src/main/java/net/pterodactylus/xdcc/core/Core.java

   1 /*
   2  * XdccDownloader - Core.java - Copyright © 2013 David Roden
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 package net.pterodactylus.xdcc.core;
  19
  20 import java.io.File;
  21 import java.io.FileNotFoundException;
  22 import java.io.FileOutputStream;
  23 import java.io.IOException;
  24 import java.io.OutputStream;
  25 import java.util.Collection;
  26 import java.util.Collections;
  27 import java.util.List;
  28 import java.util.Map;
  29 import java.util.Map.Entry;
  30 import java.util.concurrent.TimeUnit;
  31 import java.util.logging.Level;
  32 import java.util.logging.Logger;
  33
  34 import net.pterodactylus.irc.Connection;
  35 import net.pterodactylus.irc.ConnectionBuilder;
  36 import net.pterodactylus.irc.DccReceiver;
  37 import net.pterodactylus.irc.event.ChannelJoined;
  38 import net.pterodactylus.irc.event.ChannelLeft;
  39 import net.pterodactylus.irc.event.ChannelMessageReceived;
  40 import net.pterodactylus.irc.event.ClientQuit;
  41 import net.pterodactylus.irc.event.ConnectionEstablished;
  42 import net.pterodactylus.irc.event.DccAcceptReceived;
  43 import net.pterodactylus.irc.event.DccDownloadFailed;
  44 import net.pterodactylus.irc.event.DccDownloadFinished;
  45 import net.pterodactylus.irc.event.DccSendReceived;
  46 import net.pterodactylus.irc.event.NicknameChanged;
  47 import net.pterodactylus.irc.event.PrivateMessageReceived;
  48 import net.pterodactylus.irc.util.MessageCleaner;
  49 import net.pterodactylus.irc.util.RandomNickname;
  50 import net.pterodactylus.xdcc.core.event.BotAdded;
  51 import net.pterodactylus.xdcc.core.event.CoreStarted;
  52 import net.pterodactylus.xdcc.core.event.DownloadFailed;
  53 import net.pterodactylus.xdcc.core.event.DownloadFinished;
  54 import net.pterodactylus.xdcc.core.event.DownloadStarted;
  55 import net.pterodactylus.xdcc.core.event.GenericError;
  56 import net.pterodactylus.xdcc.core.event.GenericMessage;
  57 import net.pterodactylus.xdcc.core.event.MessageReceived;
  58 import net.pterodactylus.xdcc.data.Bot;
  59 import net.pterodactylus.xdcc.data.Channel;
  60 import net.pterodactylus.xdcc.data.Download;
  61 import net.pterodactylus.xdcc.data.Network;
  62 import net.pterodactylus.xdcc.data.Pack;
  63 import net.pterodactylus.xdcc.data.Server;
  64
  65 import com.google.common.base.Optional;
  66 import com.google.common.collect.HashBasedTable;
  67 import com.google.common.collect.ImmutableSet;
  68 import com.google.common.collect.Lists;
  69 import com.google.common.collect.Maps;
  70 import com.google.common.collect.Sets;
  71 import com.google.common.collect.Table;
  72 import com.google.common.eventbus.EventBus;
  73 import com.google.common.eventbus.Subscribe;
  74 import com.google.common.io.Closeables;
  75 import com.google.common.util.concurrent.AbstractExecutionThreadService;
  76 import com.google.inject.Inject;
  77
  78 /**
  79  * The core of XDCC Downloader.
  80  *
  81  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  82  */
  83 public class Core extends AbstractExecutionThreadService {
  84
  85         /** The logger. */
  86         private static final Logger logger = Logger.getLogger(Core.class.getName());
  87
  88         /** The event bus. */
  89         private final EventBus eventBus;
  90
  91         /** The temporary directory to download files to. */
  92         private final String temporaryDirectory;
  93
  94         /** The directory to move finished downloads to. */
  95         private final String finalDirectory;
  96
  97         /** The channels that should be monitored. */
  98         private final Collection<Channel> channels = Sets.newHashSet();
  99
 100         /** The channels that are currentlymonitored. */
 101         private final Collection<Channel> joinedChannels = Sets.newHashSet();
 102
 103         /** The channels that are joined but not configured. */
 104         private final Collection<Channel> extraChannels = Sets.newHashSet();
 105
 106         /** The current network connections. */
 107         private final Map<Network, Connection> networkConnections = Collections.synchronizedMap(Maps.<Network, Connection>newHashMap());
 108
 109         /** The currently known bots. */
 110         private final Table<Network, String, Bot> networkBots = HashBasedTable.create();
 111
 112         /** The current downloads. */
 113         private final Map<String, Download> downloads = Maps.newHashMap();
 114
 115         /** The current DCC receivers. */
 116         private final Collection<DccReceiver> dccReceivers = Lists.newArrayList();
 117
 118         /**
 119          * Creates a new core.
