/*
 * db.c - Parts database
 *
 * Copyright 2012 by Werner Almesberger
 *
 * 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.
 */


#include <glib.h>

#include "util.h"
#include "db.h"


static GTree *tree = NULL;


static gint comp(gconstpointer a, gconstpointer b)
{
	const struct part *pa = a;
	const struct part *pb = b;

	/*
	 * Just subtracting the pointers may produce values outside the
	 * range of gint values.
	 */
	return pa->domain == pb->domain ?
	    pa->name < pb->name ? -1 : pa->name > pb->name ? 1 : 0 :
	    pa->domain < pb->domain ? -1 : 1;
}


struct part *part_lookup(const char *domain, const char *name)
{
	struct part part = {
		.domain = domain,
		.name = name,
	};

	if (!tree)
		return NULL;
	return g_tree_lookup(tree, &part);
}


struct part *part_add(const char *domain, const char *name)
{
	struct part part = {
		.domain = domain,
		.name = name,
	};
	struct part *p;

	if (!tree)
		tree = g_tree_new(comp);
	p = g_tree_lookup(tree, &part);
	if (!p) {
		p = alloc_type(struct part);
		p->stock = NULL;
		p->next = p->prev = p;
		g_tree_insert(tree, p, p);
	}
	return p;
}


void part_alias(struct part *a, struct part *b)
{
	struct part *tmp, *tmp2;

	tmp = a->next;
	a->next = b;
	b->prev->next = tmp;

	tmp2 = b->prev;
	b->prev = a;
	tmp->prev = tmp2;
}