#include <AsynchronCall.h>
#include <InMemoryBuffer.h>

#include "Chunk.h"
#include "Constants.h"
#include "Game.h"
#include "NoBlock.h"

Chunk::Chunk(Framework::Punkt location, int dimensionId)
    : ReferenceCounter(),
      dimensionId(dimensionId),
      location(location),
      added(0),
      currentlyLoading(1)
{
    blocks = new Block*[CHUNK_SIZE * CHUNK_SIZE * WORLD_HEIGHT];
    blockIds = new unsigned short[CHUNK_SIZE * CHUNK_SIZE * WORLD_HEIGHT];
    lightData = new unsigned char[CHUNK_SIZE * CHUNK_SIZE * WORLD_HEIGHT * 6];
    memset(blocks, 0, CHUNK_SIZE * CHUNK_SIZE * WORLD_HEIGHT * sizeof(Block*));
    memset(blockIds,
        0,
        CHUNK_SIZE * CHUNK_SIZE * WORLD_HEIGHT * sizeof(unsigned short));
    memset(lightData, 0, CHUNK_SIZE * CHUNK_SIZE * WORLD_HEIGHT * 6);
    zNeighbours[0] = 0;
    zNeighbours[1] = 0;
    zNeighbours[2] = 0;
    zNeighbours[3] = 0;
}

Chunk::Chunk(Framework::Punkt location,
    int dimensionId,
    Framework::StreamReader* zReader)
    : Chunk(location, dimensionId)
{
    load(zReader);
}

Chunk::~Chunk()
{
    for (int i = 0; i < CHUNK_SIZE * CHUNK_SIZE * WORLD_HEIGHT; i++)
    {
        if (blocks[i]) blocks[i]->release();
    }
    delete[] blocks;
    delete[] blockIds;
    delete[] lightData;
}

void Chunk::lock()
{
    cs.lock();
}

void Chunk::unlock()
{
    cs.unlock();
}

void Chunk::tick(TickQueue* zQueue)
{
    for (Block* source : tickSources)
        zQueue->addToQueue(source);
}

void Chunk::postTick() {}

void Chunk::addLightSource(int index)
{
    for (int i : lightSources)
    {
        if (i == index) return;
    }
    lightSources.add(index);
}

void Chunk::removeLightSource(int index)
{
    for (auto i = lightSources.begin(); i; i++)
    {
        if (i.val() == index)
        {
            i.remove();
            return;
        }
    }
}

void Chunk::sendLightToClient(Framework::StreamWriter* zWriter)
{
    for (int z = 0; z < WORLD_HEIGHT; z++)
    {
        for (int x = -1; x <= CHUNK_SIZE; x++)
        {
            for (int y = -1; y <= CHUNK_SIZE; y++)
            {
                if ((x < 0 || x == CHUNK_SIZE) && (y < 0 || y > CHUNK_SIZE))
                {
                    continue;
                }
                bool needSend = 0;
                for (int i = 0; i < 6; i++)
                {
                    Vec3<int> pos = Vec3<int>(x, y, z)
                                  + getDirection(getDirectionFromIndex(i));
                    if (pos.z >= 0 && pos.z < WORLD_HEIGHT)
                    {
                        if (pos.x >= 0 && pos.x < CHUNK_SIZE && pos.y >= 0
                            && pos.y < CHUNK_SIZE)
                        {
                            int bi = (pos.x * CHUNK_SIZE + pos.y) * WORLD_HEIGHT
                                   + pos.z;
                            int type = blockIds[bi];
                            needSend |= type != BlockTypeEnum::NO_BLOCK
                                     && type != BlockTypeEnum::AIR;
                        }
                        else
                        {
                            if (x >= 0 && x < CHUNK_SIZE && y >= 0
                                && y < CHUNK_SIZE)
                            {
                                if (i < 4 && zNeighbours[i])
                                {
                                    Vec3<int> offset
                                        = getDirection(getDirectionFromIndex(i))
                                        * 16;
                                    int bi = ((pos.x - offset.x) * CHUNK_SIZE
                                                 + (pos.y - offset.y))
                                               * WORLD_HEIGHT
                                           + (pos.z - offset.z);
                                    int type = zNeighbours[i]->blockIds[bi];
                                    needSend |= type != BlockTypeEnum::NO_BLOCK
                                             && type != BlockTypeEnum::AIR;
                                }
                            }
                        }
                        if (needSend) break;
                    }
                }
                if (needSend)
                {
                    if (x >= 0 && x < CHUNK_SIZE && y >= 0 && y < CHUNK_SIZE)
                    {
                        int index = (x * CHUNK_SIZE + y) * WORLD_HEIGHT + z;
                        zWriter->schreibe((char*)&index, 4);
                        zWriter->schreibe((char*)(lightData + index * 6), 6);
                    }
                    else
                    {
                        int dir;
                        int index = 0;
                        if (x == -1)
                        {
                            dir = getDirectionIndex(WEST);
                            index = ((CHUNK_SIZE - 1) * CHUNK_SIZE + y)
                                      * WORLD_HEIGHT
                                  + z;
                        }
                        else if (y == -1)
                        {
                            dir = getDirectionIndex(NORTH);
                            index = (x * CHUNK_SIZE + CHUNK_SIZE - 1)

