/*
 * 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 hivemall.mix.client;

import hivemall.mix.MixEnv;
import hivemall.mix.MixMessage;
import hivemall.mix.NodeInfo;
import hivemall.utils.net.NetUtils;

import java.net.InetSocketAddress;

public final class MixRequestRouter {

    private final int numNodes;
    private final NodeInfo[] nodes;

    public MixRequestRouter(String connectInfo) {
        if (connectInfo == null) {
            throw new IllegalArgumentException();
        }
        String[] endpoints = connectInfo.split("\\s*,\\s*");
        final int numEndpoints = endpoints.length;
        if (numEndpoints < 1) {
            throw new IllegalArgumentException("Invalid connectInfo: " + connectInfo);
        }
        this.numNodes = numEndpoints;
        NodeInfo[] nodes = new NodeInfo[numEndpoints];
        for (int i = 0; i < numEndpoints; i++) {
            InetSocketAddress addr = NetUtils.getInetSocketAddress(endpoints[i],
                MixEnv.MIXSERV_DEFAULT_PORT);
            nodes[i] = new NodeInfo(addr);
        }
        this.nodes = nodes;
    }

    public NodeInfo[] getAllNodes() {
        return nodes;
    }

    public NodeInfo selectNode(MixMessage msg) {
        assert (msg != null);
        Object feature = msg.getFeature();
        int hashcode = feature.hashCode();
        int index = (hashcode & Integer.MAX_VALUE) % numNodes;
        return nodes[index];
    }

}