#include <entity.h>
#include <librr/memory.h>
#include <stdlib.h>

MtEntityLookupTree mt_create_entity_lookup_tree();
void mt_delete_entity_lookup_tree(MtEntityLookupTree lookup_tree);



MtEntityRegistry mt_create_entity_registry()
{
    MtEntityRegistry entity_registry;
    entity_registry.lookup = mt_create_entity_lookup_tree();
    entity_registry.pool = mt_create_entity_pool(16384);
    entity_registry.entity_id_counter = 1;
    return entity_registry;
}

void mt_delete_entity_registry(MtEntityRegistry *entity_registry)
{
    mt_delete_entity_lookup_tree(entity_registry->lookup);
    mt_delete_entity_pool(&entity_registry->pool);
}



MtEntityLookupTree mt_create_entity_lookup_tree()
{
    MtEntityLookupTree lookup_tree;
    rr_memset(&lookup_tree, sizeof(MtEntityLookupTree), 0x00);
    return lookup_tree;
}

void mt_delete_entity_lookup_tree(MtEntityLookupTree lookup_tree)
{
    usz_t level1_index = 0;
    while(level1_index < 256)
    {
        if(lookup_tree.sublists[level1_index] == NULL)
        {
            ++level1_index;
            continue;
        }
        MtEntityListL1 *level1_list = lookup_tree.sublists[level1_index];
        usz_t level2_index = 0;
        while(level2_index < 256)
        {
            MtEntityListL2 *level2_list = level1_list->sublists[level2_index];
            if(level2_list == NULL)
            {
                ++level2_index;
                continue;
            }
            usz_t level3_index = 0;
            while(level3_index < 256)
            {
                MtEntityListL3 *level3_list = level2_list->sublists[level3_index];
                if(level3_list == NULL)
                {
                    ++level3_index;
                    continue;
                }
                usz_t entity_index = 0;
                while(entity_index < 256)
                {
                    MtEntity *entity = level3_list->entities[entity_index];
                    if(entity == NULL)
                    {
                        ++entity_index;
                        continue;
                    }
                    mt_delete_entity_data(entity);
                    ++entity_index;
                }
                free(level3_list);
                ++level3_index;
            }
            free(level2_list);
            ++level2_index;
        }
        free(level1_list);
        ++level1_index;
    }
}



void mt_delete_entity_data(MtEntity *entity)
{
    if(entity->tags != NULL)
        free(entity->tags);
}



void mt_reset_entity_pool_allocation(MtEntityPool *pool)
{
    usz_t entity_index = 0;
    while(entity_index < pool->capacity)
    {
        pool->entities[entity_index].pool_next_free = &pool->entities[entity_index+1];
        ++entity_index;
    }
    pool->entities[pool->capacity - 1].pool_next_free = NULL;
}

MtEntityPool mt_create_entity_pool(usz_t capacity)
{
    MtEntityPool pool;
    pool.capacity = capacity;
    pool.entities = calloc(sizeof(MtEntity), pool.capacity);
    mt_reset_entity_pool_allocation(&pool);
    pool.first_free = &pool.entities[0];
    pool.continuation = NULL;
    return pool;
}

void mt_delete_entity_pool(MtEntityPool *pool)
{
    if(pool->continuation != NULL)
    {
        mt_delete_entity_pool(pool->continuation);
        free(pool->continuation);
    }
    free(pool->entities);
}



MtEntity * mt_allocate_entity_pool_slot(MtEntityPool *pool)
{
    if(pool->first_free == NULL)
    {
        if(pool->continuation == NULL)
        {
            pool->continuation = malloc(sizeof(MtEntityPool));
            *pool->continuation = mt_create_entity_pool(pool->capacity * 2);
        }
        return mt_allocate_entity_pool_slot(pool->continuation);
    }
    MtEntity *allocated = pool->first_free;
    pool->first_free =  allocated->pool_next_free;
    return allocated;
}

void mt_give_back_entity_pool_slot(MtEntityPool *pool, MtEntity *entity)
{
    entity->pool_next_free = pool->first_free;
    pool->first_free = entity;
}