/*

 * 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 jdk.test.lib.process;

import java.io.ByteArrayOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.io.PrintStream;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collections;

import java.util.concurrent.CountDownLatch;

import java.util.Map;

import java.util.concurrent.ExecutionException;

import java.util.concurrent.Future;

import java.util.concurrent.TimeUnit;

import java.util.concurrent.TimeoutException;

import java.util.function.Predicate;

import java.util.function.Consumer;

import java.util.stream.Collectors;

import jdk.test.lib.JDKToolFinder;

import jdk.test.lib.Utils;

public final class ProcessTools {

    private static final class LineForwarder extends StreamPumper.LinePump {

        private final PrintStream ps;

        private final String prefix;

        LineForwarder(String prefix, PrintStream os) {

            this.ps = os;

            this.prefix = prefix;

        }

        @Override

        protected void processLine(String line) {

            ps.println("[" + prefix + "] " + line);

        }

    }

    private ProcessTools() {

    }

    /**

     * Pumps stdout and stderr from running the process into a String.

     *

     * @param processBuilder ProcessBuilder to run.

     * @return Output from process.

     * @throws IOException If an I/O error occurs.

     */

    public static OutputBuffer getOutput(ProcessBuilder processBuilder) throws IOException {

    }

    /**

     * Pumps stdout and stderr the running process into a String.

     *

     * @param process Process to pump.

     * @return Output from process.

     * @throws IOException If an I/O error occurs.

     */

    public static OutputBuffer getOutput(Process process) throws IOException {

        ByteArrayOutputStream stderrBuffer = new ByteArrayOutputStream();

        ByteArrayOutputStream stdoutBuffer = new ByteArrayOutputStream();

        StreamPumper outPumper = new StreamPumper(process.getInputStream(), stdoutBuffer);

        StreamPumper errPumper = new StreamPumper(process.getErrorStream(), stderrBuffer);

        Thread outPumperThread = new Thread(outPumper);

        Thread errPumperThread = new Thread(errPumper);

        outPumperThread.setDaemon(true);

        errPumperThread.setDaemon(true);

        outPumperThread.start();

        errPumperThread.start();

        try {

            process.waitFor();

            outPumperThread.join();

            errPumperThread.join();

        } catch (InterruptedException e) {

            Thread.currentThread().interrupt();

            return null;

        }

        return new OutputBuffer(stdoutBuffer.toString(), stderrBuffer.toString());

    }

    /**

     * <p>Starts a process from its builder.</p>

     * <span>The default redirects of STDOUT and STDERR are started</span>

     * @param name The process name

     * @param processBuilder The process builder

     * @return Returns the initialized process

     * @throws IOException

     */

    public static Process startProcess(String name,

                                       ProcessBuilder processBuilder)

    throws IOException {

        return startProcess(name, processBuilder, (Consumer<String>)null);

    }

    /**

     * <p>Starts a process from its builder.</p>

     * <span>The default redirects of STDOUT and STDERR are started</span>

     * <p>It is possible to monitor the in-streams via the provided {@code consumer}

     * @param name The process name

     * @param consumer {@linkplain Consumer} instance to process the in-streams

     * @param processBuilder The process builder

     * @return Returns the initialized process

     * @throws IOException

     */

    @SuppressWarnings("overloads")

    public static Process startProcess(String name,

                                       ProcessBuilder processBuilder,

                                       Consumer<String> consumer)

    throws IOException {

        try {

            return startProcess(name, processBuilder, consumer, null, -1, TimeUnit.NANOSECONDS);

        } catch (InterruptedException | TimeoutException e) {

            // will never happen

            throw new RuntimeException(e);

        }

    }

    /**

     * <p>Starts a process from its builder.</p>

     * <span>The default redirects of STDOUT and STDERR are started</span>

     * <p>

     * It is possible to wait for the process to get to a warmed-up state

     * via {@linkplain Predicate} condition on the STDOUT

     * </p>

     * @param name The process name

     * @param processBuilder The process builder

     * @param linePredicate The {@linkplain Predicate} to use on the STDOUT

     *                      Used to determine the moment the target app is

     *                      properly warmed-up.

