/*

 * Copyright (c) 2016, 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.jfr.internal.tool;

import java.io.IOException;

import java.io.PrintStream;

import java.io.PrintWriter;

import java.nio.charset.Charset;

import java.nio.file.Path;

import java.util.ArrayList;

import java.util.Deque;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import java.util.function.Function;

import java.util.function.Predicate;

import jdk.jfr.EventType;

final class Print extends Command {

    @Override

    public String getName() {

        return "print";

    }

    @Override

    public List<String> getOptionSyntax() {

        List<String> list = new ArrayList<>();

        list.add("[--xml|--json]");

        list.add("[--categories <filter>]");

        list.add("[--events <filter>]");

        list.add("[--stack-depth <depth>]");

        list.add("<file>");

        return list;

    }

    @Override

    protected String getTitle() {

        return "Print contents of a recording file";

    }

    @Override

    public String getDescription() {

        return getTitle() + ". See 'jfr help print' for details.";

    }

    @Override

    public void displayOptionUsage(PrintStream stream) {

        stream.println("  --xml                   Print recording in XML format");

        stream.println();

        stream.println("  --json                  Print recording in JSON format");

        stream.println();

        stream.println("  --categories <filter>   Select events matching a category name.");

        stream.println("                          The filter is a comma-separated list of names,");

        stream.println("                          simple and/or qualified, and/or quoted glob patterns");

        stream.println();

        stream.println("  --events <filter>       Select events matching an event name.");

        stream.println("                          The filter is a comma-separated list of names,");

        stream.println("                          simple and/or qualified, and/or quoted glob patterns");

        stream.println();

        stream.println("  --stack-depth <depth>   Number of frames in stack traces, by default 5");

        stream.println();

        stream.println("  <file>                  Location of the recording file (.jfr)");

        stream.println();

        stream.println();

        stream.println("Example usage:");

        stream.println();

        stream.println(" jfr print --events OldObjectSample recording.jfr");

        stream.println();

        stream.println(" jfr print --events CPULoad,GarbageCollection recording.jfr");

        stream.println();

        stream.println(" jfr print --categories \"GC,JVM,Java*\" recording.jfr");

        stream.println();

        stream.println(" jfr print --events \"jdk.*\" --stack-depth 64 recording.jfr");

        stream.println();

        stream.println(" jfr print --json --events CPULoad recording.jfr");

    }

    @Override

    public void execute(Deque<String> options) throws UserSyntaxException, UserDataException {

        Path file = getJFRInputFile(options);

        PrintWriter pw = new PrintWriter(System.out, false, Charset.forName("UTF-8"));

        Predicate<EventType> eventFilter = null;

        int stackDepth = 5;

        EventPrintWriter eventWriter = null;

        int optionCount = options.size();

        boolean foundEventFilter = false;

        boolean foundCategoryFilter = false;

        while (optionCount > 0) {

            if (acceptFilterOption(options, "--events")) {

                if (foundEventFilter) {

                    throw new UserSyntaxException("use --events event1,event2,event3 to include multiple events");

                }

                foundEventFilter = true;

                String filter = options.remove();

                warnForWildcardExpansion("--events", filter);

                eventFilter = addEventFilter(filter, eventFilter);

            }

            if (acceptFilterOption(options, "--categories")) {

                if (foundCategoryFilter) {

                    throw new UserSyntaxException("use --categories category1,category2 to include multiple categories");

                }

                foundCategoryFilter = true;

                String filter = options.remove();

                warnForWildcardExpansion("--categories", filter);

                eventFilter = addCategoryFilter(filter, eventFilter);

            }

            if (acceptOption(options, "--stack-depth")) {

                String value = options.pop();

                try {

                    stackDepth = Integer.parseInt(value);

                    if (stackDepth < 0) {

                        throw new UserSyntaxException("stack depth must be zero or a positive integer.");

                    }

                } catch (NumberFormatException nfe) {

                    throw new UserSyntaxException("not a valid value for --stack-depth");

                }

            }

            if (acceptFormatterOption(options, eventWriter, "--json")) {

                eventWriter = new JSONWriter(pw);

            }

            if (acceptFormatterOption(options, eventWriter, "--xml")) {

                eventWriter = new XMLWriter(pw);

