/*
 * Copyright 2023, Vincent Douillet <vincent@vdouillet.fr>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 2. 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.
 *
 * 3. Neither the name of the copyright holder nor the names of its contributors
 * may be used to endorse or promote products derived from this software without
 * specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT HOLDER OR CONTRIBUTORS 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.
 */

#include <stdarg.h>
#include <stdlib.h>
#include <string.h>

char   *
str_head(const char *str, char c)
{
	char   *occ, *result;
	size_t 	head_len;

	occ = strrchr(str, c);
	if (!occ || (occ == str && *occ != c))
		return NULL;

	/* copy head to new buffer */
	head_len = occ - str + 1;
	result = malloc(sizeof(char) * head_len);
	if (result == NULL)
		return NULL;
	if (strlcpy(result, str, head_len) < head_len) {
		free(result);
		return NULL;
	}
	return result;
}

char   *
str_tail(const char *str, char c)
{
	char   *right, *result;
	size_t 	right_len;

	right = strrchr(str, c);
	if (!right || (right == str && *right != c))
		return NULL;

	/* copy right part to new buffer */
	right_len = strlen(right);
	result = malloc(sizeof(char) * right_len);
	if (result == NULL)
		return NULL;

	if (strlcpy(result, right + 1, right_len) >= right_len) {
		free(result);
		return NULL;
	}
	return result;
}

void
str_replace(char *str, char a, char b)
{
	char   *tmp;

	tmp = str;
	while (*tmp != '\0') {
		if (*tmp == a)
			*tmp = b;

		tmp++;
	}
}

size_t
str_concat(char **dst,...)
{
	va_list str_list;
	const char *str;
	char   *concat;
	size_t 	cur_size, dst_size, w_size;

	/* first compute required size */
	dst_size = 0;
	va_start(str_list, dst);
	while ((str = va_arg(str_list, char *)) != NULL) {
		dst_size += strlen(str);
	}
	va_end(str_list);
	dst_size++;

	/* alloc result string */
	*dst = malloc(sizeof(char) * dst_size);
	if (*dst == NULL)
		return 0;

	/* concatenate now */
	concat = *dst;
	concat[0] = '\0';
	w_size = 0;
	va_start(str_list, dst);
	while ((str = va_arg(str_list, char *)) != NULL) {
		cur_size = strlen(str);
		if (strlcpy(concat, str, dst_size) >= dst_size) {
			w_size = 0;
			free(dst);
			break;
		}
		w_size += cur_size;
		concat += cur_size;
		dst_size -= cur_size;
	}
	va_end(str_list);

	return w_size;
}