//---------------------------------------------------------------------------
//	Greenplum Database
//	Copyright (C) 2012 EMC Corp.
//
//	@filename:
//		CTranslatorExprToDXLUtils.h
//
//	@doc:
//		Class providing helper methods for translating from Expr to DXL
//---------------------------------------------------------------------------
#ifndef GPOPT_CTranslatorExprToDXLUtils_H
#define GPOPT_CTranslatorExprToDXLUtils_H

#include "gpos/base.h"

#include "gpopt/base/CRange.h"
#include "gpopt/mdcache/CMDAccessor.h"
#include "gpopt/metadata/CTableDescriptor.h"
#include "gpopt/operators/CExpression.h"
#include "gpopt/operators/CLogicalConstTableGet.h"
#include "gpopt/translate/CTranslatorExprToDXL.h"
#include "naucrates/dxl/operators/CDXLColDescr.h"
#include "naucrates/dxl/operators/CDXLNode.h"
#include "naucrates/dxl/operators/CDXLScalarBoolExpr.h"

// fwd decl
namespace gpmd
{
class IMDRelation;
}

namespace gpdxl
{
class CDXLPhysicalProperties;
class CDXLScalarProjElem;
}  // namespace gpdxl

namespace gpopt
{
using namespace gpos;
using namespace gpmd;
using namespace gpdxl;
using namespace gpnaucrates;

//---------------------------------------------------------------------------
//	@class:
//		CTranslatorExprToDXLUtils
//
//	@doc:
//		Class providing helper methods for translating from Expr to DXL
//
//---------------------------------------------------------------------------
class CTranslatorExprToDXLUtils
{
private:
	// create a column reference
	static CColRef *PcrCreate(CMemoryPool *mp, CMDAccessor *md_accessor,
							  CColumnFactory *col_factory, IMDId *mdid,
							  INT type_modifier, const WCHAR *wszName);


	// compute a DXL datum from a point constraint
	static CDXLDatum *PdxldatumFromPointConstraint(CMemoryPool *mp,
												   CMDAccessor *md_accessor,
												   const CColRef *pcrDistrCol,
												   CConstraint *pcnstrDistrCol);

	// compute an array of DXL datum arrays from a disjunction of point constraints
	static CDXLDatum2dArray *PdrgpdrgpdxldatumFromDisjPointConstraint(
		CMemoryPool *mp, CMDAccessor *md_accessor, const CColRef *pcrDistrCol,
		CConstraint *pcnstrDistrCol);

	// compute the direct dispatch info  from the constraints
	// on the distribution keys
	static CDXLDirectDispatchInfo *GetDXLDirectDispatchInfo(
		CMemoryPool *mp, CMDAccessor *md_accessor,
		CExpressionArray *pdrgpexprHashed, CConstraint *pcnstr);

	// compute the direct dispatch info  from the constraints
	// for a randomly distributed table
	static CDXLDirectDispatchInfo *GetDXLDirectDispatchInfoRandDist(
		CMemoryPool *mp, CMDAccessor *md_accessor, const CColRef *pcrDistrCol,
		CConstraint *pcnstrDistrCol);

	// compute the direct dispatch info for a single distribution key from the constraints
	// on the distribution key
	static CDXLDirectDispatchInfo *PdxlddinfoSingleDistrKey(
		CMemoryPool *mp, CMDAccessor *md_accessor, CExpression *pexprHashed,
		CConstraint *pcnstr);

	// check if the given constant value for a particular distribution column can be used
	// to identify which segment to direct dispatch to.
	static BOOL FDirectDispatchable(CMDAccessor *md_accessor,
									const CColRef *pcrDistrCol,
									const CDXLDatum *dxl_datum);

public:
	// construct a default properties container
	static CDXLPhysicalProperties *GetProperties(CMemoryPool *mp);

	// check if the DXL Node is a scalar const TRUE
	static BOOL FScalarConstTrue(CMDAccessor *md_accessor, CDXLNode *dxlnode);

	// check if the DXL Node is a scalar const false
	static BOOL FScalarConstFalse(CMDAccessor *md_accessor, CDXLNode *dxlnode);

	// check whether a project list has the same columns in the given array
	// and in the same order
	static BOOL FProjectListMatch(CDXLNode *pdxlnPrL,
								  CColRefArray *colref_array);

	// create a project list by creating references to the columns of the given
	// project list of the child node
	static CDXLNode *PdxlnProjListFromChildProjList(
		CMemoryPool *mp, CColumnFactory *col_factory,
		ColRefToDXLNodeMap *phmcrdxln, const CDXLNode *pdxlnProjListChild);

	// create a DXL project elem node from as a scalar identifier for the
	// child project element node
	static CDXLNode *PdxlnProjElem(CMemoryPool *mp, CColumnFactory *col_factory,
								   ColRefToDXLNodeMap *phmcrdxln,
								   const CDXLNode *pdxlnProjElemChild);

