/*##############################################################################

    Copyright (C) 2011 HPCC Systems.

    All rights reserved. This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as
    published by the Free Software Foundation, either version 3 of the
    License, or (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
############################################################################## */
#include "platform.h"
#include "jlib.hpp"
#include "jexcept.hpp"
#include "jmisc.hpp"
#include "workunit.hpp"

#include "hql.hpp"
#include "hqlexpr.hpp"
#include "hqlfold.hpp"
#include "hqlstmt.hpp"
#include "hqltrans.ipp"
#include "hqlutil.hpp"
#include "hqlattr.hpp"
#include "hqlcatom.hpp"

#include "hqlfunc.hpp"

#include "hqlcpp.ipp"
#include "hqlcpputil.hpp"

//===========================================================================

static ITypeInfo * cachedVoidType;
static IHqlExpression * cachedBoolValue[2];
static IHqlExpression * cachedZero;
static IHqlExpression * cachedNullChar;
static IHqlExpression * defaultAttrExpr;
static IHqlExpression * selfAttrExpr;

ITypeInfo * boolType;
ITypeInfo * sizetType;
ITypeInfo * signedType;
ITypeInfo * unsignedType;
ITypeInfo * defaultIntegralType;
ITypeInfo * counterType;
ITypeInfo * unknownDataType;
ITypeInfo * unknownStringType;
ITypeInfo * unknownVarStringType;
ITypeInfo * unknownUtf8Type;
ITypeInfo * constUnknownVarStringType;
ITypeInfo * unknownUnicodeType;
ITypeInfo * fposType;
ITypeInfo * doubleType;
IHqlExpression * skipActionMarker;
IHqlExpression * skipReturnMarker;
IHqlExpression * subGraphMarker;
IHqlExpression * removedAssignTag;
IHqlExpression * internalAttrExpr;
IHqlExpression * activityIdMarkerExpr;
IHqlExpression * conditionalRowMarkerExpr;

//===========================================================================

MODULE_INIT(INIT_PRIORITY_STANDARD)
{
    boolType = makeBoolType();
    signedType = makeIntType(sizeof(signed), true);
    unsignedType = makeIntType(sizeof(unsigned), false);
    sizetType = makeIntType(sizeof(size32_t), false);
    defaultIntegralType = makeIntType(8, true);
    counterType = makeIntType(8, false);
    unknownDataType = makeDataType(UNKNOWN_LENGTH);
    unknownStringType = makeStringType(UNKNOWN_LENGTH, NULL, NULL);
    unknownVarStringType = makeVarStringType(UNKNOWN_LENGTH);
    unknownUtf8Type = makeUtf8Type(UNKNOWN_LENGTH, 0);
    constUnknownVarStringType = makeConstantModifier(LINK(unknownVarStringType));
    unknownUnicodeType = makeUnicodeType(UNKNOWN_LENGTH, 0);
    fposType = makeIntType(8, false);
    doubleType = makeRealType(8);

    cachedVoidType = makeVoidType();
    cachedBoolValue[false] = createConstant(false);
    cachedBoolValue[true] = createConstant(true);
    cachedZero = createIntConstant(0);
    cachedNullChar = createConstant(createCharValue(0, makeCharType()));
    defaultAttrExpr = createAttribute(defaultAtom);
    selfAttrExpr = createAttribute(selfAtom);

