#include <math.h>
#include <float.h>
#include <string.h>
#include <stdio.h>
#include <errno.h>

#include "postgres.h"
#include "access/gist.h"
#include "access/itup.h"
#include "fmgr.h"
#include "utils/elog.h"
#include "utils/geo_decls.h"

#include "lwgeom_pg.h"
#include "liblwgeom.h"
#include "stringBuffer.h"


/* #define PGIS_DEBUG */

/* forward defs */
Datum BOX2DFLOAT4_in(PG_FUNCTION_ARGS);
Datum BOX2DFLOAT4_out(PG_FUNCTION_ARGS);
Datum LWGEOM_to_BOX2DFLOAT4(PG_FUNCTION_ARGS);
Datum BOX2DFLOAT4_expand(PG_FUNCTION_ARGS);
Datum BOX2DFLOAT4_to_BOX3D(PG_FUNCTION_ARGS);
Datum BOX2DFLOAT4_combine(PG_FUNCTION_ARGS);
Datum BOX2DFLOAT4_to_LWGEOM(PG_FUNCTION_ARGS);
Datum BOX2DFLOAT4_construct(PG_FUNCTION_ARGS);

/* parser - "BOX(xmin ymin,xmax ymax)" */
PG_FUNCTION_INFO_V1(BOX2DFLOAT4_in);
Datum BOX2DFLOAT4_in(PG_FUNCTION_ARGS)
{
	char *str = PG_GETARG_CSTRING(0);
	int nitems;
	BOX2DFLOAT4 *box = (BOX2DFLOAT4 *) palloc(sizeof(BOX2DFLOAT4));



/*printf( "box3d_in gets '%s'\n",str); */

	if (strstr(str,"BOX(") !=  str )
	{
		 pfree(box);
		 elog(ERROR,"BOX2DFLOAT4 parser - doesnt start with BOX(");
		 PG_RETURN_NULL();
	}
	nitems = sscanf(str,"BOX(%f %f,%f %f)", &box->xmin,&box->ymin,&box->xmax,&box->ymax);
	if (nitems != 4)
	{
		 pfree(box);
		 elog(ERROR,"BOX2DFLOAT4 parser - couldnt parse.  It should look like: BOX(xmin ymin,xmax ymax)");
		 PG_RETURN_NULL();
	}

	if (box->xmin > box->xmax)
	{
		float tmp = box->xmin;
		box->xmin = box->xmax;
		box->xmax = tmp;
	}
	if (box->ymin > box->ymax)
	{
		float tmp = box->ymin;
		box->ymin = box->ymax;
		box->ymax = tmp;
	}
	PG_RETURN_POINTER(box);
}

/*writer  "BOX(xmin ymin,xmax ymax)" */
PG_FUNCTION_INFO_V1(BOX2DFLOAT4_out);
Datum BOX2DFLOAT4_out(PG_FUNCTION_ARGS)
{
	BOX2DFLOAT4 *box = (BOX2DFLOAT4 *) PG_GETARG_POINTER(0);
	char tmp[500]; /* big enough */
	char *result;
	int size;

	size  = sprintf(tmp,"BOX(%.15g %.15g,%.15g %.15g)",
		box->xmin, box->ymin, box->xmax, box->ymax);

	result= palloc(size+1); /* +1= null term */

	memcpy(result,tmp,size+1);
	PG_RETURN_CSTRING(result);
}


/*convert a PG_LWGEOM to BOX2D */
PG_FUNCTION_INFO_V1(LWGEOM_to_BOX2DFLOAT4);
Datum LWGEOM_to_BOX2DFLOAT4(PG_FUNCTION_ARGS)
{
	PG_LWGEOM *lwgeom = (PG_LWGEOM *)PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
	BOX2DFLOAT4 *result;

	result = palloc(sizeof(BOX2DFLOAT4));
	if ( ! getbox2d_p(SERIALIZED_FORM(lwgeom), result) )
	{
		PG_RETURN_NULL(); /* must be the empty geometry */
	}

	PG_RETURN_POINTER(result);
}

/*----------------------------------------------------------
 *	Relational operators for BOXes.
 *		<, >, <=, >=, and == are based on box area.
 *---------------------------------------------------------*/

/*
 * box_same - are two boxes identical?
 */
PG_FUNCTION_INFO_V1(BOX2D_same);
Datum BOX2D_same(PG_FUNCTION_ARGS)
{
	BOX2DFLOAT4		   *box1 = (BOX2DFLOAT4 *) PG_GETARG_POINTER(0);
	BOX2DFLOAT4		   *box2 = (BOX2DFLOAT4 *) PG_GETARG_POINTER(1);

