;
		cellSize = _cellSize;

		cellStride = gridSize / cellSize;
		int cellCount = cellStride * cellStride;
		cells = new GridCell[cellCount];

		for(int y = 0; y < cellStride; y++)
		{
			for(int x = 0; x < cellStride; x++)
			{
				GridCell* c = cells + (y * cellStride + x);

				c->rect.minX = (float)(x * cellSize);
				c->rect.maxX = (float)(x * cellSize) + (float)cellSize;

				c->rect.minY = -((float)(y * cellSize));
				c->rect.maxY = -((float)(y * cellSize) + (float)cellSize);

				c->minHeight = 0.0f;
				c->maxHeight = 255.0f;
			}
		}
	}
	~PlantGrid()
	{
		visibleCells.clear();
		delete[] cells;
	}

	void Update(LifeGraphics::Camera* cam)
	{
		visibleCells.clear();
		for(int y = 0; y< cellStride; y++)
		{
			for(int x = 0; x< cellStride; x++)
			{
				int offset = y * cellStride + x;
				GridCell* c = cells + offset;
				LifeMath::float3 vmin(c->rect.minX, 0.0f, c->rect.maxY);
				LifeMath::float3 vmax(c->rect.maxX, 255.0f, c->rect.minY);
				LifeCore::BoundingBox3D box(vmin, vmax);

				if(cam->getFrustum()->BoxInFrustum(box))
				{
					visibleCells.push_back(c);
				}
			}
		}
		//
	}
};

struct PLANT_BEND_PARAMS
{
	float fBendScale;
	float fBendSpeed;
	LifeMath::float2 dummy;
};

class PlantClass
{
private:
	LifeGraphics::Terrain* terra;
public:
	PlantGrid* grid;
	LifeGraphics::IShader* imposterPsh;
	LifeGraphics::IShader* imposterVsh;
	LifeGraphics::IConstantBuffer* plantBendInfo;
	LifeGraphics::ITexture2D* imposterTextures[9];
	PlantClass(LifeGraphics::Terrain* _terra, LifeGraphics::IMesh* mesh)
	{
		imposterVsh = LifeGraphics::ResourceManager::me()->CompileUserShaderVS(AS_STRING("Plant_simple.vsh"));
		imposterPsh =LifeGraphics:: ResourceManager::me()->CompileUserShaderPS(AS_STRING("Plant_simple.psh"));

		terra  =_terra;
		plantCount = 0;
		plantGeom = mesh;
		grid = new PlantGrid(_terra->TerrainWidth, 64);
		plantBendInfo = LifeGraphics::CG::me()->GetRenderer()->CreateConstantBuffer(sizeof(PLANT_BEND_PARAMS));
		PLANT_BEND_PARAMS params;
		//	params.fBendScale = 1.0f / mesh->getBoundingBox()->sizeY() * 0.15f; //FIXME!!!!!!!!!!!!!!!!!!!!!!!!!!!
		params.fBendSpeed = 0.7f;
		plantBendInfo->Update(&params, sizeof(PLANT_BEND_PARAMS));

		//generate textures for imposter rendering
	}
	~PlantClass()
	{
		SAFE_DELETE(grid);
		SAFE_DELETE(plantBendInfo);
		SAFE_DELETE(plantGeom);
	}
	void AddInstance(const GRASS_INSTANCE_INFO& instance)
	{
		grid->pushInstance(instance);
	}
	LifeGraphics::IMesh* plantGeom;
	int plantCount;
};

class PlantManager
{
private:
	int currentCell;
	LifeGraphics::Terrain* terra;
	byte* coverageMask;
	PlantGrid* grid;
	std::vector<GRASS_INSTANCE_INFO*> buffers;
	std::vector<GrassCacheBlock*> cache;
	std::vector<GrassCacheBlock*> validBlocks;
	std::vector<GrassCacheBlock*> visibleBlocks;
	LifeGraphics::IVertexBuffer* plantInstBuf;
	int blockSize;
	int cacheStride;
	int blockStride;
	std::vector<LifeGraphics::IMesh*> models;
	std::vector<PlantClass*> plants;
	LifeGraphics::IShader* grassVs;
	LifeGraphics::IShader* grassPs;
	LifeGraphics::IShader* grassPs_g;
	LifeGraphics::IShader* plantTrunkVs;
	LifeGraphics::IShader* plantLeafVs;

