#include "world.h"

World::World(){}

World::~World(){}

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

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) {
    int x = 0;
    int y = 0;

    if (player.GetPosition().x > (WORLD_SIZE_X * CHUNK_SIZE_X) * .66f) ++x;
    else if (player.GetPosition().x < (WORLD_SIZE_X * CHUNK_SIZE_X) * .33f) --x;
    if (player.GetPosition().z > (WORLD_SIZE_Y * CHUNK_SIZE_Z) * .66f) ++y;
    else if (player.GetPosition().z < (WORLD_SIZE_Y * CHUNK_SIZE_Z) * .33f) --y;

    if (!x && !y) return;

    if (x != 0) 
        for (int ay = 0; ay < WORLD_SIZE_Y; ++ay) 
            for (int ax = 0; ax < abs(x); ++ay)
                if (ChunkAt(x < 0 ? (WORLD_SIZE_X - 1 - ax) * WORLD_SIZE_X : ax, 1, ay * WORLD_SIZE_Y))
                    m_tbDeleted.push_back(std::move(m_chunks.Get(x < 0? WORLD_SIZE_X - 1 - ax: ax, ay)));
    if (y != 0) 
        for (int ax = 0; ax < WORLD_SIZE_X; ++ax)
            for (int ay = 0; ay < abs(y); ++ay)
                if (ChunkAt(ax * WORLD_SIZE_X , 1, y < 0 ? (WORLD_SIZE_Y - 1 - ay) * WORLD_SIZE_Y : ay))
                    m_tbDeleted.push_back(std::move(m_chunks.Get(ax, y < 0 ? WORLD_SIZE_Y - 1 - ay: ay)));
    
    for (int ax = 0; ax < WORLD_SIZE_X; ++ax)
        for (int ay = 0; ay < WORLD_SIZE_Y; ++ay) 
            if (ax + x < WORLD_SIZE_X && ax + x > 0 &&
                ay + y < WORLD_SIZE_Y && ay + y > 0)
                m_chunks.Set(x > 0? ax: ax + x, y > 0? ay: ay + y, 
                    m_chunks.Get(x < 0 ? ax : ax + x, y < 0 ? ay : ay + y));
    if (x != 0) 
        for (int ay = 0; ay < WORLD_SIZE_Y; ++ay)
            for (int ax = 0; ax < abs(x); ++ay)
                m_chunks.Set(x > 0 ? WORLD_SIZE_X - 1 - ax : ax, ay, nullptr);
    if (y != 0) 
        for (int ax = 0; ax < WORLD_SIZE_X; ++ax)
            for (int ay = 0; ay < abs(y); ++ay)
                m_chunks.Set(ax, y > 0 ? WORLD_SIZE_Y - 1 - ay : ay, nullptr);
    
    m_center[0] += x; m_center[1] += y;
    player.Transpose(x, y);
}

void World::CleanUpWorld(int& deleteframes, bool clear = false) {
	if (clear) m_tbDeleted.clear();
    if (!m_tbDeleted.empty() && !deleteframes) {
        m_tbDeleted.pop_back();
        deleteframes = FRAMES_DELETE_CHUNKS;
    }
}

Chunk* World::RetrieveChunk(int x, int y) {
    for (int index = 0; index < m_tbDeleted.size(); ++index) {
        int cx, cy;
        m_tbDeleted.at(index)->GetPosition(cx, cy);

        if (cx == x && cy == y) 
            return std::move(m_tbDeleted.at(index));
    }

    return nullptr;
}

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

void World::Update(int& rendercount, int& badhitcount, Player& player, Transformation& world, Shader& shader, TextureAtlas& atlas, Perlin& perlin, BlockInfo* blockinfo[BTYPE_LAST]) {
	atlas.Bind();
	TransposeWorld(player);
	RenderWorld(rendercount, badhitcount, player, world, shader);
	UpdateWorld(player, perlin, blockinfo);
	shader.Disable();
}

bool World::GenerateChunk(int chx, int chy, Perlin& perlin) {
	if (chx < WORLD_SIZE_X * CHUNK_SIZE_X && chy < WORLD_SIZE_Y * CHUNK_SIZE_Z &&
		chx >= 0 && chy >= 0)
		if (!ChunkAt(chx, 1, chy)) {

