/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 at
 *
 *   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 org.apache.hyracks.algebricks.core.algebra.operators.logical;

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

import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
import org.apache.hyracks.algebricks.core.algebra.base.LogicalVariable;
import org.apache.hyracks.algebricks.core.algebra.properties.VariablePropagationPolicy;

public abstract class AbstractScanOperator extends AbstractLogicalOperator {
    protected List<LogicalVariable> variables;

    public AbstractScanOperator(List<LogicalVariable> variables) {
        this.variables = variables;
    }

    public List<LogicalVariable> getVariables() {
        return variables;
    }

    public List<LogicalVariable> getScanVariables() {
        return variables;
    }

    public void setVariables(List<LogicalVariable> variables) {
        this.variables = variables;
    }

    @Override
    public void recomputeSchema() {
        schema = new ArrayList<LogicalVariable>();
        schema.addAll(inputs.get(0).getValue().getSchema());
        schema.addAll(variables);
    }

    @Override
    public VariablePropagationPolicy getVariablePropagationPolicy() {
        return new VariablePropagationPolicy() {

            @Override
            public void propagateVariables(IOperatorSchema target, IOperatorSchema... sources)
                    throws AlgebricksException {
                if (sources.length > 0) {
                    target.addAllVariables(sources[0]);
                }
                for (LogicalVariable v : variables) {
                    target.addVariable(v);
                }
            }
        };
    }

}
