/*

 * Copyright (c) 2016, 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 static jdk.jfr.internal.EventInstrumentation.FIELD_DURATION;

import java.io.IOException;

import java.util.List;

import jdk.jfr.EventType;

import jdk.jfr.ValueDescriptor;

import jdk.jfr.internal.consumer.Parser;

import jdk.jfr.internal.consumer.RecordingInput;

/**

 * Parses an event and returns a {@link RecordedEvent}.

 *

 */

final class EventParser extends Parser {

    private final Parser[] parsers;

    private final EventType eventType;

    private final TimeConverter timeConverter;

    private final boolean hasDuration;

    private final List<ValueDescriptor> valueDescriptors;

    private final int startIndex;

    private final int length;

    private final RecordedEvent unorderedEvent;

    private boolean enabled = true;

    private RecordedEvent[] eventCache;

    private int index;

    private boolean ordered;

    private long firstNanos;

    private long thresholdNanos = -1;

    EventParser(TimeConverter timeConverter, EventType type, Parser[] parsers) {

        this.timeConverter = timeConverter;

        this.parsers = parsers;

        this.eventType = type;

        this.hasDuration = type.getField(FIELD_DURATION) != null;

        this.startIndex = hasDuration ? 2 : 1;

        this.length = parsers.length - startIndex;

        this.valueDescriptors = type.getFields();

    }

    private RecordedEvent cachedEvent() {

        if (ordered) {

            if (index == eventCache.length) {

                RecordedEvent[] cache = eventCache;

                eventCache = new RecordedEvent[eventCache.length * 2];

                System.arraycopy(cache, 0, eventCache, 0, cache.length);

            }

            RecordedEvent event = eventCache[index];

            if (event == null) {

                eventCache[index] = event;

            }

            index++;

            return event;

        } else {

            return unorderedEvent;

        }

    }

    public EventType getEventType() {

        return eventType;

    }

    public void setThresholdNanos(long thresholdNanos) {

        this.thresholdNanos = thresholdNanos;

    }

    public void setEnabled(boolean enabled) {

        this.enabled = enabled;

    }

    public boolean isEnabled() {

        return this.enabled;

    }

    public RecordedEvent parse(RecordingInput input) throws IOException {

        if (enabled) {

            long startTicks = input.readLong();

            long durationTicks = 0;

            if (hasDuration) {

                durationTicks = input.readLong();

                if (thresholdNanos > 0L) {

                    if (timeConverter.convertTimespan(durationTicks) < thresholdNanos) {

                        return null;

                    }

                }

            }

            long endTicks = startTicks + durationTicks;

            if (firstNanos > 0L) {

                if (timeConverter.convertTimestamp(endTicks) < firstNanos) {

                    return null;

                }

            }

            if (eventCache != null) {

                RecordedEvent event = cachedEvent();

                event.startTimeTicks = startTicks;

                event.endTimeTicks = endTicks;

                Object[] values = event.objects;

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

                    values[i] = parsers[startIndex + i].parse(input);

                }

                return event;

            } else {

                Object[] values = new Object[length];

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

                    values[i] = parsers[startIndex + i].parse(input);

                }

            }

        }

        return null;

    }

    @Override

    public void skip(RecordingInput input) throws IOException {

        throw new InternalError("Should not call this method. More efficent to read event size and skip ahead");

    }

    public void resetCache() {

        index = 0;

    }

    public boolean hasReuse() {

        return eventCache != null;

    }

    public void setReuse(boolean reuse) {

        if (reuse == hasReuse()) {

            return;

        }

        if (reuse) {

            eventCache = new RecordedEvent[2];

            index = 0;

        } else {

            eventCache = null;

        }

    }

    public void setFirstNanos(long firstNanos) {

        this.firstNanos = firstNanos;

    }

    public void setOrdered(boolean ordered) {

        if (this.ordered == ordered) {

            return;

        }

        this.ordered = ordered;

        this.index = 0;

    }

}