     *                      It can be null - in that case the warmup is skipped.

     * @param timeout The timeout for the warmup waiting; -1 = no wait; 0 = wait forever

     * @param unit The timeout {@linkplain TimeUnit}

     * @return Returns the initialized {@linkplain Process}

     * @throws IOException

     * @throws InterruptedException

     * @throws TimeoutException

     */

    public static Process startProcess(String name,

                                       ProcessBuilder processBuilder,

                                       final Predicate<String> linePredicate,

                                       long timeout,

                                       TimeUnit unit)

    throws IOException, InterruptedException, TimeoutException {

        return startProcess(name, processBuilder, null, linePredicate, timeout, unit);

    }

    /**

     * <p>Starts a process from its builder.</p>

     * <span>The default redirects of STDOUT and STDERR are started</span>

     * <p>

     * It is possible to wait for the process to get to a warmed-up state

     * via {@linkplain Predicate} condition on the STDOUT and monitor the

     * in-streams via the provided {@linkplain Consumer}

     * </p>

     * @param name The process name

     * @param processBuilder The process builder

     * @param lineConsumer  The {@linkplain Consumer} the lines will be forwarded to

     * @param linePredicate The {@linkplain Predicate} to use on the STDOUT

     *                      Used to determine the moment the target app is

     *                      properly warmed-up.

     *                      It can be null - in that case the warmup is skipped.

     * @param timeout The timeout for the warmup waiting; -1 = no wait; 0 = wait forever

     * @param unit The timeout {@linkplain TimeUnit}

     * @return Returns the initialized {@linkplain Process}

     * @throws IOException

     * @throws InterruptedException

     * @throws TimeoutException

     */

    public static Process startProcess(String name,

                                       ProcessBuilder processBuilder,

                                       final Consumer<String> lineConsumer,

                                       final Predicate<String> linePredicate,

                                       long timeout,

                                       TimeUnit unit)

    throws IOException, InterruptedException, TimeoutException {

        System.out.println("["+name+"]:" + processBuilder.command().stream().collect(Collectors.joining(" ")));

        StreamPumper stdout = new StreamPumper(p.getInputStream());

        StreamPumper stderr = new StreamPumper(p.getErrorStream());

        stdout.addPump(new LineForwarder(name, System.out));

        stderr.addPump(new LineForwarder(name, System.err));

        if (lineConsumer != null) {

            StreamPumper.LinePump pump = new StreamPumper.LinePump() {

                @Override

                protected void processLine(String line) {

                    lineConsumer.accept(line);

                }

            };

            stdout.addPump(pump);

            stderr.addPump(pump);

        }

        CountDownLatch latch = new CountDownLatch(1);

        if (linePredicate != null) {

            StreamPumper.LinePump pump = new StreamPumper.LinePump() {

                @Override

                protected void processLine(String line) {

                    if (latch.getCount() > 0 && linePredicate.test(line)) {

                        latch.countDown();

                    }

                }

            };

            stdout.addPump(pump);

            stderr.addPump(pump);

        } else {

            latch.countDown();

        }

        final Future<Void> stdoutTask = stdout.process();

        final Future<Void> stderrTask = stderr.process();

        try {

            if (timeout > -1) {

                if (timeout == 0) {

                    latch.await();

                } else {

                    if (!latch.await(Utils.adjustTimeout(timeout), unit)) {

                        throw new TimeoutException();

                    }

                }

            }

        } catch (TimeoutException | InterruptedException e) {

            System.err.println("Failed to start a process (thread dump follows)");

            for(Map.Entry<Thread, StackTraceElement[]> s : Thread.getAllStackTraces().entrySet()) {

                printStack(s.getKey(), s.getValue());

            }

            if (p.isAlive()) {

                p.destroyForcibly();

            }

            stdoutTask.cancel(true);

            stderrTask.cancel(true);

            throw e;

        }

        return new ProcessImpl(p, stdoutTask, stderrTask);

    }

    /**

     * <p>Starts a process from its builder.</p>

     * <span>The default redirects of STDOUT and STDERR are started</span>

     * <p>

     * It is possible to wait for the process to get to a warmed-up state

     * via {@linkplain Predicate} condition on the STDOUT. The warm-up will

     * wait indefinitely.