 120          *
 121          * @param eventBus
 122          *              The event bus
 123          * @param temporaryDirectory
 124          *              The directory to download files to
 125          * @param finalDirectory
 126          *              The directory to move finished files to
 127          */
 128         @Inject
 129         public Core(EventBus eventBus, String temporaryDirectory, String finalDirectory) {
 130                 this.eventBus = eventBus;
 131                 this.temporaryDirectory = temporaryDirectory;
 132                 this.finalDirectory = finalDirectory;
 133         }
 134
 135         //
 136         // ACCESSORS
 137         //
 138
 139         /**
 140          * Returns all configured channels. Due to various circumstances, configured
 141          * channels might not actually be joined.
 142          *
 143          * @return All configured channels
 144          */
 145         public Collection<Channel> channels() {
 146                 return ImmutableSet.copyOf(channels);
 147         }
 148
 149         /**
 150          * Returns all currently joined channels.
 151          *
 152          * @return All currently joined channels
 153          */
 154         public Collection<Channel> joinedChannels() {
 155                 return ImmutableSet.copyOf(joinedChannels);
 156         }
 157
 158         /**
 159          * Returns all currently joined channels that are not configured.
 160          *
 161          * @return All currently joined but not configured channels
 162          */
 163         public Collection<Channel> extraChannels() {
 164                 return ImmutableSet.copyOf(extraChannels);
 165         }
 166
 167         /**
 168          * Returns all currently known bots.
 169          *
 170          * @return All currently known bots
 171          */
 172         public Collection<Bot> bots() {
 173                 return networkBots.values();
 174         }
 175
 176         /**
 177          * Returns the currently active DCC receivers.
 178          *
 179          * @return The currently active DCC receivers
 180          */
 181         public Collection<DccReceiver> dccReceivers() {
 182                 return dccReceivers;
 183         }
 184
 185         //
 186         // ACTIONS
 187         //
 188
 189         /**
 190          * Adds a channel to monitor.
 191          *
 192          * @param channel
 193          *              The channel to monitor
 194          */
 195         public void addChannel(Channel channel) {
 196                 channels.add(channel);
 197         }
 198
 199         /**
 200          * Fetches the given pack from the given bot.
 201          *
 202          * @param bot
 203          *              The bot to fetch the pack from
 204          * @param pack
 205          *              The pack to fetch
 206          */
 207         public void fetch(Bot bot, Pack pack) {
 208                 Connection connection = networkConnections.get(bot.network());
 209                 if (connection == null) {
 210                         return;
 211                 }
 212
 213                 Download download = new Download(bot, pack);
 214                 downloads.put(pack.name(), download);
 215
 216                 try {
 217                         connection.sendMessage(bot.name(), "XDCC SEND " + pack.id());
 218                 } catch (IOException ioe1) {
 219                         logger.log(Level.WARNING, "Could not send message to bot!", ioe1);
 220                 }
 221         }
 222
 223         //
 224         // ABSTRACTIDLESERVICE METHODS
 225         //
 226
 227         @Override
 228         protected void startUp() {
 229                 for (Channel channel : channels) {
 230                         logger.info(String.format("Connecting to Channel %s on Network %s…", channel.name(), channel.network().name()));
 231                         connectNetwork(channel.network());
 232                 }
 233
 234                 /* notify listeners. */
 235                 eventBus.post(new CoreStarted(this));
 236         }
 237
 238         @Override
 239         protected void run() throws Exception {
 240                 while (isRunning()) {
 241                         try {
 242                                 Thread.sleep(TimeUnit.MINUTES.toMillis(1));
 243                         } catch (InterruptedException ie1) {
 244                                 /* ignore. */
 245                         }
 246
 247                         /* find channels that should be monitored but are not. */
 248                         for (Channel channel : channels) {
 249                                 if (joinedChannels.contains(channel)) {
 250                                         continue;
 251                                 }
 252
 253                                 connectNetwork(channel.network());
 254                                 Connection connection = networkConnections.get(channel.network());
 255                                 if (connection.established()) {
 256                                         eventBus.post(new GenericMessage(String.format("Trying to join %s on %s.", channel.name(), channel.network().name())));
 257                                         connection.joinChannel(channel.name());
 258                                 }
 259                         }
 260                 }
 261         }
 262
 263         @Override
 264         protected void shutDown() {
 265         }
 266
 267         //
 268         // PRIVATE METHODS
 269         //
 270
 271         /**
 272          * Starts a new connection for the given network if no such connection exists
 273          * already.