    skipActionMarker = createAttribute(skipActionMarkerAtom);
    skipReturnMarker = createAttribute(skipReturnMarkerAtom);
    subGraphMarker = createAttribute(subgraphAtom);
    removedAssignTag = createAttribute(_internal_Atom);
    internalAttrExpr = createAttribute(internalAtom);
    activityIdMarkerExpr = createAttribute(activityIdMarkerAtom);
    conditionalRowMarkerExpr = createAttribute(_conditionalRowMarker_Atom);
    return true;
}
MODULE_EXIT()
{
    conditionalRowMarkerExpr->Release();
    activityIdMarkerExpr->Release();
    internalAttrExpr->Release();
    removedAssignTag->Release();
    subGraphMarker->Release();
    skipReturnMarker->Release();
    skipActionMarker->Release();
    selfAttrExpr->Release();
    defaultAttrExpr->Release();
    boolType->Release();
    cachedVoidType->Release();
    cachedBoolValue[false]->Release();
    cachedBoolValue[true]->Release();
    cachedZero->Release();
    cachedNullChar->Release();
    unsignedType->Release();
    signedType->Release();
    defaultIntegralType->Release();
    sizetType->Release();
    counterType->Release();
    unknownDataType->Release();
    unknownStringType->Release();
    unknownVarStringType->Release();
    unknownUtf8Type->Release();
    constUnknownVarStringType->Release();
    unknownUnicodeType->Release();
    fposType->Release();
    doubleType->Release();
}


//===========================================================================

IHqlExpression * getZero()                              { return LINK(cachedZero); }
ITypeInfo *     queryBoolType()                     { return boolType; }
ITypeInfo *     queryVoidType()                     { return cachedVoidType; }

IHqlExpression * queryBoolExpr(bool value){ return cachedBoolValue[value]; }
IHqlExpression * queryNullChar()                    { return cachedNullChar; }
IHqlExpression * queryZero()                            { return cachedZero; }
IHqlExpression * getDefaultAttr() { return LINK(defaultAttrExpr); }
IHqlExpression * getSelfAttr() { return LINK(selfAttrExpr); }
IHqlExpression * queryActivityIdMarker() { return activityIdMarkerExpr; }
IHqlExpression * queryConditionalRowMarker() { return conditionalRowMarkerExpr; }

//===========================================================================

ITypeInfo * getArrayElementType(ITypeInfo * itemType)
{
    // use a var string type to get better C++ generated...
    if (storePointerInArray(itemType))
        return makeVarStringType(UNKNOWN_LENGTH);
    return LINK(itemType);
}


ITypeInfo * getConcatResultType(IHqlExpression * expr)
{
    assertex(!"not sure if this is unicode safe, but appears not to be used");
    //first work out the maximum size of the target
    unsigned max = expr->numChildren();
    unsigned idx;
    unsigned totalSize = 0;
    bool unknown = false;
    type_t resultType = type_string;

    for (idx = 0; idx < max; idx++)
    {
        ITypeInfo * type = expr->queryChild(idx)->queryType();
        unsigned size = type->getStringLen();
        if (size == UNKNOWN_LENGTH)
            unknown = true;
        else
            totalSize += size;
        if (type->getTypeCode() == type_varstring)
            resultType = type_varstring;
    }

    if (unknown)
        totalSize = 1023;
    if (resultType == type_string)
        return makeStringType(totalSize, NULL, NULL);
    return makeVarStringType(totalSize);
}


bool isCompare3Valued(ITypeInfo * type)
{
    type = type->queryPromotedType();
    switch (type->getTypeCode())
    {
        case type_string: case type_data:
            if (type->getSize() != 1)
                return true;
            break;
        case type_qstring:
        case type_varstring:
        case type_unicode:
        case type_varunicode:
        case type_decimal:
        case type_utf8:
            return true;
    }
    return false;
}

bool storePointerInArray(ITypeInfo * type) 
{ 
    return type->isReference() && isTypePassedByAddress(type); 
}

//Convert no_dataset_alias(expr, uid) to expr'
IHqlExpression * normalizeDatasetAlias(IHqlExpression * expr)
{
    IHqlExpression * uid = expr->queryProperty(_uid_Atom);
    assertex(uid);
    return appendOwnedOperand(expr->queryChild(0), LINK(uid));
}