                                      * WORLD_HEIGHT
                                  + z;
                        }
                        else if (x == CHUNK_SIZE)
                        {
                            dir = getDirectionIndex(EAST);
                            index = y * WORLD_HEIGHT + z;
                        }
                        else if (y == CHUNK_SIZE)
                        {
                            dir = getDirectionIndex(SOUTH);
                            index = (x * CHUNK_SIZE) * WORLD_HEIGHT + z;
                        }
                        if (zNeighbours[dir])
                        {
                            int i = -1;
                            zWriter->schreibe((char*)&i, 4);
                            zWriter->schreibe((char*)&x, 4);
                            zWriter->schreibe((char*)&y, 4);
                            zWriter->schreibe((char*)&z, 4);
                            zWriter->schreibe(
                                (char*)(zNeighbours[dir]->lightData + index * 6),
                                6);
                        }
                    }
                }
            }
        }
    }
    int end = -2;
    zWriter->schreibe((char*)&end, 4);
}

void Chunk::broadcastLightData(int index, bool foreground)
{
    int x = (index / WORLD_HEIGHT) / CHUNK_SIZE;
    int y = (index / WORLD_HEIGHT) % CHUNK_SIZE;
    int z = index % WORLD_HEIGHT;
    NetworkMessage* msg = new NetworkMessage();
    msg->addressDimension(Game::INSTANCE->zDimension(dimensionId));
    char* message = new char[19];
    message[0] = 5;
    *(int*)(message + 1) = x + this->location.x - CHUNK_SIZE / 2;
    *(int*)(message + 5) = y + this->location.y - CHUNK_SIZE / 2;
    *(int*)(message + 9) = z;
    memcpy(message + 13, lightData + index * 6, 6);
    msg->setMessage(message, 19);
    if (!foreground) msg->setUseBackground();
    notifyObservers(msg);
}

Framework::Either<Block*, int> Chunk::zBlockNeighbor(
    Framework::Vec3<int> location)
{
    if (location.x >= 0 && location.x < CHUNK_SIZE && location.y >= 0
        && location.y < CHUNK_SIZE && location.z >= 0
        && location.z < WORLD_HEIGHT)
    {
        int index = (location.x * CHUNK_SIZE + location.y) * WORLD_HEIGHT
                  + location.z;
        if (blocks[index])
            return blocks[index];
        else
            return (int)blockIds[index];
    }
    if (added && location.z >= 0 && location.z < WORLD_HEIGHT)
        return Game::INSTANCE->zBlockAt(
            {location.x + this->location.x - CHUNK_SIZE / 2,
                location.y + this->location.y - CHUNK_SIZE / 2,
                location.z},
            dimensionId);
    return 0;
}

