////////////////////////////////////////////////////////////////////////////////////////////////////
// PlotSquared - A plot manager and world generator for the Bukkit API                             /
// Copyright (c) 2014 IntellectualSites/IntellectualCrafters                                       /
//                                                                                                 /
// This program is free software; you can redistribute it and/or modify                            /
// it under the terms of the GNU General Public License as published by                            /
// the Free Software Foundation; either version 3 of the License, or                               /
// (at your option) any later version.                                                             /
//                                                                                                 /
// This program 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 for more details.                                                    /
//                                                                                                 /
// You should have received a copy of the GNU General Public License                               /
// along with this program; if not, write to the Free Software Foundation,                         /
// Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA                               /
//                                                                                                 /
// You can contact us via: support@intellectualsites.com                                           /
////////////////////////////////////////////////////////////////////////////////////////////////////
package com.intellectualcrafters.plot.util;

/**
 * TPS and Lag Checker.
 *
 * @author Citymonstret
 */
public class Lag implements Runnable {
    /**
     * Ticks
     */
    public final static long[] T = new long[600];
    /**
     * Tick count
     */
    public static int TC = 0;
    /**
     * something :_:
     */
    @SuppressWarnings("unused")
    public static long LT = 0L;

    /**
     * Get the server TPS
     *
     * @return server tick per second
     */
    public static double getTPS() {
        return Math.round(getTPS(100)) > 20.0D ? 20.0D : Math.round(getTPS(100));
    }

    /**
     * Return the tick per second (measured in $ticks)
     *
     * @param ticks Ticks
     *
     * @return ticks per second
     */
    public static double getTPS(final int ticks) {
        if (TC < ticks) {
            return 20.0D;
        }
        final int t = (TC - 1 - ticks) % T.length;
        final long e = System.currentTimeMillis() - T[t];
        return ticks / (e / 1000.0D);
    }

    /**
     * Get number of ticks since
     *
     * @param tI Ticks <
     *
     * @return number of ticks since $tI
     */
    public static long getElapsed(final int tI) {
        final long t = T[tI % T.length];
        return System.currentTimeMillis() - t;
    }

    /**
     * Get lag percentage
     *
     * @return lag percentage
     */
    public static double getPercentage() {
        return Math.round((1.0D - (Lag.getTPS() / 20.0D)) * 100.0D);
    }

    /**
     * Get TPS percentage (of 20)
     *
     * @return TPS percentage
     */
    public static double getFullPercentage() {
        return getTPS() * 5.0D;
    }

    @Override
    public void run() {
        T[TC % T.length] = System.currentTimeMillis();
        TC++;
    }
}