            }

            if (optionCount == options.size()) {

                // No progress made

                checkCommonError(options, "--event", "--events");

                checkCommonError(options, "--category", "--categories");

                throw new UserSyntaxException("unknown option " + options.peek());

            }

            optionCount = options.size();

        }

        if (eventWriter == null) {

            eventWriter = new PrettyWriter(pw); // default to pretty printer

        }

        eventWriter.setStackDepth(stackDepth);

        if (eventFilter != null) {

            eventFilter = addCache(eventFilter, eventType -> eventType.getId());

            eventWriter.setEventFilter(eventFilter);

        }

        try {

            eventWriter.print(file);

        } catch (IOException ioe) {

            couldNotReadError(file, ioe);

        }

        pw.flush();

    }

    private void checkCommonError(Deque<String> options, String typo, String correct) throws UserSyntaxException {

       if (typo.equals(options.peek())) {

           throw new UserSyntaxException("unknown option " + typo + ", did you mean " + correct + "?");

       }

    }

    private static boolean acceptFormatterOption(Deque<String> options, EventPrintWriter eventWriter, String expected) throws UserSyntaxException {

        if (expected.equals(options.peek())) {

            if (eventWriter != null) {

                throw new UserSyntaxException("only one format can be specified at a time");

            }

            options.remove();

            return true;

        }

        return false;

    }

    private static <T, X> Predicate<T> addCache(final Predicate<T> filter, Function<T, X> cacheFunction) {

        Map<X, Boolean> cache = new HashMap<>();

        return t -> cache.computeIfAbsent(cacheFunction.apply(t), x -> filter.test(t));

    }

    private static <T> Predicate<T> recurseIfPossible(Predicate<T> filter) {

        return x -> filter != null && filter.test(x);

    }

    private static Predicate<EventType> addCategoryFilter(String filterText, Predicate<EventType> eventFilter) throws UserSyntaxException {

        List<String> filters = explodeFilter(filterText);

        Predicate<EventType> newFilter = recurseIfPossible(eventType -> {

            for (String category : eventType.getCategoryNames()) {

                for (String filter : filters) {

                    if (match(category, filter)) {

                        return true;

                    }

                    if (category.contains(" ") && acronomify(category).equals(filter)) {

                        return true;

                    }

                }

            }

            return false;

        });

        return eventFilter == null ? newFilter : eventFilter.or(newFilter);

    }

    private static String acronomify(String multipleWords) {

        boolean newWord = true;

        String acronym = "";

        for (char c : multipleWords.toCharArray()) {

            if (newWord) {

                if (Character.isAlphabetic(c) && Character.isUpperCase(c)) {

                    acronym += c;

                }

            }

            newWord = Character.isWhitespace(c);

        }

        return acronym;

    }

    private static Predicate<EventType> addEventFilter(String filterText, final Predicate<EventType> eventFilter) throws UserSyntaxException {

        List<String> filters = explodeFilter(filterText);

        Predicate<EventType> newFilter = recurseIfPossible(eventType -> {

            for (String filter : filters) {

                String fullEventName = eventType.getName();

                if (match(fullEventName, filter)) {

                    return true;

                }

                String eventName = fullEventName.substring(fullEventName.lastIndexOf(".") + 1);

                if (match(eventName, filter)) {

                    return true;

                }

            }

            return false;

        });

        return eventFilter == null ? newFilter : eventFilter.or(newFilter);

    }

    private static boolean match(String text, String filter) {

        if (filter.length() == 0) {

            // empty filter string matches if string is empty

            return text.length() == 0;

        }

        if (filter.charAt(0) == '*') { // recursive check

            filter = filter.substring(1);

            for (int n = 0; n <= text.length(); n++) {

                if (match(text.substring(n), filter))

                    return true;

            }

        } else if (text.length() == 0) {

            // empty string and non-empty filter does not match

            return false;

        } else if (filter.charAt(0) == '?') {

            // eat any char and move on

            return match(text.substring(1), filter.substring(1));

        } else if (filter.charAt(0) == text.charAt(0)) {

            // eat chars and move on

            return match(text.substring(1), filter.substring(1));

        }

        return false;

    }

    private static List<String> explodeFilter(String filter) throws UserSyntaxException {

        List<String> list = new ArrayList<>();

        for (String s : filter.split(",")) {

            s = s.trim();

            if (!s.isEmpty()) {

                list.add(s);

            }

        }

        return list;

    }

}