	PG_RETURN_BOOL(FPeq(box1->xmax, box2->xmax) &&
				   FPeq(box1->xmin, box2->xmin) &&
				   FPeq(box1->ymax, box2->ymax) &&
				   FPeq(box1->ymin, box2->ymin));
}

/*
 * box_overlap - does box1 overlap box2?
 */
PG_FUNCTION_INFO_V1(BOX2D_overlap);
Datum BOX2D_overlap(PG_FUNCTION_ARGS)
{
	BOX2DFLOAT4		   *box1 = (BOX2DFLOAT4 *) PG_GETARG_POINTER(0);
	BOX2DFLOAT4		   *box2 = (BOX2DFLOAT4 *) PG_GETARG_POINTER(1);
	bool       result;


	result = ((FPge(box1->xmax, box2->xmax) &&
			 FPle(box1->xmin, box2->xmax)) ||
			(FPge(box2->xmax, box1->xmax) &&
			 FPle(box2->xmin, box1->xmax)))
		&&
		((FPge(box1->ymax, box2->ymax) &&
		  FPle(box1->ymin, box2->ymax)) ||
		 (FPge(box2->ymax, box1->ymax) &&
		  FPle(box2->ymin, box1->ymax)));

	PG_RETURN_BOOL(result);
}


/*
 * box_overleft - is the right edge of box1 to the left of
 *                the right edge of box2?
 */
 PG_FUNCTION_INFO_V1(BOX2D_overleft);
Datum BOX2D_overleft(PG_FUNCTION_ARGS)
{
	BOX2DFLOAT4 *box1 = (BOX2DFLOAT4 *) PG_GETARG_POINTER(0);
	BOX2DFLOAT4 *box2 = (BOX2DFLOAT4 *) PG_GETARG_POINTER(1);

	PG_RETURN_BOOL(FPle(box1->xmax, box2->xmax));
}

/* 
 * box_left - is box1 strictly left of box2?
 */
 PG_FUNCTION_INFO_V1(BOX2D_left);
Datum BOX2D_left(PG_FUNCTION_ARGS)
{
	BOX2DFLOAT4		   *box1 = (BOX2DFLOAT4 *) PG_GETARG_POINTER(0);
	BOX2DFLOAT4		   *box2 = (BOX2DFLOAT4 *) PG_GETARG_POINTER(1);

	PG_RETURN_BOOL(FPlt(box1->xmax, box2->xmin));
}

/*
 * box_right - is box1 strictly right of box2?
 */
 PG_FUNCTION_INFO_V1(BOX2D_right);
Datum BOX2D_right(PG_FUNCTION_ARGS)
{
	BOX2DFLOAT4		   *box1 = (BOX2DFLOAT4 *) PG_GETARG_POINTER(0);
	BOX2DFLOAT4		   *box2 = (BOX2DFLOAT4 *) PG_GETARG_POINTER(1);

	PG_RETURN_BOOL(FPgt(box1->xmin, box2->xmax));
}

/* 
 * box_overright - is the left edge of box1 to the right of
 *                 the left edge of box2?
 */
 PG_FUNCTION_INFO_V1(BOX2D_overright);
Datum BOX2D_overright(PG_FUNCTION_ARGS)
{
	BOX2DFLOAT4		   *box1 = (BOX2DFLOAT4 *) PG_GETARG_POINTER(0);
	BOX2DFLOAT4		   *box2 = (BOX2DFLOAT4 *) PG_GETARG_POINTER(1);

	PG_RETURN_BOOL(FPge(box1->xmin, box2->xmin));
}

/* 
 * box_overbelow - is the bottom edge of box1 below
 *                 the bottom edge of box2?
 */
 PG_FUNCTION_INFO_V1(BOX2D_overbelow);
Datum BOX2D_overbelow(PG_FUNCTION_ARGS)
{
	BOX2DFLOAT4		   *box1 = (BOX2DFLOAT4 *) PG_GETARG_POINTER(0);
	BOX2DFLOAT4		   *box2 = (BOX2DFLOAT4 *) PG_GETARG_POINTER(1);

	PG_RETURN_BOOL(FPle(box1->ymin, box2->ymin));
}

/*
 * box_below - is box1 strictly below box2?
 */
 PG_FUNCTION_INFO_V1(BOX2D_below);
Datum BOX2D_below(PG_FUNCTION_ARGS)
{
	BOX2DFLOAT4		   *box1 = (BOX2DFLOAT4 *) PG_GETARG_POINTER(0);
	BOX2DFLOAT4		   *box2 = (BOX2DFLOAT4 *) PG_GETARG_POINTER(1);