	LifeGraphics::IConstantBuffer* grassBendInfo;
	LifeGraphics::IRasterizerState* rsCullNone;
	LifeGraphics::IRasterizerState* rsCullBack;

	LifeGraphics::IInputLayout* layout;

	LifeGraphics::texture_ptr tex;

public:
	PlantManager()
		:currentCell(-1), blockSize(16), cacheStride(3)
	{
	}

	~PlantManager()
	{
		SAFE_DELETE(grassBendInfo);
		SAFE_DELETE(rsCullNone);
		SAFE_DELETE(rsCullBack);
		SAFE_DELETE(plantInstBuf);
		SAFE_DELETE(grassVs);
		SAFE_DELETE(grassPs);
		SAFE_DELETE(grassPs_g);
		SAFE_DELETE(plantLeafVs);
		SAFE_DELETE(plantTrunkVs);
		SAFE_DELETE(grassBendInfo);
		delete[]coverageMask;
		SAFE_DELETE(grid);
		//SAFE_DELETE(layout);

		tex->Release();

		//delete plants
		int pc = plants.size();
		for(int i = 0; i<pc; i++)
		{
			SAFE_DELETE(plants[i]);
		}

		pc = buffers.size();
		for(int i = 0; i<pc; i++)
		{
			SAFE_DELETE_ARRAY(buffers[i]);
		}

		pc = models.size(); //FIX IT!!!!   DELETE ALL MESHES! NOT ONLY 0 !!
		for(int i = 0; i<1; i++)
		{
			SAFE_DELETE(models[i]);
		}

		validBlocks.clear();
		visibleBlocks.clear();

		int cacheSize = cache.size();

		for(int i = 0; i<cacheSize; i++)
		{
			SAFE_DELETE(cache[i]);
		}
	}
	void AddPlant(LifeGraphics::IMesh* plant)
	{
		PlantClass* pc = new PlantClass(terra, plant);
		plants.push_back(pc);
	}

	void Render(LifeGraphics::PassType pass)
	{
		LifeGraphics::IRenderer* renderer = LifeGraphics::CG::me()->GetRenderer();
		renderer->SetRasterizerState(rsCullNone);
		renderer->SetPSTexture(tex.ptr(), 0);

		//render grass
		if(pass != LifeGraphics::PT_RENDER_SHADOW_MAP_PSSM)
		{
			renderer->SetPrimitiveTopology(PT_TRIANGLE_LIST);
			renderer->SetVertexShader(grassVs);
			renderer->SetVSConstantBuffer(grassBendInfo, 10);
			renderer->SetInputLayout(layout);

			int cnt = visibleBlocks.size();
			for(int i = 0; i<cnt; i++)
			{
				GrassCacheBlock* cb = visibleBlocks[i];
				//render each plant type
				for(size_t j = 0; j < models.size(); j++)
				{
					int plantCount = cb->counters[j];
					if(plantCount > 0)
					{
						LifeGraphics::IMesh* plant = models[j];
						renderer->SetIndexBuffer(plant->indexData);
						LifeGraphics::IVertexBuffer* buffers[2];
						buffers[0] = plant->vertexData;
						buffers[1] = cb->buffers[j];

						renderer->SetVertexBuffer(buffers,2);

						if(pass == LifeGraphics::PT_COMPOSE_G_BUF)
							renderer->SetPixelShader(grassPs_g);
						else if(pass == LifeGraphics::PT_COMPOSE_FINAL)
							renderer->SetPixelShader(grassPs);

						renderer->DrawIndexedInstanced(0, plant->subsets[0].Length, 0, plantCount);
					}
				}
			}
		}

