#include "string.h"
#include "stack.h"

stack_ret_t stack_init(stack_t * stack, void * data, size_t max_data_size, size_t element_size) {
    stack->data = data;
    stack->top_of_stack = -1;
    stack->max_data_size = max_data_size;
    stack->elem_size = element_size;

    return STACK_OK;
}

stack_ret_t stack_push(stack_t * stack, void * element) {
    if ((stack->top_of_stack != -1)  && (stack->top_of_stack >= stack->max_data_size)) {
        return STACK_FULL;
    }

    memcpy(stack->data + (stack->top_of_stack * stack->elem_size), element, stack->elem_size);

    stack->top_of_stack++;

    return STACK_OK;
}

stack_ret_t stack_pop(stack_t * stack, void * store_to) {
    if (stack->top_of_stack < 0) {
        return STACK_EMPTY;
    }

    memcpy(store_to, stack->data + ((stack->top_of_stack - 1) * stack->elem_size), stack->elem_size);

    stack->top_of_stack--;

    return STACK_OK;
}