/*
 * $Id: list.c,v 2.15.4.2 2006/10/19 15:23:28 markus Exp $
 *
 ****************************************************************************
 *
 * MODULE:       GRASS 5 gis library, list.c
 * AUTHOR(S):    unknown
 * PURPOSE:      list elements
 * COPYRIGHT:    (C) 2000 by the GRASS Development Team
 *
 *               This program is free software under the GNU General Public
 *   	    	 License (>=v2). Read the file COPYING that comes with GRASS
 *   	    	 for details.
 *
 *****************************************************************************/

/**********************************************************************
 *  G_list_element (element, desc, mapset, lister)
 *
 *      char *element    database element (eg, "cell", "cellhd", etc)
 *      char *desc       desc for element (if NULL, element is used)
 *      char *mapset     mapset to be listed.
 *                       "" to list all mapsets in mapset search list
 *                       "." will list current mapset
 *
 *      int (*lister)()  if given will call this routine to get a list
 *                       title. NULL if no titles desired.
 *
 *                       lister (name, mapset, buf)
 *                       char *name, *mapset, *buf
 *
 *                       given file 'name', and 'mapset',
 *                       lister() should copy a string into 'buf'
 *
 *                       when called with name == "", should set buf
 *                       to general title for mapset list.
 *
 *   General purpose list function. Will list files from all mapsets
 *   in the mapset list for a specified database element.
 *
 *   note:
 *      output is to stdout piped thru the more utility
 *********************************************************************/

#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include <string.h>
#include <sys/types.h>
#include <dirent.h>
#include <grass/gis.h>
#include <grass/glocale.h>

static int broken_pipe;
static int hit_return = 0;
static int list_element(FILE *,char *,char *,char *,int (*)());
static void sigpipe_catch(int);
static int pstrcmp(const void *, const void *);

int G_set_list_hit_return(int flag)
{
    hit_return = flag;
    return 0;
}

int G_list_element (
    char *element,
    char *desc,
    char *mapset,
    int (*lister)())
{
    int n;
    FILE *more;
    int count;
#ifdef SIGPIPE
    void (*sigpipe)();
#endif

/* must catch broken pipe in case "more" quits */
    broken_pipe = 0;
#ifdef SIGPIPE
    sigpipe = signal (SIGPIPE, sigpipe_catch);
#endif

    count = 0;
    if (desc == 0 || *desc == 0)
	desc = element;
/*
 * G_popen() the more command to page the output
 */
    if (isatty(1))
    {
	more = G_popen ("$GRASS_PAGER","w");
	if (!more) more = stdout;
    }
    else
	more = stdout;
    fprintf (more,"----------------------------------------------\n");

/*
 * if no specific mapset is requested, list the mapsets
 * from the mapset search list
 * otherwise just list the specified mapset
 */
    if (mapset == 0 || *mapset == 0)
	for (n = 0; !broken_pipe && (mapset = G__mapset_name (n)); n++)
	    count += list_element (more, element, desc, mapset, lister);
    else
	count += list_element (more, element, desc, mapset, lister);

    if (!broken_pipe)
    {
	if (count == 0){
	   if (mapset == 0 || *mapset == 0)
	    fprintf (more,_("no %s files available in current mapset\n"), desc);
	   else
	    fprintf (more,_("no %s files available in mapset %s\n"), desc, mapset);
	}

	fprintf (more,"----------------------------------------------\n");
    }
/*
 * close the more
 */
    if (more != stdout) G_pclose (more);
#ifdef SIGPIPE
    signal (SIGPIPE, sigpipe);
#endif
if (hit_return && isatty(1))
    {
	fprintf (stderr, _("hit RETURN to continue -->"));
	while (getchar() != '\n')
	    ;
    }

    return 0;
}

static void sigpipe_catch(int n)
{
    broken_pipe = 1;
    signal (n,sigpipe_catch);
}

static int list_element( FILE *out, char *element,
    char *desc, char *mapset, int (*lister)())
{
    char path[1000];
    DIR *dirp;
    struct dirent *dp;
    int count = 0, maxlen = 0, num_cols = 1;
    char **list;
    int i;

/*
 * convert . to current mapset
 */
    if (strcmp (mapset,".") == 0)
	mapset = G_mapset();


/*
 * get the full name of the GIS directory within the mapset
 * and list its contents (if it exists)
 *
 * if lister() routine is given, the ls command must give 1 name
 */
    G__file_name (path, element, "", mapset);
    if (access(path, 0) != 0)
    {
	fprintf(out,"\n");
    	return count;
    }

