/*
 * Copyright (c) 2009 Lukas Mejdrech
 * 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.
 */

/** @addtogroup libc
 *  @{
 */

/** @file
 *  Character string to integer map implementation.
 *  @see char_map.h
 */

#include <adt/char_map.h>

#include <errno.h>
#include <malloc.h>
#include <mem.h>
#include <unistd.h>

/** Internal magic value for a consistency check. */
#define CHAR_MAP_MAGIC_VALUE	0x12345611

/** Adds the value with the key to the map.
 *
 * Creates new nodes to map the key.
 *
 * @param[in,out] map	The character string to integer map.
 * @param[in] identifier The key zero ('\0') terminated character string.
 *			The key character string is processed until the first
 *			terminating zero ('\0') character after the given
 *			length is found.
 * @param[in] length	The key character string length. The parameter may be
 *			zero (0) which means that the string is processed until
 *			the terminating zero ('\0') character is found.
 * @param[in] value	The integral value to be stored for the key character
 *			string.
 * @return		EOK on success.
 * @return		ENOMEM if there is not enough memory left.
 * @return		EEXIST if the key character string is already used.
 */
static int
char_map_add_item(char_map_t *map, const uint8_t *identifier, size_t length,
    const int value)
{
	if (map->next == (map->size - 1)) {
		char_map_t **tmp;

		tmp = (char_map_t **) realloc(map->items,
		    sizeof(char_map_t *) * 2 * map->size);
		if (!tmp)
			return ENOMEM;

		map->size *= 2;
		map->items = tmp;
	}

	map->items[map->next] = (char_map_t *) malloc(sizeof(char_map_t));
	if (!map->items[map->next])
		return ENOMEM;

	if (char_map_initialize(map->items[map->next]) != EOK) {
		free(map->items[map->next]);
		map->items[map->next] = NULL;
		return ENOMEM;
	}

	map->items[map->next]->c = *identifier;
	identifier++;
	map->next++;
	if ((length > 1) || ((length == 0) && *identifier)) {
		map->items[map->next - 1]->value = CHAR_MAP_NULL;
		return char_map_add_item(map->items[map->next - 1], identifier,
		    length ? length - 1 : 0, value);
	} else {
		map->items[map->next - 1]->value = value;
	}

	return EOK;
}

/** Checks if the map is valid.
 *
 * @param[in] map	The character string to integer map.
 * @return		TRUE if the map is valid.
 * @return		FALSE otherwise.
 */
static int char_map_is_valid(const char_map_t *map)
{
	return map && (map->magic == CHAR_MAP_MAGIC_VALUE);
}

/** Adds the value with the key to the map.
 *
 * @param[in,out] map	The character string to integer map.
 * @param[in] identifier The key zero ('\0') terminated character string. The
 *			key character string is processed until the first
 *			terminating zero ('\0') character after the given
 *			length is found.
 * @param[in] length	The key character string length. The parameter may be
 *			zero (0) which means that the string is processed until
 *			the terminating zero ('\\0') character is found.
 * @param[in] value	The integral value to be stored for the key character
 *			string.
 * @return		EOK on success.
 * @return		EINVAL if the map is not valid.
 * @return		EINVAL if the identifier parameter is NULL.
 * @return		EINVAL if the length parameter zero (0) and the
 *			identifier parameter is an empty character string (the
 *			first character is the terminating zero ('\0')
 *			character.
 * @return		EEXIST if the key character string is already used.
 * @return		Other error codes as defined for the
 *			char_map_add_item() function.
 */
int
char_map_add(char_map_t *map, const uint8_t *identifier, size_t length,
    const int value)
{
	if (char_map_is_valid(map) && identifier && (length || *identifier)) {
		int index;

		for (index = 0; index < map->next; index++) {
			if (map->items[index]->c != *identifier)
				continue;
				
			identifier++;
			if((length > 1) || ((length == 0) && *identifier)) {
				return char_map_add(map->items[index],
				    identifier, length ? length - 1 : 0, value);
			} else {
				if (map->items[index]->value != CHAR_MAP_NULL)
					return EEXISTS;

				map->items[index]->value = value;
				return EOK;
			}
		}
		return char_map_add_item(map, identifier, length, value);
	}

	return EINVAL;
}

/** Clears and destroys the map.
 *
 * @param[in,out] map	The character string to integer map.
 */
void char_map_destroy(char_map_t *map)
{
	if (char_map_is_valid(map)) {
		int index;

		map->magic = 0;
		for (index = 0; index < map->next; index++)
			char_map_destroy(map->items[index]);