void Chunk::notifyObservers(NetworkMessage* msg)
{
    Array<int> remove;
    int index = 0;
    for (int id : observers)
    {
        Entity* zE = Game::INSTANCE->zEntity(id);
        if (!zE)
            remove.add(index, 0);
        else
            Game::INSTANCE->sendMessage(
                dynamic_cast<NetworkMessage*>(msg->getThis()), zE);
        index++;
    }
    for (int i : remove)
        observers.remove(i);
    msg->release();
}

void Chunk::addObserver(Entity* zEntity, DoLaterHandler& laterHandler)
{
    for (int id : observers)
    {
        if (id == zEntity->getId()) return;
    }
    int id = zEntity->getId();
    observers.add(id);
    laterHandler.addTodo([this, id]() {
        InMemoryBuffer buffer;
        buffer.schreibe("\4", 1);
        buffer.schreibe((char*)&location.x, 4);
        buffer.schreibe((char*)&location.y, 4);
        sendToClient(&buffer);
        sendLightToClient(&buffer);
        NetworkMessage* msg = new NetworkMessage();
        msg->addressDimension(Game::INSTANCE->zDimension(dimensionId));
        std::cout << "chunk size: " << buffer.getSize() << "b\n";
        char* message = new char[buffer.getSize()];
        buffer.lese(message, (int)buffer.getSize());
        msg->setMessage(message, (int)buffer.getSize());
        msg->setUseBackground();
        Entity* e = Game::INSTANCE->zEntity(id);
        if (e)
        {
            Game::INSTANCE->sendMessage(msg, e);
        }
        else
            msg->release();
    });
}

void Chunk::removeObserver(Entity* zEntity)
{
    int index = 0;
    for (int id : observers)
    {
        if (id == zEntity->getId())
        {
            observers.remove(index);
            return;
        }
        index++;
    }
}

void Chunk::api(Framework::StreamReader* zRequest,
    Entity* zSource,
    DoLaterHandler& laterHandler)
{
    // TODO: answer api messages
    char type;
    zRequest->lese(&type, 1);
    switch (type)
    {
    case 0:
        // register observer
        addObserver(zSource, laterHandler);
        break;
    case 1:
        // unsubscribe
        removeObserver(zSource);
        break;
    }
}

void Chunk::initializeLightning()
{
    unsigned char dayLight[6] = {255, 255, 255, 0, 0, 0};
    unsigned char noLight[6] = {0, 0, 0, 0, 0, 0};
    while (true)
    {
        bool changes = false;
        for (int z = WORLD_HEIGHT - 1; z >= 0; z--)
        {
            for (int x = 0; x < CHUNK_SIZE; x++)
            {
                for (int y = 0; y < CHUNK_SIZE; y++)
                {
                    int index = (x * CHUNK_SIZE + y) * WORLD_HEIGHT + z;
                    unsigned char* light = getLightData(Vec3<int>(x, y, z));
                    unsigned char newLight[6] = {0, 0, 0, 0, 0, 0};
                    for (int i = 0; i < 6; i++)
                    {
                        unsigned char* neighborLeight;
                        Vec3<int> neighborPos
                            = Vec3<int>(x, y, z)
                            + getDirection(getDirectionFromIndex(i));
                        if (neighborPos.z < 0 || neighborPos.x < 0
                            || neighborPos.y < 0 || neighborPos.x >= CHUNK_SIZE
                            || neighborPos.y >= CHUNK_SIZE)
                        {
                            neighborLeight = noLight;
                        }
                        else if (neighborPos.z >= WORLD_HEIGHT)
                        {
                            neighborLeight = dayLight;
                        }
                        else
                        {
                            neighborLeight = getLightData(neighborPos);
                        }
                        for (int j = 0; j < 3; j++)
                            newLight[j] = (unsigned char)MAX(newLight[j],
                                i == getDirectionIndex(TOP)
                                    ? neighborLeight[j]
                                    : (unsigned char)((float)neighborLeight[j]
                                                      * 0.8f));
                        for (int j = 3; j < 6; j++)
                            newLight[j] = (unsigned char)MAX(newLight[j],
                                (unsigned char)((float)neighborLeight[j]
                                                * 0.85f));
                    }
                    const Block* current
                        = blocks[index] ? blocks[index]
                                        : StaticRegistry<BlockType>::INSTANCE
                                              .zElement(blockIds[index])
                                              ->zDefault();
                    // add own light emission
                    for (int j = 3; j < 6; j++)
                        newLight[j] = (unsigned char)MAX(newLight[j],
                            current->getLightEmisionColor()[j - 3]);
                    current->filterPassingLight(newLight);
                    current->filterPassingLight(newLight + 3);
                    for (int i = 0; i < 6; i++)
                    {
                        if (newLight[i] != light[i])
                        {
                            changes = 1;
                            memcpy(light, newLight, 6);
                            break;
                        }
                    }
                }
            }
        }
        if (!changes) break;
    }
}