//---------------------------------------------------------------------------

bool isSelectSortedTop(IHqlExpression * selectExpr)
{
    IHqlExpression * index = selectExpr->queryChild(1);
    if (matchesConstantValue(index, 1))
    {
        IHqlExpression * ds = selectExpr->queryChild(0);
        return ((ds->getOperator() == no_sort) || (ds->getOperator() == no_topn));
    }
    return false;
}

ITypeInfo * makeRowReferenceType(IHqlExpression * ds)
{
    ITypeInfo * recordType = ds ? LINK(ds->queryRecordType()) : NULL;
    ITypeInfo * rowType = makeReferenceModifier(makeRowType(recordType));
    if (ds)
    {
        ITypeInfo * dsType = ds->queryType();
        if (hasLinkedRow(dsType))
            rowType = makeAttributeModifier(rowType, getLinkCountedAttr());
        if (hasOutOfLineModifier(dsType))
            rowType = makeOutOfLineModifier(rowType);
    }

    return rowType;
}

ITypeInfo * makeRowReferenceType(const CHqlBoundExpr & bound) 
{ 
    return makeRowReferenceType(bound.expr); 
}

IHqlExpression * addMemberSelector(IHqlExpression * expr, IHqlExpression * selector)
{
    if (!expr)
        return NULL;
    if (expr->getOperator() == no_variable)
        return createValue(no_pselect, expr->getType(), LINK(selector), LINK(expr));
    if (expr->numChildren() == 0)
        return LINK(expr);
    HqlExprArray args;
    ForEachChild(i, expr)
        args.append(*addMemberSelector(expr->queryChild(i), selector));
    return expr->clone(args);
}


//Only called on translated expressions
IHqlExpression * addExpressionModifier(IHqlExpression * expr, typemod_t modifier, IInterface * extra)
{
    //Not sure which is best implementation...
#if 1
    return createValue(no_typetransfer, makeModifier(expr->getType(), modifier, LINK(extra)), LINK(expr));
#else
    HqlExprArray args;
    unwindChildren(args, expr);
    return createValue(expr->getOperator(), makeModifier(expr->getType(), modifier, LINK(extra)), args);
#endif
}



static void expandFieldNames(StringBuffer & out, IHqlExpression * record, StringBuffer & prefix, const char * sep, IHqlExpression * formatFunc)
{
    ForEachChild(i, record)
    {
        IHqlExpression * cur = record->queryChild(i);
        switch (cur->getOperator())
        {
        case no_record:
            expandFieldNames(out, cur, prefix, sep, formatFunc);
            break;
        case no_ifblock:
            expandFieldNames(out, cur->queryChild(1), prefix, sep, formatFunc);
            break;
        case no_field:
            {
                StringBuffer lowerName;
                lowerName.append(cur->queryName()).toLowerCase();
                if (formatFunc)
                {
                    HqlExprArray args;
                    args.append(*createConstant(lowerName.str()));
                    OwnedHqlExpr bound = createBoundFunction(NULL, formatFunc, args, NULL, true);
                    OwnedHqlExpr folded = foldHqlExpression(bound, NULL, HFOthrowerror|HFOfoldimpure|HFOforcefold);
                    assertex(folded->queryValue());
                    lowerName.clear();
                    getStringValue(lowerName, folded);
                }

                switch (cur->queryType()->getTypeCode())
                {
                case type_record:
                case type_row:
                    {
                        unsigned len = prefix.length();
                        prefix.append(lowerName).append(".");
                        expandFieldNames(out, cur->queryRecord(), prefix, sep, formatFunc);
                        prefix.setLength(len);
                        break;
                    }
                default:
                    {
                        if (out.length())
                            out.append(sep);
                        out.append(prefix).append(lowerName);
                        break;
                    }
                }
                break;
            }
        }
    }
}

void expandFieldNames(StringBuffer & out, IHqlExpression * record, const char * sep, IHqlExpression * formatFunc)
{
    StringBuffer prefix;
    expandFieldNames(out, record, prefix, sep, formatFunc);
}