	PG_RETURN_BOOL(FPlt(box1->ymax, box2->ymin));
}

/*
 * box_above - is box1 strictly above box2?
 */
 PG_FUNCTION_INFO_V1(BOX2D_above);
Datum BOX2D_above(PG_FUNCTION_ARGS)
{
	BOX2DFLOAT4		   *box1 = (BOX2DFLOAT4 *) PG_GETARG_POINTER(0);
	BOX2DFLOAT4		   *box2 = (BOX2DFLOAT4 *) PG_GETARG_POINTER(1);

	PG_RETURN_BOOL(FPgt(box1->ymin, box2->ymax));
}

/*
 * box_overabove - the top edge of box1 above
 *                 the top edge of box2?
 */
 PG_FUNCTION_INFO_V1(BOX2D_overabove);
Datum BOX2D_overabove(PG_FUNCTION_ARGS)
{
	BOX2DFLOAT4		   *box1 = (BOX2DFLOAT4 *) PG_GETARG_POINTER(0);
	BOX2DFLOAT4		   *box2 = (BOX2DFLOAT4 *) PG_GETARG_POINTER(1);

	PG_RETURN_BOOL(FPge(box1->ymax, box2->ymax));
}

/*
 * box_contained - is box1 contained by box2?
 */
 PG_FUNCTION_INFO_V1(BOX2D_contained);
Datum BOX2D_contained(PG_FUNCTION_ARGS)
{
	BOX2DFLOAT4		   *box1 =(BOX2DFLOAT4 *) PG_GETARG_POINTER(0);
	BOX2DFLOAT4		   *box2 = (BOX2DFLOAT4 *) PG_GETARG_POINTER(1);

	PG_RETURN_BOOL(FPle(box1->xmax, box2->xmax) &&
				   FPge(box1->xmin, box2->xmin) &&
				   FPle(box1->ymax, box2->ymax) &&
				   FPge(box1->ymin, box2->ymin));
}

/*
 * box_contain - does box1 contain box2?
 */
 PG_FUNCTION_INFO_V1(BOX2D_contain);
Datum BOX2D_contain(PG_FUNCTION_ARGS)
{
	BOX2DFLOAT4		   *box1 = (BOX2DFLOAT4 *) PG_GETARG_POINTER(0);
	BOX2DFLOAT4		   *box2 = (BOX2DFLOAT4 *) PG_GETARG_POINTER(1);

	PG_RETURN_BOOL(FPge(box1->xmax, box2->xmax) &&
				   FPle(box1->xmin, box2->xmin) &&
				   FPge(box1->ymax, box2->ymax) &&
				   FPle(box1->ymin, box2->ymin));

}

PG_FUNCTION_INFO_V1(BOX2D_intersects);
Datum BOX2D_intersects(PG_FUNCTION_ARGS)
{
	BOX2DFLOAT4 *a = (BOX2DFLOAT4 *) PG_GETARG_POINTER(0);
	BOX2DFLOAT4 *b = (BOX2DFLOAT4 *) PG_GETARG_POINTER(1);
	BOX2DFLOAT4 *n;


	n = (BOX2DFLOAT4 *) palloc(sizeof(BOX2DFLOAT4));

	n->xmax = LWGEOM_Minf(a->xmax, b->xmax);
	n->ymax = LWGEOM_Minf(a->ymax, b->ymax);
	n->xmin = LWGEOM_Maxf(a->xmin, b->xmin);
	n->ymin = LWGEOM_Maxf(a->ymin, b->ymin);


	if (n->xmax < n->xmin || n->ymax < n->ymin)
	{
		pfree(n);
		/* Indicate "no intersection" by returning NULL pointer */
		n = NULL;
	}

	PG_RETURN_POINTER(n);
}


/*
 * union of two BOX2Ds
 */
PG_FUNCTION_INFO_V1(BOX2D_union);
Datum BOX2D_union(PG_FUNCTION_ARGS)
{
	BOX2DFLOAT4 *a = (BOX2DFLOAT4*) PG_GETARG_POINTER(0);
	BOX2DFLOAT4 *b = (BOX2DFLOAT4*) PG_GETARG_POINTER(1);
	BOX2DFLOAT4 *n;

	n = (BOX2DFLOAT4 *) lwalloc(sizeof(BOX2DFLOAT4));
	if ( ! box2d_union_p(a,b,n) ) PG_RETURN_NULL();
	PG_RETURN_POINTER(n);
}