			for (int index = 0; index < m_tbDeleted.size(); ++index) { // Vérifie l'existence d'un chunk dans le buffer de suppression avec sa position.
				int x, y;
				m_tbDeleted.at(index)->GetPosition(x, y);
					if (chx / CHUNK_SIZE_X + m_center[0] == x && 
						chy / CHUNK_SIZE_Z + m_center[1] == y) {
						GetChunks().Set(chx / CHUNK_SIZE_X, chy / CHUNK_SIZE_Z, std::move(m_tbDeleted.at(index)));
						return true;
					}
			}

			std::ostringstream pos; // Vérifie l'existence d'un fichier .chunk avec sa position.
			pos << CHUNK_PATH << chx / CHUNK_SIZE_X + m_center[0] << '_' << chy / CHUNK_SIZE_Z + m_center[1] << ".chunk";

			std::ifstream input(pos.str().c_str(), std::fstream::binary);

			if (input.fail()) {
				GetChunks().Set(chx / CHUNK_SIZE_X, chy / CHUNK_SIZE_Z, new Chunk(chx / CHUNK_SIZE_X + m_center[0], chy / CHUNK_SIZE_Z + m_center[1]));
				Chunk* chunk = GetChunks().Get(chx / CHUNK_SIZE_X, chy / CHUNK_SIZE_Z);

				for (int x = 0; x < CHUNK_SIZE_X; ++x)
					for (int z = 0; z < CHUNK_SIZE_Z; ++z) {
						Vector3f noise;
						noise.x = x * (CHUNK_SIZE_X + 1) + (CHUNK_SIZE_X - 1) * (chx + m_center[0]);
						noise.y = 0;
						noise.z = z * (CHUNK_SIZE_Z + 1) + (CHUNK_SIZE_Z - 1) * (chy + m_center[1]);
						noise.Normalize();
						float height = perlin.Get(noise.x, noise.z) * 3 - 32;
						for (int y = 0; y <= (int)height % CHUNK_SIZE_Y; ++y) 
							chunk->SetBlock(x, y, z, BTYPE_METAL, this);
					}

				for (int x = 0; x < CHUNK_SIZE_X; ++x)
					for (int z = 0; z < CHUNK_SIZE_Z; ++z) {
						Vector3f noise;
						noise.x = x * (CHUNK_SIZE_X + 1) + (CHUNK_SIZE_X - 1) * (chx + m_center[0]);
						noise.y = 0;
						noise.z = z * (CHUNK_SIZE_Z + 1) + (CHUNK_SIZE_Z - 1) * (chy + m_center[1]);
						noise.Normalize();
						float height = perlin.Get(noise.x, noise.z) + 16;
						for (int y = 0; y <= (int)height % CHUNK_SIZE_Y; ++y) {
							if (chunk->GetBlock(x, y, z) == BTYPE_AIR)
								chunk->SetBlock(x, y, z, BTYPE_GRASS, this);
						}
					}

				for (int x = 0; x < CHUNK_SIZE_X; ++x)
					for (int z = 0; z < CHUNK_SIZE_Z; ++z) {
						for (int y = 0; y <= 10; ++y) {
							if (chunk->GetBlock(x, y, z) == BTYPE_AIR)
								chunk->SetBlock(x, y, z, BTYPE_ICE, this);
						}
					}

				for (int x = 0; x < CHUNK_SIZE_X; ++x)
					for (int z = 0; z < CHUNK_SIZE_Z; ++z) {
						for (int y = 0; y < CHUNK_SIZE_Y; ++y) {
							Vector3f noise;
							noise.x = x * (CHUNK_SIZE_X + 1) + (CHUNK_SIZE_X - 1) * (chx + m_center[0]);
							noise.y = (x + z) * CHUNK_SIZE_Y + m_center[0];
							noise.z = z * (CHUNK_SIZE_Z + 1) + (CHUNK_SIZE_Z - 1) * (chy + m_center[1]);
							noise.Normalize();
							float height = perlin.Get(noise.x, noise.y, noise.z);
							if (chunk->GetBlock(x, y, z) != BTYPE_AIR && height > 18)
								chunk->SetBlock(x, y, z, BTYPE_DIRT, this);
						}
					}
			}
			else {
				input.seekg(0, std::ios_base::end);
				int size = input.tellg();
				input.seekg(0, std::ios_base::beg);

				char* data = new char[size];
				input.read(data, size);
				input.close();

