#ifndef MT_ENTITY_POOL_H
#define MT_ENTITY_POOL_H

#include <librr/types.h>
#include <librr/linear_algebra.h>

typedef struct MtEntityLookupTree   MtEntityLookupTree;
typedef struct MtEntityListL1       MtEntityListL1;
typedef struct MtEntityListL2       MtEntityListL2;
typedef struct MtEntityListL3       MtEntityListL3;
typedef struct MtEntityPool         MtEntityPool;
typedef struct MtEntityRegistry     MtEntityRegistry;
typedef struct MtEntity             MtEntity;
typedef struct MtTag                MtTag;

struct MtEntityPool
{
    usz_t                       capacity;
    struct MtEntity            *entities;
    struct MtEntity            *first_free;
    MtEntityPool               *continuation;
};

struct MtEntityLookupTree
{
    MtEntityListL1             *sublists[256];
};

struct MtEntityListL1
{
    MtEntityListL2             *sublists[256];
};

struct MtEntityListL2
{
    MtEntityListL3             *sublists[256];
};

struct MtEntityListL3
{
    struct MtEntity            *entities[256];
};

struct MtEntityRegistry
{
    MtEntityPool                pool;
    MtEntityLookupTree          lookup;
    u32_t                       entity_id_counter;
};

struct MtEntity
{
    void                       *parent_state;
    MtEntity                   *pool_next_free;

    u32_t                       identifier;
    u16_t                       tags_capacity;
    u16_t                       num_tags;
    struct MtTag               *tags;
};

struct MtTag
{
    u32_t                       identifier;
    union MtTagData
    {
        i64_t                       integer;
        f64_t                       real;
        char                       *string;
        void                       *pointer;
        rr_vec2f_s                  vec2f;
        rr_vec3f_s                  vec3f;
        rr_vec4f_s                  vec4f;
    } data;
};

MtEntityRegistry mt_create_entity_registry();
void mt_delete_entity_registry(MtEntityRegistry *entity_list);

MtEntity * mt_create_entity(void *state_voidptr, u32_t identifier);
MtEntity * mt_get_entity(void *state_voidptr, u32_t identifier);

void mt_tag_i64(MtEntity *entity, char *name, i64_t integer);
void mt_tag_f64(MtEntity *entity, char *name, f64_t real);
void mt_tag_str(MtEntity *entity, char *name, char *string);
void mt_tag_ptr(MtEntity *entity, char *name, void *pointer);
void mt_tag_vec2(MtEntity *entity, char *name, rr_vec2f_s vector);
void mt_tag_vec3(MtEntity *entity, char *name, rr_vec3f_s vector);
void mt_tag_vec4(MtEntity *entity, char *name, rr_vec4f_s vector);

void mt_untag(MtEntity *entity, char *name);

i64_t mt_get_i64_tag(MtEntity *entity, char *name);
f64_t mt_get_f64_tag(MtEntity *entity, char *name);
char * mt_get_str_tag(MtEntity *entity, char *name);
void * mt_get_ptr_tag(MtEntity *entity, char *name);
rr_vec2f_s mt_get_vec2_tag(MtEntity *entity, char *name);
rr_vec3f_s mt_get_vec3_tag(MtEntity *entity, char *name);
rr_vec4f_s mt_get_vec4_tag(MtEntity *entity, char *name);



void mt_delete_entity_data(MtEntity *entity);

MtEntityPool mt_create_entity_pool(usz_t capacity);
void mt_delete_entity_pool(MtEntityPool *pool);

MtEntity * mt_allocate_entity_pool_slot(MtEntityPool *pool);
void mt_give_back_entity_pool_slot(MtEntityPool *pool, MtEntity *entity);

#endif // MT_ENTITY_POOL_H