asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/constructors/ADateConstructorDescriptor.java

package edu.uci.ics.asterix.runtime.evaluators.constructors;

import java.io.DataOutput;
import java.io.IOException;

import edu.uci.ics.asterix.common.functions.FunctionConstants;
import edu.uci.ics.asterix.formats.nontagged.AqlSerializerDeserializerProvider;
import edu.uci.ics.asterix.om.base.ADate;
import edu.uci.ics.asterix.om.base.AMutableDate;
import edu.uci.ics.asterix.om.base.ANull;
import edu.uci.ics.asterix.om.base.temporal.ByteArrayCharSequenceAccessor;
import edu.uci.ics.asterix.om.base.temporal.ADateAndTimeParser;
import edu.uci.ics.asterix.om.base.temporal.GregorianCalendarSystem;
import edu.uci.ics.asterix.om.functions.IFunctionDescriptor;
import edu.uci.ics.asterix.om.functions.IFunctionDescriptorFactory;
import edu.uci.ics.asterix.om.types.ATypeTag;
import edu.uci.ics.asterix.om.types.BuiltinType;
import edu.uci.ics.asterix.runtime.evaluators.base.AbstractScalarFunctionDynamicDescriptor;
import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
import edu.uci.ics.hyracks.algebricks.core.algebra.functions.FunctionIdentifier;
import edu.uci.ics.hyracks.algebricks.runtime.base.ICopyEvaluator;
import edu.uci.ics.hyracks.algebricks.runtime.base.ICopyEvaluatorFactory;
import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
import edu.uci.ics.hyracks.data.std.api.IDataOutputProvider;
import edu.uci.ics.hyracks.data.std.util.ArrayBackedValueStorage;
import edu.uci.ics.hyracks.dataflow.common.data.accessors.IFrameTupleReference;

public class ADateConstructorDescriptor extends AbstractScalarFunctionDynamicDescriptor {

    private static final long serialVersionUID = 1L;
    public final static FunctionIdentifier FID = new FunctionIdentifier(FunctionConstants.ASTERIX_NS, "date", 1);
    private final static byte SER_STRING_TYPE_TAG = ATypeTag.STRING.serialize();
    private final static byte SER_NULL_TYPE_TAG = ATypeTag.NULL.serialize();

    private final static ByteArrayCharSequenceAccessor charAccessor = new ByteArrayCharSequenceAccessor();

    public static final IFunctionDescriptorFactory FACTORY = new IFunctionDescriptorFactory() {
        public IFunctionDescriptor createFunctionDescriptor() {
            return new ADateConstructorDescriptor();
        }
    };

    @Override
    public ICopyEvaluatorFactory createEvaluatorFactory(final ICopyEvaluatorFactory[] args) {
        return new ICopyEvaluatorFactory() {
            private static final long serialVersionUID = 1L;

            @Override
            public ICopyEvaluator createEvaluator(final IDataOutputProvider output) throws AlgebricksException {
                return new ICopyEvaluator() {

                    private DataOutput out = output.getDataOutput();

                    private ArrayBackedValueStorage outInput = new ArrayBackedValueStorage();
                    private ICopyEvaluator eval = args[0].createEvaluator(outInput);
                    private String errorMessage = "This can not be an instance of date";
                    private AMutableDate aDate = new AMutableDate(0);
                    @SuppressWarnings("unchecked")
                    private ISerializerDeserializer<ADate> dateSerde = AqlSerializerDeserializerProvider.INSTANCE
                            .getSerializerDeserializer(BuiltinType.ADATE);
                    @SuppressWarnings("unchecked")
                    private ISerializerDeserializer<ANull> nullSerde = AqlSerializerDeserializerProvider.INSTANCE
                            .getSerializerDeserializer(BuiltinType.ANULL);

                    @Override
                    public void evaluate(IFrameTupleReference tuple) throws AlgebricksException {

                        try {
                            outInput.reset();
                            eval.evaluate(tuple);
                            byte[] serString = outInput.getByteArray();
                            if (serString[0] == SER_STRING_TYPE_TAG) {

                                charAccessor.reset(serString, 3, 0);
                                long chrononTimeInMs = ADateAndTimeParser.parseDatePart(charAccessor, true);

                                short temp = 0;
                                if (chrononTimeInMs < 0
                                        && chrononTimeInMs % GregorianCalendarSystem.CHRONON_OF_DAY != 0) {
                                    temp = 1;
                                }

                                aDate.setValue((int) (chrononTimeInMs / GregorianCalendarSystem.CHRONON_OF_DAY) - temp);

                                dateSerde.serialize(aDate, out);
                            } else if (serString[0] == SER_NULL_TYPE_TAG) {
                                nullSerde.serialize(ANull.NULL, out);
                            } else {
                                throw new AlgebricksException(errorMessage);
                            }
                        } catch (IOException e1) {
                            throw new AlgebricksException(errorMessage);
                        } catch (Exception e2) {
                            throw new AlgebricksException(e2);
                        }
                    }
                };
            }
        };
    }

    @Override
    public FunctionIdentifier getIdentifier() {
        return FID;
    }

}