/*
 * 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.nio;

import java.io.IOException;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.spi.AbstractSelectableChannel;
import java.nio.channels.spi.AbstractSelector;
import java.util.Set;

/**
 * A selector instrumented for unit tests.
 */
public class MockSelector extends AbstractSelector {

    int wakeUpCount = 0;

    /**
     * Creates a mock selector, specifying null as the SelectorProvider.
     */
    public MockSelector() {
        super(null);
    }

    @Override
    public String toString() {
        return "{MockSelector: wake=" + wakeUpCount + "}";
    }

    @Override
    protected void implCloseSelector() throws IOException {
    }

    @Override
    protected SelectionKey register(AbstractSelectableChannel ch, int ops,
                                    Object att) {
        return null;
    }

    @Override
    public Set<SelectionKey> keys() {
        return null;
    }

    @Override
    public Set<SelectionKey> selectedKeys() {
        return null;
    }

    @Override
    public int selectNow() throws IOException {
        return 0;
    }

    @Override
    public int select(long timeout) throws IOException {
        return 0;
    }

    @Override
    public int select() throws IOException {
        return 0;
    }

    @Override
    public Selector wakeup() {
        wakeUpCount++;
        return null;
    }

}