		free(map->items);
		map->items = NULL;
	}
}

/** Returns the node assigned to the key from the map.
 *
 * @param[in] map	The character string to integer map.
 * @param[in] identifier The key zero ('\0') terminated character string. The
 *			key character string is processed until the first
 *			terminating zero ('\0') character after the given length
 *			is found.
 * @param[in] length	The key character string length. The parameter may be
 *			zero (0) which means that the string is processed until
 *			the terminating zero ('\0') character is found.
 * @return		The node holding the integral value assigned to the key
 *			character string.
 * @return		NULL if the key is not assigned a node.
 */
static char_map_t *
char_map_find_node(const char_map_t *map, const uint8_t *identifier,
    size_t length)
{
	if (!char_map_is_valid(map))
		return NULL;

	if (length || *identifier) {
		int index;

		for (index = 0; index < map->next; index++) {
			if (map->items[index]->c == *identifier) {
				identifier++;
				if (length == 1)
					return map->items[index];

				return char_map_find_node(map->items[index],
				    identifier, length ? length - 1 : 0);
			}
		}

		return NULL;
	}

	return (char_map_t *) map;
}

/** Excludes the value assigned to the key from the map.
 *
 * The entry is cleared from the map.
 *
 * @param[in,out] map	The character string to integer map.
 * @param[in] identifier The key zero ('\0') terminated character string. The
 *			key character string is processed until the first
 *			terminating zero ('\0') character after the given length
 *			is found.
 * @param[in] length	The key character string length. The parameter may be
 *			zero (0) which means that the string is processed until
 *			the terminating zero ('\0') character is found.
 * @return		The integral value assigned to the key character string.
 * @return		CHAR_MAP_NULL if the key is not assigned a value.
 */
int char_map_exclude(char_map_t *map, const uint8_t *identifier, size_t length)
{
	char_map_t *node;

	node = char_map_find_node(map, identifier, length);
	if (node) {
		int value;

		value = node->value;
		node->value = CHAR_MAP_NULL;
		return value;
	}
	return CHAR_MAP_NULL;
}

/** Returns the value assigned to the key from the map.
 *
 *  @param[in] map	The character string to integer map.
 *  @param[in] identifier The key zero ('\0') terminated character string. The
 *			key character string is processed until the first
 *			terminating zero ('\0') character after the given length
 *			is found.
 *  @param[in] length	The key character string length. The parameter may be
 *			zero (0) which means that the string is processed until
 *			the terminating zero ('\0') character is found.
 *  @return		The integral value assigned to the key character string.
 *  @return		CHAR_MAP_NULL if the key is not assigned a value.
 */
int char_map_find(const char_map_t *map, const uint8_t *identifier, size_t length)
{
	char_map_t *node;

	node = char_map_find_node(map, identifier, length);
	return node ? node->value : CHAR_MAP_NULL;
}

/** Initializes the map.
 *
 *  @param[in,out] map	The character string to integer map.
 *  @return		EOK on success.
 *  @return		EINVAL if the map parameter is NULL.
 *  @return		ENOMEM if there is not enough memory left.
 */
int char_map_initialize(char_map_t *map)
{
	if (!map)
		return EINVAL;

	map->c = '\0';
	map->value = CHAR_MAP_NULL;
	map->size = 2;
	map->next = 0;

	map->items = malloc(sizeof(char_map_t *) * map->size);
	if (!map->items) {
		map->magic = 0;
		return ENOMEM;
	}

	map->items[map->next] = NULL;
	map->magic = CHAR_MAP_MAGIC_VALUE;

	return EOK;
}

/** Adds or updates the value with the key to the map.
 *
 *  @param[in,out] map	The character string to integer map.
 *  @param[in] identifier The key zero ('\0') terminated character string. The
 *			key character string is processed until the first
 *			terminating zero ('\0') character after the given length
 *			is found.
 *  @param[in] length	The key character string length. The parameter may be
 *			zero (0) which means that the string is processed until
 *			the terminating zero ('\0') character is found.
 *  @param[in] value	The integral value to be stored for the key character
 *			string.
 *  @return		EOK on success.
 *  @return		EINVAL if the map is not valid.
 *  @return		EINVAL if the identifier parameter is NULL.
 *  @return		EINVAL if the length parameter zero (0) and the
 *			identifier parameter is an empty character string (the
 *			first character is the terminating zero ('\0) character.
 *  @return		EEXIST if the key character string is already used.
 *  @return		Other error codes as defined for the char_map_add_item()
 *			function.
 */
int
char_map_update(char_map_t *map, const uint8_t *identifier, const size_t length,
    const int value)
{
	char_map_t *node;

	node = char_map_find_node(map, identifier, length);
	if (node) {
		node->value = value;
		return EOK;
	}
	
	return char_map_add(map, identifier, length, value);
}

/** @}
 */