/*
 * 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.flink.optimizer.operators;

import org.apache.flink.api.common.operators.util.FieldList;
import org.apache.flink.optimizer.CompilerException;
import org.apache.flink.optimizer.dag.TwoInputNode;
import org.apache.flink.optimizer.dataproperties.LocalProperties;
import org.apache.flink.optimizer.dataproperties.RequestedLocalProperties;
import org.apache.flink.optimizer.plan.Channel;
import org.apache.flink.optimizer.plan.DualInputPlanNode;
import org.apache.flink.optimizer.util.Utils;
import org.apache.flink.runtime.operators.DriverStrategy;

import java.util.Collections;
import java.util.List;

/** */
public class CoGroupWithSolutionSetFirstDescriptor extends CoGroupDescriptor {

    public CoGroupWithSolutionSetFirstDescriptor(FieldList keys1, FieldList keys2) {
        super(keys1, keys2);
    }

    @Override
    protected List<LocalPropertiesPair> createPossibleLocalProperties() {
        RequestedLocalProperties none = new RequestedLocalProperties();
        RequestedLocalProperties sort =
                new RequestedLocalProperties(Utils.createOrdering(this.keys2));
        return Collections.singletonList(new LocalPropertiesPair(none, sort));
    }

    @Override
    public DualInputPlanNode instantiate(Channel in1, Channel in2, TwoInputNode node) {
        boolean[] inputOrders =
                in2.getLocalProperties().getOrdering() == null
                        ? null
                        : in2.getLocalProperties().getOrdering().getFieldSortDirections();

        if (inputOrders == null || inputOrders.length < this.keys2.size()) {
            throw new CompilerException(
                    "BUG: The input strategy does not sufficiently describe the sort orders for a CoGroup operator.");
        } else if (inputOrders.length > this.keys2.size()) {
            boolean[] tmp = new boolean[this.keys2.size()];
            System.arraycopy(inputOrders, 0, tmp, 0, tmp.length);
            inputOrders = tmp;
        }

        return new DualInputPlanNode(
                node,
                "CoGroup (" + node.getOperator().getName() + ")",
                in1,
                in2,
                DriverStrategy.CO_GROUP,
                this.keys1,
                this.keys2,
                inputOrders);
    }

    @Override
    public boolean areCoFulfilled(
            RequestedLocalProperties requested1,
            RequestedLocalProperties requested2,
            LocalProperties produced1,
            LocalProperties produced2) {
        return true;
    }

    @Override
    public LocalProperties computeLocalProperties(LocalProperties in1, LocalProperties in2) {
        return in2;
    }
}
