#include <string.h>
#include "stdint.h"
#include "circular_buffer.h"

CB_StatusTypeDef cb_init(CB_TypeDef *cb, void *buffer, uint16_t capacity, uint8_t item_size)
{
    if (buffer == NULL || cb == NULL)
    {
        return CB_ERROR;
    }

    cb->buffer = buffer;
    cb->buffer_end = (uint8_t *)cb->buffer + capacity * item_size;
    cb->capacity = capacity;
    cb->count = 0;
    cb->item_size = item_size;
    cb->head = cb->buffer;
    cb->tail = cb->buffer;

    return CB_OK;
}

CB_StatusTypeDef cb_push_back(CB_TypeDef *cb, const void *item)
{
    if (cb == NULL)
    {
        return CB_ERROR;
    }

    if (cb->count == cb->capacity)
    {
        return CB_FULL;
    }
    memcpy(cb->head, item, cb->item_size);
    cb->head = (uint8_t *)cb->head + cb->item_size;
    if (cb->head == cb->buffer_end)
        cb->head = cb->buffer;
    cb->count++;

    return CB_OK;
}

CB_StatusTypeDef cb_pop_front(CB_TypeDef *cb, void *item)
{
    if (cb == NULL)
    {
        return CB_ERROR;
    }

    if (cb->count == 0)
    {
        return CB_EMPTY;
    }

    memcpy(item, cb->tail, cb->item_size);
    cb->tail = (uint8_t *)cb->tail + cb->item_size;
    if (cb->tail == cb->buffer_end)
        cb->tail = cb->buffer;
    cb->count--;

    return CB_OK;
}