////////////////////////////////////////////////////////////////////////////////////////////////////
// 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.commands;

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import java.util.concurrent.atomic.AtomicBoolean;

import com.intellectualcrafters.plot.PS;
import com.intellectualcrafters.plot.object.Plot;
import com.intellectualcrafters.plot.object.PlotId;
import com.intellectualcrafters.plot.object.PlotPlayer;
import com.intellectualcrafters.plot.util.BlockManager;
import com.intellectualcrafters.plot.util.MainUtil;
import com.intellectualcrafters.plot.util.MathMan;
import com.intellectualcrafters.plot.util.TaskManager;
import com.plotsquared.general.commands.CommandDeclaration;

@CommandDeclaration(command = "condense", permission = "plots.admin", description = "Condense a plotworld", category = CommandCategory.DEBUG, requiredType = RequiredType.CONSOLE)
public class Condense extends SubCommand {
    
    public static boolean TASK = false;
    
    @Override
    public boolean onCommand(final PlotPlayer plr, final String... args) {
        if ((args.length != 2) && (args.length != 3)) {
            MainUtil.sendMessage(plr, "/plot condense <world> <start|stop|info> [radius]");
            return false;
        }
        final String worldname = args[0];
        if (!BlockManager.manager.isWorld(worldname) || !PS.get().isPlotWorld(worldname)) {
            MainUtil.sendMessage(plr, "INVALID WORLD");
            return false;
        }
        switch (args[1].toLowerCase()) {
            case "start": {
                if (args.length == 2) {
                    MainUtil.sendMessage(plr, "/plot condense " + worldname + " start <radius>");
                    return false;
                }
                if (TASK) {
                    MainUtil.sendMessage(plr, "TASK ALREADY STARTED");
                    return false;
                }
                if (args.length == 2) {
                    MainUtil.sendMessage(plr, "/plot condense " + worldname + " start <radius>");
                    return false;
                }
                if (!MathMan.isInteger(args[2])) {
                    MainUtil.sendMessage(plr, "INVALID RADIUS");
                    return false;
                }
                final int radius = Integer.parseInt(args[2]);
                ArrayList<Plot> plots = new ArrayList<>(PS.get().getPlotsInWorld(worldname));
                // remove non base plots
                Iterator<Plot> iter = plots.iterator();
                int maxSize = 0;
                ArrayList<Integer> sizes = new ArrayList<>();
                while (iter.hasNext()) {
                    Plot plot = iter.next();
                    if (!plot.isBasePlot()) {
                        iter.remove();
                        continue;
                    }
                    int size = plot.getConnectedPlots().size();
                    if (size > maxSize) {
                        maxSize = size;
                    }
                    sizes.add(size - 1);
                }
                // Sort plots by size (buckets?)]
                ArrayList<Plot>[] buckets = new ArrayList[maxSize];
                for (int i = 0; i < plots.size(); i++) {
                    Plot plot = plots.get(i);
                    int size = sizes.get(i);
                    ArrayList<Plot> array = buckets[size];
                    if (array == null) {
                        array = new ArrayList<Plot>();
                        buckets[size] = array;
                    }
                    array.add(plot);
                }
                final ArrayList<Plot> allPlots = new ArrayList<Plot>(plots.size());
                for (int i = buckets.length - 1; i >= 0; i--) {
                    ArrayList<Plot> array = buckets[i];
                    if (array != null) {
                        allPlots.addAll(array);
                    }
                }
                final int size = allPlots.size();
                final int minimum_radius = (int) Math.ceil((Math.sqrt(size) / 2) + 1);
                if (radius < minimum_radius) {
                    MainUtil.sendMessage(plr, "RADIUS TOO SMALL");
                    return false;
                }
                final List<PlotId> to_move = new ArrayList<>(getPlots(allPlots, radius));
                final List<PlotId> free = new ArrayList<>();
                PlotId start = new PlotId(0, 0);
                while ((start.x <= minimum_radius) && (start.y <= minimum_radius)) {
                    final Plot plot = MainUtil.getPlotAbs(worldname, start);
                    if (!plot.hasOwner()) {
                        free.add(plot.id);
                    }
                    start = Auto.getNextPlot(start, 1);
                }
                if ((free.size() == 0) || (to_move.size() == 0)) {
                    MainUtil.sendMessage(plr, "NO FREE PLOTS FOUND");
                    return false;
