#include "list.h"

void InitList (List * L)
{
    *L = (LNode *) malloc (sizeof(LNode));

    if (!*L)
    {
        fprintf(stderr,"Initialization Failed\n");
        exit(EXIT_FAILURE);
    }

    (*L)->next = NULL;

    printf("Initialization Successful!\n");
}

void DestroyList (List * L)
{
    // reserve head pointer
    List T = *L;
    List tmp;

    if (!T->next)
        printf("No element in list!\n");
    else
    {
        while (T->next)
        {
            tmp = T->next->next;
            free(T->next);
            T->next = tmp;
        }

       if (!T->next)
           printf("Destroyed list!\n");
       else
           printf("Error during destroy list");
    }
}

bool AddElem (List * L, ElemType e)
{
    List new = *L;

    while (new->next)
        new = new->next;

    new->next = (LNode *) malloc (sizeof(LNode));

    if (!new)
        return false;
    new = new->next;    
    new->data = e;
    new->next = NULL;

    return true;
}

int ListLength (List * L)
{
    int count = 0;

    List tmp = *L;

    while (tmp->next)
    {
        tmp = tmp->next;
        count++;
    }
    
    return count;
}

ElemType GetElem (List * L, int i)
{
    List tmp = *L;

    for (int j = 1; j < i; j++)
            tmp = tmp->next;
    return tmp->next->data;
}

int LocateElem (List * L, ElemType e)
{
    int i = 1;
    List tmp = *L;

    while (tmp->next && tmp->next->data != e)
    {
        tmp = tmp->next;
        i++;
    }

    if (!tmp->next)
        return 0;

    return i;
}

ElemType PriorElem(List * L, ElemType e)
{
    List tmp = *L;
    while (tmp->next->data != e)
        tmp = tmp->next;

    return tmp->data;
}

ElemType NextElem(List * L, ElemType e)
{
    List tmp = *L;
    while (tmp->next->data != e)
        tmp = tmp->next;
    
    tmp = tmp->next->next;

    return tmp->data;
}

bool InsertElem (List * L, ElemType e, int i)
{
    List scan = *L;
    List new;
    int tmp = 1;

    new = (LNode *) malloc (sizeof(LNode));

    if (!new)
        return false;

    while (scan->next && tmp < i)
    {
        scan = scan->next;
        tmp++;
    }


    if (!scan->next)
        printf("Reached list end.   Element appended on.\n");

    new->data = e;
    new->next = scan->next;
    scan->next = new;

    return true;
}

bool DeleteElem (List * L, int i)
{
    List tmp1 = *L;
    List tmp2 = tmp1->next;

    for (int j = 1; j < i; j++)
    {
            tmp1 = tmp1->next;
            tmp2 = tmp2->next;
    }

    if (!tmp2)
        return false;
    
    tmp1->next = tmp2->next;
    free(tmp2);

    return true;
}

void TraverseList (List * L)
{
    int i = 1;
    List tmp = (*L)->next;

    if (!tmp)
        printf("No element could be traversed!\n");
    else
    {
        puts("Traverse list:");
        while (tmp)
        {
            printf("Node %d:\t%d\n",i++,tmp->data);
            tmp = tmp->next;
        }
        puts("Traverse done!\n");
    }
}

void OperateMenu (void)
{
    puts("List Operation Menu\n");
    puts("\e[34ma. Add element          b. Initialize list");
    puts("c. List status          d. Get element from specific position");
    puts("e. Search element       f. Find prior element");
    puts("g. Find next element    h. Insert an element");
    puts("i. Delete an element    j. Traverse list");
    puts("k. Show Menu            l. Destroy list");
    puts("q. Quit");
}