/*
 * 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.plan;

import org.apache.flink.optimizer.costs.Costs;
import org.apache.flink.optimizer.dag.OptimizerNode;
import org.apache.flink.optimizer.dag.WorksetNode;
import org.apache.flink.optimizer.dataproperties.GlobalProperties;
import org.apache.flink.optimizer.dataproperties.LocalProperties;
import org.apache.flink.runtime.operators.DamBehavior;
import org.apache.flink.runtime.operators.DriverStrategy;
import org.apache.flink.util.Visitor;

import java.util.Collections;
import java.util.HashMap;

import static org.apache.flink.optimizer.plan.PlanNode.SourceAndDamReport.FOUND_SOURCE;
import static org.apache.flink.optimizer.plan.PlanNode.SourceAndDamReport.FOUND_SOURCE_AND_DAM;
import static org.apache.flink.optimizer.plan.PlanNode.SourceAndDamReport.NOT_FOUND;

/** Plan candidate node for partial solution of a bulk iteration. */
public class WorksetPlanNode extends PlanNode {

    private static final Costs NO_COSTS = new Costs();

    private WorksetIterationPlanNode containingIterationNode;

    private final Channel initialInput;

    public Object postPassHelper;

    public WorksetPlanNode(
            WorksetNode template,
            String nodeName,
            GlobalProperties gProps,
            LocalProperties lProps,
            Channel initialInput) {
        super(template, nodeName, DriverStrategy.NONE);

        this.globalProps = gProps;
        this.localProps = lProps;
        this.initialInput = initialInput;

        // the node incurs no cost
        this.nodeCosts = NO_COSTS;
        this.cumulativeCosts = NO_COSTS;

        if (initialInput.getSource().branchPlan != null
                && initialInput.getSource().branchPlan.size() > 0) {
            if (this.branchPlan == null) {
                this.branchPlan = new HashMap<OptimizerNode, PlanNode>();
            }

            this.branchPlan.putAll(initialInput.getSource().branchPlan);
        }
    }

    // --------------------------------------------------------------------------------------------

    public WorksetNode getWorksetNode() {
        return (WorksetNode) this.template;
    }

    public WorksetIterationPlanNode getContainingIterationNode() {
        return this.containingIterationNode;
    }

    public void setContainingIterationNode(WorksetIterationPlanNode containingIterationNode) {
        this.containingIterationNode = containingIterationNode;
    }

    // --------------------------------------------------------------------------------------------

    @Override
    public void accept(Visitor<PlanNode> visitor) {
        if (visitor.preVisit(this)) {
            visitor.postVisit(this);
        }
    }

    @Override
    public Iterable<PlanNode> getPredecessors() {
        return Collections.<PlanNode>emptyList();
    }

    @Override
    public Iterable<Channel> getInputs() {
        return Collections.<Channel>emptyList();
    }

    @Override
    public SourceAndDamReport hasDamOnPathDownTo(PlanNode source) {
        if (source == this) {
            return FOUND_SOURCE;
        }
        SourceAndDamReport res = this.initialInput.getSource().hasDamOnPathDownTo(source);
        if (res == FOUND_SOURCE_AND_DAM) {
            return FOUND_SOURCE_AND_DAM;
        } else if (res == FOUND_SOURCE) {
            return (this.initialInput.getLocalStrategy().dams()
                            || this.initialInput.getTempMode().breaksPipeline()
                            || getDriverStrategy().firstDam() == DamBehavior.FULL_DAM)
                    ? FOUND_SOURCE_AND_DAM
                    : FOUND_SOURCE;
        } else {
            return NOT_FOUND;
        }
    }
}
