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

//create a new node with the specified value
Node *LLMakeNode(int iData, Node *pNext)
{
    Node *newNode;
    newNode = (Node*)malloc(sizeof(*newNode));
    if (newNode != NULL)
    {
        newNode->iData = iData;
        newNode->pNext = pNext;
        return newNode;

    }
    printf("Null pointer - could not create node.");
    return;
}

//add the specified value to the end of the list
Node *LLAddToEnd(Node *pHead, int iData)
{
    Node *scan = pHead; //initialize scanning node to head node
    while (scan->pNext != NULL) scan = scan->pNext; //

    Node *newNode = LLMakeNode(iData, NULL); //create new node, give it the data and set its next value to null because it is the new tail node
    scan->pNext = newNode;

    return pHead;
}

//add the specified value to the appropriate position to maintain ascending order in the list
Node *LLAddInOrder(Node *pHead, int iData)
{

}

//show the node count of the linked list
int LLCount(Node *pHead)
{
    int count = 0;
    Node *current = pHead;
    while (current != NULL)
    {
        count++;
        current = current->pNext;
    }
    return count;
}

//show the list to the console, comma separated, no extra or leading commas
///we pass the head of the linked list to this function and iterate through it by using the pNext member
void LLShowList(Node *pHead)
{
    Node *current = pHead; //save current node
    if (pHead == NULL) printf("<empty>");
    while (current != NULL) //pHead is valid
    {
        if (current->pNext == NULL) //we're at last node
        {
            printf("%d", current->iData); //so don't print a comma
            break;
        }
        printf("%d, ", current->iData); //print node's data
        current = current->pNext; //grab next node
    }
}

//remove the first node
Node *LLDeleteFirst(Node *pHead)
{
    /*if (pHead != NULL)
    {
        Node *front = pHead; //save head node
        pHead = pHead->pNext; //move head down 1 node
        front->pNext = NULL; //sever front's connection to the list
        //if (front == pHead) pHead = NULL;
        free(front);
        return pHead;
    }*/

    /*if (pHead == NULL) return NULL;
    Node *front = pHead;
    pHead = pHead->pNext;
    front->pNext = NULL;
    if (front == NULL) pHead = NULL;
    free(front);
    return pHead;*/

    int ret = -1;
    Node *next = NULL;

    if (pHead == NULL) return -1;

    next = pHead->pNext;
    ret = pHead->iData;
    free(pHead);
    pHead = next;

    return ret;

}

//free the entire list
void LLDeleteList(Node *pHead)
{

}

//show the list in reverse order using tail recursion
void LLShowListReverseRec(Node *pHead)
{
    if (pHead == NULL)
        return;
    LLShowListReverseRec(pHead->pNext);
    printf("%d, ", pHead->iData);
}

//delete all the nodes in the linked list recursively
void LLDeleteListRec(Node *pHead)
{

}