/*
 * Copyright 2008-present MongoDB, Inc.
 *
 * Licensed 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 com.mongodb.connection.netty;

import com.mongodb.connection.SocketSettings;
import com.mongodb.connection.SslSettings;
import com.mongodb.connection.StreamFactory;
import com.mongodb.connection.StreamFactoryFactory;
import io.netty.buffer.ByteBufAllocator;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;

import static com.mongodb.assertions.Assertions.notNull;

A StreamFactoryFactory implementation for Netty-based streams.
Since:
3.1/**
 * A {@code StreamFactoryFactory} implementation for <a href='http://netty.io/'>Netty</a>-based streams.
 *
 * @since 3.1
 */
public class NettyStreamFactoryFactory implements StreamFactoryFactory {

    private final EventLoopGroup eventLoopGroup;
    private final Class<? extends SocketChannel> socketChannelClass;
    private final ByteBufAllocator allocator;

    
Construct an instance with the default EventLoopGroup and ByteBufAllocator. 
Deprecated:
Use builder() instead to construct the  NettyStreamFactoryFactory./**
     * Construct an instance with the default {@code EventLoopGroup} and {@code ByteBufAllocator}.
     *
     * @deprecated Use {@link NettyStreamFactoryFactory#builder()} instead to construct the {@code  NettyStreamFactoryFactory}.
     */
    @Deprecated
    public NettyStreamFactoryFactory() {
        this(builder());
    }

    
Construct an instance with the given EventLoopGroup and ByteBufAllocator. 
Params:
eventLoopGroup – the non-null event loop group
allocator – the non-null byte buf allocator
Deprecated:
Use builder() instead to construct the  NettyStreamFactoryFactory./**
     * Construct an instance with the given {@code EventLoopGroup} and {@code ByteBufAllocator}.
     *
     * @param eventLoopGroup the non-null event loop group
     * @param allocator the non-null byte buf allocator
     * @deprecated Use {@link NettyStreamFactoryFactory#builder()} instead to construct the {@code  NettyStreamFactoryFactory}.
     */
    @Deprecated
    public NettyStreamFactoryFactory(final EventLoopGroup eventLoopGroup, final ByteBufAllocator allocator) {
        this(builder().eventLoopGroup(eventLoopGroup).allocator(allocator));
    }

    
Gets a builder for an instance of NettyStreamFactoryFactory. 
Returns:
the builder
Since:
3.3/**
     * Gets a builder for an instance of {@code NettyStreamFactoryFactory}.
     * @return the builder
     * @since 3.3
     */
    public static Builder builder() {
        return new Builder();
    }

    
A builder for an instance of NettyStreamFactoryFactory. 
Since:
3.3/**
     * A builder for an instance of {@code NettyStreamFactoryFactory}.
     *
     * @since 3.3
     */
    public static final class Builder {
        private ByteBufAllocator allocator;
        private Class<? extends SocketChannel> socketChannelClass;
        private EventLoopGroup eventLoopGroup;

        private Builder() {
            allocator(ByteBufAllocator.DEFAULT);
            socketChannelClass(NioSocketChannel.class);
        }

        
Sets the allocator.
Params:
allocator – the allocator to use for ByteBuf instances
Returns:
this/**
         * Sets the allocator.
         *
         * @param allocator the allocator to use for ByteBuf instances
         * @return this
         */
        public Builder allocator(final ByteBufAllocator allocator) {
            this.allocator = notNull("allocator", allocator);
            return this;
        }

        
Sets the socket channel class
Params:
socketChannelClass – the socket channel class
Returns:
this/**
         * Sets the socket channel class
         *
         * @param socketChannelClass the socket channel class
         * @return this
         */
        public Builder socketChannelClass(final Class<? extends SocketChannel> socketChannelClass) {
            this.socketChannelClass = notNull("socketChannelClass", socketChannelClass);
            return this;
        }

        
Sets the event loop group.
It is highly recommended to supply your own event loop group and manage its shutdown.  Otherwise, the event
loop group created by default will not be shutdown properly.
Params:
eventLoopGroup – the event loop group that all channels created by this factory will be a part of
Returns:
this/**
         * Sets the event loop group.
         *
         * <p>It is highly recommended to supply your own event loop group and manage its shutdown.  Otherwise, the event
         * loop group created by default will not be shutdown properly.</p>
         *
         * @param eventLoopGroup the event loop group that all channels created by this factory will be a part of
         * @return this
         */
        public Builder eventLoopGroup(final EventLoopGroup eventLoopGroup) {
            this.eventLoopGroup = notNull("eventLoopGroup", eventLoopGroup);
            return this;
        }

        
Build an instance of NettyStreamFactoryFactory. 
Returns:
factory of the netty stream factory/**
         * Build an instance of {@code NettyStreamFactoryFactory}.
         * @return factory of the netty stream factory
         */
        public NettyStreamFactoryFactory build() {
            return new NettyStreamFactoryFactory(this);
        }
    }

    @Override
    public StreamFactory create(final SocketSettings socketSettings, final SslSettings sslSettings) {
        return new NettyStreamFactory(socketSettings, sslSettings, eventLoopGroup, socketChannelClass, allocator);
    }

    @Override
    public String toString() {
        return "NettyStreamFactoryFactory{"
                + "eventLoopGroup=" + eventLoopGroup
                + ", socketChannelClass=" + socketChannelClass
                + ", allocator=" + allocator
                + '}';
    }

    private NettyStreamFactoryFactory(final Builder builder) {
        allocator = builder.allocator;
        socketChannelClass = builder.socketChannelClass;
        if (builder.eventLoopGroup != null) {
            eventLoopGroup = builder.eventLoopGroup;
        } else {
            eventLoopGroup = new NioEventLoopGroup();
        }
    }
}