Framework::Either<Block*, int> Chunk::zBlockAt(
    Framework::Vec3<int> location) const
{
    int index
        = (location.x * CHUNK_SIZE + location.y) * WORLD_HEIGHT + location.z;
    assert(index < CHUNK_SIZE * CHUNK_SIZE * WORLD_HEIGHT);
    if (blocks[index])
        return blocks[index];
    else
        return (int)blockIds[index];
}

const Block* Chunk::zBlockConst(Framework::Vec3<int> location) const
{
    auto b = zBlockAt(location);
    if (b.isA()) return b;
    if (b.getB())
        return StaticRegistry<BlockType>::INSTANCE.zElement(b.getB())
            ->zDefault();
    return 0;
}

void Chunk::instantiateBlock(Framework::Vec3<int> location)
{
    auto b = zBlockAt(location);
    if (b.isA()) return;
    if (!b.getB()) generateBlock(location);
    b = zBlockAt(location);
    if (b.isB())
        putBlockAt(location,
            StaticRegistry<BlockType>::INSTANCE.zElement(b.getB())
                ->createBlockAt(
                    {location.x + this->location.x - CHUNK_SIZE / 2,
                        location.y + this->location.y - CHUNK_SIZE / 2,
                        location.z},
                    0));
}

void Chunk::generateBlock(Framework::Vec3<int> location)
{
    int index
        = (location.x * CHUNK_SIZE + location.y) * WORLD_HEIGHT + location.z;
    if (blockIds[index]) return;
    auto generated = Game::INSTANCE->zGenerator()->generateSingleBlock(
        {location.x + this->location.x - CHUNK_SIZE / 2,
            location.y + this->location.y - CHUNK_SIZE / 2,
            location.z},
        dimensionId);
    if (generated.isA())
        putBlockAt(location, generated);
    else
        putBlockTypeAt(location, generated);
}