		//render other plants
		for(size_t i = 0; i<plants.size(); i++)
		{
			PlantClass* c = plants[i];
			int blockCount = c->grid->visibleCells.size();

			renderer->SetVSConstantBuffer(c->plantBendInfo, 10);
			for(int j = 0; j<blockCount; j++)
			{
				GridCell* cell = c->grid->visibleCells[j];

				int plantCount = cell->instanceCount;
				if(plantCount > 0)
				{
					LifeCore::IDataStream* buf = plantInstBuf->Map(0, LifeGraphics::LF_Discard);

					buf->Write(&cell->instances[0], plantCount * sizeof(GRASS_INSTANCE_INFO));
					plantInstBuf->Unmap();

					LifeGraphics::IMesh* plant = c->plantGeom;
					renderer->SetIndexBuffer(plant->indexData);
					LifeGraphics::IVertexBuffer* buffers[2];
					buffers[0] = plant->vertexData;
					buffers[1] = plantInstBuf;

					renderer->SetVertexBuffer(buffers,2);

					if(pass != LifeGraphics::PT_RENDER_SHADOW_MAP_PSSM)
					{
						if(pass == LifeGraphics::PT_COMPOSE_G_BUF)
							renderer->SetPixelShader(grassPs_g);
						else if(pass == LifeGraphics::PT_COMPOSE_FINAL)
							renderer->SetPixelShader(grassPs);
					}

					for(int s = 0; s<plant->subsetCount; s++)
					{
						if(s==0)
						{
							renderer->SetVertexShader(plantLeafVs);
						}
						else
						{
							renderer->SetVertexShader(plantTrunkVs);
						}
						//renderer->SetPSTexture(plant->subsets[s].material.diffuseMap.ptr(),0);

						renderer->DrawIndexedInstanced(plant->subsets[s].Offset, plant->subsets[s].Length, 0, plantCount);
					}
				}
			}
		}
		LifeGraphics::CG::me()->GetRenderer()->SetRasterizerState(rsCullBack);
	}

	void Update(float timeElapsed, LifeGraphics::Camera* cam)
	{
		//update plants
		int plantCount = plants.size();
		for(int i = 0; i< plantCount; i++)
		{
			PlantClass* c = plants[i];
			c->grid->Update(cam);
		}

		//update grass
		LifeMath::float3 pos = cam->getPosition();
		int cell = grid->getCellId(pos);

		int offset[] = {0,0,0,0};

		if(cell != currentCell )
		{
			validBlocks.clear();
			currentCell = cell;
			if(currentCell != -1)
			{
				//cell has been changed! regenerate plant buffer
				int cellOffset = (cacheStride - 1) / 2;

				int col = static_cast<int>(floor(pos.X / static_cast<float>(blockSize)));
				int row = static_cast<int>(floor(-pos.Z / static_cast<float>(blockSize)));

				//scan each cache block
				for(int y = (row - cellOffset); y <= (row + cellOffset); y++)
				{
					for(int x = (col - cellOffset); x <= (col + cellOffset); x++)
					{
						int check = y * blockStride + x;
						//if we are not out of terrain bounds
						if(y>=0 && x >=0 && y < blockStride && x< blockStride)
						{
							int cacheOffset = (y - row + cellOffset) * cacheStride + (x - col + cellOffset);
							GrassCacheBlock* cb = cache[cacheOffset];
							GridCell* cell = grid->getCell(check);
							validBlocks.push_back(cb);

							//null all counters
							for(int k = 0; k<4; k++)
							{
								offset[k] = 0;
							}

							LifeMath::float3 vmin(cell->rect.minX, 0.0f, cell->rect.maxY);
							LifeMath::float3 vmax(cell->rect.maxX, 255.0f, cell->rect.minY);

							cb->bbox.resize(vmin, vmax);
							//cell is selected//run through it's  sub cells
							for(int sy = -(int)cell->rect.minY; sy < -((int)cell->rect.maxY); sy++)
							{
								for(int sx = (int)cell->rect.minX; sx < (int)cell->rect.maxX; sx++)
								{
									byte pd = coverageMask[sy * terra->TerrainWidth + sx];

									for(int i = 0; i<4; i++)
									{
										//read plants count for i grass type
										byte cnt = (pd >> (2 * i)) & (0x3);