IHqlExpression * ensurePositiveOrZeroInt64(IHqlExpression * expr)
{
    if (!expr->queryType()->isSigned())
        return LINK(expr);

    Owned<ITypeInfo> type = makeIntType(8, true);
    if (isCast(expr) && expr->queryType() == type)
    {
        ITypeInfo * uncastType = expr->queryChild(0)->queryType();
        if (!uncastType->isSigned() && uncastType->isInteger() && uncastType->getSize() < 8)
            return LINK(expr);
    }


    OwnedHqlExpr cast = ensureExprType(expr, type);
    IValue * value = cast->queryValue();
    Owned<IValue> zeroValue = type->castFrom(true, I64C(0));
    OwnedHqlExpr zero = createConstant(LINK(zeroValue));
    if (value)
    {
        if (value->compare(zeroValue) < 0)
            return LINK(zero);
        return LINK(cast);
    }

    //A bit convoluted, but we only want to evaluate impure expressions (e.g., random()!) once.
    //So force them to appear pure (so get commoned up), wrap in an alias, and then create the conditional assignment
    if (!cast->isPure())
    {
        OwnedHqlExpr localAttr = createLocalAttribute();
        OwnedHqlExpr pure = createValue(no_pure, cast->getType(), LINK(cast));
        cast.setown(createAlias(pure, localAttr));
    }

    return createValue(no_if, LINK(type), createBoolExpr(no_lt, LINK(cast), LINK(zero)), LINK(zero), LINK(cast));
}


void getOutputLibraryName(SCMStringBuffer & libraryName, IConstWorkUnit * wu)
{
    wu->getApplicationValue("LibraryModule", "name", libraryName);
}

IHqlExpression * projectCreateSetDataset(IHqlExpression * expr)
{
    IHqlExpression * ds = expr->queryChild(0);
    IHqlExpression * select = expr->queryChild(1);
    IHqlExpression * record = ds->queryRecord();

    //Project down to a single field if necessary. Not needed if selecting the only field in the dataset.
    if (queryRealChild(record, 1) || (select->getOperator() != no_select) || (record->queryChild(0) != select->queryChild(1)) || ds->queryNormalizedSelector() != select->queryChild(0))
    {
        HqlExprArray assigns;
        OwnedHqlExpr targetField;
        if (select->getOperator() == no_select)
            targetField.set(select->queryChild(1));
        else
            targetField.setown(createField(valueAtom, select->getType(), NULL));
        IHqlExpression * newRecord = createRecord(targetField);
        assigns.append(*createAssign(createSelectExpr(getSelf(newRecord), LINK(targetField)), LINK(select)));
        IHqlExpression * newTransform = createValue(no_newtransform, makeTransformType(LINK(newRecord->queryRecordType())), assigns);

        HqlExprArray args;
        args.append(*LINK(ds));
        args.append(*newRecord);
        args.append(*newTransform);
        OwnedHqlExpr projectedDs = createDataset(no_newusertable, args);

        return createValue(no_createset, expr->getType(), LINK(projectedDs), createSelectExpr(LINK(projectedDs), LINK(targetField)));
    }
    return LINK(expr);
}

IHqlExpression * mapInternalFunctionParameters(IHqlExpression * expr)
{
    switch (expr->getOperator())
    {
    case no_sortlist:
        {
            HqlExprArray args;
            ForEachChild(i, expr)
                args.append(*mapInternalFunctionParameters(expr->queryChild(i)));
            return cloneOrLink(expr, args);
        }
    case no_param:
        {
            ITypeInfo * type = expr->queryType();
            //String parameters need to be passed as c++ const string parameters
            switch (type->getTypeCode())
            {
            case type_string:
            case type_varstring:
            case type_data:
            case type_qstring:
            case type_unicode:
            case type_utf8:
            case type_varunicode:
                if (!expr->hasProperty(constAtom))
                    return appendOwnedOperand(expr, createAttribute(constAtom));
                break;
            }
            break;
        }
    }

    return LINK(expr);
}