/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*
 *  Authors: Jeffrey Stedfast <fejj@ximian.com>
 *
 *  Copyright 2002 Ximian, Inc. (www.ximian.com)
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser 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 Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Street #330, Boston, MA 02111-1307, USA.
 *
 */


#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <string.h>
#include <pthread.h>

#include "camel-string-utils.h"

int
camel_strcase_equal (gconstpointer a, gconstpointer b)
{
	return (g_ascii_strcasecmp ((const char *) a, (const char *) b) == 0);
}

guint
camel_strcase_hash (gconstpointer v)
{
	const char *p = (char *) v;
	guint h = 0, g;
	
	for ( ; *p != '\0'; p++) {
		h = (h << 4) + g_ascii_toupper (*p);
		if ((g = h & 0xf0000000)) {
			h = h ^ (g >> 24);
			h = h ^ g;
		}
	}
	
	return h;
}


static void
free_string (gpointer string, gpointer user_data)
{
	g_free (string);
}

void
camel_string_list_free (GList *string_list)
{
	if (string_list == NULL)
		return; 
	
	g_list_foreach (string_list, free_string, NULL);
	g_list_free (string_list);
}

char *
camel_strstrcase (const char *haystack, const char *needle)
{
	/* find the needle in the haystack neglecting case */
	const char *ptr;
	guint len;
	
	g_return_val_if_fail (haystack != NULL, NULL);
	g_return_val_if_fail (needle != NULL, NULL);
	
	len = strlen (needle);
	if (len > strlen (haystack))
		return NULL;
	
	if (len == 0)
		return (char *) haystack;
	
	for (ptr = haystack; *(ptr + len - 1) != '\0'; ptr++)
		if (!g_ascii_strncasecmp (ptr, needle, len))
			return (char *) ptr;
	
	return NULL;
}


const char *
camel_strdown (char *str)
{
	register char *s = str;
	
	while (*s) {
		if (*s >= 'A' && *s <= 'Z')
			*s += 0x20;
		s++;
	}
	
	return str;
}

/**
 * camel_tolower:
 * @c: 
 * 
 * ASCII to-lower function.
 * 
 * Return value: 
 **/
char camel_tolower(char c)
{
	if (c >= 'A' && c <= 'Z')
		c |= 0x20;

	return c;
}

/**
 * camel_toupper:
 * @c: 
 * 
 * ASCII to-upper function.
 * 
 * Return value: 
 **/
char camel_toupper(char c)
{
	if (c >= 'a' && c <= 'z')
		c &= ~0x20;

	return c;
}

/* working stuff for pstrings */
static pthread_mutex_t pstring_lock = PTHREAD_MUTEX_INITIALIZER;
static GHashTable *pstring_table = NULL;

/**
 * camel_pstring_add:
 * @str: string to add to the string pool
 * @own: whether the string pool will own the memory pointed to by @str, if @str is not yet in the pool
 *
 * Add the string to the pool.
 *
 * The NULL and empty strings are special cased to constant values.
 *
 * Return value: A pointer to an equivalent string of @s.  Use
 * camel_pstring_free() when it is no longer needed.
 **/
const char *
camel_pstring_add (char *str, gboolean own)
{
	void *pcount;
	char *pstr;
	int count;
	
	if (str == NULL)
		return NULL;
	
	if (str[0] == '\0') {
		if (own)
			g_free (str);
		return "";
	}
	
	pthread_mutex_lock (&pstring_lock);
	if (pstring_table == NULL)
		pstring_table = g_hash_table_new (g_str_hash, g_str_equal);
	
	if (g_hash_table_lookup_extended (pstring_table, str, (void **) &pstr, &pcount)) {
		count = GPOINTER_TO_INT (pcount) + 1;
		g_hash_table_insert (pstring_table, pstr, GINT_TO_POINTER (count));
		if (own)
			g_free (str);
	} else {
		pstr = own ? str : g_strdup (str);
		g_hash_table_insert (pstring_table, pstr, GINT_TO_POINTER (1));
	}
	
	pthread_mutex_unlock (&pstring_lock);
	
	return pstr;
}


/**
 * camel_pstring_strdup:
 * @s: String to copy.
 * 
 * Create a new pooled string entry for the string @s.  A pooled
 * string is a table where common strings are uniquified to the same
 * pointer value.  They are also refcounted, so freed when no longer
 * in use.  In a thread-safe manner.
 * 
 * The NULL and empty strings are special cased to constant values.
 *
 * Return value: A pointer to an equivalent string of @s.  Use
 * camel_pstring_free() when it is no longer needed.
 **/
const char *
camel_pstring_strdup (const char *s)
{
	return camel_pstring_add ((char *) s, FALSE);
}


/**
 * camel_pstring_free:
 * @s: String to free.
 * 
 * De-ref a pooled string. If no more refs exist to this string, it will be deallocated.
 *
 * NULL and the empty string are special cased.
 **/
void
camel_pstring_free(const char *s)
{
	char *p;
	void *pcount;
	int count;

	if (pstring_table == NULL)
		return;
	if (s == NULL || s[0] == 0)
		return;

	pthread_mutex_lock(&pstring_lock);
	if (g_hash_table_lookup_extended(pstring_table, s, (void **)&p, &pcount)) {
		count = GPOINTER_TO_INT(pcount)-1;
		if (count == 0) {
			g_hash_table_remove(pstring_table, p);
			g_free(p);
		} else {
			g_hash_table_insert(pstring_table, p, GINT_TO_POINTER(count));
		}
	} else {
		g_warning("Trying to free string not allocated from the pool '%s'", s);
	}
	pthread_mutex_unlock(&pstring_lock);
}
