/*
 * 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.cassandra.repair;

import java.net.InetAddress;

import com.google.common.util.concurrent.AbstractFuture;

import org.apache.cassandra.exceptions.RepairException;
import org.apache.cassandra.net.MessagingService;
import org.apache.cassandra.repair.messages.ValidationRequest;
import org.apache.cassandra.utils.MerkleTree;

/**
 * ValidationTask sends {@link ValidationRequest} to a replica.
 * When a replica sends back message, task completes.
 */
public class ValidationTask extends AbstractFuture<TreeResponse> implements Runnable
{
    private final RepairJobDesc desc;
    private final InetAddress endpoint;
    private final int gcBefore;

    public ValidationTask(RepairJobDesc desc, InetAddress endpoint, int gcBefore)
    {
        this.desc = desc;
        this.endpoint = endpoint;
        this.gcBefore = gcBefore;
    }

    /**
     * Send ValidationRequest to replica
     */
    public void run()
    {
        ValidationRequest request = new ValidationRequest(desc, gcBefore);
        MessagingService.instance().sendOneWay(request.createMessage(), endpoint);
    }

    /**
     * Receive MerkleTree from replica node.
     *
     * @param tree MerkleTree that is sent from replica. Null if validation failed on replica node.
     */
    public void treeReceived(MerkleTree tree)
    {
        if (tree == null)
        {
            setException(new RepairException(desc, "Validation failed in " + endpoint));
        }
        else
        {
            set(new TreeResponse(endpoint, tree));
        }
    }
}