/*
 * Copyright (c) 2008-2014 MongoDB, Inc.
 *
 * Licensed 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 com.mongodb;

import java.util.ArrayList;
import java.util.List;

class CompositeServerSelector implements ServerSelector {
    private final List<ServerSelector> serverSelectors;

    CompositeServerSelector(final List<ServerSelector> serverSelectors) {
        if (serverSelectors.isEmpty()) {
            throw new IllegalArgumentException("Server selectors can not be an empty list");
        }
        this.serverSelectors = new ArrayList<ServerSelector>(serverSelectors);
    }

    @Override
    public List<ServerDescription> choose(final ClusterDescription clusterDescription) {
        ClusterDescription curClusterDescription = clusterDescription;
        List<ServerDescription> choices = null;
        for (ServerSelector cur : serverSelectors) {
            choices = cur.choose(curClusterDescription);
            curClusterDescription = new ClusterDescription(clusterDescription.getConnectionMode(), clusterDescription.getType(), choices);
        }

        return choices;
    }

    @Override
    public String toString() {
            return "{"
                   + "serverSelectors=" + serverSelectors
                   + '}';
    }
}