#include <sys/types.h>

#include <sys/stat.h>

#include <errno.h>

#include <string.h>

#include <stdlib.h>

#include "dirent.h"





DIR*

opendir(const char* pDirName)

{

	struct stat sb;

	DIR*	pDir;

	char*	pEndDirName;

	int	nBufferLen;



	/* sanity checks */

	if (!pDirName) {

		errno = EINVAL;

		return NULL;

	}

	if (stat(pDirName, &sb) != 0) {

		errno = ENOENT;

		return NULL;

	}

	if ((sb.st_mode & S_IFMT) != S_IFDIR) {

		errno = ENOTDIR;

		return NULL;

	}



	/* allocate a DIR structure to return */

	pDir = (DIR *) malloc(sizeof (DIR));



	if (!pDir)

		return NULL;



	/* input directory name length */

	nBufferLen = strlen(pDirName);



	/* copy input directory name to DIR buffer */

	strcpy(pDir->dir_pDirectoryName, pDirName);



	/* point to end of the copied directory name */

	pEndDirName = &pDir->dir_pDirectoryName[nBufferLen - 1];



	/* if directory name did not end in '/' or '\', add '/' */

	if ((*pEndDirName != '/') && (*pEndDirName != '\\')) {

		pEndDirName++;

		*pEndDirName = '/';

	}



	/* now append the wildcard character to the buffer */

	pEndDirName++;

	*pEndDirName = '*';

	pEndDirName++;

	*pEndDirName = '\0';



	/* other values defaulted */

	pDir->dir_nNumFiles = 0;

	pDir->dir_hDirHandle = INVALID_HANDLE_VALUE;	

	pDir->dir_ulCookie = __DIRENT_COOKIE;



	return pDir;

}



void

closedir(DIR *pDir)

{

	/* got a valid pointer? */

	if (!pDir) {

		errno = EINVAL;

		return;

	}



	/* sanity check that this is a DIR pointer */

	if (pDir->dir_ulCookie != __DIRENT_COOKIE) {

		errno = EINVAL;

		return;

	}



	/* close the WINDOWS32 directory handle */

	if (pDir->dir_hDirHandle != INVALID_HANDLE_VALUE)

		FindClose(pDir->dir_hDirHandle);



	free(pDir);



	return;

}



struct dirent *

readdir(DIR* pDir)

{

	WIN32_FIND_DATA wfdFindData;



	if (!pDir) {

		errno = EINVAL;

		return NULL;

	}



	/* sanity check that this is a DIR pointer */

	if (pDir->dir_ulCookie != __DIRENT_COOKIE) {

		errno = EINVAL;

		return NULL;

	}



	if (pDir->dir_nNumFiles == 0) {

		pDir->dir_hDirHandle = FindFirstFile(pDir->dir_pDirectoryName, &wfdFindData);

		if (pDir->dir_hDirHandle == INVALID_HANDLE_VALUE)

			return NULL;

	} else if (!FindNextFile(pDir->dir_hDirHandle, &wfdFindData))

			return NULL;



	/* bump count for next call to readdir() or telldir() */

	pDir->dir_nNumFiles++;



	/* fill in struct dirent values */

	pDir->dir_sdReturn.d_ino = -1;

	strcpy(pDir->dir_sdReturn.d_name, wfdFindData.cFileName);



	return &pDir->dir_sdReturn;

}



void

rewinddir(DIR* pDir)

{

	if (!pDir) {

		errno = EINVAL;

		return;

	}



	/* sanity check that this is a DIR pointer */

	if (pDir->dir_ulCookie != __DIRENT_COOKIE) {

		errno = EINVAL;

		return;

	}



	/* close the WINDOWS32 directory handle */

	if (pDir->dir_hDirHandle != INVALID_HANDLE_VALUE)

		if (!FindClose(pDir->dir_hDirHandle))

			errno = EBADF;



	/* reset members which control readdir() */

	pDir->dir_hDirHandle = INVALID_HANDLE_VALUE;

	pDir->dir_nNumFiles = 0;



	return;

}



int

telldir(DIR* pDir)

{

	if (!pDir) {

		errno = EINVAL;

		return -1;

	}



	/* sanity check that this is a DIR pointer */

	if (pDir->dir_ulCookie != __DIRENT_COOKIE) {

		errno = EINVAL;

		return -1;

	}



	/* return number of times readdir() called */

	return pDir->dir_nNumFiles;

}



void

seekdir(DIR* pDir, long nPosition)

{

	if (!pDir)

		return;



	/* sanity check that this is a DIR pointer */

	if (pDir->dir_ulCookie != __DIRENT_COOKIE)

		return;



	/* go back to beginning of directory */

	rewinddir(pDir);



	/* loop until we have found position we care about */

	for (--nPosition; nPosition && readdir(pDir); nPosition--);



	/* flag invalid nPosition value */

	if (nPosition)

		errno = EINVAL;



	return;

}

