/*
** Portable unicode implementation of opendir()
*/
#if INTERFACE

#if defined(_WIN32)
# include <wdirent.h>
# define FOSSIL_DIR WDIR
# define fossil_dirent wdirent
# define fossil_opendir wopendir
# define fossil_readdir wreaddir
# define fossil_closedir wclosedir
#else
# include <dirent.h>
# define FOSSIL_DIR DIR
# define fossil_dirent dirent
# define fossil_opendir opendir
# define fossil_readdir readdir
# define fossil_closedir closedir

#define DIRENT_H

#include <windows.h>
#include <string.h>
#include <assert.h>


typedef struct dirent
{
   char d_name[MAX_PATH + 1]; /* current dir entry (multi-byte char string) */
   WIN32_FIND_DATAA data;     /* file attributes */
}  dirent;


typedef struct DIR
{
   dirent current;            /* Current directory entry */
   int    cached;             /* Indicates un-processed entry in memory */
   HANDLE search_handle;      /* File search handle */
   char   patt[MAX_PATH + 3]; /* search pattern (3 = pattern + "\\*\0") */
} DIR;


/* Forward declarations */
static DIR *opendir (const char *dirname);
static struct dirent *readdir (DIR *dirp);
static int closedir (DIR *dirp);
static void rewinddir(DIR* dirp);


/* Use the new safe string functions introduced in Visual Studio 2005 */
#if defined(_MSC_VER) && _MSC_VER >= 1400
# define STRNCPY(dest,src,size) strncpy_s((dest),(size),(src),_TRUNCATE)
#else
# define STRNCPY(dest,src,size) strncpy((dest),(src),(size))
#endif


/*****************************************************************************
 * Open directory stream DIRNAME for read and return a pointer to the
 * internal working area that is used to retrieve individual directory
 * entries.
 */
static DIR *opendir(const char *dirname)
{
   DIR *dirp;
   assert (dirname != NULL);
   assert (strlen (dirname) < MAX_PATH);

   /* construct new DIR structure */
   dirp = (DIR*) malloc (sizeof (struct DIR));
   if (dirp != NULL) {
      char *p;

      /* take directory name... */
      STRNCPY (dirp->patt, dirname, sizeof(dirp->patt));
      dirp->patt[MAX_PATH] = '\0';

      /* ... and append search pattern to it */
      p = strchr (dirp->patt, '\0');
      if (dirp->patt < p  &&  *(p-1) != '\\'  &&  *(p-1) != ':') {
         *p++ = '\\';
      }
      *p++ = '*';
      *p = '\0';

      /* open stream and retrieve first file */
      dirp->search_handle = FindFirstFileA (dirp->patt, &dirp->current.data);
      if (dirp->search_handle == INVALID_HANDLE_VALUE) {
         /* invalid search pattern? */
         free (dirp);
         return NULL;
      }

      /* there is an un-processed directory entry in memory now */

/*****************************************************************************
 * Read a directory entry, and return a pointer to a dirent structure
 * containing the name of the entry in d_name field.  Individual directory
 * entries returned by this very function include regular files,
 * sub-directories, pseudo-directories "." and "..", but also volume labels,
 * hidden files and system files may be returned.
 */
static struct dirent *readdir(DIR *dirp)
{
   assert (dirp != NULL);

   if (dirp->search_handle == INVALID_HANDLE_VALUE) {
      /* directory stream was opened/rewound incorrectly or ended normally */
      return NULL;
   }

   /* get next directory entry */
   if (dirp->cached != 0) {
      /* a valid directory entry already in memory */
      dirp->cached = 0;
   } else {
      /* read next directory entry from disk */
      if (FindNextFileA (dirp->search_handle, &dirp->current.data) == FALSE) {
         /* the very last file has been processed or an error occured */
         FindClose (dirp->search_handle);
         dirp->search_handle = INVALID_HANDLE_VALUE;
         return NULL;
      }
   }

/*****************************************************************************
 * Close directory stream opened by opendir() function.  Close of the
 * directory stream invalidates the DIR structure as well as any previously
 * read directory entry.
 */
static int closedir(DIR *dirp)
{
   assert (dirp != NULL);

   /* release search handle */
   if (dirp->search_handle != INVALID_HANDLE_VALUE) {
      FindClose (dirp->search_handle);
      dirp->search_handle = INVALID_HANDLE_VALUE;
   }

   /* release directory handle */
   free (dirp);
   return 0;
}


/*****************************************************************************
 * Resets the position of the directory stream to which dirp refers to the
 * beginning of the directory. It also causes the directory stream to refer
 * to the current state of the corresponding directory, as a call to opendir()
 * would have done. If dirp does not refer to a directory stream, the effect
 * is undefined.
 */
static void rewinddir(DIR* dirp)
{
   /* release search handle */
   if (dirp->search_handle != INVALID_HANDLE_VALUE) {
      FindClose (dirp->search_handle);
      dirp->search_handle = INVALID_HANDLE_VALUE;
   }

   /* open new search handle and retrieve first file */
   dirp->search_handle = FindFirstFileA (dirp->patt, &dirp->current.data);
   if (dirp->search_handle == INVALID_HANDLE_VALUE) {
      /* invalid search pattern? */
      free (dirp);
      return;
   }

   /* there is an un-processed directory entry in memory now */
   dirp->cached = 1;
}


#endif /*DIRENT_H*/