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

#include <shell.h>

size_t count_args(const char *line)
{
	const char *p = line;
	size_t n = 0;

	while (*p != '\0') {
		p += strspn(p, " \n\r");

		while (*p != '\0' && *p != ' ') {
			if (*p++ != '\"')
				continue;

			while (*p != '\0' && *p != '\"')
				++p;

			if (*p == '\"')
				++p;
		}

		++n;
	}

	return n;
}

char **parse_args(const char *line, size_t *argc)
{
	char **argv;
	char **arg;
	const char *p = line;
	char *s;
	size_t n;

	if (!argc)
		argc = &n;

	*argc = count_args(line);

	if (!(argv = malloc(*argc * sizeof(char *) + strlen(line) + 1)))
		return NULL;

	arg = argv;
	s = (char *)argv + *argc * sizeof(char *);

	while (*p != '\0') {
		p += strspn(p, " \n\r");
		*arg++ = s;

		while (*p != '\0' && *p != ' ') {
			if (*p != '\"') {
				*s++ = *p++;
				continue;
			}

			++p;

			while (*p != '\0' && *p != '\"')
				*s++ = *p++;

			if (*p == '\"')
				++p;
		}

		*s++ = '\0';
	}

	return argv;
}