#include "postgres.h"

#include <float.h>

#include "access/gist.h"
#include "access/itup.h"
#include "access/skey.h"
#include "access/tuptoaster.h"
#include "storage/bufpage.h"
#include "utils/array.h"
#include "utils/builtins.h"

#include "tsvector.h"
#include "query.h"
#include "query_cleanup.h"

PG_FUNCTION_INFO_V1(gin_extract_tsvector);
Datum       gin_extract_tsvector(PG_FUNCTION_ARGS);

Datum
gin_extract_tsvector(PG_FUNCTION_ARGS) {
	tsvector 	*vector = (tsvector *) PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
	uint32  	*nentries = (uint32*)PG_GETARG_POINTER(1);
	Datum		*entries = NULL;

	*nentries = 0;
	if ( vector->size > 0 ) {
		int i;
		WordEntry	*we = ARRPTR( vector );

		*nentries = (uint32)vector->size;
		entries = (Datum*)palloc( sizeof(Datum) * vector->size );

		for(i=0;i<vector->size;i++) {
			text 	*txt = (text*)palloc( VARHDRSZ + we->len );

			VARATT_SIZEP(txt) = VARHDRSZ + we->len; 
			memcpy( VARDATA(txt), STRPTR( vector ) + we->pos, we->len ); 

			entries[i] = PointerGetDatum( txt );

			we++;
		}
	}

	PG_FREE_IF_COPY(vector, 0);
	PG_RETURN_POINTER(entries);
}


PG_FUNCTION_INFO_V1(gin_extract_tsquery);
Datum       gin_extract_tsquery(PG_FUNCTION_ARGS);

Datum
gin_extract_tsquery(PG_FUNCTION_ARGS) {
	QUERYTYPE *query = (QUERYTYPE*) PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
	uint32      *nentries = (uint32*)PG_GETARG_POINTER(1);
	StrategyNumber	strategy = DatumGetUInt16( PG_GETARG_DATUM(2) ); 
	Datum       *entries = NULL;

	*nentries = 0;
	if ( query->size > 0 ) {
		int4 i, j=0, len;
		ITEM *item;

		item = clean_NOT_v2(GETQUERY(query), &len);
		if ( !item )
			elog(ERROR,"Query requires full scan, GIN doesn't support it");

		item = GETQUERY(query);

		for(i=0; i<query->size; i++)
			if ( item[i].type == VAL )
				(*nentries)++;

		entries = (Datum*)palloc( sizeof(Datum) * (*nentries) );

		for(i=0; i<query->size; i++)
			if ( item[i].type == VAL ) {
				text 	*txt;

				txt = (text*)palloc( VARHDRSZ + item[i].length );

				VARATT_SIZEP(txt) = VARHDRSZ + item[i].length; 
				memcpy( VARDATA(txt), GETOPERAND( query ) + item[i].distance, item[i].length );

				entries[j++] = PointerGetDatum( txt );

				if ( strategy == 1 && item[i].weight != 0 )
					elog(ERROR,"With class of lexeme restrictions use @@@ operation");
			}

	}

	PG_FREE_IF_COPY(query, 0);
	PG_RETURN_POINTER(entries);
}

typedef struct {
	ITEM	*frst;
	bool	*mapped_check;
} GinChkVal; 

static bool
checkcondition_gin(void *checkval, ITEM * val) {
	GinChkVal	*gcv = (GinChkVal*)checkval;

	return gcv->mapped_check[ val - gcv->frst ];
}

PG_FUNCTION_INFO_V1(gin_ts_consistent);
Datum       gin_ts_consistent(PG_FUNCTION_ARGS);

Datum
gin_ts_consistent(PG_FUNCTION_ARGS) {
	bool    *check = (bool*)PG_GETARG_POINTER(0);
	QUERYTYPE *query = (QUERYTYPE*) PG_DETOAST_DATUM(PG_GETARG_DATUM(2));
	bool	res = FALSE;

	if ( query->size > 0 ) {
		int4 i, j=0;
		ITEM *item;
		GinChkVal	gcv;

		gcv.frst = item = GETQUERY(query); 
		gcv.mapped_check= (bool*)palloc( sizeof(bool) * query->size );

		for(i=0; i<query->size; i++)
			if ( item[i].type == VAL )
				gcv.mapped_check[ i ] = check[ j++ ];


		res = TS_execute(
			GETQUERY(query),
			&gcv,
			true,
			checkcondition_gin
		);

	}

	PG_FREE_IF_COPY(query, 2);
	PG_RETURN_BOOL(res);
}