PlotSquared/PlotSquared/src/main/java/com/intellectualcrafters/plot/uuid/UUIDFetcher.java

////////////////////////////////////////////////////////////////////////////////////////////////////
// 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.uuid;

import com.google.common.collect.ImmutableList;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;

import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.nio.ByteBuffer;
import java.util.*;
import java.util.concurrent.Callable;

/**
 * UUID Fetcher From Bukkit
 */
public class UUIDFetcher implements Callable<Map<String, UUID>> {
    private static final double PROFILES_PER_REQUEST = 100;
    private static final String PROFILE_URL = "https://api.mojang.com/profiles/minecraft";
    private final JSONParser jsonParser = new JSONParser();
    private final List<String> names;
    private final boolean rateLimiting;

    public UUIDFetcher(final List<String> names, final boolean rateLimiting) {
        this.names = ImmutableList.copyOf(names);
        this.rateLimiting = rateLimiting;
    }

    public UUIDFetcher(final List<String> names) {
        this(names, true);
    }

    private static void writeBody(final HttpURLConnection connection, final String body) throws Exception {
        final OutputStream stream = connection.getOutputStream();
        stream.write(body.getBytes());
        stream.flush();
        stream.close();
    }

    private static HttpURLConnection createConnection() throws Exception {
        final URL url = new URL(PROFILE_URL);
        final HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        connection.setRequestMethod("POST");
        connection.setRequestProperty("Content-Type", "application/json");
        connection.setUseCaches(false);
        connection.setDoInput(true);
        connection.setDoOutput(true);
        return connection;
    }

    public static UUID getUUID(final String id) {
        return UUID.fromString(id.substring(0, 8) + "-" + id.substring(8, 12) + "-" + id.substring(12, 16) + "-" + id.substring(16, 20) + "-" + id.substring(20, 32));
    }

    @SuppressWarnings("unused")
    public static byte[] toBytes(final UUID uuid) {
        final ByteBuffer byteBuffer = ByteBuffer.wrap(new byte[16]);
        byteBuffer.putLong(uuid.getMostSignificantBits());
        byteBuffer.putLong(uuid.getLeastSignificantBits());
        return byteBuffer.array();
    }

    @SuppressWarnings("unused")
    public static UUID fromBytes(final byte[] array) {
        if (array.length != 16) {
            throw new IllegalArgumentException("Illegal byte array length: " + array.length);
        }
        final ByteBuffer byteBuffer = ByteBuffer.wrap(array);
        final long mostSignificant = byteBuffer.getLong();
        final long leastSignificant = byteBuffer.getLong();
        return new UUID(mostSignificant, leastSignificant);
    }

    @SuppressWarnings("unused")
    public static UUID getUUIDOf(final String name) throws Exception {
        return new UUIDFetcher(Arrays.asList(name)).call().get(name);
    }

    @Override
    public Map<String, UUID> call() throws Exception {
        final Map<String, UUID> uuidMap = new HashMap<>();
        final int requests = (int) Math.ceil(this.names.size() / PROFILES_PER_REQUEST);
        for (int i = 0; i < requests; i++) {
            final HttpURLConnection connection = createConnection();
            final String body = JSONArray.toJSONString(this.names.subList(i * 100, Math.min((i + 1) * 100, this.names.size())));
            writeBody(connection, body);
            final JSONArray array = (JSONArray) this.jsonParser.parse(new InputStreamReader(connection.getInputStream()));
            for (final Object profile : array) {
                final JSONObject jsonProfile = (JSONObject) profile;
                final String id = (String) jsonProfile.get("id");
                final String name = (String) jsonProfile.get("name");
                final UUID uuid = UUIDFetcher.getUUID(id);
                uuidMap.put(name, uuid);
            }
            if (this.rateLimiting && (i != (requests - 1))) {
                Thread.sleep(100L);
            }
        }
        return uuidMap;
    }
}