#include <voxula/internals/utility/uuid.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdlib.h>

vx_uuid_table_s * vx_new_uuid_table()
{
    vx_uuid_table_s *table = malloc(sizeof(vx_uuid_table_s));
    table->num_blocks = 0;
    table->block_capacity = 32;
    table->blocks = malloc(table->block_capacity * sizeof(vx_uuid_block_s *));
    return table;
}

bool vx_uuid_block_exists(vx_uuid_table_s *table, uint32_t offset)
{
    uint32_t block_index = 0;
    while(block_index < table->num_blocks)
    {
        if(table->blocks[block_index]->offset == offset)
        {
            return true;
        }
        ++block_index;
    }
    return false;
}

bool vx_uuid_exists_in_block(vx_uuid_block_s *block, vx_uuid_d uuid)
{
    uint32_t entry_index = 0;
    while(entry_index < block->num_ids)
    {
        if(block->entries[entry_index].uuid == uuid)
        {
            return true;
        }
        ++entry_index;
    }
    return false;
}

vx_uuid_d vx_allocate_uuid_in_block(vx_uuid_block_s *block)
{
    vx_uuid_d last_id = 0;
    if(block->num_ids)
    {
        last_id = block->entries[block->num_ids - 1].uuid;
    }
    vx_uuid_d uuid =
        block->offset * 4096
      + last_id * 53;
    block->entries[block->num_ids].uuid = uuid;
    ++block->num_ids;
    while(vx_uuid_exists_in_block(block, uuid))
    {
        ++uuid;
    }
    return uuid;
}

vx_uuid_block_s * vx_allocate_new_id_block(vx_uuid_table_s *table)
{
    vx_uuid_block_s *block = NULL;
    if(table->num_blocks >= table->block_capacity)
    {
        table->block_capacity *= 2;
        if( ! table->block_capacity)
        {
            table->block_capacity = 32;
        }
        table->blocks = realloc(table->blocks, table->block_capacity * sizeof(vx_uuid_block_s *));
    }
    table->blocks[table->num_blocks] = malloc(sizeof(vx_uuid_block_s));
    block = table->blocks[table->num_blocks];
    block->num_ids = 0;
    block->offset = (table->num_blocks * 7) * 4096;
    ++table->num_blocks;
    return block;
}

vx_uuid_d vx_new_uuid(vx_uuid_table_s *table)
{
    vx_uuid_block_s *block = NULL;

    uint32_t block_index = 0;
    while(block_index < table->num_blocks)
    {
        if(table->blocks[block_index]->num_ids != 255)
        {
            block = table->blocks[block_index];
            break;
        }
        ++block_index;
    }
    if( ! block)
    {
        block = vx_allocate_new_id_block(table);
    }
    return vx_allocate_uuid_in_block(block);
}