void Chunk::putBlockAt(Framework::Vec3<int> location, Block* block)
{
    int index
        = (location.x * CHUNK_SIZE + location.y) * WORLD_HEIGHT + location.z;
    assert(index < CHUNK_SIZE * CHUNK_SIZE * WORLD_HEIGHT && index >= 0);
    Block* old = blocks[index];
    if (old && old->isTickSource())
    { // remove from tick sorces
        for (Framework::Iterator<Block*> obj = tickSources.begin(); obj; obj++)
        {
            if (obj.val() == old)
            {
                obj.remove();
                break;
            }
        }
    }
    bool change = 0;
    bool wasLightSource
        = old ? old->zBlockType()->isLightSource()
              : StaticRegistry<BlockType>::INSTANCE.zElement(blockIds[index])
                    ->isLightSource();
    bool isLightSource = 0;
    if (block)
    {
        change
            = blockIds[index] != (unsigned short)block->zBlockType()->getId();
        blockIds[index] = (unsigned short)block->zBlockType()->getId();
        isLightSource = block->zBlockType()->isLightSource();
    }
    else
    {
        if (old != 0)
        {
            blockIds[index] = BlockTypeEnum::NO_BLOCK;
        }
        change = old != 0;
    }
    blocks[index] = block;
    for (int i = 0; i < 6; i++)
    {
        Direction d = getDirectionFromIndex(i);
        Either<Block*, int> neighbor
            = zBlockNeighbor(location + getDirection(d));
        if (neighbor.isA())
        {
            if (block)
            {
                ((Block*)neighbor)
                    ->setNeighbour(getOppositeDirection(d), block);
            }
            else
            {
                ((Block*)neighbor)
                    ->setNeighbour(getOppositeDirection(d), blockIds[index]);
            }
        }
        if (block) block->setNeighbour(d, neighbor);
    }
    if (old) old->release();
    if (block && block->isTickSource())
    { // add to tick sources
        tickSources.add(block);
    }
    if (change)
    {
        if (isLightSource != wasLightSource)
        {
            if (isLightSource)
                addLightSource(index);
            else
                removeLightSource(index);
        }
        if (added)
        {
            sendBlockInfo(location);
            if (block)
            {
                Game::INSTANCE->updateLightningWithoutWait(getDimensionId(),
                    Vec3<int>(location.x + this->location.x - CHUNK_SIZE / 2,
                        location.y + this->location.y - CHUNK_SIZE / 2,
                        location.z));
            }
        }
    }
}

void Chunk::putBlockTypeAt(Framework::Vec3<int> location, int type)
{
    int index
        = (location.x * CHUNK_SIZE + location.y) * WORLD_HEIGHT + location.z;
    assert(index < CHUNK_SIZE * CHUNK_SIZE * WORLD_HEIGHT);
    bool wasLightSource
        = StaticRegistry<BlockType>::INSTANCE.zElement(blockIds[index])
              ->isLightSource();
    bool isLightSource
        = StaticRegistry<BlockType>::INSTANCE.zElement(type)->isLightSource();
    if (blockIds[index] != (unsigned short)type)
    {
        blockIds[index] = (unsigned short)type;
        for (int i = 0; i < 6; i++)
        {
            Direction d = getDirectionFromIndex(i);
            Either<Block*, int> neighbor
                = zBlockNeighbor(location + getDirection(d));
            if (neighbor.isA())
                ((Block*)neighbor)
                    ->setNeighbourType(getOppositeDirection(d), type);
        }
        if (isLightSource != wasLightSource)
        {
            if (isLightSource)
                addLightSource(index);
            else
                removeLightSource(index);
        }
        if (added)
        {
            sendBlockInfo(location);
            Game::INSTANCE->updateLightningWithoutWait(getDimensionId(),
                Vec3<int>(location.x + this->location.x - CHUNK_SIZE / 2,
                    location.y + this->location.y - CHUNK_SIZE / 2,
                    location.z));
        }
    }
}

void Chunk::sendBlockInfo(Framework::Vec3<int> location)
{
    int index
        = (location.x * CHUNK_SIZE + location.y) * WORLD_HEIGHT + location.z;
    char* msg = new char[9];
    msg[0] = 0; // set block
    *(int*)(msg + 1) = index;
    *(int*)(msg + 5) = blockIds[index];
    NetworkMessage* message = new NetworkMessage();
    message->addressChunck(this);
    message->setMessage(msg, 9);
    notifyObservers(message);
    for (int i = 0; i < 6; i++)
    {
        Direction d = getDirectionFromIndex(i);
        Framework::Vec3<int> loc = location + getDirection(d);
        if (loc.x >= 0 && loc.x < CHUNK_SIZE && loc.y >= 0 && loc.y < CHUNK_SIZE
            && loc.z >= 0 && loc.z < WORLD_HEIGHT)
        {
            int index
                = (loc.x * CHUNK_SIZE + loc.y) * WORLD_HEIGHT + loc.z;
            broadcastLightData(index, true);
        }
        else if (loc.z >= 0 && loc.z < WORLD_HEIGHT && i < 4 && zNeighbours[i])
        {
            NetworkMessage* msg = new NetworkMessage();
            msg->addressDimension(Game::INSTANCE->zDimension(dimensionId));
            char* message = new char[19];
            message[0] = 5;
            *(int*)(message + 1) = loc.x + this->location.x - CHUNK_SIZE / 2;
            *(int*)(message + 5) = loc.y + this->location.y - CHUNK_SIZE / 2;
            *(int*)(message + 9) = loc.z;
            loc -= getDirection(d) * CHUNK_SIZE;
            memcpy(message + 13, zNeighbours[i]->getLightData(loc), 6);
            msg->setMessage(message, 19);
            notifyObservers(msg);
        }
    }
}

