/*
 * Copyright (c) 2015 Michal Koutny
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef SYSMAN_DEP_H
#define SYSMAN_DEP_H

#include <adt/list.h>

#include "unit.h"

typedef enum {
	DEP_EMBRYO,
	DEP_VALID
} dependency_state_t;

/** Dependency edge between unit in dependency graph
 *
 * @code
 * dependant ---> dependency
 * @endcode
 *
 */
typedef struct {
	/** Link to dependants list */
	link_t dependants;
	/** Link to dependencies list */
	link_t dependencies;

	dependency_state_t state;

	/** Unit that depends on another */
	unit_t *dependant;

	/** Unit that is dependency for another */
	unit_t *dependency;

	/** Name of the dependency unit, for resolved dependencies it's NULL
	 *
	 * @note Either dependency or dependency_name is set. Never both nor
	 *       none.
	 */
	char *dependency_name;
} unit_dependency_t;

extern unit_dependency_t *dep_dependency_create(void);
extern void dep_dependency_destroy(unit_dependency_t **);

extern int dep_sprout_dependency(unit_t *, const char *);
extern void dep_resolve_dependency(unit_dependency_t *, unit_t *);

extern int dep_add_dependency(unit_t *, unit_t *);
extern void dep_remove_dependency(unit_dependency_t **);


#endif