#include <stdio.h>
#include <math.h>
#include <float.h>
#include <grass/gis.h>
#include <grass/Vect.h>
#include <grass/display.h>
#include "sw_defs.h"
#include "defs.h"
#include "write.h"

int 
write_triple (struct Site *s1, struct Site *s2, struct Site *s3 )
{
    int i;
    int node;
    static struct line_pnts *Points = NULL;
    static struct line_cats *Cats = NULL;
    struct Site *sa, *sb;
    
    
    if ( !Points ) {
	Points = Vect_new_line_struct ();
	Cats = Vect_new_cats_struct ();
    }
    
    if(triangulate) { 
	for ( i = 0; i < 3; i++ ) {
	    switch ( i ) {
		case 0:
		    sa = s1;
		    sb = s2;
		    break;
		case 1:
		    sa = s2;
		    sb = s3;
		    break;
		case 2:
		    sa = s3;
		    sb = s1;
		    break;
	    }

	    /* Look if the line already exists */
	    node = Vect_find_node ( &Out, sa->coord.x, sa->coord.y, 0.0, 0.0, 0 );

	    if ( node > 0  ) { /* node found */
		int j, nlines;
		int found = 0;
		double x, y;
		
		nlines = Vect_get_node_n_lines ( &Out, node );

		for ( j = 0; j < nlines; j++ ) {
		    int line, node2;
		    
		    line = Vect_get_node_line ( &Out, node, j );
		    
		    if ( line > 0 ) 
			Vect_get_line_nodes ( &Out, line, NULL, &node2 );
		    else 
			Vect_get_line_nodes ( &Out, abs(line), &node2, NULL );
		
		    Vect_get_node_coor ( &Out, node2, &x, &y, NULL );
		    
		    if ( x == sb->coord.x && y == sb->coord.y ) {
			found = 1;
			break;
		    }
		}

		if ( found ) continue; /* next segment */
	    }

	    /* Not found, write it */
	    Vect_reset_line ( Points );
	    Vect_append_point ( Points, sa->coord.x, sa->coord.y, 0.0 );
	    Vect_append_point ( Points, sb->coord.x, sb->coord.y, 0.0 );
	    Vect_write_line ( &Out, Type, Points, Cats );
	}
    }

    return 0;
}