void Chunk::setNeighbor(Direction dir, Chunk* zChunk)
{
    zNeighbours[getDirectionIndex(dir)] = zChunk;
    for (int i = 0; i < CHUNK_SIZE; i++)
    {
        for (int z = 0; z < WORLD_HEIGHT; z++)
        {
            int index = 0;
            int j = 0;
            if (dir == NORTH)
            {
                index = i * CHUNK_SIZE * WORLD_HEIGHT + z;
                j = (i * CHUNK_SIZE + CHUNK_SIZE - 1) * WORLD_HEIGHT + z;
            }
            else if (dir == EAST)
            {
                index = ((CHUNK_SIZE - 1) * CHUNK_SIZE + i) * WORLD_HEIGHT + z;
                j = i * WORLD_HEIGHT + z;
            }
            else if (dir == SOUTH)
            {
                index = (i * CHUNK_SIZE + CHUNK_SIZE - 1) * WORLD_HEIGHT + z;
                j = i * CHUNK_SIZE * WORLD_HEIGHT + z;
            }
            else if (dir == WEST)
            {
                index = i * WORLD_HEIGHT + z;
                j = ((CHUNK_SIZE - 1) * CHUNK_SIZE + i) * WORLD_HEIGHT + z;
            }
            if (blocks[index])
            {
                if (zChunk && zChunk->blocks[j])
                    blocks[index]->setNeighbour(dir, zChunk->blocks[j]);
                else
                {
                    blocks[index]->setNeighbour(dir, 0);
                    blocks[index]->setNeighbourType(
                        dir, zChunk ? zChunk->blockIds[j] : 0);
                }
            }
            if (zChunk)
            {
                if (!blocks[index])
                {
                    if (zChunk->blockIds[j] == BlockTypeEnum::AIR
                        && !blockIds[index])
                    {
                        generateBlock(
                            Vec3<int>((index / WORLD_HEIGHT) / CHUNK_SIZE,
                                (index / WORLD_HEIGHT) % CHUNK_SIZE,
                                index % WORLD_HEIGHT));
                    }
                }
                if (blockIds[index] != BlockTypeEnum::AIR
                    && blockIds[index] != BlockTypeEnum::NO_BLOCK)
                {
                    zChunk->broadcastLightData(j, true);
                }
            }
        }
    }
}

void Chunk::load(Framework::StreamReader* zReader)
{
    for (int index = 0; index < WORLD_HEIGHT * CHUNK_SIZE * CHUNK_SIZE; index++)
    {
        unsigned short blockType;
        zReader->lese((char*)&blockType, 2);
        if (blockType)
        {
            Framework::Vec3<int> pos
                = Framework::Vec3<int>((index / WORLD_HEIGHT) / CHUNK_SIZE,
                    (index / WORLD_HEIGHT) % CHUNK_SIZE,
                    index % WORLD_HEIGHT);
            bool d;
            zReader->lese((char*)&d, 1);
            if (d)
            {
                putBlockAt(pos,
                    StaticRegistry<BlockType>::INSTANCE.zElement(blockType)
                        ->loadBlock(Framework::Vec3<int>(
                                        pos.x + location.x - CHUNK_SIZE / 2,
                                        pos.y + location.y - CHUNK_SIZE / 2,
                                        pos.z),
                            zReader,
                            dimensionId));
            }
            else
            {
                putBlockTypeAt(pos, blockType);
            }
        }
    }
    initializeLightning();
}

