#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <dirent.h>
#include <unistd.h>
#include <grass/dbmi.h>
#include <grass/gis.h>

static
char *dbmscap_files[] = {
    "/etc/dbmscap",
    "/lib/dbmscap",
    "/usr/lib/dbmscap",
    "/usr/local/lib/dbmscap",
    "/usr/local/dbmi/lib/dbmscap",
    NULL };

extern char *getenv();
static void add_entry();

static char *
dbmscap_filename(err_flag)
{
    char *file;
    int i;

    file = getenv ("DBMSCAP");
    if (file)
	return file;

    for (i = 0; file = dbmscap_files[i]; i++)
    {
	if (access (file, 0) == 0)
	    return file;
    }
    if(err_flag)
	db_error ("DBMSCAP not set");
    return ((char *)NULL);
}

/*!
 \fn 
 \brief 
 \return 
 \param 
*/
char *
db_dbmscap_filename()
{
    return dbmscap_filename(1);
}

/*!
 \fn 
 \brief 
 \return 
 \param 
*/
int
db_has_dbms()
{
    return (dbmscap_filename(0) != NULL);
}

/*!
 \fn 
 \brief 
 \return 
 \param 
*/
void
db_copy_dbmscap_entry (dbDbmscap *dst, dbDbmscap *src)

{
    strcpy (dst->driverName, src->driverName);
    strcpy (dst->comment, src->comment);
    strcpy (dst->startup, src->startup);
}

/*!
 \fn 
 \brief 
 \return 
 \param 
*/
/* dbmscap file was used in grass5.0 but it is not used in
 * grass5.7 until we find it necessary. All code for dbmscap
 * file is commented here. 
 *
 * Instead of in dbmscap file db_read_dbmscap() searches 
 * for available dbmi drivers in $(GISBASE)/driver/db/  */ 

dbDbmscap *
db_read_dbmscap()
{
    /*	
    FILE *fd;
    char *file;
    char name[1024];
    char startup[1024];
    char comment[1024];
    int  line;
    */
    char   buf[1024];
    char   *dirpath;
    DIR    *dir;	
    struct dirent *ent;	

    dbDbmscap *list = NULL;

/* START OF OLD CODE FOR dbmscap FILE - NOT USED, BUT KEEP IT FOR FUTURE */
    /* get the full name of the dbmscap file */
    /*
    file = db_dbmscap_filename();
    if (file == NULL)
	return (dbDbmscap *) NULL;
    */
    
    /* open the dbmscap file */
    /*
    fd = fopen (file, "r");
    if (fd == NULL)
    {
	db_syserror (file);
	return (dbDbmscap *) NULL;
    }
    */ 
    
    /* find all valid entries
     * blank lines and lines with # as first non blank char are ignored
     * format is:
     *   driver name:startup command:comment
     */
    /*
    for (line = 1; fgets (buf, sizeof buf, fd); line++)
    {
	if (sscanf (buf, "%1s", comment) != 1 || *comment == '#')
	    continue;
	if (sscanf (buf, "%[^:]:%[^:]:%[^:\n]", name, startup, comment) == 3)
	    add_entry (&list, name, startup, comment);
	else if (sscanf (buf, "%[^:]:%[^:\n]", name, startup) == 2)
	    add_entry (&list, name, startup, "");
	else
	{
	    fprintf (stderr, "%s: line %d: invalid entry\n", file, line);
	    fprintf (stderr,"%d:%s\n", line, buf);
	}
	if (list == NULL)
	    break;
    }
    fclose (fd);
    */
/* END OF OLD CODE FOR dbmscap FILE */

/* START OF NEW CODE FOR SEARCH IN $(GISBASE)/driver/db/ */
    
    /* opend db drivers directory */
#ifdef __MINGW32__
    dirpath = G_malloc ( strlen("\\driver\\db\\") + strlen(G_gisbase()) + 1 );
    sprintf ( dirpath, "%s\\driver\\db\\", G_gisbase());
#else
    G_asprintf (&dirpath, "%s/driver/db/", G_gisbase());
#endif

    G_debug ( 2, "opendir %s\n", dirpath );
    dir = opendir(dirpath);
    if (dir == NULL)
    {
	db_syserror ("Cannot open drivers directory");
	return (dbDbmscap *) NULL;
    }
    G_free (dirpath);
    
    /* read all drivers */
    while ( ent = readdir (dir) )
      {
	char *name;

        if ( (strcmp (ent->d_name, ".") == 0) 
	    || (strcmp (ent->d_name, "..") == 0) ) continue;	

	/* Remove '.exe' from name (windows extension) */
	name = G_str_replace ( ent->d_name, ".exe", "" );
	
#ifdef __MINGW32__
        dirpath = G_malloc ( strlen("\\driver\\db\\") 
                  + strlen(G_gisbase()) + strlen(ent->d_name) + 1 );
        sprintf ( dirpath, "%s\\driver\\db\\%s", G_gisbase(), ent->d_name);
#else
        G_asprintf (&dirpath, "%s/driver/db/%s", G_gisbase(),ent->d_name);
#endif
	add_entry (&list, name, dirpath, "");
	G_free (name);
	G_free (dirpath);
      }
    
    closedir (dir);

    return list;
}

static void
add_entry  (dbDbmscap **list, char *name, char *startup, char *comment)

{
    dbDbmscap *head, *cur, *tail;

/* add this entry to the head of a linked list */
    tail = head = *list;
    while (tail && tail->next)
	tail = tail->next;
    *list = NULL;

    cur = (dbDbmscap *) db_malloc (sizeof(dbDbmscap));
    if (cur == NULL)
	return; /* out of memory */
    cur->next = NULL;

/* copy each item to the dbmscap structure */
    strcpy (cur->driverName, name);
    strcpy (cur->startup, startup);
    strcpy (cur->comment, comment);

/* handle the first call (head == NULL) */
    if (tail)
	tail->next = cur;
    else
	head = cur;

    *list = head;
}

/*!
 \fn 
 \brief 
 \return 
 \param 
*/
void
db_free_dbmscap  (dbDbmscap *list)

{
    dbDbmscap *next, *cur;

    for (cur = list; cur; cur = next)
    {
	next = cur->next;
	free (cur);
    }
}