#include "btree_gist.h"
#include "btree_utils_num.h"

typedef struct
{
	Interval	lower,
				upper;
}	intvKEY;


/*
** Interval ops
*/
PG_FUNCTION_INFO_V1(gbt_intv_compress);
PG_FUNCTION_INFO_V1(gbt_intv_decompress);
PG_FUNCTION_INFO_V1(gbt_intv_union);
PG_FUNCTION_INFO_V1(gbt_intv_picksplit);
PG_FUNCTION_INFO_V1(gbt_intv_consistent);
PG_FUNCTION_INFO_V1(gbt_intv_penalty);
PG_FUNCTION_INFO_V1(gbt_intv_same);

Datum		gbt_intv_compress(PG_FUNCTION_ARGS);
Datum		gbt_intv_decompress(PG_FUNCTION_ARGS);
Datum		gbt_intv_union(PG_FUNCTION_ARGS);
Datum		gbt_intv_picksplit(PG_FUNCTION_ARGS);
Datum		gbt_intv_consistent(PG_FUNCTION_ARGS);
Datum		gbt_intv_penalty(PG_FUNCTION_ARGS);
Datum		gbt_intv_same(PG_FUNCTION_ARGS);


static bool
gbt_intvgt(const void *a, const void *b)
{
	return DatumGetBool(DirectFunctionCall2(interval_gt, IntervalPGetDatum(a), IntervalPGetDatum(b)));
}

static bool
gbt_intvge(const void *a, const void *b)
{
	return DatumGetBool(DirectFunctionCall2(interval_ge, IntervalPGetDatum(a), IntervalPGetDatum(b)));
}

static bool
gbt_intveq(const void *a, const void *b)
{
	return DatumGetBool(DirectFunctionCall2(interval_eq, IntervalPGetDatum(a), IntervalPGetDatum(b)));
}

static bool
gbt_intvle(const void *a, const void *b)
{
	return DatumGetBool(DirectFunctionCall2(interval_le, IntervalPGetDatum(a), IntervalPGetDatum(b)));
}

static bool
gbt_intvlt(const void *a, const void *b)
{
	return DatumGetBool(DirectFunctionCall2(interval_lt, IntervalPGetDatum(a), IntervalPGetDatum(b)));
}

static int
gbt_intvkey_cmp(const void *a, const void *b)
{
	return DatumGetInt32(
						 DirectFunctionCall2(interval_cmp,
									  IntervalPGetDatum(((Nsrt *) a)->t),
									   IntervalPGetDatum(((Nsrt *) b)->t)
											 )
		);
}


static double
intr2num(const Interval *i)
{
	double		ret = 0.0;
	struct pg_tm tm;
	fsec_t		fsec;

	interval2tm(*i, &tm, &fsec);
	ret += (tm.tm_year * 360.0 * 86400.0);
	ret += (tm.tm_mon * 12.0 * 86400.0);
	ret += (tm.tm_mday * 86400.0);
	ret += (tm.tm_hour * 3600.0);
	ret += (tm.tm_min * 60.0);
	ret += (tm.tm_sec);
	ret += (fsec / 1000000.0);

	return (ret);
}

#define INTERVALSIZE 12

static const gbtree_ninfo tinfo =
{
	gbt_t_intv,
	sizeof(Interval),
	gbt_intvgt,
	gbt_intvge,
	gbt_intveq,
	gbt_intvle,
	gbt_intvlt,
	gbt_intvkey_cmp
};


/**************************************************
 * interval ops
 **************************************************/


Datum
gbt_intv_compress(PG_FUNCTION_ARGS)
{
	GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
	GISTENTRY  *retval = entry;

	if (entry->leafkey || INTERVALSIZE != sizeof(Interval))
	{
		char	   *r = (char *) palloc(2 * INTERVALSIZE);

		retval = palloc(sizeof(GISTENTRY));

		if (entry->leafkey)
		{
			Interval   *key = DatumGetIntervalP(entry->key);

			memcpy((void *) r, (void *) key, INTERVALSIZE);
			memcpy((void *) (r + INTERVALSIZE), (void *) key, INTERVALSIZE);
		}
		else
		{
			intvKEY    *key = (intvKEY *) DatumGetPointer(entry->key);

			memcpy(r, &key->lower, INTERVALSIZE);
			memcpy(r + INTERVALSIZE, &key->upper, INTERVALSIZE);
		}
		gistentryinit(*retval, PointerGetDatum(r),
					  entry->rel, entry->page,
					  entry->offset, 2 * INTERVALSIZE, FALSE);
	}

