/*

 * 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

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package jdk.jfr.internal.tool;

import java.io.IOException;

import java.io.PrintStream;

import java.nio.file.Path;

import java.time.Instant;

import java.time.ZoneOffset;

import java.time.format.DateTimeFormatter;

import java.util.ArrayList;

import java.util.Collections;

import java.util.Deque;

import java.util.HashMap;

import java.util.List;

import java.util.Locale;

import jdk.jfr.EventType;

import jdk.jfr.internal.MetadataDescriptor;

import jdk.jfr.internal.Type;

import jdk.jfr.internal.consumer.ChunkHeader;

import jdk.jfr.internal.consumer.RecordingInput;

final class Summary extends Command {

    private final DateTimeFormatter DATE_FORMAT = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss").withLocale(Locale.UK).withZone(ZoneOffset.UTC);

    @Override

    public String getName() {

        return "summary";

    }

    private static class Statistics {

        Statistics(String name) {

            this.name = name;

        }

        String name;

        long count;

        long size;

    }

    @Override

    public List<String> getOptionSyntax() {

        return Collections.singletonList("<file>");

    }

    @Override

    public void displayOptionUsage(PrintStream stream) {

        stream.println("  <file>   Location of the recording file (.jfr) to display information about");

    }

    @Override

    public String getDescription() {

        return "Display general information about a recording file (.jfr)";

    }

    @Override

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

        ensureMaxArgumentCount(options, 1);

        Path p = getJFRInputFile(options);

        try {

            printInformation(p);

        } catch (IOException e) {

            couldNotReadError(p, e);

        }

    }

    private void printInformation(Path p) throws IOException {

        long totalDuration = 0;

        long chunks = 0;

            ChunkHeader first = new ChunkHeader(input);

            ChunkHeader ch = first;

            String eventPrefix = Type.EVENT_NAME_PREFIX;

            if (first.getMajor() == 1) {

                eventPrefix = "com.oracle.jdk.";

            }

            HashMap<Long, Statistics> stats = new HashMap<>();

            stats.put(0L, new Statistics(eventPrefix + "Metadata"));

            stats.put(1L, new Statistics(eventPrefix + "CheckPoint"));

            int minWidth = 0;

            while (true) {

                long chunkEnd = ch.getEnd();

                MetadataDescriptor md = ch.readMetadata();

                for (EventType eventType : md.getEventTypes()) {

                    stats.computeIfAbsent(eventType.getId(), (e) -> new Statistics(eventType.getName()));

                    minWidth = Math.max(minWidth, eventType.getName().length());

                }

                totalDuration += ch.getDurationNanos();

                chunks++;

                input.position(ch.getEventStart());

                while (input.position() < chunkEnd) {

                    long pos = input.position();

                    int size = input.readInt();

                    long eventTypeId = input.readLong();

                    Statistics s = stats.get(eventTypeId);

                    if (s != null) {

                        s.count++;

                        s.size += size;

                    }

                    input.position(pos + size);

                }

                if (ch.isLastChunk()) {

                    break;

                }

                ch = ch.nextHeader();

            }

            println();

            long epochSeconds = first.getStartNanos() / 1_000_000_000L;

            long adjustNanos = first.getStartNanos() - epochSeconds * 1_000_000_000L;

            println(" Version: " + first.getMajor() + "." + first.getMinor());

            println(" Chunks: " + chunks);

            println(" Start: " + DATE_FORMAT.format(Instant.ofEpochSecond(epochSeconds, adjustNanos)) + " (UTC)");

            println(" Duration: " + (totalDuration + 500_000_000) / 1_000_000_000 + " s");

            List<Statistics> statsList = new ArrayList<>(stats.values());

            Collections.sort(statsList, (u, v) -> Long.compare(v.count, u.count));

            println();

            String header = "      Count  Size (bytes) ";

            String typeHeader = " Event Type";

            minWidth = Math.max(minWidth, typeHeader.length());

            println(typeHeader + pad(minWidth - typeHeader.length(), ' ') + header);

            println(pad(minWidth + header.length(), '='));

            for (Statistics s : statsList) {

                System.out.printf(" %-" + minWidth + "s%10d  %12d\n", s.name, s.count, s.size);

            }

        }

    }

    private String pad(int count, char c) {

        StringBuilder sb = new StringBuilder();

        for (int i = 0; i < count; i++) {

            sb.append(c);

        }

        return sb.toString();

    }

}