#include <stdio.h>
#include <stdlib.h>
#include "simple.h"

/* this is all out of pathgeom.h and will eventually get included */

typedef struct Pxy_t {
    double x, y;
} Pxy_t;

typedef struct Pxy_t Ppoint_t;
typedef struct Pxy_t Pvector_t;

typedef struct Ppoly_t {
    Ppoint_t *ps;
    int pn;
} Ppoly_t;

typedef Ppoly_t Ppolyline_t;

typedef struct Pedge_t {
    Ppoint_t a, b;
} Pedge_t;


#ifdef NOTDEF
int main(int argc, char **argv)	{
	Ppoly_t	polys[2], *polys_ptr[2];

	polys[0].ps = (Ppoint_t *) malloc(3 * sizeof (Ppoint_t));
	polys[1].ps = (Ppoint_t *) malloc(3 * sizeof (Ppoint_t));
	polys[0].pn  = 3;
	polys[1].pn  = 3;

	polys[0].ps[0].x = 0.0; polys[0].ps[0].y = 0.0;
	polys[0].ps[1].x = 0.0; polys[0].ps[1].y = 100.0;
	polys[0].ps[2].x = 100.0; polys[0].ps[2].y = 0.0;

	polys[1].ps[0].x = 70.0; polys[1].ps[0].y = 70.0;
	polys[1].ps[1].x = 70.0; polys[1].ps[1].y = 100.0;
	polys[1].ps[2].x = 100.0; polys[1].ps[2].y = 70.0;

	polys_ptr[0] = &polys[0];
	polys_ptr[1] = &polys[1];

	if (Plegal_arrangement(polys_ptr, 2 ))
		printf(" it is legal\n");
	else
		printf(" it is not legal\n");
}
#endif

#ifdef NOTDEF
struct vertex *after(struct vertex *v) {
	if (v == v->poly->finish) return v->poly->start;
	else return v + 1;
}

struct vertex *before(struct vertex *v) {
	if (v == v->poly->start) return v->poly->finish;
	else return v - 1;
}
#endif

void find_ints(struct vertex vertex_list[], struct polygon polygon_list[], 
	       struct data *input, struct intersection ilist[]);

int Plegal_arrangement( Ppoly_t	**polys, int	n_polys)	 {

	int	i, j, vno, nverts, rv;

	struct vertex 		*vertex_list;
	struct polygon 		*polygon_list;
	struct data 		input ;
	struct intersection   	ilist[10000];

	polygon_list = (struct polygon *)
		malloc(n_polys * sizeof(struct polygon));

	for (i = nverts = 0 ; i < n_polys; i++ )
		nverts += polys[i]->pn;

	vertex_list = (struct vertex *)
		malloc(nverts * sizeof(struct vertex));

	for (i = vno = 0 ; i < n_polys; i++ )	{
		polygon_list[i].start = &vertex_list[vno];
		for (j = 0 ; j < polys[i]->pn ; j++ )	{
			vertex_list[vno].pos.x = polys[i]->ps[j].x;
			vertex_list[vno].pos.y = polys[i]->ps[j].y;
			vertex_list[vno].poly = &polygon_list[i];
			vno++;
			}
		polygon_list[i].finish = &vertex_list[vno-1];
		}

	input.nvertices = nverts;
	input.npolygons = n_polys;

	find_ints(vertex_list, polygon_list, &input, ilist);


#define EQ_PT(v,w) (((v).x == (w).x) && ((v).y == (w).y))
	rv = 1;
	{
	int	i;
	struct position	 vft, vsd, avft, avsd;
	for (i = 0; i < input.ninters; i++) {
		vft = ilist[i].firstv->pos;
		avft = after(ilist[i].firstv)->pos;
		vsd = ilist[i].secondv->pos;
		avsd = after(ilist[i].secondv)->pos;
		if ( ((vft.x != avft.x) && (vsd.x != avsd.x)) ||
			((vft.x == avft.x)  &&
				!EQ_PT(vft,ilist[i]) &&
				!EQ_PT(avft,ilist[i])) || 
			((vsd.x == avsd.x)  &&
				!EQ_PT(vsd,ilist[i]) &&
				!EQ_PT(avsd,ilist[i])) )  {
			rv = 0;
			fprintf(stderr,"\nintersection %d at %.3f %.3f\n",
				i,ilist[i].x,ilist[i].y);
			fprintf(stderr,"seg#1 : (%.3f, %.3f) (%.3f, %.3f)\n"
				,(double)(ilist[i].firstv->pos.x) 
				,(double)(ilist[i].firstv->pos.y)
				,(double)(after(ilist[i].firstv)->pos.x)
				,(double)(after(ilist[i].firstv)->pos.y));
			fprintf(stderr,"seg#2 : (%.3f, %.3f) (%.3f, %.3f)\n"
				,(double)(ilist[i].secondv->pos.x)
				,(double)(ilist[i].secondv->pos.y)
				,(double)(after(ilist[i].secondv)->pos.x)
				,(double)(after(ilist[i].secondv)->pos.y));
			}
	}
	}
	free(polygon_list);
	free(vertex_list);
	return rv;
}