	PG_RETURN_POINTER(retval);

}

Datum
gbt_intv_decompress(PG_FUNCTION_ARGS)
{
	GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
	GISTENTRY  *retval = entry;

	if (INTERVALSIZE != sizeof(Interval))
	{
		intvKEY    *r = palloc(sizeof(intvKEY));
		char	   *key = DatumGetPointer(entry->key);

		retval = palloc(sizeof(GISTENTRY));
		memcpy(&r->lower, key, INTERVALSIZE);
		memcpy(&r->upper, key + INTERVALSIZE, INTERVALSIZE);

		gistentryinit(*retval, PointerGetDatum(r),
					  entry->rel, entry->page,
					  entry->offset, sizeof(intvKEY), FALSE);
	}
	PG_RETURN_POINTER(retval);
}


Datum
gbt_intv_consistent(PG_FUNCTION_ARGS)
{
	GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
	Interval   *query = PG_GETARG_INTERVAL_P(1);
	intvKEY    *kkk = (intvKEY *) DatumGetPointer(entry->key);
	GBT_NUMKEY_R key;
	StrategyNumber strategy = (StrategyNumber) PG_GETARG_UINT16(2);

	key.lower = (GBT_NUMKEY *) & kkk->lower;
	key.upper = (GBT_NUMKEY *) & kkk->upper;

	PG_RETURN_BOOL(
				   gbt_num_consistent(&key, (void *) query, &strategy, GIST_LEAF(entry), &tinfo)
		);
}


Datum
gbt_intv_union(PG_FUNCTION_ARGS)
{
	GistEntryVector *entryvec = (GistEntryVector *) PG_GETARG_POINTER(0);
	void	   *out = palloc(sizeof(intvKEY));

	*(int *) PG_GETARG_POINTER(1) = sizeof(intvKEY);
	PG_RETURN_POINTER(gbt_num_union((void *) out, entryvec, &tinfo));
}


Datum
gbt_intv_penalty(PG_FUNCTION_ARGS)
{
	intvKEY    *origentry = (intvKEY *) DatumGetPointer(((GISTENTRY *) PG_GETARG_POINTER(0))->key);
	intvKEY    *newentry = (intvKEY *) DatumGetPointer(((GISTENTRY *) PG_GETARG_POINTER(1))->key);
	float	   *result = (float *) PG_GETARG_POINTER(2);
	double		iorg[2],
				inew[2],
				res;

	iorg[0] = intr2num(&origentry->lower);
	iorg[1] = intr2num(&origentry->upper);
	inew[0] = intr2num(&newentry->lower);
	inew[1] = intr2num(&newentry->upper);

	penalty_range_enlarge(iorg[0], iorg[1], inew[0], inew[1]);

	*result = 0.0;

	if (res > 0)
	{
		*result += FLT_MIN;
		*result += (float) (res / (res + iorg[1] - iorg[0]));
		*result *= (FLT_MAX / (((GISTENTRY *) PG_GETARG_POINTER(0))->rel->rd_att->natts + 1));
	}

	PG_RETURN_POINTER(result);

}

Datum
gbt_intv_picksplit(PG_FUNCTION_ARGS)
{
	PG_RETURN_POINTER(gbt_num_picksplit(
								(GistEntryVector *) PG_GETARG_POINTER(0),
								  (GIST_SPLITVEC *) PG_GETARG_POINTER(1),
										&tinfo
										));
}

Datum
gbt_intv_same(PG_FUNCTION_ARGS)
{
	intvKEY    *b1 = (intvKEY *) PG_GETARG_POINTER(0);
	intvKEY    *b2 = (intvKEY *) PG_GETARG_POINTER(1);
	bool	   *result = (bool *) PG_GETARG_POINTER(2);

	*result = gbt_num_same((void *) b1, (void *) b2, &tinfo);
	PG_RETURN_POINTER(result);
}
