#include "sequence.h"

void InitList(Elem * L)
{
    L->elem = (ElemType *) malloc (sizeof(ElemType) * MAXSIZE);

    if (!(L->elem))
    {
        fprintf(stderr,"Initialization Failed\nPlease run as debug mode\n");
        exit(EXIT_FAILURE);
    }

    L->length = 0;

    puts("Initialization Successful!");
    printf("You now have %d storage sequence list!\n",MAXSIZE);
}

void DestroyList(Elem * L)
{
    if (L->elem)
        free(L->elem);
    else
        printf("Sequence list is not exist!\n");
}

void AddElem (Elem * L, ElemType e)
{
    if (L->length >= MAXSIZE)
    {
        printf("No memory for more data\n"
            "You could try to release some unused item.\n");
        puts("Add failed");
    }

    else
    {
        int i = 0;

        while (i < L->length)
            i++;

        *(L->elem + i) = e;
        L->length++;
    }
}

bool ListEmpty (Elem * L)
{
    return L->length = 0 ? true:false;
}

ElemType ListLength (Elem * L)
{
    return L->length; 
}

ElemType GetElem (Elem * L, int i)
{
    if (i > L->length)
    {
        fprintf(stderr,"%d is out of index\n"
                "Please keep index between 0 and %d\n",
                i, L->length);
        return -1;
    }
    return *(L->elem + i - 1);
}

ElemType LocateElem (Elem * L, ElemType e)
{
    for (int i = 0; i < L->length; i++)
    {
        if (e == *(L->elem + i))
            return i + 1;
    }

    return 0;
}

ElemType PriorELem (Elem * L, ElemType e)
{
    ElemType i = 0;

    while (e != *(L->elem + i) && (i < L->length))
        i++;
    if (i == 0)
    {
        printf("The value is at first, so no element before it\n");
        free(L->elem);
        exit(EXIT_FAILURE);
    }
    else if (i >= L->length)
    {
        printf("The element is not found.\n");
        free(L->elem);
        exit(EXIT_FAILURE);
    }
    return *(L->elem + i - 1);
}

ElemType NextElem (Elem * L, ElemType e)
{
    ElemType i = 0;

    while (e != *(L->elem + i) && (i < L->length - 1))
        i++;
    if (i == L->length - 1)
    {
        printf("Not found this element in list.\n");
        free(L->elem);
        exit(EXIT_FAILURE);
    }
    return *(L->elem + i);
}

bool ListInsert (Elem * L, ElemType e, int i)
{
    if (i < 1 || i >= L->length)
    {
        fprintf(stderr,"Index should be between 0 and %d\n",
                L->length);
        return false;
    }

    for (int n = L->length; n > i - 1; n--)
        L->elem[n] = L->elem[n - 1];
    L->elem[i-1] = e;
    L->length++;

    return true;
}

bool ListDelete (Elem * L, int i)
{
    if (i < 1 || i >= L->length)
    {
        fprintf(stderr,"Index should be between 0 and %d\n",
                L->length);
        return false;
    }

    printf("Element %d has been deleted\n", L->elem[i-1]);

    for (int n = i; n < L->length; n++)
    {
        L->elem[n-1] = L->elem[n];        
    }
    L->length--;
    return true;
}