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

linkstack_t pkt_creat_linkstack(void)
{
    linkstack_t s ;
    if ((s = (linkstack_t)malloc(sizeof(struct linkstack))) == NULL)
    {
        printf("malloc failed!\n");
        return NULL;
    }

    s->next = NULL;
    return s;
}

int pkt_empty_linkstack(linkstack_t s)
{
    return s->next == NULL;
}

stack_frame_t pkt_get_linkstack_top(linkstack_t s)
{
    if (pkt_empty_linkstack(s))
    {
        printf("linkstack is empty!\n");
        return NULL;
    }

    return &s->next->frame;
}

int pkt_linkstack_push(linkstack_t s, stack_frame_t frame)
{
    PKT_ASSERT(s);
    PKT_ASSERT(frame);
    linkstack_t f;
    if ((f = (linkstack_t)malloc(sizeof(struct linkstack))) == NULL)
    {
        printf("malloc failed!\n");
        return -1;
    }
    f->frame = *frame;
    f->next = s->next;
    s->next = f;
    return 0;
}

struct stack_frame pkt_linkstack_pop(linkstack_t s)
{
    struct stack_frame f = {0};

    if (pkt_empty_linkstack(s))
    {
        printf("linkstack is empty!\n");
        return f;
    }
    
    linkstack_t d = s->next;
    s->next = d->next;
    f = d->frame;
    free(d);
    return f;
}

int pkt_clear_linkstack(linkstack_t s)
{
    linkstack_t d = s->next;
    while (d)
    {
        s->next = d->next;
        free(d);
        d = s->next;
    }
    return 0;
}

int pkt_free_linkstack(linkstack_t s) /* include free head */
{
    linkstack_t d = s;

    while (d)
    {
        s = d->next;
        free(d);
        d = s;
    }
    return 0;
}


int main(void)
{
    linkstack_t s = pkt_creat_linkstack();

    struct stack_frame frame;

    for (int i = 0; i < 10; i++)
    {
        frame.data = i;
        pkt_linkstack_push(s, &frame);
    }

    while (!pkt_empty_linkstack(s))
    {
        printf("%d\n", pkt_linkstack_pop(s).data);
    }
    pkt_free_linkstack(s);
    return 0;
}