/*
 * Copyright 2008-present 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.internal.selector;

import com.mongodb.ServerAddress;
import com.mongodb.connection.ClusterDescription;
import com.mongodb.connection.ServerDescription;
import com.mongodb.connection.ServerType;
import org.junit.Test;

import java.net.UnknownHostException;
import java.util.Arrays;
import java.util.concurrent.TimeUnit;

import static com.mongodb.connection.ClusterConnectionMode.MULTIPLE;
import static com.mongodb.connection.ClusterType.REPLICA_SET;
import static com.mongodb.connection.ServerConnectionState.CONNECTED;
import static org.junit.Assert.assertEquals;

public class LatencyMinimizingServerSelectorTest {
    @Test
    public void testLatencyDifferentialMinimization() throws UnknownHostException {
        LatencyMinimizingServerSelector selector = new LatencyMinimizingServerSelector(20, TimeUnit.MILLISECONDS);
        ServerDescription primary = ServerDescription.builder()
                                                     .state(CONNECTED)
                                                     .address(new ServerAddress())
                                                     .ok(true)
                                                     .type(ServerType.REPLICA_SET_PRIMARY)
                                                     .roundTripTime(10, TimeUnit.MILLISECONDS)
                                                     .build();
        ServerDescription secondaryOne = ServerDescription.builder()
                                                          .state(CONNECTED)
                                                          .address(new ServerAddress("localhost:27018"))
                                                          .ok(true)
                                                          .type(ServerType.REPLICA_SET_SECONDARY)
                                                          .roundTripTime(15, TimeUnit.MILLISECONDS)
                                                          .build();
        ServerDescription secondaryTwo = ServerDescription.builder()
                                                          .state(CONNECTED)
                                                          .address(new ServerAddress("localhost:27019"))
                                                          .ok(true)
                                                          .type(ServerType.REPLICA_SET_SECONDARY)
                                                          .roundTripTime(31, TimeUnit.MILLISECONDS)
                                                          .build();
        ServerDescription secondaryThree = ServerDescription.builder()
                                                            .state(CONNECTED)
                                                            .address(new ServerAddress("localhost:27020"))
                                                            .ok(true)
                                                            .type(ServerType.REPLICA_SET_SECONDARY)
                                                            .roundTripTime(30, TimeUnit.MILLISECONDS)
                                                            .build();
        assertEquals(Arrays.asList(primary, secondaryOne, secondaryThree),
                     selector.select(new ClusterDescription(MULTIPLE, REPLICA_SET,
                                                            Arrays.asList(primary, secondaryOne, secondaryTwo, secondaryThree))));
    }

    @Test
    public void testZeroLatencyDifferentialTolerance() throws UnknownHostException {
        LatencyMinimizingServerSelector selector = new LatencyMinimizingServerSelector(0, TimeUnit.NANOSECONDS);
        ServerDescription primary = ServerDescription.builder()
                                                     .state(CONNECTED)
                                                     .address(new ServerAddress())
                                                     .ok(true)
                                                     .type(ServerType.REPLICA_SET_PRIMARY)
                                                     .roundTripTime(10, TimeUnit.NANOSECONDS)
                                                     .build();
        ServerDescription secondaryOne = ServerDescription.builder()
                                                          .state(CONNECTED)
                                                          .address(new ServerAddress("localhost:27018"))
                                                          .ok(true)
                                                          .type(ServerType.REPLICA_SET_SECONDARY)
                                                          .roundTripTime(11, TimeUnit.NANOSECONDS)
                                                          .build();
        assertEquals(Arrays.asList(primary), selector.select(new ClusterDescription(MULTIPLE, REPLICA_SET,
                                                                                    Arrays.asList(primary, secondaryOne))));
    }
}