/*
 * 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.core.algebra.operators.physical;

import java.util.ArrayList;

import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
import edu.uci.ics.hyracks.algebricks.common.utils.Triple;
import edu.uci.ics.hyracks.algebricks.core.algebra.base.IHyracksJobBuilder;
import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalOperator;
import edu.uci.ics.hyracks.algebricks.core.algebra.base.IOptimizationContext;
import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalVariable;
import edu.uci.ics.hyracks.algebricks.core.algebra.base.PhysicalOperatorTag;
import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.AbstractLogicalOperator;
import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.IOperatorSchema;
import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.UnionAllOperator;
import edu.uci.ics.hyracks.algebricks.core.algebra.properties.ILocalStructuralProperty;
import edu.uci.ics.hyracks.algebricks.core.algebra.properties.IPartitioningProperty;
import edu.uci.ics.hyracks.algebricks.core.algebra.properties.IPartitioningRequirementsCoordinator;
import edu.uci.ics.hyracks.algebricks.core.algebra.properties.IPhysicalPropertiesVector;
import edu.uci.ics.hyracks.algebricks.core.algebra.properties.PhysicalRequirements;
import edu.uci.ics.hyracks.algebricks.core.algebra.properties.StructuralPropertiesVector;
import edu.uci.ics.hyracks.algebricks.core.jobgen.impl.JobGenContext;
import edu.uci.ics.hyracks.algebricks.core.jobgen.impl.JobGenHelper;
import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
import edu.uci.ics.hyracks.api.job.IOperatorDescriptorRegistry;
import edu.uci.ics.hyracks.dataflow.std.union.UnionAllOperatorDescriptor;

public class UnionAllPOperator extends AbstractPhysicalOperator {

    @Override
    public PhysicalOperatorTag getOperatorTag() {
        return PhysicalOperatorTag.UNION_ALL;
    }

    @Override
    public boolean isMicroOperator() {
        return false;
    }

    @Override
    public void computeDeliveredProperties(ILogicalOperator op, IOptimizationContext context) {
        AbstractLogicalOperator op2 = (AbstractLogicalOperator) op.getInputs().get(0).getValue();
        IPartitioningProperty pp = op2.getDeliveredPhysicalProperties().getPartitioningProperty();
        this.deliveredProperties = new StructuralPropertiesVector(pp, new ArrayList<ILocalStructuralProperty>(0));

    }

    @Override
    public PhysicalRequirements getRequiredPropertiesForChildren(ILogicalOperator op,
            IPhysicalPropertiesVector reqdByParent) {
        StructuralPropertiesVector pv0 = StructuralPropertiesVector.EMPTY_PROPERTIES_VECTOR;
        StructuralPropertiesVector pv1 = StructuralPropertiesVector.EMPTY_PROPERTIES_VECTOR;
        return new PhysicalRequirements(new StructuralPropertiesVector[] { pv0, pv1 },
                IPartitioningRequirementsCoordinator.NO_COORDINATION);
    }

    @Override
    public void contributeRuntimeOperator(IHyracksJobBuilder builder, JobGenContext context, ILogicalOperator op,
            IOperatorSchema opSchema, IOperatorSchema[] inputSchemas, IOperatorSchema outerPlanSchema)
            throws AlgebricksException {
        UnionAllOperator unionOp = (UnionAllOperator) op;
        int n = unionOp.getVariableMappings().size();
        int[] leftColumns = new int[n];
        int[] rightColumns = new int[n];
        int i = 0;
        for (Triple<LogicalVariable, LogicalVariable, LogicalVariable> t : unionOp.getVariableMappings()) {
            int posLeft = inputSchemas[0].findVariable(t.first);
            leftColumns[i] = posLeft;
            int posRight = inputSchemas[1].findVariable(t.second);
            rightColumns[i] = posRight;
            ++i;
        }

        IOperatorDescriptorRegistry spec = builder.getJobSpec();
        RecordDescriptor recordDescriptor = JobGenHelper.mkRecordDescriptor(context.getTypeEnvironment(op), opSchema, context);

        // at algebricks level, union all only accepts two inputs, although at
        // hyracks
        // level, there is no restrictions
        UnionAllOperatorDescriptor opDesc = new UnionAllOperatorDescriptor(spec, 2, recordDescriptor);
        contributeOpDesc(builder, (AbstractLogicalOperator) op, opDesc);
        ILogicalOperator src1 = op.getInputs().get(0).getValue();
        builder.contributeGraphEdge(src1, 0, op, 0);
        ILogicalOperator src2 = op.getInputs().get(1).getValue();
        builder.contributeGraphEdge(src2, 0, op, 1);
    }

}