                }
                MainUtil.sendMessage(plr, "TASK STARTED...");
                Runnable run = new Runnable() {
                    @Override
                    public void run() {
                        if (!TASK) {
                            MainUtil.sendMessage(plr, "TASK CANCELLED.");
                        }
                        if (allPlots.size() == 0) {
                            TASK = false;
                            MainUtil.sendMessage(plr, "TASK COMPLETE. PLEASE VERIFY THAT NO NEW PLOTS HAVE BEEN CLAIMED DURING TASK.");
                            return;
                        }
                        final Runnable task = this;
                        final Plot origin = allPlots.remove(0);
                        int i = 0;
                        while (free.size() > i) {
                            final Plot possible = MainUtil.getPlotAbs(origin.world, free.get(i));
                            if (possible.owner != null) {
                                free.remove(i);
                                continue;
                            }
                            i++;
                            final AtomicBoolean result = new AtomicBoolean(false);
                            result.set(MainUtil.move(origin, possible, new Runnable() {
                                @Override
                                public void run() {
                                    if (result.get()) {
                                        MainUtil.sendMessage(plr, "Moving: " + origin + " -> " + possible);
                                        TaskManager.runTaskLater(task, 1);
                                    }
                                }
                            }, false));
                            if (result.get()) {
                                break;
                            }
                        }
                        if (free.size() == 0) {
                            TASK = false;
                            MainUtil.sendMessage(plr, "TASK FAILED. NO FREE PLOTS FOUND!");
                            return;
                        }
                        if (i >= free.size()) {
                            MainUtil.sendMessage(plr, "SKIPPING COMPLEX PLOT: " + origin);
                        }
                    }
                };
                TASK = true;
                TaskManager.runTaskAsync(run);
                return true;
            }
            case "stop": {
                if (!TASK) {
                    MainUtil.sendMessage(plr, "TASK ALREADY STOPPED");
                    return false;
                }
                TASK = false;
                MainUtil.sendMessage(plr, "TASK STOPPED");
                return true;
            }
            case "info": {
                if (args.length == 2) {
                    MainUtil.sendMessage(plr, "/plot condense " + worldname + " info <radius>");
                    return false;
                }
                if (!MathMan.isInteger(args[2])) {
                    MainUtil.sendMessage(plr, "INVALID RADIUS");
                    return false;
                }
                final int radius = Integer.parseInt(args[2]);
                final Collection<Plot> plots = PS.get().getPlotsInWorld(worldname);
                final int size = plots.size();
                final int minimum_radius = (int) Math.ceil((Math.sqrt(size) / 2) + 1);
                if (radius < minimum_radius) {
                    MainUtil.sendMessage(plr, "RADIUS TOO SMALL");
                    return false;
                }
                final int max_move = getPlots(plots, minimum_radius).size();
                final int user_move = getPlots(plots, radius).size();
                MainUtil.sendMessage(plr, "=== DEFAULT EVAL ===");
                MainUtil.sendMessage(plr, "MINIMUM RADIUS: " + minimum_radius);
                MainUtil.sendMessage(plr, "MAXIMUM MOVES: " + max_move);
                MainUtil.sendMessage(plr, "=== INPUT EVAL ===");
                MainUtil.sendMessage(plr, "INPUT RADIUS: " + radius);
                MainUtil.sendMessage(plr, "ESTIMATED MOVES: " + user_move);
                MainUtil.sendMessage(plr, "ESTIMATED TIME: " + "No idea, times will drastically change based on the system performance and load");
                MainUtil.sendMessage(plr, "&e - Radius is measured in plot width");
                return true;
            }
        }
        MainUtil.sendMessage(plr, "/plot condense " + worldname + " <start|stop|info> [radius]");
        return false;
    }
    
    public Set<PlotId> getPlots(final Collection<Plot> plots, final int radius) {
        final HashSet<PlotId> outside = new HashSet<>();
        for (final Plot plot : plots) {
            if ((plot.id.x > radius) || (plot.id.x < -radius) || (plot.id.y > radius) || (plot.id.y < -radius)) {
                outside.add(plot.id);
            }
        }
        return outside;
    }
}