     * </p>

     * @param name The process name

     * @param processBuilder The process builder

     * @param linePredicate The {@linkplain Predicate} to use on the STDOUT

     *                      Used to determine the moment the target app is

     *                      properly warmed-up.

     *                      It can be null - in that case the warmup is skipped.

     * @return Returns the initialized {@linkplain Process}

     * @throws IOException

     * @throws InterruptedException

     * @throws TimeoutException

     */

    @SuppressWarnings("overloads")

    public static Process startProcess(String name,

                                       ProcessBuilder processBuilder,

                                       final Predicate<String> linePredicate)

    throws IOException, InterruptedException, TimeoutException {

        return startProcess(name, processBuilder, linePredicate, 0, TimeUnit.SECONDS);

    }

    /**

     * Get the process id of the current running Java process

     *

     * @return Process id

     */

    public static long getProcessId() throws Exception {

        return ProcessHandle.current().pid();

    }

    /**

     * Create ProcessBuilder using the java launcher from the jdk to be tested and

     * with any platform specific arguments prepended

     */

    public static ProcessBuilder createJavaProcessBuilder(String... command) {

        return createJavaProcessBuilder(false, command);

    }

    /**

     * Create ProcessBuilder using the java launcher from the jdk to be tested,

     * and with any platform specific arguments prepended.

     *

     * @param addTestVmAndJavaOptions If true, adds test.vm.opts and test.java.opts

     *        to the java arguments.

     * @param command Arguments to pass to the java command.

     * @return The ProcessBuilder instance representing the java command.

     */

    public static ProcessBuilder createJavaProcessBuilder(boolean addTestVmAndJavaOptions, String... command) {

        String javapath = JDKToolFinder.getJDKTool("java");

        ArrayList<String> args = new ArrayList<>();

        args.add(javapath);

        args.add("-cp");

        args.add(System.getProperty("java.class.path"));

        if (addTestVmAndJavaOptions) {

            Collections.addAll(args, Utils.getTestJavaOpts());

        }

        Collections.addAll(args, command);

        // Reporting

        StringBuilder cmdLine = new StringBuilder();

        for (String cmd : args)

            cmdLine.append(cmd).append(' ');

        System.out.println("Command line: [" + cmdLine.toString() + "]");

        return new ProcessBuilder(args.toArray(new String[args.size()]));

    }

    private static void printStack(Thread t, StackTraceElement[] stack) {

        System.out.println("\t" +  t +

                           " stack: (length = " + stack.length + ")");

        if (t != null) {

            for (StackTraceElement stack1 : stack) {

                System.out.println("\t" + stack1);

            }

            System.out.println();

        }

    }

    /**

     * Executes a test jvm process, waits for it to finish and returns the process output.

     * The default jvm options from jtreg, test.vm.opts and test.java.opts, are added.

     * The java from the test.jdk is used to execute the command.

     *

     * The command line will be like:

     * {test.jdk}/bin/java {test.vm.opts} {test.java.opts} cmds

     *

     * The jvm process will have exited before this method returns.

     *

     * @param cmds User specified arguments.

     * @return The output from the process.

     */

    public static OutputAnalyzer executeTestJvm(String... cmds) throws Exception {

        ProcessBuilder pb = createJavaProcessBuilder(Utils.addTestJavaOpts(cmds));

        return executeProcess(pb);

    }

    /**

     * @see #executeTestJvm(String...)

     * @param cmds User specified arguments.

     * @return The output from the process.

     */

    public static OutputAnalyzer executeTestJava(String... cmds) throws Exception {

        return executeTestJvm(cmds);

    }

    /**

     * Executes a process, waits for it to finish and returns the process output.