	// create a scalar identifier node for the given column reference
	static CDXLNode *PdxlnIdent(CMemoryPool *mp,
								ColRefToDXLNodeMap *phmcrdxlnSubplans,
								ColRefToDXLNodeMap *phmcrdxlnIndexLookup,
								ColRefToUlongMap *phmcrulPartColId,
								const CColRef *colref);

	// replace subplan entry in the given map with a dxl column reference
	static void ReplaceSubplan(CMemoryPool *mp,
							   ColRefToDXLNodeMap *phmcrdxlnSubplans,
							   const CColRef *colref,
							   CDXLScalarProjElem *pdxlopPrEl);

	// create a project elem from a given col ref
	static CDXLNode *PdxlnProjElem(CMemoryPool *mp,
								   ColRefToDXLNodeMap *phmcrdxlnSubplans,
								   const CColRef *colref);

	// construct an array of NULL datums for a given array of columns
	static IDatumArray *PdrgpdatumNulls(CMemoryPool *mp,
										CColRefArray *colref_array);

	// map an array of columns to a new array of columns
	static CColRefArray *PdrgpcrMapColumns(CMemoryPool *mp,
										   CColRefArray *pdrgpcrInput,
										   ColRefToUlongMap *phmcrul,
										   CColRefArray *pdrgpcrMapDest);

	// combine two boolean expressions using the given boolean operator
	static CDXLNode *PdxlnCombineBoolean(CMemoryPool *mp,
										 CDXLNode *first_child_dxlnode,
										 CDXLNode *second_child_dxlnode,
										 EdxlBoolExprType boolexptype);

	// create a DXL result node
	static CDXLNode *PdxlnResult(CMemoryPool *mp,
								 CDXLPhysicalProperties *dxl_properties,
								 CDXLNode *pdxlnPrL, CDXLNode *filter_dxlnode,
								 CDXLNode *one_time_filter,
								 CDXLNode *child_dxlnode);

	// create a DXL ValuesScan node
	static CDXLNode *PdxlnValuesScan(CMemoryPool *mp,
									 CDXLPhysicalProperties *dxl_properties,
									 CDXLNode *pdxlnPrL,
									 IDatum2dArray *pdrgpdrgdatum);

	// build hashmap based on a column array, where the key is the column
	// and the value is the index of that column in the array
	static ColRefToUlongMap *PhmcrulColIndex(CMemoryPool *mp,
											 CColRefArray *colref_array);

	// set statistics of the operator
	static void SetStats(CMemoryPool *mp, CMDAccessor *md_accessor,
						 CDXLNode *dxlnode, const IStatistics *stats,
						 BOOL fRoot);

	// set direct dispatch info of the operator
	static void SetDirectDispatchInfo(
		CMemoryPool *mp, CMDAccessor *md_accessor, CDXLNode *dxlnode,
		CExpression *pexpr, CDistributionSpecArray *pdrgpdsBaseTables);

	// is the aggregate a local hash aggregate that is safe to stream
	static BOOL FLocalHashAggStreamSafe(CExpression *pexprAgg);

	// if operator is a scalar cast or func allowed for Partition selection, extract type and function
	static void ExtractCastFuncMdids(COperator *pop, IMDId **ppmdidType,
									 IMDId **ppmdidCastFunc);

	// produce DXL representation of a datum
	static CDXLDatum *
	GetDatumVal(CMemoryPool *mp, CMDAccessor *md_accessor, IDatum *datum)
	{
		IMDId *mdid = datum->MDId();
		return md_accessor->RetrieveType(mdid)->GetDatumVal(mp, datum);
	}

	// return a copy the dxl node's physical properties
	static CDXLPhysicalProperties *PdxlpropCopy(CMemoryPool *mp,
												CDXLNode *dxlnode);

	// check if given dxl operator exists in the given list
	static BOOL FDXLOpExists(const CDXLOperator *pop,
							 const gpdxl::Edxlopid *peopid, ULONG ulOps);

	// check if given dxl node has any operator in the given list
	static BOOL FHasDXLOp(const CDXLNode *dxlnode,
						  const gpdxl::Edxlopid *peopid, ULONG ulOps);

	// check if the project lists contains subplans with broadcast motion
	static BOOL FProjListContainsSubplanWithBroadCast(CDXLNode *pdxlnPrLNew);

	// check if the dxl node imposes a motion hazard
	static BOOL FMotionHazard(CMemoryPool *mp, CDXLNode *dxlnode,
							  const gpdxl::Edxlopid *peopid, ULONG ulOps,
							  CBitSet *pbsPrjCols);

	// check if the dxl operator does not impose a motion hazard
	static BOOL FMotionHazardSafeOp(CDXLNode *dxlnode);

	// extract the column ids of the ident from project list
	static void ExtractIdentColIds(CDXLNode *dxlnode, CBitSet *pbs);

	// is this Filter node direct dispatchable?
	static BOOL FDirectDispatchableFilter(CExpression *pexprFilter);
};
}  // namespace gpopt

#endif	// !GPOPT_CTranslatorExprToDXLUtils_H

// EOF