 274          *
 275          * @param network
 276          *              The network to connect to
 277          */
 278         private void connectNetwork(Network network) {
 279                 if (!networkConnections.containsKey(network)) {
 280                                 /* select a random server. */
 281                         List<Server> servers = Lists.newArrayList(network.servers());
 282                         if (servers.isEmpty()) {
 283                                 eventBus.post(new GenericError(String.format("Network %s does not have any servers.", network.name())));
 284                                 return;
 285                         }
 286                         Server server = servers.get((int) (Math.random() * servers.size()));
 287                         Connection connection = new ConnectionBuilder(eventBus).connect(server.hostname()).port(server.unencryptedPorts().iterator().next()).build();
 288                         connection.username(RandomNickname.get()).realName(RandomNickname.get());
 289                         networkConnections.put(network, connection);
 290                         connection.start();
 291                 }
 292         }
 293
 294         //
 295         // EVENT HANDLERS
 296         //
 297
 298         /**
 299          * If a connection to a network has been established, the channels associated
 300          * with this network are joined.
 301          *
 302          * @param connectionEstablished
 303          *              The connection established event
 304          */
 305         @Subscribe
 306         public void connectionEstablished(ConnectionEstablished connectionEstablished) {
 307
 308                 /* get network for connection. */
 309                 Optional<Network> network = getNetwork(connectionEstablished.connection());
 310
 311                 /* found network? */
 312                 if (!network.isPresent()) {
 313                         return;
 314                 }
 315
 316                 /* join all channels on this network. */
 317                 for (Channel channel : channels) {
 318                         if (channel.network().equals(network.get())) {
 319                                 try {
 320                                         connectionEstablished.connection().joinChannel(channel.name());
 321                                 } catch (IOException ioe1) {
 322                                         logger.log(Level.WARNING, String.format("Could not join %s on %s!", channel.name(), network.get().name()), ioe1);
 323                                 }
 324                         }
 325                 }
 326         }
 327
 328         /**
 329          * Shows a message when a channel was joined by us.
 330          *
 331          * @param channelJoined
 332          *              The channel joined event
 333          */
 334         @Subscribe
 335         public void channelJoined(ChannelJoined channelJoined) {
 336                 if (channelJoined.connection().isSource(channelJoined.client())) {
 337                         Optional<Network> network = getNetwork(channelJoined.connection());
 338                         if (!network.isPresent()) {
 339                                 return;
 340                         }
 341
 342                         Optional<Channel> channel = getChannel(network.get(), channelJoined.channel());
 343                         if (!channel.isPresent()) {
 344                                 /* it’s an extra channel. */
 345                                 extraChannels.add(new Channel(network.get(), channelJoined.channel()));
 346                                 logger.info(String.format("Joined extra Channel %s on %s.", channelJoined.channel(), network.get().name()));
 347                                 return;
 348                         }
 349
 350                         joinedChannels.add(channel.get());
 351                         logger.info(String.format("Joined Channel %s on %s.", channelJoined.channel(), network.get().name()));
 352                 }
 353         }
 354
 355         /**
 356          * Removes bots that leave a channel, or channels when it’s us that’s leaving.
