#include "world.h"

World::World() {}

World::~World() {}

Array2d<Chunk*>& World::GetChunks() { return m_chunks; }

void World::SetSeed(uint64_t seed) {
	m_seed = seed;
}

Chunk* World::ChunkAt(float x, float y, float z) const {
	int cx = (int)x / CHUNK_SIZE_X;
	int cz = (int)z / CHUNK_SIZE_Z;

	if (x < 0 || y < 0 || z < 0 ||
		x >= WORLD_SIZE_X * CHUNK_SIZE_X ||
		z >= CHUNK_SIZE_Z * WORLD_SIZE_Y ||
		y > CHUNK_SIZE_Y)
		return 0;

	return m_chunks.Get(cx, cz);
}

Chunk* World::ChunkAt(const Vector3f& pos) const { return ChunkAt(pos.x, pos.y, pos.z); }

BlockType World::BlockAt(float x, float y, float z, BlockType defaultBlockType) const {
	Chunk* c = ChunkAt(x, y, z);

	if (!c)
		return defaultBlockType;

	int bx = (int)x % CHUNK_SIZE_X;
	int by = (int)y % CHUNK_SIZE_Y;
	int bz = (int)z % CHUNK_SIZE_Z;

	return c->GetBlock(bx, by, bz);
}

BlockType World::BlockAt(const Vector3f& pos, BlockType defaultBlockType) const {
	return BlockAt(pos.x, pos.y, pos.z, defaultBlockType);
}

void World::TransposeWorld(Player& player, Bullet* bullets[MAX_BULLETS]) {
	int x = 0, y = 0;

	if (player.GetPosition().x > (WORLD_SIZE_X * CHUNK_SIZE_X) * .6f) ++x;
	else if (player.GetPosition().x < (WORLD_SIZE_X * CHUNK_SIZE_X) * .4f) --x;
	if (player.GetPosition().z > (WORLD_SIZE_Y * CHUNK_SIZE_Z) * .6f) ++y;
	else if (player.GetPosition().z < (WORLD_SIZE_Y * CHUNK_SIZE_Z) * .4f) --y;

	if (!x && !y) return;

	if (x > 0) {
		for (int ax = 0; ax < WORLD_SIZE_X; ++ax)
			for (int ay = 0; ay < WORLD_SIZE_Y; ++ay)
				if (ax - x >= 0) {
					m_chunks.Set(ax - x, ay,
						m_chunks.Remove(ax, ay));
					if (ax == WORLD_SIZE_X - 1 && m_chunks.Get(ax - x, ay))
						m_chunks.Get(ax - x, ay)->MakeDirty();
				}
				else if (m_chunks.Get(ax, ay)) m_tbDeleted.emplace_back(m_chunks.Remove(ax, ay));
	}
	else if (x < 0) {
		for (int ax = WORLD_SIZE_X - 1; ax >= 0; --ax)
			for (int ay = WORLD_SIZE_Y - 1; ay >= 0; --ay)
				if (ax - x < WORLD_SIZE_X) {
					m_chunks.Set(ax - x, ay,
						m_chunks.Remove(ax, ay));
					if (ax == 0 && m_chunks.Get(ax - x, ay))
						m_chunks.Get(ax - x, ay)->MakeDirty();
				}
				else if (m_chunks.Get(ax, ay)) m_tbDeleted.emplace_back(m_chunks.Remove(ax, ay));
	}

	if (y > 0) {
		for (int ax = 0; ax < WORLD_SIZE_X; ++ax)
			for (int ay = 0; ay < WORLD_SIZE_Y; ++ay)
				if (ay - y >= 0) {
					m_chunks.Set(ax, ay - y,
						m_chunks.Remove(ax, ay));
					if (ay == WORLD_SIZE_Y - 1 && m_chunks.Get(ax, ay - y))
						m_chunks.Get(ax, ay - y)->MakeDirty();
				}
				else if (m_chunks.Get(ax, ay)) m_tbDeleted.emplace_back(m_chunks.Remove(ax, ay));
	}
	else if (y < 0) {
		for (int ax = WORLD_SIZE_X - 1; ax >= 0; --ax)
			for (int ay = WORLD_SIZE_Y - 1; ay >= 0; --ay)
				if (ay - y < WORLD_SIZE_Y) {
					m_chunks.Set(ax, ay - y,
						m_chunks.Remove(ax, ay));
					if (ay == 0 && m_chunks.Get(ax, ay - y))
						m_chunks.Get(ax, ay - y)->MakeDirty();
				}
				else if (m_chunks.Get(ax, ay)) m_tbDeleted.emplace_back(m_chunks.Remove(ax, ay));
	}

