/*

 * Copyright (c) 2001, 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.

 *

 * 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

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 * questions.

 */

package nsk.share;

import java.io.BufferedReader;

import java.io.ByteArrayOutputStream;

import java.io.IOException;

import java.io.PrintStream;

import java.io.PrintWriter;

import java.io.StringReader;

import java.util.Enumeration;

import java.util.HashMap;

import java.util.Map;

import java.util.Set;

import java.util.HashSet;

import java.util.Vector;

import nsk.share.test.LazyFormatString;

/**

 * This class helps to print test-execution trace messages

 * and filter them when execution mode is not verbose.

 * <p>

 * Verbose mode if defined by providing <i>-verbose</i> command line

 * option, handled by <code>ArgumentParser</code>. Use <code>verbose()</code>

 * method to determine which mode is used.

 * <p>

 * <code>Log</code> provides with two main methods to print messages:

 * <ul>

 *   <li> <code>complain(String)</code> - to print error message

 *   <li> <code>display(String)</code> - to print additional log message

 * </ul>

 * No other way to print messages to the log stream should be used.

 * <p>

 * Error messages appeares in log stream in all modes. Additional log massages,

 * printed with <code>display()</code> method will be filtered out, if log mode

 * is not verbose. In verbose log made messages of both types are printed.

 * Additionally, in verbose mode a summary of all occured errors will be printed

 * at the program exit, by automatically invoking method

 * <code>printErrorsSummary()</code>.

 * <p>

 * To provide printing messages from different sources into one log

 * with distinct prefixes use internal <code>Log.Logger</code> class.

 *

 * @see #verbose()

 * @see #complain(String)

 * @see #display(String)

 * @see ArgumentParser

 * @see Log.Logger

 */

public class Log extends FinalizableObject {

    /**

     * Report step-by-step activity to this stream.

     *

     * @deprecated  Tests should not use this field directly.

     */

    protected PrintStream out = null;

    /**

     * Is log-mode verbose?

     * Default value is <code>false</code>.

     */

    private boolean verbose = false;

    /**

     * Should log messages prefixed with timestamps?

     * Default value is <code>false</code>.

     */

    private boolean timestamp = false;

    /**

     * Names for trace levels

     */

    public static final class TraceLevel {

        public static final int TRACE_NONE = 0;

        public static final int TRACE_IMPORTANT = 1;

        public static final int TRACE_NORMAL = 2;

        public static final int TRACE_VERBOSE = 3;

        public static final int TRACE_DEBUG = 4;

        public static final int DEFAULT = TRACE_IMPORTANT;

        public static final Map<String, Integer> NAME_TO_LEVEL_MAP = new HashMap<String, Integer>();

        static {

            NAME_TO_LEVEL_MAP.put("none", TRACE_NONE);

            NAME_TO_LEVEL_MAP.put("important", TRACE_IMPORTANT);

            NAME_TO_LEVEL_MAP.put("info", TRACE_NORMAL);

            NAME_TO_LEVEL_MAP.put("verbose", TRACE_VERBOSE);

            NAME_TO_LEVEL_MAP.put("debug", TRACE_DEBUG);

            NAME_TO_LEVEL_MAP.put("default", DEFAULT);

        }

        public static int nameToLevel(String value) throws IllegalArgumentException {

            Integer level = NAME_TO_LEVEL_MAP.get(value.toLowerCase());

            if ( level == null )

                throw new IllegalArgumentException("Wrong trace level: " + value);

            return level;

        }

        public static String getLevelsString() {

            StringBuffer result = new StringBuffer();

            for ( String s : NAME_TO_LEVEL_MAP.keySet() ) {

                result.append(s).append(", ");

            }

            return result.substring(0, result.length() - 3);

        }

    }

    /**

     * Threshold value for printing trace messages for debugging purpose.

