/***************************************************************************
*
* MODULE:    r.buffer
*
* AUTHOR(S): Michael Shapiro, US Army Construction Engineering Research Laboratory
*	     James Westervelt, US Army CERL
*
* PURPOSE:   This program creates distance zones from non-zero
*	     cells in a grid layer. Distances are specified in
*	     meters (on the command-line). Window does not have to
*	     have square cells. Works both for planimetric (UTM,
*	     State Plane) and lat-long.
*
* COPYRIGHT: (c) 2006 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.
*
**************************************************************************/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define GLOBAL
#include "distance.h"
#include "local_proto.h"
#include <grass/glocale.h>

int main (int argc, char *argv[])
{
    struct Distance *pd;
    char *input, *output, *mapset;
    char **zone_list;
    double to_meters;
    char *units;
    int offset;
    int count;
    int step, nsteps;
    struct History hist;
    int quiet;

    struct GModule *module;
    struct Option *opt1, *opt2, *opt3, *opt4;
    struct Flag *flag1;
    struct Flag *flag2;
    int ZEROFLAG;

    /* initialize GRASS */
    G_gisinit(argv[0]);

    pgm_name = argv[0];

    module = G_define_module();
    module->keywords = _("raster, buffer");
    module->description =
		_("Creates a raster map layer showing buffer zones "
		"surrounding cells that contain non-NULL category values.");

    opt1 = G_define_standard_option(G_OPT_R_INPUT);

    opt2 = G_define_standard_option(G_OPT_R_OUTPUT);

    opt3 = G_define_option() ;
    opt3->key        = "distances" ;
    opt3->type       = TYPE_DOUBLE;
    opt3->required   = YES ;
    opt3->multiple   = YES;
    opt3->description= _("Distance zone(s)") ;

    opt4 = G_define_option() ;
    opt4->key        = "units" ;
    opt4->options    = "meters,kilometers,feet,miles,nautmiles";
    opt4->type       = TYPE_STRING ;
    opt4->required   = NO ;
    opt4->description= _("Units of distance") ;
    opt4->answer     = "meters";

    flag1 = G_define_flag() ;
    flag1->key         = 'q';
    flag1->description = _("Run quietly");

    flag2 = G_define_flag() ;
    flag2->key         = 'z' ;  
    flag2->description = _("Ignore zero (0) data cells instead of NULL cells") ;

    if (G_parser(argc, argv))
        exit(EXIT_FAILURE);

    init_grass();

    /* get input, output map names */
    input     = opt1->answer; 
    output    = opt2->answer; 
    zone_list = opt3->answers;
    units     = opt4->answer;

    quiet = flag1->answer;
    ZEROFLAG = 0; /* default: use NULL for non-data cells */
    ZEROFLAG = (flag2->answer);                                               
        
    mapset = G_find_cell (input, "");
    if (mapset == NULL)
	G_fatal_error(_("%s: %s - not found"), pgm_name, input);

    if (G_legal_filename(output) < 0)
	G_fatal_error(_("%s: %s - illegal name"), pgm_name, output);

        /* parse units */
    if (opt4->answer == NULL)
	units = "meters";

    if (strcmp(units, "meters") == 0)
	to_meters = 1.0;
    else if (strcmp(units, "feet") == 0)
	to_meters = FEET_TO_METERS;
    else if (strcmp(units, "kilometers") == 0)
	to_meters = KILOMETERS_TO_METERS;
    else if (strcmp(units, "miles") == 0)
	to_meters = MILES_TO_METERS;
    else if (strcmp(units, "nautmiles") == 0)
	to_meters = NAUT_MILES_TO_METERS;
    else
	G_fatal_error(_("%s: %s - illegal units"), pgm_name, units);

	/* parse distances */
    if(!(count = parse_distances (zone_list, to_meters)))
        G_fatal_error(_("parse distances error"));


	/* need to keep track of distance zones - in memory.
	 * process MAX_DIST at a time
	 *
	 * Coding: 0 == not-yet determined, 1 == input cells,
	 *         2 == distance zone #1,   3 == distance zone #2, etc.
	 */

    read_input_map (input, mapset, quiet, ZEROFLAG);

    offset = 0;

    nsteps = (count - 1) / MAX_DIST + 1;
	
    pd = distances;
    for (step = 1; count > 0; step++)
    {
	if(!quiet) {
	    if (nsteps > 1)
		G_message(_("Pass %d (of %d)"), step, nsteps);
	}
	ndist = count;
	if (ndist > MAX_DIST)
	    ndist = MAX_DIST;
	if(count_rows_with_data > 0) 
	    execute_distance(quiet);
	write_output_map(output, offset, quiet);
	offset += ndist;
	distances += ndist;
	count -= ndist;
    }
    distances = pd;
    make_support_files (output, units);

    /* write map history (meta data) */
    G_short_history(output, "raster", &hist);
    sprintf(hist.datsrc_1, "%s", input);
    if( strlen(opt3->answer) < (RECORD_LEN - 14) ) {
	sprintf(hist.edhist[0], "Buffer distance%s:", ndist>1 ? "s" : "");
	sprintf(hist.edhist[1], " %s %s", opt3->answer, units);
	hist.edlinecnt = 2;
    }
    G_command_history(&hist);
    G_write_history (output, &hist);


    exit(EXIT_SUCCESS);
}