     * The process will have exited before this method returns.

     * @param pb The ProcessBuilder to execute.

     * @return The {@linkplain OutputAnalyzer} instance wrapping the process.

     */

    public static OutputAnalyzer executeProcess(ProcessBuilder pb) throws Exception {

        OutputAnalyzer output = null;

        Process p = null;

        boolean failed = false;

        try {

            output = new OutputAnalyzer(p);

            p.waitFor();

            return output;

        } catch (Throwable t) {

            if (p != null) {

                p.destroyForcibly().waitFor();

            }

            failed = true;

            System.out.println("executeProcess() failed: " + t);

            throw t;

        } finally {

            if (failed) {

                System.err.println(getProcessLog(pb, output));

            }

        }

    }

    /**

     * Executes a process, waits for it to finish and returns the process output.

     *

     * The process will have exited before this method returns.

     *

     * @param cmds The command line to execute.

     * @return The output from the process.

     */

    public static OutputAnalyzer executeProcess(String... cmds) throws Throwable {

        return executeProcess(new ProcessBuilder(cmds));

    }

    /**

     * Used to log command line, stdout, stderr and exit code from an executed process.

     * @param pb The executed process.

     * @param output The output from the process.

     */

    public static String getProcessLog(ProcessBuilder pb, OutputAnalyzer output) {

        String stderr = output == null ? "null" : output.getStderr();

        String stdout = output == null ? "null" : output.getStdout();

        String exitValue = output == null ? "null": Integer.toString(output.getExitValue());

        StringBuilder logMsg = new StringBuilder();

        final String nl = System.getProperty("line.separator");

        logMsg.append("--- ProcessLog ---" + nl);

        logMsg.append("cmd: " + getCommandLine(pb) + nl);

        logMsg.append("exitvalue: " + exitValue + nl);

        logMsg.append("stderr: " + stderr + nl);

        logMsg.append("stdout: " + stdout + nl);

        return logMsg.toString();

    }

    /**

     * @return The full command line for the ProcessBuilder.

     */

    public static String getCommandLine(ProcessBuilder pb) {

        if (pb == null) {

            return "null";

        }

        StringBuilder cmd = new StringBuilder();

        for (String s : pb.command()) {

            cmd.append(s).append(" ");

        }

        return cmd.toString().trim();

    }

    /**

     * Executes a process, waits for it to finish, prints the process output

     * to stdout, and returns the process output.

     *

     * The process will have exited before this method returns.

     *

     * @param cmds The command line to execute.

     * @return The {@linkplain OutputAnalyzer} instance wrapping the process.

     */

    public static OutputAnalyzer executeCommand(String... cmds)

            throws Throwable {

        String cmdLine = Arrays.stream(cmds).collect(Collectors.joining(" "));

        System.out.println("Command line: [" + cmdLine + "]");

        OutputAnalyzer analyzer = ProcessTools.executeProcess(cmds);

        System.out.println(analyzer.getOutput());

        return analyzer;

    }

    /**

     * Executes a process, waits for it to finish, prints the process output

     * to stdout and returns the process output.

     *

     * The process will have exited before this method returns.

     *

     * @param pb The ProcessBuilder to execute.

     * @return The {@linkplain OutputAnalyzer} instance wrapping the process.

     */

    public static OutputAnalyzer executeCommand(ProcessBuilder pb)

            throws Throwable {

        String cmdLine = pb.command().stream().collect(Collectors.joining(" "));

        System.out.println("Command line: [" + cmdLine + "]");

        OutputAnalyzer analyzer = ProcessTools.executeProcess(pb);

        System.out.println(analyzer.getOutput());

        return analyzer;

    }

    private static class ProcessImpl extends Process {

        private final Process p;

        private final Future<Void> stdoutTask;

        private final Future<Void> stderrTask;

        public ProcessImpl(Process p, Future<Void> stdoutTask, Future<Void> stderrTask) {

            this.p = p;

            this.stdoutTask = stdoutTask;

            this.stderrTask = stderrTask;

        }