/*
 * 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.core.entity;

import static org.apache.brooklyn.test.Asserts.assertEqualsIgnoringOrder;
import static org.testng.Assert.assertEquals;
import static org.testng.Assert.assertFalse;
import static org.testng.Assert.assertTrue;
import static org.testng.Assert.fail;

import org.apache.brooklyn.api.entity.Application;
import org.apache.brooklyn.api.entity.Entity;
import org.apache.brooklyn.core.entity.AbstractApplication;
import org.apache.brooklyn.core.entity.AbstractEntity;
import org.apache.brooklyn.core.entity.Entities;
import org.testng.annotations.AfterMethod;
import org.testng.annotations.BeforeMethod;
import org.testng.annotations.Test;

import com.google.common.collect.ImmutableList;

public class OwnedChildrenTest {

    private Application app;

    @BeforeMethod(alwaysRun=true)
    public void setUp() {
        app = new AbstractApplication() {};
    }

    @AfterMethod(alwaysRun = true)
    public void tearDown(){
        if (app != null) Entities.destroyAll(app.getManagementContext());
    }

    // Tests that the deprecated "owner" still works
    @Test
    public void testSetOwnerInConstructorMap() {
        Entity e = new AbstractEntity(app) {};
        
        assertEquals(e.getParent(), app);
        assertEqualsIgnoringOrder(app.getChildren(), ImmutableList.of(e));
        assertEquals(e.getApplication(), app);
    }
    
    @Test
    public void testSetParentInConstructorMap() {
        Entity e = new AbstractEntity(app) {};
        
        assertEquals(e.getParent(), app);
        assertEqualsIgnoringOrder(app.getChildren(), ImmutableList.of(e));
        assertEquals(e.getApplication(), app);
    }
    
    @Test
    public void testSetParentInConstructorArgument() {
        Entity e = new AbstractEntity(app) {};
        
        assertEquals(e.getParent(), app);
        assertEqualsIgnoringOrder(app.getChildren(), ImmutableList.of(e));
        assertEquals(e.getApplication(), app);
    }
    
    @Test
    public void testSetParentInSetterMethod() {
        Entity e = new AbstractEntity() {};
        e.setParent(app);
        
        assertEquals(e.getParent(), app);
        assertEqualsIgnoringOrder(app.getChildren(), ImmutableList.of(e));
        assertEquals(e.getApplication(), app);
    }

    @Test
    public void testAddChild() {
        Entity e = new AbstractEntity() {};
        app.addChild(e);
        
        assertEquals(e.getParent(), app);
        assertEqualsIgnoringOrder(app.getChildren(), ImmutableList.of(e));
        assertEquals(e.getApplication(), app);
    }
    
    @Test
    public void testSetParentWhenMatchesParentSetInConstructor() {
        Entity e = new AbstractEntity(app) {};
        e.setParent(app);
        
        assertEquals(e.getParent(), app);
        assertEqualsIgnoringOrder(app.getChildren(), ImmutableList.of(e));
    }
    
    @Test(expectedExceptions = UnsupportedOperationException.class)
    public void testSetParentWhenDiffersFromParentSetInConstructor() {
        Entity e = new AbstractEntity(app) {};
        Entity e2 = new AbstractEntity() {};
        e.setParent(e2);
        fail();
    }
    
    @Test
    public void testParentCanHaveMultipleChildren() {
        Entity e = new AbstractEntity(app) {};
        Entity e2 = new AbstractEntity(app) {};
        
        assertEquals(e.getParent(), app);
        assertEquals(e2.getParent(), app);
        assertEqualsIgnoringOrder(app.getChildren(), ImmutableList.of(e,e2));
    }
    
    @Test
    public void testHierarchyOfOwners() {
        Entity e = new AbstractEntity(app) {};
        Entity e2 = new AbstractEntity(e) {};
        Entity e3 = new AbstractEntity(e2) {};
        
        assertEquals(app.getParent(), null);
        assertEquals(e.getParent(), app);
        assertEquals(e2.getParent(), e);
        assertEquals(e3.getParent(), e2);
        
        assertEqualsIgnoringOrder(app.getChildren(), ImmutableList.of(e));
        assertEqualsIgnoringOrder(e.getChildren(), ImmutableList.of(e2));
        assertEqualsIgnoringOrder(e2.getChildren(), ImmutableList.of(e3));
        assertEqualsIgnoringOrder(e3.getChildren(), ImmutableList.of());
    }
    
    @Test(enabled = false) // FIXME fails currently
    public void testRemoveChild() {
        Entity e = new AbstractEntity(app) {};
        app.removeChild(e);
        
        assertEqualsIgnoringOrder(app.getChildren(), ImmutableList.of());
        assertEquals(e.getParent(), null);
    }
    
    @Test
    public void testParentalLoopForbiddenViaAddChild() {
        Entity e = new AbstractEntity() {};
        Entity e2 = new AbstractEntity(e) {};
        try {
            e2.addChild(e);
            fail();
        } catch (IllegalStateException ex) {
            // success
        }
        
        assertEqualsIgnoringOrder(e.getChildren(), ImmutableList.of(e2));
        assertEqualsIgnoringOrder(e2.getChildren(), ImmutableList.of());
        assertEquals(e.getParent(), null);
        assertEquals(e2.getParent(), e);
    }
    
    @Test
    public void testParentalLoopForbiddenViaSetParent() {
        Entity e = new AbstractEntity() {};
        Entity e2 = new AbstractEntity(e) {};
        try {
            e.setParent(e2);
            fail();
        } catch (IllegalStateException ex) {
			ex.printStackTrace();
            // success
        }
        assertEqualsIgnoringOrder(e.getChildren(), ImmutableList.of(e2));
        assertEqualsIgnoringOrder(e2.getChildren(), ImmutableList.of());
        assertEquals(e.getParent(), null);
        assertEquals(e2.getParent(), e);
    }
    
    @Test(expectedExceptions = IllegalStateException.class)
    public void testParentingOneselfForbidden() {
        AbstractEntity e = new AbstractEntity() {};
        e.addChild(e);
        fail();
    }
    
    @Test
    public void testIsAncestor() {
        AbstractEntity e = new AbstractEntity(app) {};
        AbstractEntity e2 = new AbstractEntity(e) {};
        
		assertTrue(Entities.isAncestor(e2, app));
		assertTrue(Entities.isAncestor(e2, e));
		assertFalse(Entities.isAncestor(e2, e2));
    }
    
    @Test
    public void testIsDescendant() {
        AbstractEntity e = new AbstractEntity(app) {};
        AbstractEntity e2 = new AbstractEntity(e) {};

		assertTrue(Entities.isDescendant(app, e));
		assertTrue(Entities.isDescendant(app, e2));
		assertFalse(Entities.isDescendant(e2, e));
    }
}