     * Default value is <code>0</code> a.k.a. <code>TraceLevel.INFO</code>;

     */

    private int traceLevel = TraceLevel.DEFAULT;

    /**

     * Is printing errors summary enabled? Default value is <code>true</code>;

     */

    private boolean errorsSummaryEnabled = true;

    /**

     * Is printing saved verbose messages on error enabled? Default value is <code>true</code>;

     */

    private boolean verboseOnErrorEnabled = true;

    /**

     * This <code>errosBuffer</code> will keep all messages printed via

     * <code>complain()</code> method for final summary output.

     * Ensure that buffer has enough room for messages to keep,

     * to minimize probability or OutOfMemory error while keeping

     * an error message in stress tests.

     */

    private Vector<String> errorsBuffer = new Vector<String>(1000);

    /**

     * Most tests in nsk do not log exceptions, they only log an error message.

     * This makes failure analysis harder.

     * To solve this we will automatically generate Exceptions for error logs.

     * To not log too many Exceptions, we try to log each unique error only once.

     * <code>loggedExceptions</code> contains all messages that have already been logged.

     */

    private Set<String> loggedExceptions = new HashSet<String>();

    /**

     * This <code>logBuffer</code> will keep all messages printed via

     * <code>display()</code> method in non-verbose mode until

     * swithching verbose mode on or invoking <code>complain()</code>.

     * Ensure that buffer has enough room for messages to keep,

     * to minimize probability or OutOfMemory error while keeping

     * an error message in stress tests.

     */

    private Vector<String> logBuffer = new Vector<String>(1000);

    /**

     * Did I already warned if output stream is not assigned?

     */

    private boolean noOutWarned = false;

    /////////////////////////////////////////////////////////////////

    /**

     * Create new Log's only with <code>Log(out)</code> or with

     * <code>Log(out,argsHandler)</code> constructors.

     *

     * @deprecated  Extending test class with Log is obsolete.

     */

    protected Log() {

        // install finalizer to print errors summary at exit

        Finalizer finalizer = new Finalizer(this);

        finalizer.activate();

        // Don't log exceptions from this method. It would just add unnecessary logs.

        loggedExceptions.add("nsk.share.jdi.SerialExecutionDebugger.executeTests");

    }

    /**

     * Incarnate new Log for the given <code>stream</code> and

     * for non-verbose mode.

     */

    public Log(PrintStream stream) {

        this();

        out = stream;

    }

    /**

     * Incarnate new Log for the given <code>stream</code>; and

     * either for verbose or for non-verbose mode accordingly to

     * the given <code>verbose</code> key.

     */

    public Log(PrintStream stream, boolean verbose) {

        this(stream);

        this.verbose = verbose;

    }

    /**

     * Incarnate new Log for the given <code>stream</code>; and

     * either for verbose or for non-verbose mode accordingly to

     * the given <code>argsHandler</code>.

     */

    public Log(PrintStream stream, ArgumentParser argsParser) {

        this(stream, argsParser.verbose());

        traceLevel = argsParser.getTraceLevel();

        timestamp = argsParser.isTimestamp();

    }

    /////////////////////////////////////////////////////////////////

    /**

     * Return <i>true</i> if log mode is verbose.

     */

    public boolean verbose() {

        return verbose;

    }

    /**

     * Return <i>true</i> if printing errors summary at exit is enabled.

     */

    public boolean isErrorsSummaryEnabled() {

        return errorsSummaryEnabled;

    }

    /**

     * Enable or disable printing errors summary at exit.

     */

    public void enableErrorsSummary(boolean enable) {

        errorsSummaryEnabled = enable;

    }

    /**

     * Return <i>true</i> if printing saved verbose messages on error is enabled.

     */

    public boolean isVerboseOnErrorEnabled() {

        return errorsSummaryEnabled;

    }

    /**

     * Enable or disable printing saved verbose messages on error.

     */

    public void enableVerboseOnError(boolean enable) {

        verboseOnErrorEnabled = enable;

    }

    /**

     * Enable or disable verbose mode for printing messages.

