#include "client/rendering/ChunkRenderer.h"
#include "client/rendering/block/BlockRenderers.h"
#include "client/rendering/block/BlockRenderer.h"

ChunkRenderer::ChunkRenderer() : blockTexture("resources/textures.png")
{
    mesh = new NormalTextureMesh[chunkX * chunkZ * Chunk::HEIGHT_PARTIONS];
}

ChunkRenderer::~ChunkRenderer()
{
    delete[] mesh;
}

void ChunkRenderer::renderTick(Shader& shader, Camera3D camera, DirectRenderer& dr, float lag)
{
    blockTexture.bind();
    
    for(int x = 0; x < chunkX; x++)
    {
        for(int z = 0; z < chunkZ; z++)
        {
            int sx = x * Chunk::WIDTH;
            int sz = z * Chunk::DEPTH;
            int ex = sx + Chunk::WIDTH;
            int ez = sz + Chunk::DEPTH;
            
            if(camera.isInFrustum(sx, 0, sz, ex, Chunk::HEIGHT, ez))
            {
                shader.translateTo(x * Chunk::WIDTH, 0, z * Chunk::DEPTH);
                shader.updateModelMatrix();

                for(int l = 0; l < Chunk::HEIGHT_PARTIONS; l++)
                {
                    if(camera.isInFrustum(sx, l * Chunk::PARTION_HEIGHT, sz, ex, (l + 1) * Chunk::PARTION_HEIGHT, ez))
                    {
                        mesh[l + z * Chunk::HEIGHT_PARTIONS + x * chunkZ * Chunk::HEIGHT_PARTIONS].draw();
                    }
                }
            }
        }
    }
}

void ChunkRenderer::updateChunk(Chunk& c, Chunk* north, Chunk* east, Chunk* south, Chunk* west)
{
    int x = c.getChunkX();
    int z = c.getChunkZ();
    if(x < 0 || x >= chunkX || z < 0 || z >= chunkZ)
    {
        return;
    }
    cout << "UPDATE: " << x << " " << z << endl;
    for(int l = 0; l < Chunk::HEIGHT_PARTIONS; l++)
    {
        if(c.isDirty(l))
        {
            buildChunk(l, c, north, east, south, west);
        }
    }
}

void ChunkRenderer::buildChunk(int partionY, Chunk& c, Chunk* north, Chunk* east, Chunk* south, Chunk* west)
{    
    Mesh& m = mesh[partionY + c.getChunkZ() * Chunk::HEIGHT_PARTIONS + c.getChunkX() * chunkZ * Chunk::HEIGHT_PARTIONS];
    
    int max = (partionY + 1) * Chunk::PARTION_HEIGHT;
    for(int y = partionY * Chunk::PARTION_HEIGHT; y < max; y++)
    {
        for(int x = 0; x < Chunk::WIDTH; x++)
        {
            for(int z = 0; z < Chunk::DEPTH; z++)
            {
                const Block& block = c.getBlock(x, y, z);
                if(!block.isEmpty())
                {
                    BlockRenderers::getBlockRenderer(block.getId()).addToMesh(m, x, y, z,
                        Face::getCullData(
                            // top
                            y + 1 < Chunk::HEIGHT && c.getBlock(x, y + 1, z).isBlockingFace(Face::DOWN), 
                            // bottom
                            y > 0 && c.getBlock(x, y - 1, z).isBlockingFace(Face::UP), 
                            // north
                            (x + 1 >= Chunk::WIDTH || c.getBlock(x + 1, y, z).isBlockingFace(Face::SOUTH)) && 
                            (x + 1 < Chunk::WIDTH || (north != nullptr && north->getBlock(x + 1 - Chunk::WIDTH, y, z).isBlockingFace(Face::SOUTH))), 
                            // south
                            (x - 1 < 0 || c.getBlock(x - 1, y, z).isBlockingFace(Face::NORTH)) && 
                            (x - 1 >= 0 || (south != nullptr && south->getBlock(x - 1 + Chunk::WIDTH, y, z).isBlockingFace(Face::NORTH))), 
                            // east
                            (z + 1 >= Chunk::DEPTH || c.getBlock(x, y, z + 1).isBlockingFace(Face::WEST)) && 
                            (z + 1 < Chunk::DEPTH || (east != nullptr && east->getBlock(x, y, z + 1 - Chunk::DEPTH).isBlockingFace(Face::WEST))), 
                            // west
                            (z - 1 < 0 || c.getBlock(x, y, z - 1).isBlockingFace(Face::EAST)) && 
                            (z - 1 >= 0 || (west != nullptr && west->getBlock(x, y, z - 1 + Chunk::DEPTH).isBlockingFace(Face::EAST)))));
                }
            }
        }
    }
    
    m.build();
}