#include "dyn_arr.h"

#include <stdio.h>
#include <assert.h>

void *_da_create(size_t type_size, int init_cap)
{
        init_cap = init_cap < DA_MIN_CAP
                ? DA_MIN_CAP
                : init_cap;

        int *arr = (int*)mem_alloc(type_size * init_cap + sizeof(int) * 2);

        arr[0] = 0;
        arr[1] = init_cap;
        return (void*)(arr + 2);
}

void *_da_append_slot(size_t type_size, void **arr)
{
        int *cap = da_cap_ptr(*arr);
        int *len = da_len_ptr(*arr);

        (*len)++;

        if (*len > *cap) {
                *cap *= DA_GROW_RATE;

                void* base = da_base(*arr);
                base = mem_realloc(base, (type_size * *cap) + sizeof(int) * 2);
                assert(base != NULL); // Just to handle the case
                *arr = (void*)((int*)base + 2);

                len = da_len_ptr(*arr);
        }

        return (char*)*arr + ((*len - 1) * type_size);
}

void da_free(void *arr)
{
        void *base = da_base(arr);
        mem_free(base);
}