/*
 * 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.onlab.graph;

import com.google.common.testing.EqualsTester;
import org.junit.Test;

import static com.google.common.collect.ImmutableList.of;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNull;

/**
 * Test of the default mutable path.
 */
public class DefaultMutablePathTest extends DefaultPathTest {

    @Test
    public void equality() {
        DefaultPath<TestVertex, TestEdge> p1 =
                new DefaultPath<>(of(new TestEdge(A, B, 1),
                                     new TestEdge(B, C, 1)), 2.0);
        DefaultPath<TestVertex, TestEdge> p2 =
                new DefaultPath<>(of(new TestEdge(A, B, 1),
                                     new TestEdge(B, D, 1)), 2.0);
        new EqualsTester().addEqualityGroup(new DefaultMutablePath<>(p1),
                                            new DefaultMutablePath<>(p1))
                .addEqualityGroup(new DefaultMutablePath<>(p2))
                .testEquals();
    }

    @Test
    public void empty() {
        MutablePath<TestVertex, TestEdge> p = new DefaultMutablePath<>();
        assertNull("src should be null", p.src());
        assertNull("dst should be null", p.dst());
        assertEquals("incorrect edge count", 0, p.edges().size());
        assertEquals("incorrect path cost", 0.0, p.cost(), 0.1);
    }

    @Test
    public void pathCost() {
        MutablePath<TestVertex, TestEdge> p = new DefaultMutablePath<>();
        p.setCost(4);
        assertEquals("incorrect path cost", 4.0, p.cost(), 0.1);
    }

    private void validatePath(Path<TestVertex, TestEdge> p,
                              TestVertex src, TestVertex dst, int length) {
        validatePath(p, src, dst, length, 0.0);
    }

    @Test
    public void insertEdge() {
        MutablePath<TestVertex, TestEdge> p = new DefaultMutablePath<>();
        p.insertEdge(new TestEdge(B, C, 1));
        p.insertEdge(new TestEdge(A, B, 1));
        validatePath(p, A, C, 2);
    }

    @Test
    public void appendEdge() {
        MutablePath<TestVertex, TestEdge> p = new DefaultMutablePath<>();
        p.appendEdge(new TestEdge(A, B, 1));
        p.appendEdge(new TestEdge(B, C, 1));
        validatePath(p, A, C, 2);
    }

    @Test
    public void removeEdge() {
        MutablePath<TestVertex, TestEdge> p = new DefaultMutablePath<>();
        p.appendEdge(new TestEdge(A, B, 1));
        p.appendEdge(new TestEdge(B, C, 1));
        p.appendEdge(new TestEdge(C, C, 2));
        p.appendEdge(new TestEdge(C, D, 1));
        validatePath(p, A, D, 4);

        p.removeEdge(new TestEdge(A, B, 1));
        validatePath(p, B, D, 3);

        p.removeEdge(new TestEdge(C, C, 2));
        validatePath(p, B, D, 2);

        p.removeEdge(new TestEdge(C, D, 1));
        validatePath(p, B, C, 1);
    }

    @Test
    public void toImmutable() {
        MutablePath<TestVertex, TestEdge> p = new DefaultMutablePath<>();
        p.appendEdge(new TestEdge(A, B, 1));
        p.appendEdge(new TestEdge(B, C, 1));
        validatePath(p, A, C, 2);

        assertEquals("immutables should equal", p.toImmutable(), p.toImmutable());
        validatePath(p.toImmutable(), A, C, 2);
    }
}