/*
 * min(a,b)
 */
float LWGEOM_Minf(float a, float b)
{
	if (a<b)
		return a;
	return b;
}

/*
 * max(a,b)
 */
float LWGEOM_Maxf(float a, float b)
{
	if (b>a) return b;
	return a;
}

PG_FUNCTION_INFO_V1(BOX2DFLOAT4_expand);
Datum BOX2DFLOAT4_expand(PG_FUNCTION_ARGS)
{
	BOX2DFLOAT4 *box = (BOX2DFLOAT4 *)PG_GETARG_POINTER(0);
	double d = PG_GETARG_FLOAT8(1);
	BOX2DFLOAT4 *result = (BOX2DFLOAT4 *)palloc(sizeof(BOX2DFLOAT4));

	memcpy(result, box, sizeof(BOX2DFLOAT4));
	expand_box2d(result, d);

	PG_RETURN_POINTER(result);
}

PG_FUNCTION_INFO_V1(BOX2DFLOAT4_to_BOX3D);
Datum BOX2DFLOAT4_to_BOX3D(PG_FUNCTION_ARGS)
{
	BOX2DFLOAT4 *box = (BOX2DFLOAT4 *)PG_GETARG_POINTER(0);
	BOX3D *result = palloc(sizeof(BOX3D));

	box2df_to_box3d_p(box, result);

	PG_RETURN_POINTER(result);
}


#define KEEP_OBSOLETED_FUNX 1
#if KEEP_OBSOLETED_FUNX
Datum BOX2DFLOAT4_xmin(PG_FUNCTION_ARGS);
Datum BOX2DFLOAT4_ymin(PG_FUNCTION_ARGS);
Datum BOX2DFLOAT4_xmax(PG_FUNCTION_ARGS);
Datum BOX2DFLOAT4_ymax(PG_FUNCTION_ARGS);
PG_FUNCTION_INFO_V1(BOX2DFLOAT4_xmin);
Datum BOX2DFLOAT4_xmin(PG_FUNCTION_ARGS)
{
	BOX2DFLOAT4 *box = (BOX2DFLOAT4 *)PG_GETARG_POINTER(0);
	PG_RETURN_FLOAT4(box->xmin);
}
PG_FUNCTION_INFO_V1(BOX2DFLOAT4_ymin);
Datum BOX2DFLOAT4_ymin(PG_FUNCTION_ARGS)
{
	BOX2DFLOAT4 *box = (BOX2DFLOAT4 *)PG_GETARG_POINTER(0);
	PG_RETURN_FLOAT4(box->ymin);
}
PG_FUNCTION_INFO_V1(BOX2DFLOAT4_xmax);
Datum BOX2DFLOAT4_xmax(PG_FUNCTION_ARGS)
{
	BOX2DFLOAT4 *box = (BOX2DFLOAT4 *)PG_GETARG_POINTER(0);
	PG_RETURN_FLOAT4(box->xmax);
}
PG_FUNCTION_INFO_V1(BOX2DFLOAT4_ymax);
Datum BOX2DFLOAT4_ymax(PG_FUNCTION_ARGS)
{
	BOX2DFLOAT4 *box = (BOX2DFLOAT4 *)PG_GETARG_POINTER(0);
	PG_RETURN_FLOAT4(box->ymax);
}
#endif

PG_FUNCTION_INFO_V1(BOX2DFLOAT4_combine);
Datum BOX2DFLOAT4_combine(PG_FUNCTION_ARGS)
{
	Pointer box2d_ptr = PG_GETARG_POINTER(0);
	Pointer geom_ptr = PG_GETARG_POINTER(1);
	BOX2DFLOAT4 *a,*b;
	PG_LWGEOM *lwgeom;
	BOX2DFLOAT4 box, *result;

	if  ( (box2d_ptr == NULL) && (geom_ptr == NULL) )
	{
		PG_RETURN_NULL(); /* combine_box2d(null,null) => null */
	}

	result = (BOX2DFLOAT4 *)palloc(sizeof(BOX2DFLOAT4));

	if (box2d_ptr == NULL)
	{
		lwgeom = (PG_LWGEOM *)PG_DETOAST_DATUM(PG_GETARG_DATUM(1));
		/* empty geom would make getbox2d_p return NULL */
		if ( ! getbox2d_p(SERIALIZED_FORM(lwgeom), &box) ) PG_RETURN_NULL();
		memcpy(result, &box, sizeof(BOX2DFLOAT4));
		PG_RETURN_POINTER(result);
	}