     */

    public void enableVerbose(boolean enable) {

        if (!verbose) {

            flushLogBuffer();

        }

        verbose = enable;

    }

    public int getTraceLevel() {

        return traceLevel;

    }

    /**

     * Set threshold for printing trace messages.

     * Warning: trace level changes may NOT be observed by other threads immediately.

     */

    public void setTraceLevel(int level) {

        traceLevel = level;

    }

    /**

     * Return output stream of this <code>Log</code> object.

     */

    public PrintStream getOutStream() {

        return out;

    }

    /**

     * Returns a string that contains prefix concatenated

     * with Throwable.printStackTrace() output.

     */

    public static String printExceptionToString(Object prefix, Throwable exception) {

        ByteArrayOutputStream bos = new ByteArrayOutputStream();

        PrintWriter pw = new PrintWriter(bos);

        pw.println(prefix);

        exception.printStackTrace(pw);

        pw.close();

        return bos.toString();

    }

    /**

     * Print <code>message</code> to the assigned output stream.

     *

     * @deprecated  Test ought to be quiet if log mode is non-verbose

     *              and there is no errors found by the test. Methods

     *              <code>display()</code> and <code>complain()</code>

     *              are enough for testing purposes.

     */

    public synchronized void println(String message) {

        doPrint(message);

        if (!verbose() && isVerboseOnErrorEnabled()) {

            keepLog(composeLine(message));

        }

    }

    /**

     * Print <code>message</code> to the assigned output stream,

     * if log mode is <i>non</i>-verbose.

     *

     * @deprecated  Test ought to be quiet if log mode is non-verbose

     *              and there is no errors found by the test. Methods

     *              <code>display()</code> and <code>complain()</code>

     *              are enough for testing purposes.

     */

    public synchronized void comment(String message) {

        if (!verbose()) {

            doPrint(message);

        }

    }

    /**

     * Print trace <code>message</code> to the assigned output stream,

     * only if specified <code>level</code> is less or equal for the

     * trace level specified in command line by <code>-trace.level</code>

     * option.

     */

    public void trace(int level, Object message) {

        if (level <= traceLevel) {

            synchronized ( this ) {

                doPrint("### TRACE " + level + ": " + message);

            }

        }

    }

    /**

     * Print trace <code>message</code> and <code>exception</code> to

     * the assigned output stream,

     * only if specified <code>level</code> is less or equal for the

     * trace level specified in command line by <code>-trace.level</code>

     * option.

     */

    public void trace(int level, Object message, Throwable exception) {

        if (level <= traceLevel) {

            trace(level, printExceptionToString(message, exception));

        }

    }

    /**

     * Print <code>message</code> to the assigned output stream,

     * if log mode is verbose. The <code>message</code> will be lost,

     * if execution mode is non-verbose, and there is no error messages

     * printed.

     */

    public synchronized void display(Object message) {

        if (verbose()) {

            doPrint(message.toString());

        } else if (isVerboseOnErrorEnabled()) {

            keepLog(composeLine(message.toString()));

        } else {

            // ignore

        }

    }

    /**

     * Print error <code>message</code> to the assigned output stream

     * (or to stderr if output is not specified) and keep the message

     * into <code>errorsBuffer</code>.

     */

    public synchronized void complain(Object message) {

        if (!verbose() && isVerboseOnErrorEnabled()) {

            PrintStream stream = findOutStream();

            stream.println("#>  ");

            stream.println("#>  WARNING: switching log to verbose mode,");

            stream.println("#>      because error is complained");

            stream.println("#>  ");

            stream.flush();

            enableVerbose(true);

        }

        String msgStr = message.toString();

        printError(msgStr);

        if (isErrorsSummaryEnabled()) {

            keepError(msgStr);

        }

        logExceptionForFailureAnalysis(msgStr);

    }

    /**

     * Print error <code>message</code> and <code>exception</code>

     * to the assigned output stream

     * (or to stderr if output is not specified) and keep the message

     * into <code>errorsBuffer</code>.

