#ifndef TC_CHUNK_H
#define TC_CHUNK_H

#include <utility/location.h>
#include <entity.h>

typedef struct  tc_chunk                tc_chunk_s;
typedef struct  tc_chunkloader                  tc_chunkloader_s;

struct tc_chunk
{
    void                       *pool_entry;
    
    tc_chunk_location_s         location;
    u32_t                       blocks[32][32][32];
    
    i32_t                       refcounter;
    
    u32_t                       num_vertices;
    f32_t                      *vertex_positions;
    f32_t                      *vertex_uvs;
    
    u32_t                       vao;
    u32_t                       vbo;
    
    bool_t                      is_renderable;
};


// tc_load_chunk_at: Looks if there's a chunk already loaded at 'location' and gets it if
//  there is one. If it isn't loaded, this function will return NULL. The reference counter
//  will be increased.
tc_entity_s *       tc_load_chunk_at                        (tc_chunk_location_s location);

// tc_unload_chunk_at: Looks if there's a chunk already loaded at 'location' and decreases
//  the reference counter by one, possibly free'ing the chunk and its related structures.
void                tc_unload_chunk_at                      (tc_chunkloader_s *loader, tc_chunk_location_s location);
bool_t              tc_chunk_is_loaded                      (tc_chunk_location_s location);
void                tc_meshize_chunk                        (tc_chunk_s *chunk);
void                tc_upload_chunk                         (tc_chunk_s *chunk);



typedef struct  tc_chunklist_entry              tc_chunklist_entry_s;
typedef struct  tc_chunklist                    tc_chunklist_s;

struct tc_chunklist_entry
{
    tc_chunklist_entry_s       *next;
    tc_chunklist_entry_s       *previous;
    tc_entity_s                *entity;
};

struct tc_chunklist
{
    tc_chunklist_entry_s       *first;
    tc_chunklist_entry_s       *first_free;
    
    u32_t                       capacity;
    tc_chunklist_entry_s       *entries;
};

tc_chunklist_s      tc_create_chunklist             (u32_t capacity);
void                tc_delete_chunklist             (tc_chunklist_s list);

// tc_chunklist_remove_item: Adds a chunk to the chunklist.
//  THIS FUNCTION DOES NOT UPDATE THE REFERENCE COUNTER OF THE CHUNK!
void                tc_chunklist_add_item           (tc_chunklist_s *list, tc_entity_s *chunk);

// tc_chunklist_remove_item: Removes a chunk from the chunklist.
//  THIS FUNCTION DOES NOT UPDATE THE REFERENCE COUNTER OF THE CHUNK!
void                tc_chunklist_remove_item        (tc_chunklist_s *list, tc_entity_s *chunk);

tc_entity_s *       tc_chunklist_find_chunk_at      (tc_chunklist_s *list, tc_chunk_location_s location);



struct tc_chunkloader
{
    tc_chunk_location_s         center;
    tc_vec3i_s                  extent;
    
    tc_chunklist_s              chunklist;
    bool_t                      needs_reload;
    bool_t                      is_rendered;
};

tc_chunkloader_s    tc_create_chunkloader                   (tc_chunk_location_s location);
void                tc_delete_chunkloader                   (tc_chunkloader_s chunkloader);

void                tc_draw_chunkloader_zone                (tc_chunkloader_s *loader);

#endif // TC_CHUNK_H