				GetChunks().Set(chx / CHUNK_SIZE_X, chy / CHUNK_SIZE_Z, new Chunk(chx / CHUNK_SIZE_X + m_center[0], chy / CHUNK_SIZE_Z + m_center[1], data));

				delete[] data;
			}
			std::cout << "Chunk generated: " << chx / CHUNK_SIZE_X + m_center[0] << ", " << chy / CHUNK_SIZE_Z + m_center[1] << std::endl;

			return true;
		}
	return false;
}

void World::UpdateChunk(int& generates, int& updates, int chx, int chy, Perlin& perlin, BlockInfo* blockinfo[BTYPE_LAST]) {
	if (generates == 0 && GenerateChunk(chx, chy, perlin)) generates = FRAMES_RENDER_CHUNKS;
	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::RenderWorld(int& rendercount, int& badhitcount, Player& player, Transformation& world, Shader& shader) {
	shader.Use();
	rendercount = 0;
	badhitcount = 0;
	static std::vector<Vector3i> renderManifest;
	Vector3f angle;
	Vector3f cursor;
	Vector3f direct = player.GetDirection();
	Vector3f pos = player.GetPosition() - direct;

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

	for (int dist = VIEW_DISTANCE; dist >= 0; dist -= CHUNK_SIZE_X) {
		// Configuration du radar.
		angle.x = direct.z + direct.x;
		angle.y = 0;
		angle.z = direct.z - direct.x;
		angle.Normalize();

		float sinus = .01745240643; // sin(1 degré)
		float cosinus = .99984769515; // cos(1 degré)
		int echantillons = 90;

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

			angle.x = x * cosinus - z * sinus;
			angle.z = 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 = 1;

			bool valide = true;

			if (ChunkAt(cursor)) {
				int chx, chy;
				ChunkAt(cursor)->GetPosition(chx, chy);
				for (int index = 0; index < renderManifest.size(); ++index)
					if (renderManifest[index] == Vector3i(chx, 0, chy)) {
						valide = false;
						++badhitcount;
					}

				if (valide) {
					world.ApplyTranslation((chx - m_center[0]) * CHUNK_SIZE_X, 0, (chy - m_center[1]) * CHUNK_SIZE_Z);
					world.Use();
					float dist = (pos - cursor).Length();
					float blend = ((float)VIEW_DISTANCE - dist * 2.f + 128.f) / (float)VIEW_DISTANCE;
					glBlendColor(0.f, 0.f, 0.f, blend);
					ChunkAt(cursor)->Render();
					world.ApplyTranslation(-(chx - m_center[0]) * CHUNK_SIZE_X, 0, -(chy - m_center[1]) * CHUNK_SIZE_Z);
					renderManifest.push_back(Vector3i(chx, 0, chy));
					++rendercount;
				}
			}
		}
	}
	shader.Disable();
};

void World::UpdateWorld(Player& player, Perlin& perlin, BlockInfo* blockinfo[BTYPE_LAST]) {
	int cx = player.GetPosition().x;
	int cy = player.GetPosition().z;
	static int frameGenerate = 0;
	static int frameUpdate = 0;
	static int frameDelete = 0;
	int side = 0;

	if (frameGenerate > 0) --frameGenerate;
	if (frameUpdate > 0) --frameUpdate;
	if (frameDelete > 0) --frameDelete;

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

			for (; tx <= side; ++tx)
				UpdateChunk(frameGenerate, frameUpdate, cx + tx * CHUNK_SIZE_X, cy + ty * CHUNK_SIZE_Z, perlin, blockinfo);
			for (; ty <= side; ++ty)
				UpdateChunk(frameGenerate, frameUpdate, cx + tx * CHUNK_SIZE_X, cy + ty * CHUNK_SIZE_Z, perlin, blockinfo);
			for (; tx >= -side; --tx)
				UpdateChunk(frameGenerate, frameUpdate, cx + tx * CHUNK_SIZE_X, cy + ty * CHUNK_SIZE_Z, perlin, blockinfo);
			for (; ty >= -side; --ty)
				UpdateChunk(frameGenerate, frameUpdate, cx + tx * CHUNK_SIZE_X, cy + ty * CHUNK_SIZE_Z, perlin, blockinfo);

			++side;
		}

	CleanUpWorld(frameDelete);
}