/* 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;
}

static inline lnode_t* pivot(lnode_t *l, lnode_t *r) {

    lnode_t *c = l->prev;

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

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

    return c;
}

static void quick_sort(lnode_t* l, lnode_t* r) {
    lnode_t* p;

    if (!is_null(r) && l != r && l != r->next) {
        p = pivot(l, r);

        quick_sort(l, p->prev);
        quick_sort(p->next, r);
    }
}

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

void list_sort(list_t* x) {
    return quick_sort(x->first, x->last);
}


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;
    }
}