	m_center[0] += x; m_center[1] += y;
	player.Teleport(x, y);

	for (int index = 0; index < MAX_BULLETS; ++index)
		if (bullets[index]) bullets[index]->Transpose(x, y);
}

void World::CleanUpWorld(int& deleteframes, bool clear = false) {
	if (clear) {
		while (m_tbDeleted.size() > 0) {
			delete m_tbDeleted.back();
			m_tbDeleted.pop_back();
		}
	}
	if (!m_tbDeleted.empty() && !deleteframes) {
		int deleted = 0;
		while (deleted < THREADS_DELETE_CHUNKS) {


		}
		delete m_tbDeleted.back();
		m_tbDeleted.pop_back();
		deleteframes = FRAMES_DELETE_CHUNKS;
	}
}

void World::GetScope(unsigned int& x, unsigned int& y) {
	x = m_center[0];
	y = m_center[1];
}

void World::Update(int& rendercount, Bullet* bullets[MAX_BULLETS], Player& player, Transformation& world, Shader& shader, TextureAtlas& atlas, BlockInfo* blockinfo[BTYPE_LAST]) {
	glStencilFunc(GL_EQUAL, 1, 0x00);
	glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);
	atlas.Bind();
	RenderWorld(rendercount, player, world, shader);
	UpdateWorld(player, blockinfo);
	//TransposeWorld(player, bullets);
	shader.Disable();
	glStencilFunc(GL_GREATER, 1, 0xFF);
}

void World::UpdateChunk(int& updates, unsigned int chx, unsigned int chy, BlockInfo* blockinfo[BTYPE_LAST]) {
	if (updates == 0 && ChunkAt(chx, 1, chy) &&
		ChunkAt(chx, 1, chy)->IsDirty()) {
		ChunkAt(chx, 1, chy)->Update(blockinfo, this);
		updates = FRAMES_UPDATE_CHUNKS;
	}

}

void World::ChangeBlockAtCursor(BlockType blockType, Player& player, bool& block) {
	Vector3f currentPos = player.GetPosition();
	Vector3f currentBlock = currentPos;
	Vector3f ray = player.GetDirection();
	bool found = false;

	if (block) return;

	while ((currentPos - currentBlock).Length() <= MAX_SELECTION_DISTANCE && !found) {
		currentBlock += ray / 10.f;

		BlockType bt = BlockAt(currentBlock);

		if (bt != BTYPE_AIR)
			found = true;
	}

	if (found)
		if (blockType != BTYPE_AIR) {
			found = false;
			while ((currentPos - currentBlock).Length() >= 1.7f && !found) {
				currentBlock -= ray / 10.f;

				BlockType bt = BlockAt(currentBlock);

				if (bt == BTYPE_AIR) { // Vérification pour être sûr que le bloc à changer n'est pas dans le joueur.
					int Bx = (int)currentBlock.x;
					int By = (int)currentBlock.y;
					int Bz = (int)currentBlock.z;

					int Px = (int)currentPos.x;
					int PyA = (int)currentPos.y;
					int PyB = (int)(currentPos.y - .9f);
					int PyC = (int)(currentPos.y - 1.7f);
					int Pz = (int)currentPos.z;

					if (!(Bx == Px &&
						(By == PyA ||
							By == PyB ||
							By == PyC) &&
						Bz == Pz))
						found = true;
				}
			}
		}

	if (found && (int)currentBlock.y < CHUNK_SIZE_Y) {
		int bx = (int)currentBlock.x % CHUNK_SIZE_X;
		int by = (int)currentBlock.y % CHUNK_SIZE_Y;
		int bz = (int)currentBlock.z % CHUNK_SIZE_Z;

		ChunkAt(currentBlock)->SetBlock(bx, by, bz, blockType, this);
		ChunkAt(currentBlock)->MakeModified();
		block = true;
	}
}

void World::ChangeBlockAtPosition(BlockType blockType, Vector3f pos) {
	int bx = (int)pos.x % CHUNK_SIZE_X;
	int by = (int)pos.y % CHUNK_SIZE_Y;
	int bz = (int)pos.z % CHUNK_SIZE_Z;

	ChunkAt(pos)->SetBlock(bx, by, bz, blockType, this);
	ChunkAt(pos)->MakeModified();
}

void World::RenderWorld(int& rendercount, Player& player, Transformation& world, Shader& shader) {
	shader.Use();
	rendercount = 0;
	Vector3f angle;
	Vector3f cursor;
	Vector3f direct = player.GetDirection();
	Vector3f pos = player.GetPosition() - direct;

	direct.y = 0;
	direct.Normalize();
	pos.y = 1;

	static Vector3<unsigned int> renderManifest[VIEW_DISTANCE * 8]; // Nombre de Chunks maximal à être rendus.