     */

    public void complain(Object message, Throwable exception) {

        if ( exception != null )

            complain(printExceptionToString(message, exception));

        else

            complain(message);

    }

    /**

     * Create an Exception and print the stack trace for an error msg.

     * This makes it possible to detect a failure reason for this error.

     */

    private void logExceptionForFailureAnalysis(String msg) {

        // Some error messages are formatted in multiple lines and with tabs.

        // We clean the messages to help parse the stack traces for failure analysis.

        // We keep at most 2 lines, otherwise the error message may be too long.

        String[] lines = msg.split("[\r\n]+");

        msg = lines.length >= 2 ? lines[0] + " " + lines[1] : lines[0];

        msg = msg.replaceAll("\t", " ");

        // Create a dummy exception just so we can print the stack trace.

        TestFailure e = new TestFailure(msg);

        StackTraceElement[] elements = e.getStackTrace();

        final int callerIndex = 2; // 0=this function, 1=complain(), 2=caller

        if (elements.length <= callerIndex) {

            return;

        }

        // Only log the first complain message from each function.

        // The reason is that some functions splits an error message

        // into multiple lines and call complain() many times.

        // We do not want a RULE for each of those calls.

        // This means that we may miss some rules, but that

        // is better than to create far too many rules.

        String callerClass = elements[callerIndex].getClassName();

        String callerMethod = elements[callerIndex].getMethodName();

        String callerKey = callerClass + "." + callerMethod;

        boolean isAlreadyLogged = loggedExceptions.contains(msg) || loggedExceptions.contains(callerKey);

        if (!isAlreadyLogged) {

            PrintStream stream = findOutStream();

            stream.println("The following stacktrace is for failure analysis.");

            e.printStackTrace(stream);

        }

        loggedExceptions.add(callerKey);

        loggedExceptions.add(msg);

    }

    /////////////////////////////////////////////////////////////////

    /**

     * Redirect log to the given <code>stream</code>, and switch

     * log mode to verbose.

     * Prints errors summary to current stream, cancel current stream

     * and switches to new stream. Turns on verbose mode for new stream.

     *

     * @deprecated  This method is obsolete.

     */

    protected synchronized void logTo(PrintStream stream) {

        finalize(); // flush older log stream

        out = stream;

        verbose = true;

    }

    /////////////////////////////////////////////////////////////////

    /**

     * Print all messages from log buffer which were hidden because

     * of non-verbose mode,

     */

    private synchronized void flushLogBuffer() {

        if (!logBuffer.isEmpty()) {

            PrintStream stream = findOutStream();

            for (int i = 0; i < logBuffer.size(); i++) {

                stream.println(logBuffer.elementAt(i));

            }

            stream.flush();

        }

    }

    /**

     * Return <code>out</code> stream if defined or <code>Sytem.err<code> otherwise;

     * print a warning message when <code>System.err</code> is used first time.

     */

    private synchronized PrintStream findOutStream() {

        PrintStream stream = out;

        if (stream == null) {

            stream = System.err;

            if (!noOutWarned) {

                noOutWarned = true;

                stream.println("#>  ");

                stream.println("#>  WARNING: switching log stream to stderr,");

                stream.println("#>      because no output stream is assigned");

                stream.println("#>  ");

            };

        };

        stream.flush();

        return stream;

    }

    /**

     * Compose line to print possible prefixing it with timestamp.

     */

    private String composeLine(String message) {

        if (timestamp) {

            long time = System.currentTimeMillis();

            long ms = time % 1000;

            time /= 1000;

            long secs = time % 60;

            time /= 60;

            long mins = time % 60;

            time /= 60;

            long hours = time % 24;

            return "[" + hours + ":" + mins + ":" + secs + "." + ms + "] " + message;

        }

        return message;

    }

    /**

     * Print the given <code>message</code> either to <code>out</code>

     * stream, or to <code>System.err</code> if <code>out</code>