#include "session_queue.h"
#include "session_private.h"

struct session_queue
{
    struct session *head;
    struct session *tail;
    int count;
};

struct session_queue *session_queue_new()
{
    struct session_queue *queue = (struct session_queue *)calloc(1, sizeof(struct session_queue));
    if (queue == NULL)
    {
        return NULL;
    }
    return queue;
}

void session_queue_free(struct session_queue *queue)
{
    if (queue)
    {
        free(queue);
        queue = NULL;
    }
}

void session_queue_push(struct session_queue *queue, struct session *sess)
{
    if (queue == NULL || sess == NULL)
    {
        return;
    }

    if (queue->head == NULL)
    {
        queue->head = sess;
        queue->tail = sess;
    }
    else
    {
        queue->tail->next_ready_ptr = sess;
        queue->tail = sess;
    }
    sess->next_ready_ptr = NULL;
    queue->count++;
}

struct session *session_queue_pop(struct session_queue *queue)
{
    if (queue == NULL)
    {
        return NULL;
    }

    struct session *sess = queue->head;
    if (sess == NULL)
    {
        return NULL;
    }

    if (queue->head == queue->tail)
    {
        queue->head = NULL;
        queue->tail = NULL;
    }
    else
    {
        queue->head = sess->next_ready_ptr;
    }
    sess->next_ready_ptr = NULL;
    queue->count--;

    return sess;
}