// SPDX-License-Identifier: GPL-2.0-only
/*
 * Based on strlist.c by:
 * (c) 2009 Arnaldo Carvalho de Melo <acme@redhat.com>
 */

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>

#include "rblist.h"

int rblist__add_node(struct rblist *rblist, const void *new_entry)
{
        struct rb_node **p = &rblist->entries.rb_root.rb_node;
        struct rb_node *parent = NULL, *new_node;
        bool leftmost = true;

        while (*p != NULL) {
                int rc;

                parent = *p;

                rc = rblist->node_cmp(parent, new_entry);
                if (rc > 0)
                        p = &(*p)->rb_left;
                else if (rc < 0) {
                        p = &(*p)->rb_right;
                        leftmost = false;
                }
                else
                        return -EEXIST;
        }

        new_node = rblist->node_new(rblist, new_entry);
        if (new_node == NULL)
                return -ENOMEM;

        rb_link_node(new_node, parent, p);
        rb_insert_color_cached(new_node, &rblist->entries, leftmost);
        ++rblist->nr_entries;

        return 0;
}

void rblist__remove_node(struct rblist *rblist, struct rb_node *rb_node)
{
        rb_erase_cached(rb_node, &rblist->entries);
        --rblist->nr_entries;
        rblist->node_delete(rblist, rb_node);
}

static struct rb_node *__rblist__findnew(struct rblist *rblist,
                                         const void *entry,
                                         bool create)
{
        struct rb_node **p = &rblist->entries.rb_root.rb_node;
        struct rb_node *parent = NULL, *new_node = NULL;
        bool leftmost = true;

        while (*p != NULL) {
                int rc;

                parent = *p;

                rc = rblist->node_cmp(parent, entry);
                if (rc > 0)
                        p = &(*p)->rb_left;
                else if (rc < 0) {
                        p = &(*p)->rb_right;
                        leftmost = false;
                }
                else
                        return parent;
        }

        if (create) {
                new_node = rblist->node_new(rblist, entry);
                if (new_node) {
                        rb_link_node(new_node, parent, p);
                        rb_insert_color_cached(new_node,
                                               &rblist->entries, leftmost);
                        ++rblist->nr_entries;
                }
        }

        return new_node;
}

struct rb_node *rblist__find(struct rblist *rblist, const void *entry)
{
        return __rblist__findnew(rblist, entry, false);
}

struct rb_node *rblist__findnew(struct rblist *rblist, const void *entry)
{
        return __rblist__findnew(rblist, entry, true);
}

void rblist__init(struct rblist *rblist)
{
        if (rblist != NULL) {
                rblist->entries  = RB_ROOT_CACHED;
                rblist->nr_entries = 0;
        }

        return;
}

void rblist__exit(struct rblist *rblist)
{
        struct rb_node *pos, *next = rb_first_cached(&rblist->entries);

        while (next) {
                pos = next;
                next = rb_next(pos);
                rblist__remove_node(rblist, pos);
        }
}

void rblist__delete(struct rblist *rblist)
{
        if (rblist != NULL) {
                rblist__exit(rblist);
                free(rblist);
        }
}

struct rb_node *rblist__entry(const struct rblist *rblist, unsigned int idx)
{
        struct rb_node *node;

        for (node = rb_first_cached(&rblist->entries); node;
             node = rb_next(node)) {
                if (!idx--)
                        return node;
        }

        return NULL;
}