void Chunk::save(Framework::StreamWriter* zWriter)
{
    for (int index = 0; index < WORLD_HEIGHT * CHUNK_SIZE * CHUNK_SIZE; index++)
    {
        unsigned short blockType
            = blocks[index]
                ? (unsigned short)blocks[index]->zBlockType()->getId()
                : blockIds[index];
        zWriter->schreibe((char*)&blockType, 2);
        if (blockType)
        {
            if (blocks[index])
            {
                bool d = 1;
                zWriter->schreibe((char*)&d, 1);
                StaticRegistry<BlockType>::INSTANCE.zElement(blockType)
                    ->saveBlock(blocks[index], zWriter);
            }
            else
            {
                bool d = 0;
                zWriter->schreibe((char*)&d, 1);
            }
        }
    }
}

void Chunk::sendToClient(Framework::StreamWriter* zWriter)
{
    for (int x = 0; x < CHUNK_SIZE; x++)
    {
        for (int y = 0; y < CHUNK_SIZE; y++)
        {
            for (int z = 0; z < WORLD_HEIGHT; z++)
            {
                int index = (x * CHUNK_SIZE + y) * WORLD_HEIGHT + z;
                unsigned short blockType
                    = blocks[index]
                        ? (unsigned short)blocks[index]->zBlockType()->getId()
                        : blockIds[index];
                if (blockType)
                {
                    bool visible = 0;
                    if (!visible)
                    {
                        if (!blocks[index])
                        {
                            if (CONST_BLOCK(0, blockIds[index])->isTransparent()
                                || CONST_BLOCK(0, blockIds[index])
                                       ->isPassable())
                                visible = 1;
                            else
                            {
                                for (int d = 0; d < 6 && !visible; d++)
                                {
                                    Vec3<int> pos
                                        = getDirection(
                                              (Directions)getDirectionFromIndex(
                                                  d))
                                        + Framework::Vec3<int>(x, y, z);
                                    auto n = zBlockNeighbor(pos);
                                    if (n.isA()
                                        && (((Block*)n)->isPassable()
                                            || ((Block*)n)->isTransparent()))
                                        visible = 1;
                                    if (n.isB()
                                        && (CONST_BLOCK(0, n)->isTransparent()
                                            || CONST_BLOCK(0, n)->isPassable()))
                                        visible = 1;
                                    if (pos.x < 0 || pos.y < 0 || pos.z < 0
                                        || pos.x >= CHUNK_SIZE
                                        || pos.y >= CHUNK_SIZE
                                        || pos.z >= WORLD_HEIGHT)
                                        visible = 1;
                                }
                            }
                        }
                        else
                            visible = blocks[index]->isVisible();
                    }
                    if (visible
                        && (blocks[index] || blockType != BlockTypeEnum::AIR))
                    {
                        zWriter->schreibe((char*)&blockType, 2);
                        zWriter->schreibe((char*)&index, 4);
                    }
                }
            }
        }
    }
    unsigned short end = 0;
    zWriter->schreibe((char*)&end, 2);
}

