/*

 * Copyright (c) 2015, 2018, 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.internal.net.http;

import jdk.internal.net.http.common.Utils;

import jdk.internal.net.http.websocket.RawChannel;

import java.io.IOException;

import java.nio.ByteBuffer;

import java.nio.channels.SelectableChannel;

import java.nio.channels.SocketChannel;

import java.util.function.Supplier;

/*

 * Each RawChannel corresponds to a TCP connection (SocketChannel) but is

 * connected to a Selector and an ExecutorService for invoking the send and

 * receive callbacks. Also includes SSL processing.

 */

final class RawChannelImpl implements RawChannel {

    private final HttpClientImpl client;

    private final HttpConnection.DetachedConnectionChannel detachedChannel;

    private final Object         initialLock = new Object();

    private Supplier<ByteBuffer> initial;

    RawChannelImpl(HttpClientImpl client,

                   HttpConnection connection,

                   Supplier<ByteBuffer> initial)

            throws IOException

    {

        this.client = client;

        this.detachedChannel = connection.detachChannel();

        this.initial = initial;

        SocketChannel chan = connection.channel();

        client.cancelRegistration(chan);

        // Constructing a RawChannel is supposed to have a "hand over"

        // semantics, in other words if construction fails, the channel won't be

        // needed by anyone, in which case someone still needs to close it

        try {

            chan.configureBlocking(false);

        } catch (IOException e) {

            try {

                chan.close();

            } catch (IOException e1) {

                e.addSuppressed(e1);

            } finally {

                detachedChannel.close();

            }

            throw e;

        }

    }

    private class NonBlockingRawAsyncEvent extends AsyncEvent {

        private final RawEvent re;

        NonBlockingRawAsyncEvent(RawEvent re) {

            // !BLOCKING & !REPEATING

            this.re = re;

        }

        @Override

        public SelectableChannel channel() {

            return detachedChannel.channel();

        }

        @Override

        public int interestOps() {

            return re.interestOps();

        }

        @Override

        public void handle() {

            re.handle();

        }

        @Override

        public void abort(IOException ioe) { }

    }

    @Override

    public void registerEvent(RawEvent event) throws IOException {

        client.registerEvent(new NonBlockingRawAsyncEvent(event));

    }

    @Override

    public ByteBuffer read() throws IOException {

        assert !detachedChannel.channel().isBlocking();

        // connection.read() will no longer be available.

        return detachedChannel.read();

    }

    @Override

    public ByteBuffer initialByteBuffer() {

        synchronized (initialLock) {

            if (initial == null) {

                throw new IllegalStateException();

            }

            ByteBuffer ref = initial.get();

            ref = ref.hasRemaining() ? Utils.copy(ref)

                    : Utils.EMPTY_BYTEBUFFER;

            initial = null;

            return ref;

        }

    }

    @Override

    public long write(ByteBuffer[] src, int offset, int len) throws IOException {

        // this makes the whitebox driver test fail.

        return detachedChannel.write(src, offset, len);

    }

    @Override

    public void shutdownInput() throws IOException {

        detachedChannel.shutdownInput();

    }

    @Override

    public void shutdownOutput() throws IOException {

        detachedChannel.shutdownOutput();

    }

    @Override

    public void close() throws IOException {

        detachedChannel.close();

    }

    @Override

    public String toString() {

        return super.toString()+"("+ detachedChannel.toString() + ")";

    }

}