 357          *
 358          * @param channelLeft
 359          *              The channel left event
 360          */
 361         @Subscribe
 362         public void channelLeft(ChannelLeft channelLeft) {
 363                 Optional<Network> network = getNetwork(channelLeft.connection());
 364                 if (!network.isPresent()) {
 365                         return;
 366                 }
 367
 368                 Bot bot = networkBots.get(network.get(), channelLeft.client().nick().get());
 369                 if (bot == null) {
 370                         /* maybe it was us? */
 371                         if (channelLeft.connection().isSource(channelLeft.client())) {
 372                                 Optional<Channel> channel = getChannel(network.get(), channelLeft.channel());
 373                                 if (!channel.isPresent()) {
 374                                         /* maybe it was an extra channel? */
 375                                         channel = getExtraChannel(network.get(), channelLeft.channel());
 376                                         if (!channel.isPresent()) {
 377                                                 /* okay, whatever. */
 378                                                 return;
 379                                         }
 380
 381                                         extraChannels.remove(channel);
 382                                 } else {
 383                                         channels.remove(channel.get());
 384                                 }
 385
 386                                 eventBus.post(new GenericMessage(String.format("Left Channel %s on %s.", channel.get().name(), channel.get().network().name())));
 387                         }
 388
 389                         return;
 390                 }
 391
 392                 Bot removedBot = networkBots.remove(network.get(), channelLeft.client().nick().get());
 393                 if (removedBot != null) {
 394                         eventBus.post(new GenericMessage(String.format("Bot %s (%s) was removed, %d packs removed.", removedBot.name(), removedBot.network().name(), removedBot.packs().size())));
 395                 }
 396         }
 397
 398         /**
 399          * Removes a client (which may be a bot) from the table of known bots.
 400          *
 401          * @param clientQuit
 402          *              The client quit event
 403          */
 404         @Subscribe
 405         public void clientQuit(ClientQuit clientQuit) {
 406                 Optional<Network> network = getNetwork(clientQuit.connection());
 407                 if (!network.isPresent()) {
 408                         return;
 409                 }
 410
 411                 Bot removedBot = networkBots.remove(network.get(), clientQuit.client().nick().get());
 412                 if (removedBot != null) {
 413                         eventBus.post(new GenericMessage(String.format("Bot %s (%s) was removed, %d packs removed.", removedBot.name(), removedBot.network().name(), removedBot.packs().size())));
 414                 }
 415         }
 416
 417         /**
 418          * If the nickname of a bit changes, remove it from the old name and store it
 419          * under the new name.
 420          *
 421          * @param nicknameChanged
 422          *              The nickname changed event
 423          */
 424         @Subscribe
 425         public void nicknameChanged(NicknameChanged nicknameChanged) {
 426                 Optional<Network> network = getNetwork(nicknameChanged.connection());
 427                 if (!network.isPresent()) {
 428                         return;
 429                 }
 430
 431                 Bot bot = networkBots.remove(network.get(), nicknameChanged.client().nick().get());
 432                 if (bot == null) {
 433                         return;
 434                 }
 435
 436                 networkBots.put(network.get(), nicknameChanged.newNickname(), bot);
 437         }
 438
 439         /**
 440          * If a message on a channel is received, it is parsed for pack information
 441          * with is then added to a bot.
 442          *
 443          * @param channelMessageReceived
 444          *              The channel message received event
 445          */
 446         @Subscribe
 447         public void channelMessageReceived(ChannelMessageReceived channelMessageReceived) {
 448                 String message = MessageCleaner.getDefaultInstance().clean(channelMessageReceived.message());
 449                 if (!message.startsWith("#")) {
 450                         /* most probably not a pack announcement. */
 451                         return;
 452                 }
 453
 454                 Optional<Network> network = getNetwork(channelMessageReceived.connection());
 455                 if (!network.isPresent()) {
 456                         /* message for unknown connection? */
 457                         return;
 458                 }
 459
 460                 /* parse pack information. */
 461                 Optional<Pack> pack = parsePack(message);
 462                 if (!pack.isPresent()) {
 463                         return;
 464                 }
 465
 466                 Bot bot;
 467                 synchronized (networkBots) {
 468                         if (!networkBots.contains(network.get(), channelMessageReceived.source().nick().get())) {
 469                                 bot = new Bot(network.get()).name(channelMessageReceived.source().nick().get());
 470                                 networkBots.put(network.get(), channelMessageReceived.source().nick().get(), bot);
 471                                 eventBus.post(new BotAdded(bot));
 472                         } else {
 473                                 bot = networkBots.get(network.get(), channelMessageReceived.source().nick().get());
 474                         }
 475                 }
 476
 477                 /* add pack. */
 478                 bot.addPack(pack.get());
 479                 logger.fine(String.format("Bot %s now has %d packs.", bot, bot.packs().size()));
 480         }
 481
 482         /**
 483          * Forward all private messages to every console.
 484          *
 485          * @param privateMessageReceived
 486          *              The private message recevied event
 487          */
 488         @Subscribe
 489         public void privateMessageReceived(PrivateMessageReceived privateMessageReceived) {
 490                 eventBus.post(new MessageReceived(privateMessageReceived.source(), privateMessageReceived.message()));
 491         }
 492
 493         /**
 494          * Starts a DCC download.
