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

#include "utils/datetime.h"


typedef struct
{
	Timestamp	lower;
	Timestamp	upper;
}	tsKEY;

/*
** timestamp ops
*/
PG_FUNCTION_INFO_V1(gbt_ts_compress);
PG_FUNCTION_INFO_V1(gbt_tstz_compress);
PG_FUNCTION_INFO_V1(gbt_ts_union);
PG_FUNCTION_INFO_V1(gbt_ts_picksplit);
PG_FUNCTION_INFO_V1(gbt_ts_consistent);
PG_FUNCTION_INFO_V1(gbt_tstz_consistent);
PG_FUNCTION_INFO_V1(gbt_ts_penalty);
PG_FUNCTION_INFO_V1(gbt_ts_same);

Datum		gbt_ts_compress(PG_FUNCTION_ARGS);
Datum		gbt_tstz_compress(PG_FUNCTION_ARGS);
Datum		gbt_ts_union(PG_FUNCTION_ARGS);
Datum		gbt_ts_picksplit(PG_FUNCTION_ARGS);
Datum		gbt_ts_consistent(PG_FUNCTION_ARGS);
Datum		gbt_tstz_consistent(PG_FUNCTION_ARGS);
Datum		gbt_ts_penalty(PG_FUNCTION_ARGS);
Datum		gbt_ts_same(PG_FUNCTION_ARGS);


#define P_TimestampGetDatum(x)  PointerGetDatum( &(x) )

static bool
gbt_tsgt(const void *a, const void *b)
{
	return DatumGetBool(
						DirectFunctionCall2(timestamp_gt, PointerGetDatum(a), PointerGetDatum(b))
		);
}

static bool
gbt_tsge(const void *a, const void *b)
{
	return DatumGetBool(
						DirectFunctionCall2(timestamp_ge, PointerGetDatum(a), PointerGetDatum(b))
		);
}

static bool
gbt_tseq(const void *a, const void *b)
{
	return DatumGetBool(
						DirectFunctionCall2(timestamp_eq, PointerGetDatum(a), PointerGetDatum(b))
		);
}

static bool
gbt_tsle(const void *a, const void *b)
{
	return DatumGetBool(
						DirectFunctionCall2(timestamp_le, PointerGetDatum(a), PointerGetDatum(b))
		);
}

static bool
gbt_tslt(const void *a, const void *b)
{
	return DatumGetBool(
						DirectFunctionCall2(timestamp_lt, PointerGetDatum(a), PointerGetDatum(b))
		);
}


static int
gbt_tskey_cmp(const void *a, const void *b)
{
	if (gbt_tsgt((void *) &(((Nsrt *) a)->t[0]), (void *) &(((Nsrt *) b)->t[0])))
		return 1;
	else if (gbt_tslt((void *) &(((Nsrt *) a)->t[0]), (void *) &(((Nsrt *) b)->t[0])))
		return -1;
	return 0;
}


static const gbtree_ninfo tinfo =
{
	gbt_t_ts,
	sizeof(Timestamp),
	gbt_tsgt,
	gbt_tsge,
	gbt_tseq,
	gbt_tsle,
	gbt_tslt,
	gbt_tskey_cmp
};


/**************************************************
 * timestamp ops
 **************************************************/



static Timestamp *
tstz_to_ts_gmt(Timestamp *gmt, TimestampTz *ts)
{
	int			val,
				tz;

	*gmt = *ts;
	DecodeSpecial(0, "gmt", &val);

	if (!TIMESTAMP_NOT_FINITE(*ts))
	{
		tz = val * 60;

#ifdef HAVE_INT64_TIMESTAMP
		*gmt -= (tz * INT64CONST(1000000));
#else
		*gmt -= tz;
		*gmt = JROUND(*gmt);
#endif

	}
	return gmt;
}




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

	PG_RETURN_POINTER(gbt_num_compress(retval, entry, &tinfo));
}


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

	if (entry->leafkey)
	{
		tsKEY	   *r = (tsKEY *) palloc(sizeof(tsKEY));

		TimestampTz ts = *(TimestampTz *) DatumGetPointer(entry->key);
		Timestamp	gmt;

		tstz_to_ts_gmt(&gmt, &ts);

		retval = palloc(sizeof(GISTENTRY));
		r->lower = r->upper = gmt;
		gistentryinit(*retval, PointerGetDatum(r),
					  entry->rel, entry->page,
					  entry->offset, sizeof(tsKEY), FALSE);
	}
	else
		retval = entry;

	PG_RETURN_POINTER(retval);
}


Datum
gbt_ts_consistent(PG_FUNCTION_ARGS)
{
	GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
	Timestamp  *query = (Timestamp *) PG_GETARG_POINTER(1);
	tsKEY	   *kkk = (tsKEY *) 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_tstz_consistent(PG_FUNCTION_ARGS)
{
	GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
	TimestampTz *query = (Timestamp *) PG_GETARG_POINTER(1);
	char	   *kkk = (char *) DatumGetPointer(entry->key);
	GBT_NUMKEY_R key;
	StrategyNumber strategy = (StrategyNumber) PG_GETARG_UINT16(2);
	Timestamp	qqq;

	key.lower = (GBT_NUMKEY *) & kkk[0];
	key.upper = (GBT_NUMKEY *) & kkk[MAXALIGN(tinfo.size)];
	tstz_to_ts_gmt(&qqq, query);

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


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

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


Datum
gbt_ts_penalty(PG_FUNCTION_ARGS)
{

	tsKEY	   *origentry = (tsKEY *) DatumGetPointer(((GISTENTRY *) PG_GETARG_POINTER(0))->key);
	tsKEY	   *newentry = (tsKEY *) DatumGetPointer(((GISTENTRY *) PG_GETARG_POINTER(1))->key);
	float	   *result = (float *) PG_GETARG_POINTER(2);
	Interval   *intr;

#ifdef HAVE_INT64_TIMESTAMP
	int64		res;
#else
	double		res;
#endif

	intr = DatumGetIntervalP(DirectFunctionCall2(
												 timestamp_mi,
									  P_TimestampGetDatum(newentry->upper),
									  P_TimestampGetDatum(origentry->upper)
												 ));

	/* see interval_larger */

	res = Max(intr->time + intr->month * (30 * 86400), 0);

	intr = DatumGetIntervalP(DirectFunctionCall2(
												 timestamp_mi,
									 P_TimestampGetDatum(origentry->lower),
									   P_TimestampGetDatum(newentry->lower)
												 ));

	/* see interval_larger */
	res += Max(intr->time + intr->month * (30 * 86400), 0);

	*result = 0.0;

	if (res > 0)
	{
		intr = DatumGetIntervalP(DirectFunctionCall2(
													 timestamp_mi,
									 P_TimestampGetDatum(origentry->upper),
									  P_TimestampGetDatum(origentry->lower)
													 ));
		*result += FLT_MIN;
		*result += (float) (res / ((double) (res + intr->time + intr->month * (30 * 86400))));
		*result *= (FLT_MAX / (((GISTENTRY *) PG_GETARG_POINTER(0))->rel->rd_att->natts + 1));
	}

	PG_RETURN_POINTER(result);
}


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

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

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