/*
 * Copyright 2014 The Netty Project
 *
 * The Netty Project 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 io.netty.channel;

import static java.util.Objects.requireNonNull;

import io.netty.util.internal.StringUtil;

import java.lang.reflect.Constructor;

/**
 * A {@link ChannelFactory} that instantiates a new {@link Channel} by invoking its default constructor reflectively.
 */
public class ReflectiveChannelFactory<T extends Channel> implements ChannelFactory<T> {

    private final Constructor<? extends T> constructor;

    public ReflectiveChannelFactory(Class<? extends T> clazz) {
        requireNonNull(clazz, "clazz");
        try {
            this.constructor = clazz.getConstructor(EventLoop.class);
        } catch (NoSuchMethodException e) {
            throw new IllegalArgumentException("Class " + StringUtil.simpleClassName(clazz) +
                    " does not have a public constructor that takes an EventLoop instance", e);
        }
    }

    @Override
    public T newChannel(EventLoop eventLoop) throws Exception {
        try {
            return constructor.newInstance(eventLoop);
        } catch (Throwable t) {
            throw new ChannelException("Unable to create Channel from class " + constructor.getDeclaringClass(), t);
        }
    }

    @Override
    public String toString() {
        return StringUtil.simpleClassName(ReflectiveChannelFactory.class) +
                '(' + StringUtil.simpleClassName(constructor.getDeclaringClass()) + ".class)";
    }
}
