asterix-om/src/main/java/edu/uci/ics/asterix/om/typecomputer/impl/OpenRecordConstructorResultType.java

package edu.uci.ics.asterix.om.typecomputer.impl;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.apache.commons.lang3.mutable.Mutable;

import edu.uci.ics.asterix.om.base.AString;
import edu.uci.ics.asterix.om.constants.AsterixConstantValue;
import edu.uci.ics.asterix.om.typecomputer.base.IResultTypeComputer;
import edu.uci.ics.asterix.om.typecomputer.base.TypeComputerUtilities;
import edu.uci.ics.asterix.om.types.ARecordType;
import edu.uci.ics.asterix.om.types.IAType;
import edu.uci.ics.asterix.om.types.TypeHelper;
import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalExpression;
import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalExpressionTag;
import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.AbstractFunctionCallExpression;
import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.ConstantExpression;
import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.IVariableTypeEnvironment;
import edu.uci.ics.hyracks.algebricks.core.algebra.metadata.IMetadataProvider;

public class OpenRecordConstructorResultType implements IResultTypeComputer {

    public static final OpenRecordConstructorResultType INSTANCE = new OpenRecordConstructorResultType();

    @Override
    public IAType computeType(ILogicalExpression expression, IVariableTypeEnvironment env,
            IMetadataProvider<?, ?> metadataProvider) throws AlgebricksException {
        AbstractFunctionCallExpression f = (AbstractFunctionCallExpression) expression;

        /**
         * if type has been top-down propagated, use the enforced type
         */
        ARecordType type = TypeComputerUtilities.getRequiredType(f);
        if (type != null)
            return type;

        int n = 0;
        Iterator<Mutable<ILogicalExpression>> argIter = f.getArguments().iterator();
        List<String> namesList = new ArrayList<String>();
        List<IAType> typesList = new ArrayList<IAType>();
        while (argIter.hasNext()) {
            ILogicalExpression e1 = argIter.next().getValue();
            ILogicalExpression e2 = argIter.next().getValue();
            IAType t2 = (IAType) env.getType(e2);
            if (e1.getExpressionTag() == LogicalExpressionTag.CONSTANT && t2 != null && TypeHelper.isClosed(t2)) {
                ConstantExpression nameExpr = (ConstantExpression) e1;
                AsterixConstantValue acv = (AsterixConstantValue) nameExpr.getValue();
                namesList.add(((AString) acv.getObject()).getStringValue());
                typesList.add(t2);
                n++;
            }
        }
        String[] fieldNames = new String[n];
        IAType[] fieldTypes = new IAType[n];
        fieldNames = namesList.toArray(fieldNames);
        fieldTypes = typesList.toArray(fieldTypes);
        return new ARecordType(null, fieldNames, fieldTypes, true);
    }
}