/*
 * 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.ignite.raft.jraft.rpc;

import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
import org.apache.ignite.internal.logger.IgniteLogger;
import org.apache.ignite.internal.logger.Loggers;
import org.apache.ignite.raft.jraft.Closure;
import org.apache.ignite.raft.jraft.RaftMessagesFactory;
import org.apache.ignite.raft.jraft.Status;

/**
 * RPC request Closure encapsulates the RPC contexts.
 */
public class RpcRequestClosure implements Closure {
    private static final IgniteLogger LOG = Loggers.forClass(RpcRequestClosure.class);

    private static final AtomicIntegerFieldUpdater<RpcRequestClosure> STATE_UPDATER = AtomicIntegerFieldUpdater
        .newUpdater(RpcRequestClosure.class, "state");

    private static final int PENDING = 0;
    private static final int RESPOND = 1;

    private final RpcContext rpcCtx;
    private final RaftMessagesFactory msgFactory;

    private volatile int state = PENDING; // NOPMD

    public RpcRequestClosure(RpcContext rpcCtx, RaftMessagesFactory msgFactory) {
        this.rpcCtx = rpcCtx;
        this.msgFactory = msgFactory;
    }

    public RpcContext getRpcCtx() {
        return rpcCtx;
    }

    public RaftMessagesFactory getMsgFactory() {
        return msgFactory;
    }

    public void sendResponse(final Message msg) {
        if (!STATE_UPDATER.compareAndSet(this, PENDING, RESPOND)) {
            LOG.warn("A response: {} sent repeatedly!", msg);
            return;
        }

        this.rpcCtx.sendResponse(msg);
    }

    @Override
    public void run(final Status status) {
        sendResponse(RaftRpcFactory.DEFAULT.newResponse(msgFactory, status));
    }
}
