/*******************************************************************************
 * Copyright (c) 2011, 2014 Ericsson
 *
 * All rights reserved. This program and the accompanying materials are
 * made available under the terms of the Eclipse Public License 2.0 which
 * accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *   Francois Chouinard - Initial API and implementation
 *   Bernd Hufmann - Added setter and getter and bar width support
 *   Francois Chouinard - Moved from LTTng to TMF
 *   Patrick Tasse - Support selection range
 *   Jean-Christian Kouamé - Support to manage lost events
 *   Xavier Raynaud - Support multi-trace coloring
 *******************************************************************************/

package org.eclipse.tracecompass.tmf.ui.views.histogram;

import java.util.Arrays;

/**
 * Convenience class/struct for scaled histogram data.
 *
 * @version 1.0
 * @author Francois Chouinard
 */
public class HistogramScaledData {

    // ------------------------------------------------------------------------
    // Constants
    // ------------------------------------------------------------------------

    /**
     * Indicator value that bucket is out of range (not filled).
     */
    public static final int OUT_OF_RANGE_BUCKET = -1;

    // ------------------------------------------------------------------------
    // Attributes
    // ------------------------------------------------------------------------
    /**
     * Width of histogram canvas (number of pixels).
     */
    public int fWidth;
    /**
     * Height of histogram canvas (number of pixels).
     */
    public int fHeight;
    /**
     * Width of one histogram bar (number of pixels).
     */
    public int fBarWidth;
    /**
     * Array of scaled values
     */
    public HistogramBucket[] fData;
    /**
     * Array of scaled values combined including the lost events. This array
     * contains the number of lost events for each bar in the histogram
     */
    public final int[] fLostEventsData;
    /**
     * The bucket duration of a scaled data bucket.
     */
    public double fBucketDuration;
    /**
     * The maximum number of events of all buckets.
     */
    public long fMaxValue;
    /**
     * the maximum of events of all buckets including the lost events
     */
    public long fMaxCombinedValue;
    /**
     * The index of the selection begin bucket.
     */
    public int fSelectionBeginBucket;
    /**
     * The index of the selection end bucket.
     */
    public int fSelectionEndBucket;
    /**
     * The index of the last bucket.
     */
    public int fLastBucket;
    /**
     * The scaling factor used to fill the scaled data.
     */
    public double fScalingFactor;
    /**
     * The scaling factor used to fill the scaled data including the lost
     * events.
     */
    public double fScalingFactorCombined;
    /**
     * The scaling factor used to fill the combining scaled data including lost
     * events
     */
    /**
     * Time of first bucket.
     */
    public long fFirstBucketTime;
    /**
     * The time of the first event.
     */
    public long fFirstEventTime;
    /**
     * show the lost events or not
     */
    public static volatile boolean hideLostEvents = false;

    // ------------------------------------------------------------------------
    // Constructor
    // ------------------------------------------------------------------------

    /**
     * Constructor.
     *
     * @param width
     *            the canvas width
     * @param height
     *            the canvas height
     * @param barWidth
     *            the required bar width
     */
    public HistogramScaledData(int width, int height, int barWidth) {
        fWidth = width;
        fHeight = height;
        fBarWidth = barWidth;
        fData = new HistogramBucket[width / fBarWidth];
        fLostEventsData = new int[width / fBarWidth];
        fBucketDuration = 1;
        fMaxValue = 0;
        fMaxCombinedValue = 0;
        fSelectionBeginBucket = 0;
        fSelectionEndBucket = 0;
        fLastBucket = 0;
        fScalingFactor = 1;
        fScalingFactorCombined = 1;
        fFirstBucketTime = 0;
    }

    /**
     * Copy constructor
     *
     * @param other
     *            another scaled data.
     */
    public HistogramScaledData(HistogramScaledData other) {
        fWidth = other.fWidth;
        fHeight = other.fHeight;
        fBarWidth = other.fBarWidth;
        fData = Arrays.copyOf(other.fData, other.fData.length);
        fLostEventsData = Arrays.copyOf(other.fLostEventsData, other.fLostEventsData.length);
        fBucketDuration = other.fBucketDuration;
        fMaxValue = other.fMaxValue;
        fMaxCombinedValue = other.fMaxCombinedValue;
        fSelectionBeginBucket = other.fSelectionBeginBucket;
        fSelectionEndBucket = other.fSelectionEndBucket;
        fLastBucket = other.fLastBucket;
        fScalingFactor = other.fScalingFactor;
        fScalingFactorCombined = other.fScalingFactorCombined;
        fFirstBucketTime = other.fFirstBucketTime;
    }

    // ------------------------------------------------------------------------
    // Setter and Getter
    // ------------------------------------------------------------------------

    /**
     * Returns the time of the first bucket of the scaled data.
     *
     * @return the time of the first bucket.
     */
    public long getFirstBucketTime() {
        return fFirstBucketTime;
    }

    /**
     * Set the first event time.
     *
     * @param firstEventTime
     *            The time to set
     */
    public void setFirstBucketTime(long firstEventTime) {
        fFirstBucketTime = firstEventTime;
    }

    /**
     * Returns the time of the last bucket.
     *
     * @return last bucket time
     */
    public long getLastBucketTime() {
        return getBucketStartTime(fLastBucket);
    }

    /**
     * Returns the time of the bucket start time for given index.
     *
     * @param index
     *            A bucket index.
     * @return the time of the bucket start time
     */
    public long getBucketStartTime(int index) {
        return fFirstBucketTime + (long) (getOffsetIndex(index) * fBucketDuration);
    }

    private int getOffsetIndex(int index) {
        if (fBucketDuration != 0) {
            double nbBuckets = fWidth * fBucketDuration;
            /**
             * Add half a bucket to get the offset right, this is so we show 1/2
             * of the last bucket
             */
            double threshold = (0.5 / nbBuckets) * fWidth;
            return (int) (index + threshold);
        }
        return index;
    }

    /**
     * Returns the time of the bucket end time for given index.
     *
     * @param index
     *            A bucket index.
     * @return the time of the bucket end time
     */
    public long getBucketEndTime(int index) {
        return getBucketStartTime(index + 1);
    }
}