/*
 * 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.brooklyn.entity.group.zoneaware;

import java.util.List;

import org.apache.brooklyn.api.entity.Entity;
import org.apache.brooklyn.api.entity.EntitySpec;
import org.apache.brooklyn.api.location.Location;
import org.apache.brooklyn.api.location.LocationSpec;
import org.apache.brooklyn.core.location.SimulatedLocation;
import org.apache.brooklyn.core.test.BrooklynAppUnitTestSupport;
import org.apache.brooklyn.core.test.entity.TestEntity;
import org.apache.brooklyn.entity.group.zoneaware.BalancingNodePlacementStrategy;
import org.apache.brooklyn.test.Asserts;
import org.testng.annotations.BeforeMethod;
import org.testng.annotations.Test;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.LinkedHashMultimap;

public class BalancingNodePlacementStrategyTest extends BrooklynAppUnitTestSupport {

    private TestEntity entity1;
    private TestEntity entity2;
    private TestEntity entity3;
    private SimulatedLocation loc1;
    private SimulatedLocation loc2;
    private BalancingNodePlacementStrategy placementStrategy;
    
    @BeforeMethod(alwaysRun=true)
    @Override
    public void setUp() throws Exception {
        super.setUp();
        loc1 = mgmt.getLocationManager().createLocation(LocationSpec.create(SimulatedLocation.class));
        loc2 = mgmt.getLocationManager().createLocation(LocationSpec.create(SimulatedLocation.class));
        entity1 = app.createAndManageChild(EntitySpec.create(TestEntity.class));
        Thread.sleep(10); // tiny sleep is to ensure creation time is different for each entity
        entity2 = app.createAndManageChild(EntitySpec.create(TestEntity.class));
        Thread.sleep(10);
        entity3 = app.createAndManageChild(EntitySpec.create(TestEntity.class));
        placementStrategy = new BalancingNodePlacementStrategy();
    }

    @Test
    public void testAddsBalancedWhenEmpty() throws Exception {
        LinkedHashMultimap<Location, Entity> currentMembers = LinkedHashMultimap.<Location,Entity>create();
        List<Location> result = placementStrategy.locationsForAdditions(currentMembers, ImmutableList.of(loc1, loc2), 4);
        Asserts.assertEqualsIgnoringOrder(result, ImmutableList.of(loc1, loc1, loc2, loc2));
    }

    @Test
    public void testAddsToBalanceWhenPopulated() throws Exception {
        LinkedHashMultimap<Location, Entity> currentMembers = LinkedHashMultimap.<Location,Entity>create();
        currentMembers.put(loc1, entity1);
        currentMembers.put(loc1, entity2);
        List<Location> result = placementStrategy.locationsForAdditions(currentMembers, ImmutableList.of(loc1, loc2), 4);
        Asserts.assertEqualsIgnoringOrder(result, ImmutableList.of(loc1, loc2, loc2, loc2));
    }

    @Test
    public void testAddWillIgnoredDisallowedLocation() throws Exception {
        LinkedHashMultimap<Location, Entity> currentMembers = LinkedHashMultimap.<Location,Entity>create();
        currentMembers.put(loc1, entity1);
        currentMembers.put(loc2, entity2);
        List<Location> result = placementStrategy.locationsForAdditions(currentMembers, ImmutableList.of(loc1), 2);
        Asserts.assertEqualsIgnoringOrder(result, ImmutableList.of(loc1, loc1));
    }

    @Test
    public void testRemovesNewest() throws Exception {
        LinkedHashMultimap<Location, Entity> currentMembers = LinkedHashMultimap.<Location,Entity>create();
        currentMembers.put(loc1, entity1);
        currentMembers.put(loc1, entity2);
        List<Entity> result = placementStrategy.entitiesToRemove(currentMembers, 1);
        Asserts.assertEqualsIgnoringOrder(result, ImmutableList.of(entity2));
    }

    @Test
    public void testRemovesFromBiggestLocation() throws Exception {
        LinkedHashMultimap<Location, Entity> currentMembers = LinkedHashMultimap.<Location,Entity>create();
        currentMembers.put(loc1, entity1);
        currentMembers.put(loc1, entity2);
        currentMembers.put(loc2, entity3);
        List<Entity> result = placementStrategy.entitiesToRemove(currentMembers, 1);
        Asserts.assertEqualsIgnoringOrder(result, ImmutableList.of(entity2));

        // and confirm that not just taking first location!
        currentMembers = LinkedHashMultimap.<Location,Entity>create();
        currentMembers.put(loc1, entity3);
        currentMembers.put(loc2, entity1);
        currentMembers.put(loc2, entity2);
        result = placementStrategy.entitiesToRemove(currentMembers, 1);
        Asserts.assertEqualsIgnoringOrder(result, ImmutableList.of(entity2));
    }

    @Test
    public void testRemovesFromBiggestLocation2() throws Exception {
    }
}