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

#include "btree_gist.h"
#include "btree_utils_var.h"
#include "utils/bytea.h"
#include "utils/varbit.h"

/*
** Bit ops
*/
PG_FUNCTION_INFO_V1(gbt_bit_compress);
PG_FUNCTION_INFO_V1(gbt_bit_union);
PG_FUNCTION_INFO_V1(gbt_bit_picksplit);
PG_FUNCTION_INFO_V1(gbt_bit_consistent);
PG_FUNCTION_INFO_V1(gbt_bit_penalty);
PG_FUNCTION_INFO_V1(gbt_bit_same);

extern "C" Datum gbt_bit_compress(PG_FUNCTION_ARGS);
extern "C" Datum gbt_bit_union(PG_FUNCTION_ARGS);
extern "C" Datum gbt_bit_picksplit(PG_FUNCTION_ARGS);
extern "C" Datum gbt_bit_consistent(PG_FUNCTION_ARGS);
extern "C" Datum gbt_bit_penalty(PG_FUNCTION_ARGS);
extern "C" Datum gbt_bit_same(PG_FUNCTION_ARGS);

/* define for comparison */

static bool gbt_bitgt(const void* a, const void* b, Oid collation)
{
    return DatumGetBool(DirectFunctionCall2(bitgt, PointerGetDatum(a), PointerGetDatum(b)));
}

static bool gbt_bitge(const void* a, const void* b, Oid collation)
{
    return DatumGetBool(DirectFunctionCall2(bitge, PointerGetDatum(a), PointerGetDatum(b)));
}

static bool gbt_biteq(const void* a, const void* b, Oid collation)
{
    return DatumGetBool(DirectFunctionCall2(biteq, PointerGetDatum(a), PointerGetDatum(b)));
}

static bool gbt_bitle(const void* a, const void* b, Oid collation)
{
    return DatumGetBool(DirectFunctionCall2(bitle, PointerGetDatum(a), PointerGetDatum(b)));
}

static bool gbt_bitlt(const void* a, const void* b, Oid collation)
{
    return DatumGetBool(DirectFunctionCall2(bitlt, PointerGetDatum(a), PointerGetDatum(b)));
}

static int32 gbt_bitcmp(const void* a, const void* b, Oid collation)
{
    return DatumGetInt32(DirectFunctionCall2(byteacmp, PointerGetDatum(a), PointerGetDatum(b)));
}

static bytea* gbt_bit_xfrm(bytea* leaf)
{
    bytea* out = leaf;
    int s = INTALIGN(VARBITBYTES(leaf) + VARHDRSZ);

    out = (bytea*)palloc(s);
    SET_VARSIZE(out, s);
    memcpy((void*)VARDATA(out), (void*)VARBITS(leaf), VARBITBYTES(leaf));
    return out;
}

static GBT_VARKEY* gbt_bit_l2n(GBT_VARKEY* leaf)
{

    GBT_VARKEY* out = leaf;
    GBT_VARKEY_R r = gbt_var_key_readable(leaf);
    bytea* o = NULL;

    o = gbt_bit_xfrm(r.lower);
    r.upper = r.lower = o;
    out = gbt_var_key_copy(&r, TRUE);
    pfree(o);

    return out;
}

static const gbtree_vinfo tinfo = {
    gbt_t_bit, 0, TRUE, gbt_bitgt, gbt_bitge, gbt_biteq, gbt_bitle, gbt_bitlt, gbt_bitcmp, gbt_bit_l2n};

/**************************************************
 * Bit ops
 **************************************************/

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

    PG_RETURN_POINTER(gbt_var_compress(entry, &tinfo));
}

Datum gbt_bit_consistent(PG_FUNCTION_ARGS)
{
    GISTENTRY* entry = (GISTENTRY*)PG_GETARG_POINTER(0);
    void* query = (void*)DatumGetByteaP(PG_GETARG_DATUM(1));
    StrategyNumber strategy = (StrategyNumber)PG_GETARG_UINT16(2);

    bool* recheck = (bool*)PG_GETARG_POINTER(4);
    bool retval = false;
    GBT_VARKEY* key = (GBT_VARKEY*)DatumGetPointer(entry->key);
    GBT_VARKEY_R r = gbt_var_key_readable(key);

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

    if (GIST_LEAF(entry))
        retval = gbt_var_consistent(&r, query, strategy, PG_GET_COLLATION(), TRUE, &tinfo);
    else {
        bytea* q = gbt_bit_xfrm((bytea*)query);

        retval = gbt_var_consistent(&r, q, strategy, PG_GET_COLLATION(), FALSE, &tinfo);
    }
    PG_RETURN_BOOL(retval);
}

Datum gbt_bit_union(PG_FUNCTION_ARGS)
{
    GistEntryVector* entryvec = (GistEntryVector*)PG_GETARG_POINTER(0);
    int32* size = (int*)PG_GETARG_POINTER(1);

    PG_RETURN_POINTER(gbt_var_union(entryvec, size, PG_GET_COLLATION(), &tinfo));
}

Datum gbt_bit_picksplit(PG_FUNCTION_ARGS)
{
    GistEntryVector* entryvec = (GistEntryVector*)PG_GETARG_POINTER(0);
    GIST_SPLITVEC* v = (GIST_SPLITVEC*)PG_GETARG_POINTER(1);

    gbt_var_picksplit(entryvec, v, PG_GET_COLLATION(), &tinfo);
    PG_RETURN_POINTER(v);
}

Datum gbt_bit_same(PG_FUNCTION_ARGS)
{
    Datum d1 = PG_GETARG_DATUM(0);
    Datum d2 = PG_GETARG_DATUM(1);
    bool* result = (bool*)PG_GETARG_POINTER(2);

    *result = gbt_var_same(d1, d2, PG_GET_COLLATION(), &tinfo);
    PG_RETURN_POINTER(result);
}

Datum gbt_bit_penalty(PG_FUNCTION_ARGS)
{
    GISTENTRY* o = (GISTENTRY*)PG_GETARG_POINTER(0);
    GISTENTRY* n = (GISTENTRY*)PG_GETARG_POINTER(1);
    float* result = (float*)PG_GETARG_POINTER(2);

    PG_RETURN_POINTER(gbt_var_penalty(result, o, n, PG_GET_COLLATION(), &tinfo));
}