/*

 * 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.

 *

 * 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 org.graalvm.compiler.debug;

import static org.graalvm.compiler.debug.DebugOptions.PrintGraphHost;

import static org.graalvm.compiler.debug.DebugOptions.PrintGraphPort;

import java.io.File;

import java.io.IOException;

import java.io.InterruptedIOException;

import java.net.InetSocketAddress;

import java.nio.ByteBuffer;

import java.nio.channels.ClosedByInterruptException;

import java.nio.channels.FileChannel;

import java.nio.channels.SocketChannel;

import java.nio.channels.WritableByteChannel;

import java.nio.file.Path;

import java.nio.file.StandardOpenOption;

import java.util.function.Supplier;

import org.graalvm.compiler.debug.DebugOptions.PrintGraphTarget;

import org.graalvm.compiler.options.OptionValues;

import jdk.vm.ci.common.NativeImageReinitialize;

final class IgvDumpChannel implements WritableByteChannel {

    private final Supplier<Path> pathProvider;

    private final OptionValues options;

    private WritableByteChannel sharedChannel;

    private boolean closed;

    IgvDumpChannel(Supplier<Path> pathProvider, OptionValues options) {

        this.pathProvider = pathProvider;

        this.options = options;

    }

    @Override

    public int write(ByteBuffer src) throws IOException {

        WritableByteChannel channel = channel();

        return channel == null ? 0 : channel.write(src);

    }

    @Override

    public boolean isOpen() {

        return !closed;

    }

    @Override

    public void close() throws IOException {

    }

    void realClose() throws IOException {

        closed = true;

        if (sharedChannel != null) {

            sharedChannel.close();

            sharedChannel = null;

        }

    }

    WritableByteChannel channel() throws IOException {

        if (closed) {

            throw new IOException();

        }

        if (sharedChannel == null) {

            PrintGraphTarget target = DebugOptions.PrintGraph.getValue(options);

            if (target == PrintGraphTarget.File) {

                sharedChannel = createFileChannel(pathProvider, null);

            } else if (target == PrintGraphTarget.Network) {

                sharedChannel = createNetworkChannel(pathProvider, options);

            } else {

                TTY.println("WARNING: Graph dumping requested but value of %s option is %s", DebugOptions.PrintGraph.getName(), PrintGraphTarget.Disable);

            }

        }

        return sharedChannel;

    }

    private static WritableByteChannel createNetworkChannel(Supplier<Path> pathProvider, OptionValues options) throws IOException {

        String host = PrintGraphHost.getValue(options);

        int port = PrintGraphPort.getValue(options);

        try {

            WritableByteChannel channel = SocketChannel.open(new InetSocketAddress(host, port));

            String targetAnnouncement = String.format("Connected to the IGV on %s:%d", host, port);

            maybeAnnounceTarget(targetAnnouncement);

            return channel;

        } catch (ClosedByInterruptException | InterruptedIOException e) {

            /*

             * Interrupts should not count as errors because they may be caused by a cancelled Graal

             * compilation. ClosedByInterruptException occurs if the SocketChannel could not be

             * opened. InterruptedIOException occurs if new Socket(..) was interrupted.

             */

            return null;

        } catch (IOException e) {

            String networkFailure = String.format("Could not connect to the IGV on %s:%d", host, port);

            if (pathProvider != null) {

                return createFileChannel(pathProvider, networkFailure);

            } else {

                throw new IOException(networkFailure, e);

            }

        }

    }

    @NativeImageReinitialize private static String lastTargetAnnouncement;

    private static void maybeAnnounceTarget(String targetAnnouncement) {

        if (!targetAnnouncement.equals(lastTargetAnnouncement)) {

            // Ignore races - an extra announcement is ok

            lastTargetAnnouncement = targetAnnouncement;

            TTY.println(targetAnnouncement);

        }

    }

    private static WritableByteChannel createFileChannel(Supplier<Path> pathProvider, String networkFailure) throws IOException {

        Path path = pathProvider.get();

        try {

            FileChannel channel = FileChannel.open(path, StandardOpenOption.WRITE, StandardOpenOption.CREATE);

            File dir = path.toFile();

            if (!dir.isDirectory()) {

                dir = dir.getParentFile();

            }

            if (networkFailure == null) {

                maybeAnnounceTarget("Dumping IGV graphs in " + dir);

            } else {

                maybeAnnounceTarget(networkFailure + ". Dumping IGV graphs in " + dir);

            }

            return channel;

        } catch (IOException e) {

            throw new IOException(String.format("Failed to open %s to dump IGV graphs", path), e);

        }

    }

}