 495          *
 496          * @param dccSendReceived
 497          *              The DCC SEND event
 498          */
 499         @Subscribe
 500         public void dccSendReceived(DccSendReceived dccSendReceived) {
 501                 Optional<Network> network = getNetwork(dccSendReceived.connection());
 502                 if (!network.isPresent()) {
 503                         return;
 504                 }
 505
 506                 Download download = downloads.get(dccSendReceived.filename());
 507                 if (download == null) {
 508                         /* unknown download, ignore. */
 509                         return;
 510                 }
 511
 512                 /* check if the file already exists. */
 513                 File outputFile = new File(temporaryDirectory, dccSendReceived.filename());
 514                 if (outputFile.exists()) {
 515                         long existingFileSize = outputFile.length();
 516
 517                         /* file already complete? */
 518                         if ((dccSendReceived.filesize() > -1) && (existingFileSize >= dccSendReceived.filesize())) {
 519                                 /* file is apparently already complete. just move it. */
 520                                 if (outputFile.renameTo(new File(finalDirectory, download.pack().name()))) {
 521                                         eventBus.post(new GenericMessage(String.format("File %s already downloaded.", download.pack().name())));
 522                                 } else {
 523                                         eventBus.post(new GenericMessage(String.format("File %s already downloaded but not moved to %s.", download.pack().name(), finalDirectory)));
 524                                 }
 525
 526                                 /* remove download. */
 527                                 downloads.remove(download);
 528                                 return;
 529                         }
 530
 531                         /* file not complete yet, DCC resume it. */
 532                         try {
 533                                 download.remoteAddress(dccSendReceived.inetAddress()).filesize(dccSendReceived.filesize());
 534                                 dccSendReceived.connection().sendDccResume(dccSendReceived.source().nick().get(), dccSendReceived.filename(), dccSendReceived.port(), existingFileSize);
 535                         } catch (IOException ioe1) {
 536                                 eventBus.post(new GenericError(String.format("Could not send DCC RESUME %s to %s (%s).", dccSendReceived.filename(), dccSendReceived.source().nick().get(), ioe1.getMessage())));
 537                         }
 538
 539                         return;
 540                 }
 541
 542                 /* file does not exist, start the download. */
 543                 try {
 544                         OutputStream fileOutputStream = new FileOutputStream(outputFile);
 545                         DccReceiver dccReceiver = new DccReceiver(eventBus, dccSendReceived.inetAddress(), dccSendReceived.port(), dccSendReceived.filename(), dccSendReceived.filesize(), fileOutputStream);
 546                         download.filename(outputFile.getPath()).outputStream(fileOutputStream).dccReceiver(dccReceiver);
 547                         dccReceivers.add(dccReceiver);
 548                         dccReceiver.start();
 549                         eventBus.post(new DownloadStarted(download));
 550                 } catch (FileNotFoundException fnfe1) {
 551                         eventBus.post(new GenericError(String.format("Could not start download of %s from %s (%s).", dccSendReceived.filename(), dccSendReceived.source().nick().get(), fnfe1.getMessage())));
 552                 }
 553         }
 554
 555         @Subscribe
 556         public void dccAcceptReceived(DccAcceptReceived dccAcceptReceived) {
 557                 Optional<Network> network = getNetwork(dccAcceptReceived.connection());
 558                 if (!network.isPresent()) {
 559                         return;
 560                 }
 561
 562                 Download download = downloads.get(dccAcceptReceived.filename());
 563                 if (download == null) {
 564                         /* unknown download, ignore. */
 565                         return;
 566                 }
 567
 568                 try {
 569                         File outputFile = new File(temporaryDirectory, dccAcceptReceived.filename());
 570                         if (outputFile.length() != dccAcceptReceived.position()) {
 571                                 eventBus.post(new GenericError(String.format("Download %s from %s does not start at the right position!")));
 572                                 logger.log(Level.WARNING, String.format("Download %s from %s: have %d bytes but wants to resume from %d!", dccAcceptReceived.filename(), dccAcceptReceived.source(), outputFile.length(), dccAcceptReceived.position()));
 573
 574                                 downloads.remove(download);
 575                                 return;
 576                         }
 577                         OutputStream outputStream = new FileOutputStream(outputFile, true);
 578                         DccReceiver dccReceiver = new DccReceiver(eventBus, download.remoteAddress(), dccAcceptReceived.port(), dccAcceptReceived.filename(), dccAcceptReceived.position(), download.filesize(), outputStream);
 579                         download.filename(outputFile.getPath()).outputStream(outputStream).dccReceiver(dccReceiver);
 580                         dccReceivers.add(dccReceiver);
 581                         dccReceiver.start();
 582                         eventBus.post(new DownloadStarted(download));
 583                 } catch (FileNotFoundException fnfe1) {
 584                 }
 585         }
 586
 587         /**
 588          * Closes the output stream of the download and moves the file to the final
 589          * location.
