#include <stdlib.h>
#include <stdio.h>
#include "doubly.h"

struct node *cons(int v, struct node *lst){
	struct node *new = malloc(sizeof(struct node));
	if(new == NULL){
		printf("cons: out of memory sucka\n");
		abort();
	}
	new->first = v;
	new->rest = lst;
	new->prev = NULL;
	if(lst != NULL)
		lst->prev = new;
	return(new);
}

void add_after(int v, struct node *nptr){
	if(nptr == NULL){
		printf("add_after: Cannot be NULL fool!\n");
		abort();
	}
	else{
		struct node *temp = nptr->rest;
		nptr->rest = cons(v, temp);
		nptr->rest->prev = nptr;
	}
}

struct node *remove_first(struct node *lst, int key){
	if(lst == NULL)
		return(lst);
	struct node *temp = lst->rest, *orig = lst;
	if(lst->first == key){
		free(lst);
		free(orig);
		if(temp != NULL)
			temp->prev = NULL;
		return(temp);
	}
	else{
		while(temp != NULL){
			if(temp->first == key){
				lst->rest = temp->rest;
				if(lst->rest != NULL)
					lst->rest->prev = lst;
				free(temp);	
				free(lst);
				return(orig);
			}
			else{
				lst = lst->rest;
				temp = temp->rest;
			}
		}
	}
	return(orig);
}