	/* combine_bbox(BOX3D, null) => BOX3D */
	if (geom_ptr == NULL)
	{
		memcpy(result, (char *)PG_GETARG_DATUM(0), sizeof(BOX2DFLOAT4));
		PG_RETURN_POINTER(result);
	}

	/*combine_bbox(BOX3D, geometry) => union(BOX3D, geometry->bvol) */

	lwgeom = (PG_LWGEOM *)PG_DETOAST_DATUM(PG_GETARG_DATUM(1));
	if ( ! getbox2d_p(SERIALIZED_FORM(lwgeom), &box) )
	{
		/* must be the empty geom */
		memcpy(result, (char *)PG_GETARG_DATUM(0), sizeof(BOX2DFLOAT4));
		PG_RETURN_POINTER(result);
	}

	a = (BOX2DFLOAT4 *)PG_GETARG_DATUM(0);
	b = &box;

	result->xmax = LWGEOM_Maxf(a->xmax, b->xmax);
	result->ymax = LWGEOM_Maxf(a->ymax, b->ymax);
	result->xmin = LWGEOM_Minf(a->xmin, b->xmin);
	result->ymin = LWGEOM_Minf(a->ymin, b->ymin);

	PG_RETURN_POINTER(result);
}

PG_FUNCTION_INFO_V1(BOX2DFLOAT4_to_LWGEOM);
Datum BOX2DFLOAT4_to_LWGEOM(PG_FUNCTION_ARGS)
{
	BOX2DFLOAT4 *box = (BOX2DFLOAT4 *)PG_GETARG_POINTER(0);
	POINT2D *pts = palloc(sizeof(POINT2D)*5);
	POINTARRAY *pa[1];
	LWPOLY *poly;
	int wantbbox = 0;
	PG_LWGEOM *result;
	uchar *ser;

	/* Assign coordinates to POINT2D array */
	pts[0].x = box->xmin; pts[0].y = box->ymin;
	pts[1].x = box->xmin; pts[1].y = box->ymax;
	pts[2].x = box->xmax; pts[2].y = box->ymax;
	pts[3].x = box->xmax; pts[3].y = box->ymin;
	pts[4].x = box->xmin; pts[4].y = box->ymin;

	/* Construct point array */
	pa[0] = palloc(sizeof(POINTARRAY));
	pa[0]->serialized_pointlist = (uchar *)pts;
	TYPE_SETZM(pa[0]->dims, 0, 0);
	pa[0]->npoints = 5;

	/* Construct polygon */
	poly = lwpoly_construct(-1, NULL, 1, pa);

	/* Serialize polygon */
	ser = lwpoly_serialize(poly);

	/* Construct PG_LWGEOM  */
	result = PG_LWGEOM_construct(ser, -1, wantbbox);
	
	PG_RETURN_POINTER(result);
}

PG_FUNCTION_INFO_V1(BOX2DFLOAT4_construct);
Datum BOX2DFLOAT4_construct(PG_FUNCTION_ARGS)
{
	PG_LWGEOM *min = (PG_LWGEOM *)PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
	PG_LWGEOM *max = (PG_LWGEOM *)PG_DETOAST_DATUM(PG_GETARG_DATUM(1));
	BOX2DFLOAT4 *result = palloc(sizeof(BOX2DFLOAT4));
	LWGEOM *minpoint, *maxpoint;
	POINT2D minp, maxp;

	minpoint = lwgeom_deserialize(SERIALIZED_FORM(min));
	maxpoint = lwgeom_deserialize(SERIALIZED_FORM(max));

	if ( TYPE_GETTYPE(minpoint->type) != POINTTYPE ||
		TYPE_GETTYPE(maxpoint->type) != POINTTYPE )
	{
		elog(ERROR, "BOX2DFLOAT4_construct: args must be points");
		PG_RETURN_NULL();
	}

	errorIfSRIDMismatch(minpoint->SRID, maxpoint->SRID);

	getPoint2d_p(((LWPOINT *)minpoint)->point, 0, &minp);
	getPoint2d_p(((LWPOINT *)maxpoint)->point, 0, &maxp);

	result->xmax = maxp.x;
	result->ymax = maxp.y;

	result->xmin = minp.x;
	result->ymin = minp.y;

	PG_RETURN_POINTER(result);
}