/*

 * Copyright (c) 2015, 2017, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package jdk.incubator.http;

import jdk.incubator.http.internal.common.ByteBufferReference;

import jdk.incubator.http.internal.common.MinimalFuture;

import jdk.incubator.http.HttpResponse.BodyHandler;

import java.io.IOException;

import java.net.InetSocketAddress;

import java.nio.ByteBuffer;

import java.nio.channels.SocketChannel;

import java.util.concurrent.CompletableFuture;

import java.util.function.Consumer;

import java.util.function.Supplier;

/**

 * A plain text socket tunnel through a proxy. Uses "CONNECT" but does not

 * encrypt. Used by WebSocket, as well as HTTP over SSL + Proxy.

 * Wrapped in SSLTunnelConnection or AsyncSSLTunnelConnection for encryption.

 */

class PlainTunnelingConnection extends HttpConnection implements AsyncConnection {

    final PlainHttpConnection delegate;

    protected final InetSocketAddress proxyAddr;

    private volatile boolean connected;

    @Override

    public CompletableFuture<Void> connectAsync() {

        return delegate.connectAsync()

            .thenCompose((Void v) -> {

                HttpRequestImpl req = new HttpRequestImpl("CONNECT", client, address);

                MultiExchange<Void,Void> mconnectExchange = new MultiExchange<>(req, client, this::ignore);

                return mconnectExchange.responseAsync()

                    .thenCompose((HttpResponseImpl<Void> resp) -> {

                        CompletableFuture<Void> cf = new MinimalFuture<>();

                        if (resp.statusCode() != 200) {

                            cf.completeExceptionally(new IOException("Tunnel failed"));

                        } else {

                            connected = true;

                            cf.complete(null);

                        }

                        return cf;

                    });

            });

    }

    private HttpResponse.BodyProcessor<Void> ignore(int status, HttpHeaders hdrs) {

        return HttpResponse.BodyProcessor.discard((Void)null);

    }

    @Override

    public void connect() throws IOException, InterruptedException {

        delegate.connect();

        HttpRequestImpl req = new HttpRequestImpl("CONNECT", client, address);

        MultiExchange<Void,Void> mul = new MultiExchange<>(req, client, BodyHandler.<Void>discard(null));

        Exchange<Void> connectExchange = new Exchange<>(req, mul);

        Response r = connectExchange.responseImpl(delegate);

        if (r.statusCode() != 200) {

            throw new IOException("Tunnel failed");

        }

        connected = true;

    }

    @Override

    boolean connected() {

        return connected;

    }

    protected PlainTunnelingConnection(InetSocketAddress addr,

                                       InetSocketAddress proxy,

                                       HttpClientImpl client) {

        super(addr, client);

        this.proxyAddr = proxy;

        delegate = new PlainHttpConnection(proxy, client);

    }

    @Override

    SocketChannel channel() {

        return delegate.channel();

    }

    @Override

    ConnectionPool.CacheKey cacheKey() {

        return new ConnectionPool.CacheKey(null, proxyAddr);

    }

    @Override

    long write(ByteBuffer[] buffers, int start, int number) throws IOException {

        return delegate.write(buffers, start, number);

    }

    @Override

    long write(ByteBuffer buffer) throws IOException {

        return delegate.write(buffer);

    }

    @Override

    public void writeAsync(ByteBufferReference[] buffers) throws IOException {

        delegate.writeAsync(buffers);

    }

    @Override

    public void writeAsyncUnordered(ByteBufferReference[] buffers) throws IOException {

        delegate.writeAsyncUnordered(buffers);

    }

    @Override

    public void flushAsync() throws IOException {

        delegate.flushAsync();

    }

    @Override

    public void close() {

        delegate.close();

        connected = false;

    }

    @Override

    void shutdownInput() throws IOException {

        delegate.shutdownInput();

    }

    @Override

    void shutdownOutput() throws IOException {

        delegate.shutdownOutput();

    }

    @Override

    CompletableFuture<Void> whenReceivingResponse() {

        return delegate.whenReceivingResponse();

    }

    @Override

    protected ByteBuffer readImpl() throws IOException {

        return delegate.readImpl();

    }

    @Override

    boolean isSecure() {

        return false;

    }

    @Override

    boolean isProxied() {

        return true;

    }

    @Override

    public void setAsyncCallbacks(Consumer<ByteBufferReference> asyncReceiver,

            Consumer<Throwable> errorReceiver,

            Supplier<ByteBufferReference> readBufferSupplier) {

        delegate.setAsyncCallbacks(asyncReceiver, errorReceiver, readBufferSupplier);

    }

    @Override

    public void startReading() {

        delegate.startReading();

    }

    @Override

    public void stopAsyncReading() {

        delegate.stopAsyncReading();

    }

    @Override

    public void enableCallback() {

        delegate.enableCallback();

    }

    @Override

    synchronized void configureMode(Mode mode) throws IOException {

        super.configureMode(mode);

        delegate.configureMode(mode);

    }

}