										//and finally generate plants info
										for(byte j = 0; j < (cnt); j++)
										{
											srand(sy * sx *(i + 1 + j));
											GRASS_INSTANCE_INFO ni;
											ni.info.X = (float)sx + ((float)(rand() % 100)) / 100.0f;
											ni.info.Z = -((float)sy + ((float)(rand() % 100)) / 100.0f);
											ni.info.Y = terra->GetHeight(ni.info.X, ni.info.Z);
											ni.info.W = 1.0f;
											buffers[i][offset[i]] = ni;
											offset[i] = offset[i] + 1;
										}
									}
								}
							}
							for(int l = 0; l<4; l++)
							{
								cb->UpdateBuffer(l, buffers[l],offset[l]);
							}
						}
					}
				}
			}
		}

		int vc = validBlocks.size();
		visibleBlocks.clear();
		for(int i = 0; i<vc; i++)
		{
			if(cam->getFrustum()->BoxInFrustum(validBlocks[i]->bbox))
				visibleBlocks.push_back(validBlocks[i]);
		}

		/*	printf("Visible grass chunks: %i\n", visibleBlocks.size());
		for(int i = 0; i<visibleBlocks.size(); i++)
		{
		GrassCacheBlock* b = visibleBlocks[i];
		for(int j = 0; j<4; j++)
		{
		printf("Visible block #%i, grass layer #%i, instance count:%i\n", i, j, b->counters[j] );
		}
		}*/
	}

	void Init(LifeGraphics::Terrain* _terra)
	{
		grassBendInfo = LifeGraphics::CG::me()->GetRenderer()->CreateConstantBuffer(sizeof(PLANT_BEND_PARAMS));
		PLANT_BEND_PARAMS params;
		params.fBendScale = 0.09f;
		params.fBendSpeed = 0.5f;

		grassBendInfo->Update(&params, sizeof(PLANT_BEND_PARAMS));

		rsCullNone = LifeGraphics::CG::me()->GetRenderer()->CreateRasterizerState(FILL_SOLID, CULL_NONE);
		rsCullBack = LifeGraphics::CG::me()->GetRenderer()->CreateRasterizerState(FILL_SOLID, CULL_BACK);

		plantInstBuf = LifeGraphics::CG::me()->GetRenderer()->CreateVertexBufferDynamic(128 * sizeof(GRASS_INSTANCE_INFO), sizeof(GRASS_INSTANCE_INFO));

		grassVs = LifeGraphics::ResourceManager::me()->CompileUserShaderVS(AS_STRING("Grass.vsh"));
		grassPs = LifeGraphics::ResourceManager::me()->CompileUserShaderPS(AS_STRING("Grass.psh"));
		grassPs_g = LifeGraphics::ResourceManager::me()->CompileUserShaderPS(AS_STRING("Grass_g.psh"));

		plantLeafVs = LifeGraphics::ResourceManager::me()->CompileUserShaderVS(AS_STRING("Plant_leafs.vsh"));
		plantTrunkVs = LifeGraphics::ResourceManager::me()->CompileUserShaderVS(AS_STRING("Plant_trunk.vsh"));

		tex = LifeGraphics::ResourceManager::me()->GetTexture(AS_STRING("root/Data/Textures/cst_grass_long.dds"));

		terra = _terra;
		coverageMask = new byte[terra->TerrainWidth * terra->TerrainWidth];
		for(int i = 0; i< (terra->TerrainWidth * terra->TerrainWidth); i++)
		{
			coverageMask[i] = ((byte)(0x3 << 6)) | ((byte)(0x0 << 4)) | ((byte)(0x0 << 2)) | ((byte)(0x0 << 0));
		}

