/*
 * Copyright (C) 2025  Johnny Richard <johnny@johnnyrichard.com>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
#include <assert.h>
#include <stdint.h>
#include <stdlib.h>

#include <obe/arena.h>
#include <obe/array.h>

void*
obe_array_new(obe_arena_t* arena, size_t item_size)
{
    obe_array_header_t* h = obe_arena_alloc(
      arena,
      (item_size * OBE_ARRAY_INITIAL_CAPACITY) + sizeof(obe_array_header_t));
    if (h == NULL) {
        return NULL;
    }
    h->arena = arena;
    h->length = 0;
    h->item_size = item_size;
    h->capacity = OBE_ARRAY_INITIAL_CAPACITY;

    return ((uint8_t *)h) + sizeof(obe_array_header_t);
}

obe_array_header_t*
obe_array_get_header(void* arr)
{
    return (obe_array_header_t*)(((uint8_t *)arr) - sizeof(obe_array_header_t));
}

void*
obe_array_grow(void* arr)
{
    obe_array_header_t* h = obe_array_get_header(arr);

    size_t old_size = sizeof(obe_array_header_t) + (h->capacity * h->item_size);
    h->capacity *= 2;
    size_t new_size = sizeof(obe_array_header_t) + (h->capacity * h->item_size);

    h = obe_arena_realloc(h->arena, h, old_size, new_size);

    return ((uint8_t *)h) + sizeof(obe_array_header_t);
}

size_t
obe_array_length(void* arr)
{
    assert(arr);
    obe_array_header_t* header = obe_array_get_header(arr);
    return header->length;
}