	//for (int dist = VIEW_DISTANCE; dist >= 0; dist -= CHUNK_SIZE_X) {
	for (int dist = 0; dist <= VIEW_DISTANCE; dist += CHUNK_SIZE_X) {
		// Configuration du radar.
		float sinus, cosinus;
		int echantillons;

		if (dist > VIEW_DISTANCE * .1f) {
			sinus = .00872653549f; // sin(1/2 degré)
			cosinus = .99996192306; // cos(1/2 degré)
			echantillons = 180;
		}
		//else if (dist > VIEW_DISTANCE * .3f) {
		//	sinus = .01151891831f; // sin(2/3 degré)
		//	cosinus = .99993365506; // cos(2/3 degré)
		//	echantillons = 120;
		//}
		//else if (dist > VIEW_DISTANCE * .2f) {
		//	sinus = .01745240643; // sin(1 degré)
		//	cosinus = .99984769515; // cos(1 degré)
		//	echantillons = 90;
		//}
		//else if (dist > VIEW_DISTANCE * .1f) {
		//	sinus = .0261769483;
		//	cosinus = .99965732497;
		//	echantillons = 60;
		//}
		else {
			sinus = .0348994967;
			cosinus = .99939082701;
			echantillons = 45;
		}

		angle.x = direct.z + direct.x;
		angle.z = direct.z - direct.x;
		angle.y = 0;
		angle.Normalize();

		for (int radar = 0; radar < echantillons; ++radar) {
			float x = angle.x;

			angle.x = angle.x * cosinus - angle.z * sinus;
			angle.z = angle.z * cosinus + x * sinus;
			angle.Normalize();

			cursor = pos - direct * CHUNK_SIZE_X * 2 + angle * dist;
			if (cursor.y >= 128.f || cursor.y >= 0.f) cursor.y = CHUNK_SIZE_Y / 2.f;


			if (ChunkAt(cursor)) {
				bool valide = true;
				unsigned int chx, chy;
				ChunkAt(cursor)->GetPosition(chx, chy);
				for (int index = 0; index < rendercount; ++index) // Permet de vérifier seulement contre celles ajoutées dans la frame, et ne pas avoir à refaire l'array à chaque frame.
					if (renderManifest[index].x == chx && renderManifest[index].z == chy)
						valide = false;

				if (valide) renderManifest[rendercount++] = Vector3<unsigned int>(chx, 
					(VIEW_DISTANCE - (pos - cursor).Length() * 3.f + 256.f) < 0.f? 0: 
					(VIEW_DISTANCE - (pos - cursor).Length() * 3.f + 256.f) * 1000, 
					chy);
			}
		}
	}
	for (int index = 0; index < rendercount; ++index) {
		int chx = (renderManifest[index].x - m_center[0]) * CHUNK_SIZE_X, chy = (renderManifest[index].z - m_center[1]) * CHUNK_SIZE_Z;

		world.ApplyTranslation(chx, 0, chy);
		world.Use();
		float blcolor = renderManifest[index].y / (VIEW_DISTANCE / 50.f);
		glBlendColor(blcolor, blcolor, blcolor, 1.f);
		ChunkAt(chx, 1, chy)->Render();
		world.ApplyTranslation(-chx, 0, -chy);
	}
	shader.Disable();
};

void World::UpdateWorld(Player& player, BlockInfo* blockinfo[BTYPE_LAST]) {
	int cx = player.GetPosition().x;
	int cy = player.GetPosition().z;
	static int frameGenerate = 1;
	static int frameUpdate = 2;
	static int frameDelete = 3;
	int side = 0;
	int threads = 0;
	std::future<Chunk*> genThList[THREADS_GENERATE_CHUNKS];
	std::future<Chunk*> updateThList[THREADS_UPDATE_CHUNKS];
	std::future<void> delThList[THREADS_DELETE_CHUNKS];

	if (frameGenerate > 0) --frameGenerate;
	if (frameUpdate > 0) --frameUpdate;
	if (frameDelete > 0) --frameDelete;
	