		//memset(coverageMask, 0, terra->TerrainWidth * terra->TerrainWidth);

		grid = new PlantGrid(terra->TerrainWidth, blockSize);

		for(int i = 0; i<4; i++)
			buffers.push_back(new GRASS_INSTANCE_INFO[blockSize*blockSize*3]);

		blockStride = terra->TerrainWidth / blockSize;

		for(int i = 0; i< (cacheStride * cacheStride); i++)
		{
			cache.push_back(new GrassCacheBlock(blockSize,1,4));
		}

		//load grass meshes
		LifeGraphics::IMesh* tm = LifeGraphics::ResourceManager::me()->GetMesh(AS_STRING("root/Data/Objects/grass_a.vmf"));
		models.push_back(tm);
		models.push_back(tm);
		models.push_back(tm);
		models.push_back(tm);
		/*models.push_back(ResourceManager::me()->GetMesh(AS_STRING("root/Data/Objects/g_1.vmf")));
		models.push_back(ResourceManager::me()->GetMesh(AS_STRING("root/Data/Objects/g_2.vmf")));
		models.push_back(ResourceManager::me()->GetMesh(AS_STRING("root/Data/Objects/g_3.vmf")));*/

		LifeGraphics::IInputElement* elements = new LifeGraphics::IInputElement[6];
		elements[0] = LifeGraphics::IInputElement("POSITION", 0, 0, FORMAT_R32G32B32_FLOAT, 0, 0, 0);
		elements[1] = LifeGraphics::IInputElement("TEXCOORD", 0, 12, FORMAT_R32G32_FLOAT, 0, 0, 0);
		elements[2] = LifeGraphics::IInputElement("NORMAL", 0, 20, FORMAT_R32G32B32_FLOAT, 0, 0, 0);
		elements[3] = LifeGraphics::IInputElement("TANGENT", 0, 32, FORMAT_R32G32B32_FLOAT, 0, 0, 0);
		elements[4] = LifeGraphics::IInputElement("BINORMAL", 0, 44, FORMAT_R32G32B32_FLOAT, 0, 0, 0);
		elements[5] = LifeGraphics::IInputElement("INSTANCEDATA", 0, 0, FORMAT_R32G32B32A32_FLOAT, 1, 1, 1);

		layout = LifeGraphics::CG::me()->GetRenderer()->CreateInputLayout(elements, 6, grassVs);
		//fix up models declaration
		for(int i = 0; i<1; i++)
		{
			LifeGraphics::IMesh* m = models[i];
			m->inputLayout = layout;
		}

		LifeGraphics::IMesh* elka = LifeGraphics::ResourceManager::me()->GetMesh(AS_STRING("root/Data/Objects/Tree_test.vmf"));

		//IMesh* elka = ResourceManager::me()->GetMesh(AS_STRING("root/Data/Objects/Tree_test.vmf"));
		//elka->subsets[0].material.diffuseMap = ResourceManager::me()->GetTexture(AS_STRING("root/Data/Textures/Tree_2_2.dds"));
		//elka->subsets[2].material.diffuseMap = ResourceManager::me()->GetTexture(AS_STRING("root/Data/Textures/BARK5.jpg"));
		//	elka->subsets[1].material.diffuseMap = ResourceManager::me()->GetTexture(AS_STRING("root/Data/Textures/BARK5.jpg"));
		//elka->subsets[0].material.diffuseMap = ResourceManager::me()->GetTexture(AS_STRING("root/Data/Textures/cod5_tree_branch.dds"));
		AddPlant(elka);
		PlantClass* pc = plants[0];
		GRASS_INSTANCE_INFO tree;

		for(int x = 0; x<10; x++)
		{
			for(int y = 0; y<10; y++)
			{
				tree.info = LifeMath::float4( (float)x*6.0f + 100.0f,terra->GetHeight((float)x*6.0f + 100.0f, -(float)y*6.0f - 20.0f), -(float)y*6.0f - 20.0f, 1.0f );
				pc->AddInstance(tree);
			}
		}

		//tree.info = LifeMath::float4(70.0f,terra->GetHeight(70.0f, -20.0f), -20.0f, 1.0f );
		//pc->AddInstance(tree);
	}
};
#endif // PlantManager_h__