#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <grass/dbmi.h>
/* NOTE: these should come from <unistd.h> or from <sys/file.h> */
#define R_OK 4
#define W_OK 2
#define X_OK 1

#include <sys/types.h>
#ifdef USE_DIRECT
# include <sys/dir.h>
  typedef struct direct dir_entry;
#else
# include <dirent.h>
  typedef struct dirent dir_entry;
#endif

extern DIR       *opendir();
extern dir_entry *readdir();

static int get_perm();
static void sort_dirent();


/*!
 \fn 
 \brief 
 \return 
 \param 
*/
/* read directory and build an array of dbDirent's */
/* append one entry with name = NULL to mark end of array */
dbDirent *
db_dirent  (char *dirname, int *n)

{
    DIR  *dp;
    dir_entry *entry;
    dbDirent *dirent;
    int i, count;
    char *path;
    int len, max;

    db_clear_error();

    *n = 0;
    dp = opendir(dirname);
    if (dp == NULL)
    {
	db_syserror(dirname);
	return (dbDirent *) NULL; 
    }


/* count the number of entries and get the strlen of the longest name */
    count = 0;
    max = 0;
    while (entry = readdir(dp))
    {
	count++;
	len = strlen (entry->d_name);
	if (len > max) max = len;
    }
    rewinddir(dp);

    path = db_malloc (strlen(dirname) + max + 2); /* extra 2 for / and NULL */
    if (path == NULL)
    {
	closedir(dp);
	return (dbDirent *) NULL; 
    }
    dirent = db_alloc_dirent_array (count);
    if (dirent == NULL)
    {
	closedir(dp);
	return (dbDirent *) NULL; 
    }
    *n = count;
    for (i = 0; i < count; i++)
    {
	entry = readdir(dp);
	if (entry == NULL)  /* this shouldn't happen */
	    break;

	if(DB_OK != db_set_string (&dirent[i].name, entry->d_name))
	    break;
	sprintf (path, "%s/%s", dirname, entry->d_name);
	dirent[i].perm = get_perm(path);
	dirent[i].isdir = (db_isdir(path) == DB_OK);
    }
    closedir(dp);
    free (path);

    sort_dirent(dirent, *n);

    return dirent;
}

/*!
 \fn 
 \brief 
 \return 
 \param 
*/
void
db_free_dirent_array  (dbDirent *dirent, int  count)

{
    int i;

    if (dirent)
    {
	for (i = 0; i < count; i++)
	    db_free_string(&dirent[i].name);
	free(dirent);
    }
}

static int
get_perm  (char *path)

{
    int perm;

    perm = 0;

    if (access(path,R_OK) == 0)
	perm |= DB_PERM_R;
    if (access(path,W_OK) == 0)
	perm |= DB_PERM_W;
    if (access(path,X_OK) == 0)
	perm |= DB_PERM_X;

    return perm;
}

static int
cmp_dirent  (const void *aa, const void *bb)

{
    const dbDirent *a = aa;
    const dbDirent *b = bb;
    return strcmp (db_get_string(&a->name), db_get_string(&b->name));
}

static void
sort_dirent  (dbDirent *a, int n)

{
    qsort (a, n, sizeof(dbDirent), cmp_dirent);
}

/*!
 \fn 
 \brief 
 \return 
 \param 
*/
dbDirent *
db_alloc_dirent_array  (int count)

{
    int i;
    dbDirent *dirent;

    dirent = (dbDirent *) db_calloc (count, sizeof(dbDirent));
    if (dirent == NULL)
	return dirent;

    for (i = 0; i < count; i++)
	db_init_string(&dirent[i].name);

    return dirent;
}