	if (!frameGenerate)
		while (side * CHUNK_SIZE_X <= VIEW_DISTANCE * 2 + CHUNK_SIZE_X) {
			int tx = -side, ty = -side;
			int chx = 0;
			int chy = 0;

			for (; tx <= side; ++tx) {
				if (frameGenerate)
					break;
				chx = cx + tx * CHUNK_SIZE_X;
				chy = cy + ty * CHUNK_SIZE_Z;
				if (chx < WORLD_SIZE_X * CHUNK_SIZE_X && chy < WORLD_SIZE_Y * CHUNK_SIZE_Z &&
					chx >= 0 && chy >= 0 && !ChunkAt(chx, 1, chy))
					genThList[threads++] = std::async(std::launch::async, 
						[](unsigned int x, unsigned int y, uint64_t seed) { 
							return new Chunk(x, y, seed); }, 
							chx / CHUNK_SIZE_X + m_center[0], 
							chy / CHUNK_SIZE_Z + m_center[1], 
							m_seed);
				if (threads == THREADS_GENERATE_CHUNKS) frameGenerate = FRAMES_RENDER_CHUNKS;
			}
			for (; ty <= side; ++ty) {
				if (frameGenerate)
					break;
				chx = cx + tx * CHUNK_SIZE_X;
				chy = cy + ty * CHUNK_SIZE_Z;
				if (chx < WORLD_SIZE_X * CHUNK_SIZE_X && chy < WORLD_SIZE_Y * CHUNK_SIZE_Z &&
					chx >= 0 && chy >= 0 && !ChunkAt(chx, 1, chy))
					genThList[threads++] = std::async(std::launch::async, 
						[](unsigned int x, unsigned int y, uint64_t seed) { 
							return new Chunk(x, y, seed); }, 
							chx / CHUNK_SIZE_X + m_center[0], 
							chy / CHUNK_SIZE_Z + m_center[1], 
							m_seed);
				if (threads == THREADS_GENERATE_CHUNKS) frameGenerate = FRAMES_RENDER_CHUNKS;
			}
			for (; tx >= -side; --tx) {
				if (frameGenerate)
					break;
				chx = cx + tx * CHUNK_SIZE_X;
				chy = cy + ty * CHUNK_SIZE_Z;
				if (chx < WORLD_SIZE_X * CHUNK_SIZE_X && chy < WORLD_SIZE_Y * CHUNK_SIZE_Z &&
					chx >= 0 && chy >= 0 && !ChunkAt(chx, 1, chy))
					genThList[threads++] = std::async(std::launch::async, 
						[](unsigned int x, unsigned int y, uint64_t seed) { 
							return new Chunk(x, y, seed); }, 
							chx / CHUNK_SIZE_X + m_center[0], 
							chy / CHUNK_SIZE_Z + m_center[1], 
							m_seed);
				if (threads == THREADS_GENERATE_CHUNKS) frameGenerate = FRAMES_RENDER_CHUNKS;
			}
			for (; ty >= -side; --ty) {
				if (frameGenerate)
					break;
				chx = cx + tx * CHUNK_SIZE_X;
				chy = cy + ty * CHUNK_SIZE_Z;
				if (chx < WORLD_SIZE_X * CHUNK_SIZE_X && chy < WORLD_SIZE_Y * CHUNK_SIZE_Z &&
					chx >= 0 && chy >= 0 && !ChunkAt(chx, 1, chy))
					genThList[threads++] = std::async(std::launch::async, 
						[](unsigned int x, unsigned int y, uint64_t seed) { 
							return new Chunk(x, y, seed); }, 
							chx / CHUNK_SIZE_X + m_center[0], 
							chy / CHUNK_SIZE_Z + m_center[1],
							m_seed);
				if (threads == THREADS_GENERATE_CHUNKS) frameGenerate = FRAMES_RENDER_CHUNKS;
			}
			if (frameGenerate)
				break;
			++side;
		}

	if (threads > 0) {
		for (int i = 0; i < threads; ++i)
			genThList[i].wait();

		for (int i = 0; i < threads; ++i) {
			unsigned int x, y;
			Chunk* chunk = genThList[i].get();
			chunk->GetPosition(x, y);
			m_chunks.Set(x - m_center[0], y - m_center[1], chunk);
		}
	}

	side = 0;
	threads = 0;

	if (!frameUpdate)
		while (side * CHUNK_SIZE_X <= VIEW_DISTANCE * 2) {
			int tx = -side, ty = -side;