void Chunk::removeUnusedBlocks()
{
    for (int i = 0; i < CHUNK_SIZE * CHUNK_SIZE * WORLD_HEIGHT; i++)
    {
        if (!blocks[i] && blockIds[i])
        {
            int x = (i / WORLD_HEIGHT) / CHUNK_SIZE;
            int y = (i / WORLD_HEIGHT) % CHUNK_SIZE;
            int z = i % WORLD_HEIGHT;
            bool visible = 0;
            if (CONST_BLOCK(0, blockIds[i])->isTransparent()
                || CONST_BLOCK(0, blockIds[i])->isPassable())
                visible = 1;
            else
            {
                for (int d = 0; d < 6 && !visible; d++)
                {
                    auto n = zBlockNeighbor(
                        getDirection((Directions)getDirectionFromIndex(d))
                        + Framework::Vec3<int>(x, y, z));
                    if (n.isA()
                        && (((Block*)n)->isPassable()
                            || ((Block*)n)->isTransparent()))
                        visible = 1;
                    if (n.isB()
                        && (CONST_BLOCK(0, n)->isTransparent()
                            || CONST_BLOCK(0, n)->isPassable()))
                        visible = 1;
                }
            }
            if (!visible)
            {
                putBlockAt({x, y, z}, 0);
            }
        }
    }
    int count = 0;
    for (int i = 0; i < CHUNK_SIZE * CHUNK_SIZE * WORLD_HEIGHT; i++)
    {
        if (blockIds[i] && blockIds[i] != BlockTypeEnum::AIR) count++;
    }
    std::cout << "chunk " << location.x << ", " << location.y
              << " was generated with " << count << " blocks.\n";
}

int Chunk::getDimensionId() const
{
    return dimensionId;
}

void Chunk::onLoaded()
{
    for (int i = 0; i < CHUNK_SIZE * CHUNK_SIZE * WORLD_HEIGHT; i++)
    {
        if (blocks[i]) blocks[i]->onLoaded();
    }
    currentlyLoading = 0;
}

void Chunk::onUnloaded()
{
    for (int i = 0; i < CHUNK_SIZE * CHUNK_SIZE * WORLD_HEIGHT; i++)
    {
        if (blocks[i]) blocks[i]->onUnloaded();
    }
}

Framework::Punkt Chunk::getCenter() const
{
    return location;
}

Framework::Vec3<int> Chunk::getMin() const
{
    return {location.x - CHUNK_SIZE / 2, location.y - CHUNK_SIZE / 2, 0};
}

Framework::Vec3<int> Chunk::getMax() const
{
    return {
        location.x + CHUNK_SIZE / 2, location.y + CHUNK_SIZE / 2, WORLD_HEIGHT};
}

void Chunk::prepareRemove()
{
    added = 0;
    for (int i = 0; i < 4; i++)
    {
        if (zNeighbours[i])
        {
            zNeighbours[i]->setNeighbor(
                getOppositeDirection(getDirectionFromIndex(i)), 0);
            zNeighbours[i] = 0;
        }
    }
}

void Chunk::setAdded()
{
    added = 1;
}

bool Chunk::hasObservers() const
{
    return observers.getEintragAnzahl() > 0 || currentlyLoading;
}

unsigned char* Chunk::getLightData(Framework::Vec3<int> location) const
{
    int index
        = ((location.x * CHUNK_SIZE + location.y) * WORLD_HEIGHT + location.z)
        * 6;
    assert(index < CHUNK_SIZE * CHUNK_SIZE * WORLD_HEIGHT);
    return lightData + index;
}

void Chunk::setLightData(
    Framework::Vec3<int> location, unsigned char* data, bool foreground)
{
    int index
        = (location.x * CHUNK_SIZE + location.y) * WORLD_HEIGHT + location.z;
    memcpy(lightData + index * 6, data, 6);
    // check if neighbor is a visible block and send update to clients
    bool needSend = 0;
    for (int i = 0; i < 6; i++)
    {
        Vec3<int> pos = location + getDirection(getDirectionFromIndex(i));
        if (pos.z >= 0 && pos.z < WORLD_HEIGHT)
        {
            if (pos.x >= 0 && pos.x < CHUNK_SIZE && pos.y >= 0
                && pos.y < CHUNK_SIZE)
            {
                int bi = (pos.x * CHUNK_SIZE + pos.y) * WORLD_HEIGHT + pos.z;
                int type = blockIds[bi];
                needSend |= type != BlockTypeEnum::NO_BLOCK
                         && type != BlockTypeEnum::AIR;
                if (needSend) break;
            }
            else
            {
                needSend = 1; // TODO: check if the block is visible
            }
        }
    }
    if (needSend)
    {
        broadcastLightData(index, foreground);
    }
}