#include "node.h"

#include <string.h>
#include <stdlib.h>

/* Insert after node */
node_t *node_insert(node_t *node, int val)
{
    /* Create new node */
    node_t *newNode = (node_t *)malloc(sizeof(node_t));
    if (newNode == NULL) {
        return NULL;
    }

    newNode->val = val;
    newNode->prev = node;

    /* Check if there is node before */
    if (node == NULL) {
        /* If not then there is no after */
        newNode->next = NULL;
        return newNode;
    }

    /* Set next node */
    newNode->next = node->next;
    node->next = newNode;

    /* Check node after */
    if (newNode->next != NULL) {
        /* Backlink next node */
        newNode->next->prev = newNode;
    }

    return newNode;
}

/* Pop node */
int node_pop(node_t *node)
{
    int val = node->val;

    /* Check prev */
    if (node->prev != NULL) {
        /* Point last node to next node */
        node->prev->next = node->next;
    }

    /* Check next */
    if (node->next != NULL) {
        node->next->prev = node->prev;
    }

    /* Free memory */
    free(node);

    return val;
}