#include "chunk.h"

Chunk::Chunk() { m_blocks.Reset(BTYPE_AIR); }

Chunk::~Chunk() { }

void Chunk::RemoveBlock(int x, int y, int z) {
    m_blocks.Set(x, y, z, BTYPE_AIR);
    m_isDirty = true;
}

void Chunk::SetBlock(int x, int y, int z, BlockType type) {
    m_blocks.Set(x, y, z, type);
    m_isDirty = true;
}

BlockType Chunk::GetBlock(int x, int y, int z) { return m_blocks.Get(x, y, z); }

void Chunk::Update() {
    // Update mesh
    if (m_isDirty) {
        int maxVertexCount = (CHUNK_SIZE_X * CHUNK_SIZE_Y * CHUNK_SIZE_Z) * (6 * 4);
        VertexBuffer::VertexData* vd = new VertexBuffer::VertexData[maxVertexCount];
        int count = 0;
        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) {
                    if (count > USHRT_MAX)
                        break;
                    BlockType bt = GetBlock(x, y, z);
                    if (bt != BTYPE_AIR) {
                        AddBlockToMesh(vd, count, bt, x, y, z);
                    }
                }
            }
        }
        if (count > USHRT_MAX) {
            count = USHRT_MAX;
            std::cout << "[ Chunk :: Update ] Chunk data truncaned , too much vertices to have a 16 bit index " << std::endl;
        }
        m_vertexBuffer.SetMeshData(vd, count);
        delete[] vd;
    }
    m_isDirty = false;
}

void Chunk::AddBlockToMesh(VertexBuffer::VertexData* vd, int& count, BlockType bt, int x, int y, int z) {
    
    vd[count++] = VertexBuffer::VertexData(x - .5f, y - .5f, z + .5f, 1.f, 1.f, 1.f, 0.f, 0.f);
    vd[count++] = VertexBuffer::VertexData(x + .5f, y - .5f, z + .5f, 1.f, 1.f, 1.f, 1.f, 0.f);
    vd[count++] = VertexBuffer::VertexData(x + .5f, y + .5f, z + .5f, 1.f, 1.f, 1.f, 1.f, 1.f);
    vd[count++] = VertexBuffer::VertexData(x - .5f, y + .5f, z + .5f, 1.f, 1.f, 1.f, 0.f, 1.f);

	vd[count++] = VertexBuffer::VertexData(x - .5f, y + .5f, z - .5f, 1.f, 1.f, 1.f, 0.f, 1.f);
    vd[count++] = VertexBuffer::VertexData(x + .5f, y + .5f, z - .5f, 1.f, 1.f, 1.f, 1.f, 1.f);
    vd[count++] = VertexBuffer::VertexData(x + .5f, y - .5f, z - .5f, 1.f, 1.f, 1.f, 1.f, 0.f);
    vd[count++] = VertexBuffer::VertexData(x - .5f, y - .5f, z - .5f, 1.f, 1.f, 1.f, 0.f, 0.f);

	vd[count++] = VertexBuffer::VertexData(x - .5f, y + .5f, z + .5f, 1.f, 1.f, 1.f, 0.f, 1.f);
	vd[count++] = VertexBuffer::VertexData(x - .5f, y + .5f, z - .5f, 1.f, 1.f, 1.f, 1.f, 1.f);
	vd[count++] = VertexBuffer::VertexData(x - .5f, y - .5f, z - .5f, 1.f, 1.f, 1.f, 1.f, 0.f);
	vd[count++] = VertexBuffer::VertexData(x - .5f, y - .5f, z + .5f, 1.f, 1.f, 1.f, 0.f, 0.f);

    vd[count++] = VertexBuffer::VertexData(x + .5f, y - .5f, z - .5f, 1.f, 1.f, 1.f, 0.f, 0.f);
	vd[count++] = VertexBuffer::VertexData(x + .5f, y + .5f, z - .5f, 1.f, 1.f, 1.f, 0.f, 1.f);
	vd[count++] = VertexBuffer::VertexData(x + .5f, y + .5f, z + .5f, 1.f, 1.f, 1.f, 1.f, 1.f);
	vd[count++] = VertexBuffer::VertexData(x + .5f, y - .5f, z + .5f, 1.f, 1.f, 1.f, 1.f, 0.f);

    vd[count++] = VertexBuffer::VertexData(x - .5f, y + .5f, z - .5f, 1.f, 1.f, 1.f, 0.f, 0.f);
    vd[count++] = VertexBuffer::VertexData(x - .5f, y + .5f, z + .5f, 1.f, 1.f, 1.f, 0.f, 1.f);
    vd[count++] = VertexBuffer::VertexData(x + .5f, y + .5f, z + .5f, 1.f, 1.f, 1.f, 1.f, 1.f);
    vd[count++] = VertexBuffer::VertexData(x + .5f, y + .5f, z - .5f, 1.f, 1.f, 1.f, 1.f, 0.f);

    vd[count++] = VertexBuffer::VertexData(x - .5f, y - .5f, z + .5f, 1.f, 1.f, 1.f, 0.f, 0.f);
    vd[count++] = VertexBuffer::VertexData(x - .5f, y - .5f, z - .5f, 1.f, 1.f, 1.f, 0.f, 1.f);
    vd[count++] = VertexBuffer::VertexData(x + .5f, y - .5f, z - .5f, 1.f, 1.f, 1.f, 1.f, 1.f);
    vd[count++] = VertexBuffer::VertexData(x + .5f, y - .5f, z + .5f, 1.f, 1.f, 1.f, 1.f, 0.f);
}

void Chunk::Render() const { m_vertexBuffer.Render(); }

bool Chunk::IsDirty() const { return m_isDirty; }