/*
 * Copyright 2009-2010 by The Regents of the University of California
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * you may obtain a copy of the License from
 * 
 *     http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package edu.uci.ics.hyracks.algebricks.runtime.operators.std;

import java.nio.ByteBuffer;

import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
import edu.uci.ics.hyracks.algebricks.data.IBinaryBooleanInspector;
import edu.uci.ics.hyracks.algebricks.data.IBinaryBooleanInspectorFactory;
import edu.uci.ics.hyracks.algebricks.runtime.base.IScalarEvaluator;
import edu.uci.ics.hyracks.algebricks.runtime.base.IScalarEvaluatorFactory;
import edu.uci.ics.hyracks.algebricks.runtime.operators.base.AbstractOneInputOneOutputOneFramePushRuntime;
import edu.uci.ics.hyracks.algebricks.runtime.operators.base.AbstractOneInputOneOutputRuntimeFactory;
import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
import edu.uci.ics.hyracks.data.std.api.IPointable;
import edu.uci.ics.hyracks.data.std.primitive.VoidPointable;

public class StreamSelectRuntimeFactory extends AbstractOneInputOneOutputRuntimeFactory {

    private static final long serialVersionUID = 1L;

    private IScalarEvaluatorFactory cond;

    private IBinaryBooleanInspectorFactory binaryBooleanInspectorFactory;

    /**
     * @param cond
     * @param projectionList
     *            if projectionList is null, then no projection is performed
     */
    public StreamSelectRuntimeFactory(IScalarEvaluatorFactory cond, int[] projectionList,
            IBinaryBooleanInspectorFactory binaryBooleanInspectorFactory) {
        super(projectionList);
        this.cond = cond;
        this.binaryBooleanInspectorFactory = binaryBooleanInspectorFactory;
    }

    @Override
    public String toString() {
        return "stream-select " + cond.toString();
    }

    @Override
    public AbstractOneInputOneOutputOneFramePushRuntime createOneOutputPushRuntime(final IHyracksTaskContext ctx) {
        final IBinaryBooleanInspector bbi = binaryBooleanInspectorFactory.createBinaryBooleanInspector(ctx);
        return new AbstractOneInputOneOutputOneFramePushRuntime() {
            private IPointable p = VoidPointable.FACTORY.createPointable();
            private IScalarEvaluator eval;

            @Override
            public void open() throws HyracksDataException {
                if (eval == null) {
                    initAccessAppendRef(ctx);
                    try {
                        eval = cond.createScalarEvaluator(ctx);
                    } catch (AlgebricksException ae) {
                        throw new HyracksDataException(ae);
                    }
                }
                writer.open();
            }

            @Override
            public void nextFrame(ByteBuffer buffer) throws HyracksDataException {
                tAccess.reset(buffer);
                int nTuple = tAccess.getTupleCount();
                for (int t = 0; t < nTuple; t++) {
                    tRef.reset(tAccess, t);
                    try {
                        eval.evaluate(tRef, p);
                    } catch (AlgebricksException ae) {
                        throw new HyracksDataException(ae);
                    }
                    if (bbi.getBooleanValue(p.getByteArray(), p.getStartOffset(), p.getLength())) {
                        if (projectionList != null) {
                            appendProjectionToFrame(t, projectionList);
                        } else {
                            appendTupleToFrame(t);
                        }
                    }
                }
            }

        };
    }

}