/*

 * Copyright (c) 2019, 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.consumer;

import java.io.IOException;

import java.nio.file.Path;

import java.security.AccessControlContext;

import java.security.AccessController;

import java.time.Duration;

import java.time.Instant;

import java.util.Arrays;

import java.util.Objects;

import java.util.function.Consumer;

import jdk.jfr.internal.consumer.FileAccess;

import jdk.jfr.internal.consumer.RecordingInput;

/**

 * Implementation of an event stream that operates against a recording file.

 *

 */

final class EventFileStream implements EventStream {

    private final static class FileStream extends AbstractEventStream {

        private static final int DEFAULT_ARRAY_SIZE = 100_000;

        private final RecordingInput input;

        private ChunkParser chunkParser;

        private RecordedEvent[] sortedList;

        public FileStream(AccessControlContext acc, Path path) throws IOException {

            super(acc, false);

            this.input = new RecordingInput(path.toFile(), FileAccess.UNPRIVILIGED);

;        }

        @Override

        public void process() throws IOException {

            final StreamConfiguration c1 = configuration;

            long start = 0;

            long end = Long.MAX_VALUE;

            if (c1.getStartTime() != null) {

                start = c1.getStartNanos();

            }

            if (c1.getEndTime() != null) {

                end = c1.getEndNanos();

            }

            chunkParser = new ChunkParser(input, c1.getReuse());

            while (!isClosed()) {

                if (chunkParser.getStartNanos() > end) {

                    close();

                    return;

                }

                StreamConfiguration c2 = configuration;

                boolean ordered = c2.getOrdered();

                chunkParser.setFirstNanos(start);

                chunkParser.setLastNanos(end);

                chunkParser.setReuse(c2.getReuse());

                chunkParser.setOrdered(ordered);

                chunkParser.resetEventCache();

                chunkParser.setParserFilter(c2.getFiler());

                chunkParser.updateEventParsers();

                clearLastDispatch();

                if (ordered) {

                    processOrdered();

                } else {

                    processUnordered();

                }

                if (chunkParser.isLastChunk()) {

                    return;

                }

                chunkParser = chunkParser.nextChunkParser();

            }

        }

        private void processOrdered() throws IOException {

            if (sortedList == null) {

                sortedList = new RecordedEvent[DEFAULT_ARRAY_SIZE];

            }

            RecordedEvent event;

            int index = 0;

            while (true) {

                event = chunkParser.readEvent();

                if (event == null) {

                    Arrays.sort(sortedList, 0, index, END_TIME);

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

                        dispatch(sortedList[i]);

                    }

                    return;

                }

                if (index == sortedList.length) {

                    RecordedEvent[] tmp = sortedList;

                    sortedList = new RecordedEvent[2 * tmp.length];

                    System.arraycopy(tmp, 0, sortedList, 0, tmp.length);

                }

                sortedList[index++] = event;

            }

        }

        private void processUnordered() throws IOException {

            RecordedEvent event;

            while (!isClosed()) {

                event = chunkParser.readEvent();

                if (event == null) {

                    return;

                }

                dispatch(event);

            }

        }

        @Override

        public void close() {

            setClosed(true);;

            runCloseActions();

            try {

                input.close();

            } catch (IOException e) {

                // ignore

            }

        }

    }

    private final FileStream eventStream;

    public EventFileStream(Path path, Instant from, Instant to) throws IOException {

        Objects.requireNonNull(path);

        eventStream = new FileStream(AccessController.getContext(), path);

    }

    @Override

    public void onEvent(Consumer<RecordedEvent> action) {

        Objects.requireNonNull(action);

        eventStream.onEvent(action);

    }

    @Override

    public void onEvent(String eventName, Consumer<RecordedEvent> action) {

        Objects.requireNonNull(eventName);

        Objects.requireNonNull(action);

        eventStream.onEvent(eventName, action);

    }

    @Override

    public void onFlush(Runnable action) {

        Objects.requireNonNull(action);

        eventStream.onFlush(action);

    }

    @Override

    public void onClose(Runnable action) {

        Objects.requireNonNull(action);

        eventStream.addCloseAction(action);

    }

    @Override

    public void close() {

        eventStream.close();

    }

    @Override

    public boolean remove(Object action) {

        Objects.requireNonNull(action);

        return eventStream.remove(action);

    }

    @Override

    public void start() {

        eventStream.start(0);

    }

    @Override

    public void setReuse(boolean reuse) {

        eventStream.setReuse(reuse);

    }

    @Override

    public void startAsync() {

        eventStream.startAsync(0);

    }

    @Override

    public void awaitTermination(Duration timeout) {

        Objects.requireNonNull(timeout);

        eventStream.awaitTermination(timeout);

    }

    @Override

    public void awaitTermination() {

        eventStream.awaitTermination();

    }

    @Override

    public void setOrdered(boolean ordered) {

        eventStream.setOrdered(ordered);

    }

    @Override

    public void setStartTime(Instant startTime) {

        eventStream.setStartTime(startTime);

    }

    @Override

    public void setEndTime(Instant endTime) {

        eventStream.setEndTime(endTime);

    }

}