			for (; tx <= side; ++tx) {
				if (frameUpdate)
					break;
				unsigned int chx = cx + tx * CHUNK_SIZE_X, chy = cy + ty * CHUNK_SIZE_Z;
				if (ChunkAt(chx, 1, chy) &&
					ChunkAt(chx, 1, chy)->IsDirty()) {
					updateThList[threads++] =
						std::async(std::launch::async,
							[](Chunk* chunk, BlockInfo* blockinfo[BTYPE_LAST], World* world) {
								chunk->Update(blockinfo, world); return chunk; }, ChunkAt(chx, 1, chy), blockinfo, this);
					if (threads == THREADS_UPDATE_CHUNKS) frameUpdate = FRAMES_UPDATE_CHUNKS;
				}
			}
			for (; ty <= side; ++ty) {
				if (frameUpdate)
					break;
				unsigned int chx = cx + tx * CHUNK_SIZE_X, chy = cy + ty * CHUNK_SIZE_Z;
				if (ChunkAt(chx, 1, chy) &&
					ChunkAt(chx, 1, chy)->IsDirty()) {
					updateThList[threads++] =
						std::async(std::launch::async,
							[](Chunk* chunk, BlockInfo* blockinfo[BTYPE_LAST], World* world) {
								chunk->Update(blockinfo, world); return chunk; }, ChunkAt(chx, 1, chy), blockinfo, this);
					if (threads == THREADS_UPDATE_CHUNKS) frameUpdate = FRAMES_UPDATE_CHUNKS;
				}
			}
			for (; tx >= -side; --tx) {
				if (frameUpdate)
					break;
				unsigned int chx = cx + tx * CHUNK_SIZE_X, chy = cy + ty * CHUNK_SIZE_Z;
				if (ChunkAt(chx, 1, chy) &&
					ChunkAt(chx, 1, chy)->IsDirty()) {
					updateThList[threads++] =
						std::async(std::launch::async,
							[](Chunk* chunk, BlockInfo* blockinfo[BTYPE_LAST], World* world) {
								chunk->Update(blockinfo, world); return chunk; }, ChunkAt(chx, 1, chy), blockinfo, this);
					if (threads == THREADS_UPDATE_CHUNKS) frameUpdate = FRAMES_UPDATE_CHUNKS;
				}
			}
			for (; ty >= -side; --ty) {
				if (frameUpdate)
					break;
				unsigned int chx = cx + tx * CHUNK_SIZE_X, chy = cy + ty * CHUNK_SIZE_Z;
				if (ChunkAt(chx, 1, chy) &&
					ChunkAt(chx, 1, chy)->IsDirty()) {
					updateThList[threads++] =
						std::async(std::launch::async,
							[](Chunk* chunk, BlockInfo* blockinfo[BTYPE_LAST], World* world) {
								chunk->Update(blockinfo, world); return chunk; }, ChunkAt(chx, 1, chy), blockinfo, this);
					if (threads == THREADS_UPDATE_CHUNKS) frameUpdate = FRAMES_UPDATE_CHUNKS;
				}
			}
			if (frameUpdate)
				break;
			++side;
		}

	if (threads > 0) {
		for (int i = 0; i < threads; ++i) {
			updateThList[i].wait();
			Chunk* chunk = updateThList[i].get();
			chunk->FlushMeshToVBO();
		}
	}

	threads = 0;

	int del = THREADS_DELETE_CHUNKS;
	while (!m_tbDeleted.empty() && del--) { // Moins rapide que le bout en dessous, mais -beaucoup- plus stable.
		m_tbDeleted.back()->FlushVBO();
		m_tbDeleted.back()->~Chunk();
		m_tbDeleted.pop_back();
	}

	/*while (!m_tbDeleted.empty() && !frameDelete) {
		if (m_tbDeleted.back()) {
			m_tbDeleted.back()->FlushVBO();
			delThList[threads] =
				std::async(std::launch::async,
					[](Chunk* chunk) { delete chunk; }, m_tbDeleted.back());
			m_tbDeleted.pop_back();
			if (++threads > THREADS_DELETE_CHUNKS) frameDelete = FRAMES_DELETE_CHUNKS;
		}
		else m_tbDeleted.pop_back();
	}*/

	for (int x = 0; x < threads; ++x) {
		delThList[x].wait();
		delThList[x].get();
	}
}

int World::GettbDeleted() const { return m_tbDeleted.size(); }