/*
 * if a title so that we can call lister() with the names
 * otherwise the ls must be forced into columnar form.
 */

    if ((dirp = opendir(path)) == NULL)
    	G_fatal_error("ERROR: %s: open failed.", path);

    if (!lister)
    {
    	while((dp = readdir(dirp)) != NULL)
    	{
    		if (dp->d_name[0] == '.')
    			continue;
    		if (maxlen < (i = strlen(dp->d_name)))
    			maxlen = i;
    	}
    	rewinddir(dirp);

    	num_cols = 80 / (maxlen + 1); /* + 1: column separator */
    }

    if (num_cols < 1)
        num_cols = 1;

    list = NULL;
    while ((dp = readdir(dirp)) != NULL)
    {
        if (dp->d_name[0] == '.')
    	    continue;

        if ((list=(char **)G_realloc(list, (count+1)*sizeof(char *))) == NULL ||
           (list[count] = (char *)G_malloc(strlen(dp->d_name)+1)) == NULL)
    	    G_fatal_error("ERROR: memory allocation error!");
        strcpy(list[count++], dp->d_name);
    }
    closedir(dirp);

    if (count > 0)
    {
        fprintf(out, _("%s files available in mapset %s:\n"), desc, mapset);
        if (lister)
        {
    	    char title[400];
    	    char name[GNAME_MAX];

    	    *name = *title = 0;
    	    lister (name, mapset, title);
    	    if (*title)
    	        fprintf(out,"\n%-18s %-.60s\n",name,title);
        }
    }

    qsort(list, (size_t)count, sizeof(char *), pstrcmp);

    for(i = 0; i < count; i++)
    {
        if (lister)
        {
	    char title[400];
            char *b;
    
            /* remove the trailing newline */
            for (b = list[i]; *b; b++)
        	if (*b == '\n')
        	    *b = 0;
    
            lister (list[i], mapset, title);
            fprintf(out,"%-18s %-.60s\n",list[i],title);
        }
        else
	{
	    if ((i+1) % num_cols)
                fprintf(out,"%-*s", maxlen+1, list[i]);
	    else
                fprintf(out,"%s", list[i]);
	}

        if (!lister && !((i+1) % num_cols))
            fprintf(out, "\n");

	G_free(list[i]);
    }

    if (!lister && (count % num_cols))
        fprintf(out,"\n");

    fprintf(out, "\n");

    if (list)
        G_free(list);

    return count;
}

static int pstrcmp(const void *s1, const void *s2)
{
    return strcmp(*(char **)s1, *(char **)s2);
}

/*!
 * \brief List specified type of elements. Application must release
          the allocated memory.
 * \param element Element type (G_ELEMENT_RASTER, G_ELEMENT_VECTOR, 
                                G_ELEMENT_REGION )
 * \param gisbase Path to GISBASE
 * \param location Location name
 * \param mapset Mapset name
 * \return Zero terminated array of element names
 */
char **G_list(int element, const char *gisbase, const char *location, const char* mapset)
{
    char *el;
    char *buf;
    DIR *dirp;
    struct dirent *dp;
    int count;
    char **list;
    
    switch ( element )
    {
        case G_ELEMENT_RASTER:
            el = "cell";
            break;

        case G_ELEMENT_GROUP:
            el = "group";
            break;

        case G_ELEMENT_VECTOR:
            el = "vector";
            break;

        case G_ELEMENT_REGION:
            el = "window";
            break;

        default:
            G_fatal_error ("G_list: Unknown element type." );
    }			
	
    buf = (char *) G_malloc ( strlen(gisbase) + strlen(location)
                              + strlen(mapset) + strlen(el) + 4 );

    sprintf ( buf, "%s/%s/%s/%s", gisbase, location, mapset, el );

    dirp = opendir(buf);
    G_free ( buf );		

    if ( dirp == NULL ) /* this can happen if element does not exist */
    {
        list = (char **) G_calloc ( 1, sizeof(char *) );
        return list;
    }

    count = 0;
    while((dp = readdir(dirp)) != NULL)
    {
	if (dp->d_name[0] == '.') continue;
        count++;
    }
    rewinddir(dirp);

    list = (char **) G_calloc ( count+1, sizeof(char *) );
    
    count = 0;
    while ((dp = readdir(dirp)) != NULL)
    {
        if (dp->d_name[0] == '.') continue;

        list[count] = (char *) G_malloc( strlen(dp->d_name)+1 );
        strcpy ( list[count], dp->d_name );
        count++;
    }
    closedir(dirp);

    return list;
}

void G_free_list(char **list)
{
    int i = 0;

    if ( !list ) return;
   
    while ( list[i] )
    {
        G_free (list[i]);
        i++;
    }
    G_free (list);
}