/* This software is licensed by the MIT License, see LICENSE file */
/*                                Copyright © 2022 Gregory Lirent */

#include "include.h"

/*#####################################################################################################################*/

static inline void lnode_swap(lnode_t* s0, lnode_t* s1) {
    vnode_t v = s0->node;
    vtype   t = s0->type;

    s0->node = s1->node;
    s0->type = s1->type;

    s1->node = v;
    s1->type = t;
}


void list_sort(list_t* x) {
    stack_t  z = { .prev = 0, .value = x->last};
    lnode_t *l;
    lnode_t *r;

    stack_push(&z, x->first);

    while (z.value) {

        l = stack_pop(&z);
        r = stack_pop(&z);

        if (!is_null(r) && l != r && l != r->next) {

            lnode_t *p = l->prev;

            for (lnode_t* c = l; c != r; c = c->next) {
                if (lnode_compare(c, r) < 0) {
                    p = (is_null(p)) ? l : p->next;
                    lnode_swap(p, c);
                }
            }

            p = (is_null(p)) ? l : p->next;
            lnode_swap(p, r);

            stack_push(&z, r);
            stack_push(&z, p->next);
            stack_push(&z, p->prev);
            stack_push(&z, l);
        }
    }
}


void list_reverse(list_t* x) {
    lnode_t *l = x->first;
    lnode_t *r = x->last;

    while (l != r) {
        lnode_swap(l, r);
        if ((r = r->prev) == l)
            break;
        l = l->next;
    }
}