#include <fcntl.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <stdio.h>

#include "private_at_functions.h"


/**************************************************************************
 *
 * D E C L A R A T I O N   O F   T H E   P R I V A T E   F U N C T I O N S
 *
 **************************************************************************/


/**
 * Internal function getting the full path of a file or a directory from its
 * path relative to a directory file descriptor.
 *
 *
 * @warning The returned pointer has to be freed by the caller.
 *
 * @param directory_file_descriptor the file descriptor for the directory to which
 * 									path_name is relative
 * @param path_name the path name for the file or directory, relative to directory_file_descriptor
 *
 * @return a pointer to the full path
 * @retvalue <full_path> if everything is ok
 * @retvalue NULL if an error occurs
 *
 * ###Error values
 * 		- OBIDMS_MEMORY_ERROR    : something wrong occurred during memory allocation.
 * 		- OBIDMS_LONG_NAME_ERROR : the database name exceeds the limit.
 *
 * @since June 2015
 * @author Celine Mercier (celine.mercier@metabarcoding.org)
 */
static char* get_full_path(int directory_file_descriptor, const char* path_name);


/************************************************************************
 *
 * D E F I N I T I O N   O F   T H E   P R I V A T E   F U N C T I O N S
 *
 ************************************************************************/


static char* get_full_path(int directory_file_descriptor, const char* path_name)
{
	char full_path[MAX_PATH_LEN];

	if (fcntl(directory_file_descriptor, F_GETPATH, full_path) < 0)
		return NULL;

	if (strlcat(full_path, "/", MAX_PATH_LEN) >= sizeof(full_path))
		return NULL;

	if (strlcat(full_path, path_name, MAX_PATH_LEN) >= sizeof(full_path))
		return NULL;

	return full_path;
}


/**********************************************************************
 *
 * D E F I N I T I O N   O F   T H E   P U B L I C   F U N C T I O N S
 *
 **********************************************************************/


int private_openat(int directory_file_descriptor, const char* path_name, int flags)
{
	int file_descriptor;
	char full_path[MAX_PATH_LEN];

	full_path = get_full_path(directory_file_descriptor, path_name);
	if (full_path == NULL)
		return -1;

	file_descriptor = open(full_path, flags);

	return file_descriptor;
}


int private_mkdirat(int directory_file_descriptor, const char* path_name, mode_t mode)
{
	int file_descriptor;
	char full_path[MAX_PATH_LEN];

	full_path = get_full_path(directory_file_descriptor, path_name);
	if (full_path == NULL)
		return -1;

	file_descriptor = mkdir(full_path, mode);

	return file_descriptor;
}


int private_opendirat(int directory_file_descriptor, const char* path_name)
{
	int file_descriptor;
	char full_path[MAX_PATH_LEN];

	full_path = get_full_path(directory_file_descriptor, path_name);
	if (full_path == NULL)
		return -1;

	file_descriptor = opendir(full_path);

	return file_descriptor;
}


int private_closedirat(int directory_file_descriptor, const char* path_name)
{
	int file_descriptor;
	char full_path[MAX_PATH_LEN];

	full_path = get_full_path(directory_file_descriptor, path_name);
	if (full_path == NULL)
		return -1;

	file_descriptor = closedir(full_path);

	return file_descriptor;
}