/*
    edge.c -- edge tree management
    Copyright (C) 2000-2003 Guus Sliepen <guus@sliepen.eu.org>,
                  2000-2003 Ivo Timmermans <ivo@o2w.nl>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

    $Id: edge.c,v 1.1.2.23 2003/07/24 12:08:15 guus Exp $
*/

#include "system.h"

#include "avl_tree.h"
#include "edge.h"
#include "logger.h"
#include "netutl.h"
#include "node.h"
#include "utils.h"
#include "xalloc.h"

avl_tree_t *edge_weight_tree;	/* Tree with all edges, sorted on weight */

static int edge_compare(const edge_t *a, const edge_t *b)
{
	return strcmp(a->to->name, b->to->name);
}

static int edge_weight_compare(const edge_t *a, const edge_t *b)
{
	int result;

	result = a->weight - b->weight;

	if(result)
		return result;

	result = strcmp(a->from->name, b->from->name);

	if(result)
		return result;

	return strcmp(a->to->name, b->to->name);
}

void init_edges(void)
{
	cp();

	edge_weight_tree =
		avl_alloc_tree((avl_compare_t) edge_weight_compare, NULL);
}

avl_tree_t *new_edge_tree(void)
{
	cp();

	return avl_alloc_tree((avl_compare_t) edge_compare, NULL);
}

void free_edge_tree(avl_tree_t *edge_tree)
{
	cp();

	avl_delete_tree(edge_tree);
}

void exit_edges(void)
{
	cp();

	avl_delete_tree(edge_weight_tree);
}

/* Creation and deletion of connection elements */

edge_t *new_edge(void)
{
	cp();

	return (edge_t *) xmalloc_and_zero(sizeof(edge_t));
}

void free_edge(edge_t *e)
{
	cp();

	free(e);
}

void edge_add(edge_t *e)
{
	cp();

	avl_insert(edge_weight_tree, e);
	avl_insert(e->from->edge_tree, e);

	e->reverse = lookup_edge(e->to, e->from);

	if(e->reverse)
		e->reverse->reverse = e;
}

void edge_del(edge_t *e)
{
	cp();

	if(e->reverse)
		e->reverse->reverse = NULL;

	avl_delete(e->from->edge_tree, e);
	avl_delete(edge_weight_tree, e);
}

edge_t *lookup_edge(const node_t *from, const node_t *to)
{
	edge_t v = {
		.from = from,
		.to = to
	};

	cp();

	return avl_search(from->edge_tree, &v);
}

void dump_edges(void)
{
	avl_node_t *node, *node2;
	node_t *n;
	edge_t *e;
	char *address;

	cp();

	logger(LOG_DEBUG, _("Edges:"));

	for(node = node_tree->head; node; node = node->next) {
		n = (node_t *) node->data;
		for(node2 = n->edge_tree->head; node2; node2 = node2->next) {
			e = (edge_t *) node2->data;
			address = sockaddr2hostname(&e->address);
			logger(LOG_DEBUG, _(" %s to %s at %s options %lx weight %d"),
				   e->from->name, e->to->name, address, e->options, e->weight);
			free(address);
		}
	}

	logger(LOG_DEBUG, _("End of edges."));
}