/*
 * contrib/btree_gist/btree_date.c
 */
#include "postgres.h"
#include "knl/knl_variable.h"

#include "btree_gist.h"
#include "btree_utils_num.h"
#include "utils/date.h"

typedef struct {
    DateADT lower;
    DateADT upper;
} dateKEY;

/*
** date ops
*/
PG_FUNCTION_INFO_V1(gbt_date_compress);
PG_FUNCTION_INFO_V1(gbt_date_union);
PG_FUNCTION_INFO_V1(gbt_date_picksplit);
PG_FUNCTION_INFO_V1(gbt_date_consistent);
PG_FUNCTION_INFO_V1(gbt_date_distance);
PG_FUNCTION_INFO_V1(gbt_date_penalty);
PG_FUNCTION_INFO_V1(gbt_date_same);

extern "C" Datum gbt_date_compress(PG_FUNCTION_ARGS);
extern "C" Datum gbt_date_union(PG_FUNCTION_ARGS);
extern "C" Datum gbt_date_picksplit(PG_FUNCTION_ARGS);
extern "C" Datum gbt_date_consistent(PG_FUNCTION_ARGS);
extern "C" Datum gbt_date_distance(PG_FUNCTION_ARGS);
extern "C" Datum gbt_date_penalty(PG_FUNCTION_ARGS);
extern "C" Datum gbt_date_same(PG_FUNCTION_ARGS);

static bool gbt_dategt(const void* a, const void* b)
{
    return DatumGetBool(
        DirectFunctionCall2(date_gt, DateADTGetDatum(*((const DateADT*)a)), DateADTGetDatum(*((const DateADT*)b))));
}

static bool gbt_datege(const void* a, const void* b)
{
    return DatumGetBool(
        DirectFunctionCall2(date_ge, DateADTGetDatum(*((const DateADT*)a)), DateADTGetDatum(*((const DateADT*)b))));
}

static bool gbt_dateeq(const void* a, const void* b)
{
    return DatumGetBool(
        DirectFunctionCall2(date_eq, DateADTGetDatum(*((const DateADT*)a)), DateADTGetDatum(*((const DateADT*)b))));
}

static bool gbt_datele(const void* a, const void* b)
{
    return DatumGetBool(
        DirectFunctionCall2(date_le, DateADTGetDatum(*((const DateADT*)a)), DateADTGetDatum(*((const DateADT*)b))));
}

static bool gbt_datelt(const void* a, const void* b)
{
    return DatumGetBool(
        DirectFunctionCall2(date_lt, DateADTGetDatum(*((const DateADT*)a)), DateADTGetDatum(*((const DateADT*)b))));
}

static int gbt_datekey_cmp(const void* a, const void* b)
{
    dateKEY* ia = (dateKEY*)(((const Nsrt*)a)->t);
    dateKEY* ib = (dateKEY*)(((const Nsrt*)b)->t);
    int res;

    res = DatumGetInt32(DirectFunctionCall2(date_cmp, DateADTGetDatum(ia->lower), DateADTGetDatum(ib->lower)));
    if (res == 0)
        return DatumGetInt32(DirectFunctionCall2(date_cmp, DateADTGetDatum(ia->upper), DateADTGetDatum(ib->upper)));

    return res;
}

static float8 gdb_date_dist(const void* a, const void* b)
{
    /* we assume the difference can't overflow */
    Datum diff =
        DirectFunctionCall2(date_mi, DateADTGetDatum(*((const DateADT*)a)), DateADTGetDatum(*((const DateADT*)b)));

    return (float8)Abs(DatumGetInt32(diff));
}

static const gbtree_ninfo tinfo = {gbt_t_date,
    sizeof(DateADT),
    gbt_dategt,
    gbt_datege,
    gbt_dateeq,
    gbt_datele,
    gbt_datelt,
    gbt_datekey_cmp,
    gdb_date_dist};

PG_FUNCTION_INFO_V1(date_dist);
extern "C" Datum date_dist(PG_FUNCTION_ARGS);
Datum date_dist(PG_FUNCTION_ARGS)
{
    /* we assume the difference can't overflow */
    Datum diff = DirectFunctionCall2(date_mi, PG_GETARG_DATUM(0), PG_GETARG_DATUM(1));

    PG_RETURN_INT32(Abs(DatumGetInt32(diff)));
}

/**************************************************
 * date ops
 **************************************************/

Datum gbt_date_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_date_consistent(PG_FUNCTION_ARGS)
{
    GISTENTRY* entry = (GISTENTRY*)PG_GETARG_POINTER(0);
    DateADT query = PG_GETARG_DATEADT(1);
    StrategyNumber strategy = (StrategyNumber)PG_GETARG_UINT16(2);

    bool* recheck = (bool*)PG_GETARG_POINTER(4);
    dateKEY* kkk = (dateKEY*)DatumGetPointer(entry->key);
    GBT_NUMKEY_R key;

    /* All cases served by this function are exact */
    *recheck = false;

    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_date_distance(PG_FUNCTION_ARGS)
{
    GISTENTRY* entry = (GISTENTRY*)PG_GETARG_POINTER(0);
    DateADT query = PG_GETARG_DATEADT(1);

    dateKEY* kkk = (dateKEY*)DatumGetPointer(entry->key);
    GBT_NUMKEY_R key;

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

    PG_RETURN_FLOAT8(gbt_num_distance(&key, (void*)&query, GIST_LEAF(entry), &tinfo));
}

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

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

Datum gbt_date_penalty(PG_FUNCTION_ARGS)
{
    dateKEY* origentry = (dateKEY*)DatumGetPointer(((GISTENTRY*)PG_GETARG_POINTER(0))->key);
    dateKEY* newentry = (dateKEY*)DatumGetPointer(((GISTENTRY*)PG_GETARG_POINTER(1))->key);
    float* result = (float*)PG_GETARG_POINTER(2);
    int32 diff, res;

    diff = DatumGetInt32(
        DirectFunctionCall2(date_mi, DateADTGetDatum(newentry->upper), DateADTGetDatum(origentry->upper)));

    res = Max(diff, 0);

    diff = DatumGetInt32(
        DirectFunctionCall2(date_mi, DateADTGetDatum(origentry->lower), DateADTGetDatum(newentry->lower)));

    res += Max(diff, 0);

    *result = 0.0;

    if (res > 0) {
        diff = DatumGetInt32(
            DirectFunctionCall2(date_mi, DateADTGetDatum(origentry->upper), DateADTGetDatum(origentry->lower)));
        *result += FLT_MIN;
        *result += (float)(res / ((double)(res + diff)));
        *result *= (FLT_MAX / (((GISTENTRY*)PG_GETARG_POINTER(0))->rel->rd_att->natts + 1));
    }

    PG_RETURN_POINTER(result);
}

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

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

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