#include "world.h"

#include <stdlib.h>
#include <stdio.h>

void tc_on_each_chunkloader(tc_world_s *world, bool (*fn_do)(tc_chunkloader_s *loader, void *userdata), void *userdata)
{
    for(uint32_t loader_index = 0; loader_index < world->num_loaders; ++loader_index)
        if(fn_do(&world->loaders[loader_index], userdata)) return;
}

void tc_on_each_loaded_chunk(tc_world_s *world, bool (*fn_do)(tc_chunk_s *chunk, void *userdata), void *userdata)
{
    for(uint32_t loader_index = 0; loader_index < world->num_loaders; ++loader_index)
        for(uint32_t chunk_index = 0; chunk_index < world->loaders[loader_index].num_chunks; ++chunk_index)
            if(fn_do(world->loaders[loader_index].chunks[chunk_index], userdata)) return;
}

void tc_on_each_chunk_of_loader(tc_chunkloader_s *loader, bool (*fn_do)(tc_chunk_s *chunk, void *userdata), void *userdata)
{
    uint32_t            chunk_index     = 0;
    while(chunk_index < loader->num_chunks)
    {
        if(fn_do(loader->chunks[chunk_index], userdata)) return;
        ++chunk_index;
    }
}


bool tc_coord_is_within_loaders_range(tc_chunkloader_s *loader, tc_vec3i_s coord)
{
    if(coord.x < (loader->center.x - loader->extent.x / 2))     return false;
    if(coord.y < (loader->center.y - loader->extent.y / 2))     return false;
    if(coord.z < (loader->center.z - loader->extent.z / 2))     return false;
    
    if(coord.x > (loader->center.x + loader->extent.x / 2))     return false;
    if(coord.y > (loader->center.y + loader->extent.y / 2))     return false;
    if(coord.z > (loader->center.z + loader->extent.z / 2))     return false;
    
    return true;
}

tc_chunkloader_s * tc_get_corresponding_loader(tc_world_s *world, tc_vec3i_s coord)
{
    for(uint32_t loader_index = 0; loader_index < world->num_loaders; ++loader_index)
        if(tc_coord_is_within_loaders_range(&world->loaders[loader_index], coord))
            return &world->loaders[loader_index];
    
    return NULL;
}

tc_chunk_s * tc_get_chunk_of_loader(tc_chunkloader_s *loader, tc_vec3i_s coord)
{
    for(uint32_t chunk_index = 0; chunk_index < loader->num_chunks; ++chunk_index)
        if(tc_vec3i_equ(loader->chunks[chunk_index]->position, coord))
            return loader->chunks[chunk_index];
    
    return NULL;
}

tc_chunk_s * tc_get_loaded_chunk(tc_world_s *world, tc_vec3i_s coord)
{
    tc_chunkloader_s *loader = tc_get_corresponding_loader(world, coord);
    if(loader == NULL) return NULL;
    
    return tc_get_chunk_of_loader(loader, coord);
}

tc_chunk_s * tc_load_chunk_of_loader(tc_chunkloader_s *loader, tc_vec3i_s coord)
{
    tc_chunk_s         *chunk          = tc_get_chunk_of_loader(loader, coord);
    
    if(chunk == NULL)
    {
        printf("Creating chunk at: %d %d %d\n", coord.x, coord.y, coord.z);
        
        chunk                   = tc_allocate_chunk(loader->world);
        chunk->position         = coord;
        
        loader->world->worldgen->fn_generate_chunk(loader->world->worldgen, chunk);
        tc_upload_chunk(chunk);
        
        tc_add_chunk_to_loader(loader, chunk);
   }
    return chunk;
}

void tc_reload_chunk_of_loader(tc_chunkloader_s *loader, tc_vec3i_s coord)
{
    tc_chunk_s *chunk = tc_get_chunk_of_loader(loader, coord);
    if(chunk == NULL) return;
    
    tc_meshize_chunk(chunk);
    tc_upload_chunk(chunk);
}

void tc_reload_chunk(tc_world_s *world, tc_vec3i_s coord)
{
    tc_chunkloader_s *loader = tc_get_corresponding_loader(world, coord);
    if(loader == NULL) return;
    
    tc_reload_chunk_of_loader(loader, coord);
}

void tc_remove_loaders_chunk(tc_chunkloader_s *loader, uint32_t index)
{
    tc_free_chunk(loader->world, loader->chunks[index]);
    
    // This is is NOT last element
    if((index+1) < loader->num_chunks)
    {
        loader->chunks[index] = loader->chunks[loader->num_chunks-1]; // move last chunk into gap
    }
    
    --loader->num_chunks;
}

void tc_remove_unnecessary_chunks_of_loader(tc_chunkloader_s *loader)
{
    for(uint32_t chunk_index = 0; chunk_index < loader->num_chunks; ++chunk_index)
    {
        tc_chunk_s *chunk = loader->chunks[chunk_index];
        if(!tc_coord_is_within_loaders_range(loader, chunk->position))
        {
            printf("Chunk at %d %d %d isn't in range\n", chunk->position.x, chunk->position.y, chunk->position.z); 
            tc_remove_loaders_chunk(loader, chunk_index);
        }
    }
}

void tc_load_all_chunks_of_chunkloader(tc_chunkloader_s *loader)
{
    for(uint32_t x = 0; x < loader->extent.x; ++x)
    {
        for(uint32_t y = 0; y < loader->extent.y; ++y)
        {
            for(uint32_t z = 0; z < loader->extent.z; ++z)
            {
                tc_vec3i_s      coords;
                /*
                coords.x = ((x + loader->center.x) - (loader->extent.x / 2)) + loader->extent.x;
                coords.y = ((y + loader->center.y) - (loader->extent.y / 2)) + loader->extent.y;
                coords.z = ((z + loader->center.z) - (loader->extent.z / 2)) + loader->extent.z;
                */
                coords.x = loader->center.x + (x - (loader->extent.x / 2));
                coords.y = loader->center.y + (y - (loader->extent.y / 2));
                coords.z = loader->center.z + (z - (loader->extent.z / 2));
                
                tc_load_chunk_of_loader(loader, coords);
            }
        }
    }
}

void tc_reload_chunkloader_zone(tc_chunkloader_s *loader)
{
    tc_remove_unnecessary_chunks_of_loader(loader);
    tc_load_all_chunks_of_chunkloader(loader);
}

void tc_update_world(tc_world_s *world)
{    
    world->loaders[0].center.x     = world->loading_center.x;
    world->loaders[0].center.y     = world->loading_center.y;
    world->loaders[0].center.z     = world->loading_center.z;
    
    uint32_t chunkloader_index = 0;
    while(chunkloader_index < world->num_loaders)
    {
        if(world->loaders[chunkloader_index].needs_reload)
        {
            tc_reload_chunkloader_zone(&world->loaders[chunkloader_index]);
        }
        ++chunkloader_index;
    }
}

// TODO: Set center chunk