 590          *
 591          * @param dccDownloadFinished
 592          *              The DCC download finished event
 593          */
 594         @Subscribe
 595         public void dccDownloadFinished(DccDownloadFinished dccDownloadFinished) {
 596                 Download download = downloads.get(dccDownloadFinished.dccReceiver().filename());
 597                 if (download == null) {
 598                         /* probably shouldn’t happen. */
 599                         return;
 600                 }
 601
 602                 try {
 603                         download.outputStream().close();
 604                         File file = new File(download.filename());
 605                         file.renameTo(new File(finalDirectory, download.pack().name()));
 606                         eventBus.post(new DownloadFinished(download));
 607                         dccReceivers.remove(dccDownloadFinished.dccReceiver());
 608                         downloads.remove(download);
 609                 } catch (IOException ioe1) {
 610                         /* TODO - handle all the errors. */
 611                         logger.log(Level.WARNING, String.format("Could not move file %s to directory %s.", download.filename(), finalDirectory), ioe1);
 612                 }
 613         }
 614
 615         /**
 616          * Closes the output stream and notifies all listeners of the failure.
 617          *
 618          * @param dccDownloadFailed
 619          *              The DCC download failed event
 620          */
 621         @Subscribe
 622         public void dccDownloadFailed(DccDownloadFailed dccDownloadFailed) {
 623                 Download download = downloads.get(dccDownloadFailed.dccReceiver().filename());
 624                 if (download == null) {
 625                         /* probably shouldn’t happen. */
 626                         return;
 627                 }
 628
 629                 try {
 630                         Closeables.close(download.outputStream(), true);
 631                         eventBus.post(new DownloadFailed(download));
 632                         dccReceivers.remove(dccDownloadFailed.dccReceiver());
 633                         downloads.remove(download);
 634                 } catch (IOException ioe1) {
 635                         /* swallow silently. */
 636                 }
 637         }
 638
 639         //
 640         // PRIVATE METHODS
 641         //
 642
 643         /**
 644          * Searches all current connections for the given connection, returning the
 645          * associated network.
 646          *
 647          * @param connection
 648          *              The connection to get the network for
 649          * @return The network belonging to the connection, or {@link
 650          *         Optional#absent()}
 651          */
 652         private Optional<Network> getNetwork(Connection connection) {
 653                 for (Entry<Network, Connection> networkConnectionEntry : networkConnections.entrySet()) {
 654                         if (networkConnectionEntry.getValue().equals(connection)) {
 655                                 return Optional.of(networkConnectionEntry.getKey());
 656                         }
 657                 }
 658                 return Optional.absent();
 659         }
 660
 661         /**
 662          * Returns the configured channel for the given network and name.
 663          *
 664          * @param network
 665          *              The network the channel is located on
 666          * @param channelName
 667          *              The name of the channel
 668          * @return The configured channel, or {@link Optional#absent()} if no
 669          *         configured channel matching the given network and name was found
 670          */
 671         public Optional<Channel> getChannel(Network network, String channelName) {
 672                 for (Channel channel : channels) {
 673                         if (channel.network().equals(network) && (channel.name().equalsIgnoreCase(channelName))) {
 674                                 return Optional.of(channel);
 675                         }
 676                 }
 677                 return Optional.absent();
 678         }
 679
 680         /**
 681          * Returns the extra channel for the given network and name.
 682          *
 683          * @param network
 684          *              The network the channel is located on
 685          * @param channelName
 686          *              The name of the channel
 687          * @return The extra channel, or {@link Optional#absent()} if no extra channel
 688          *         matching the given network and name was found
 689          */
 690         public Optional<Channel> getExtraChannel(Network network, String channelName) {
 691                 for (Channel channel : extraChannels) {
 692                         if (channel.network().equals(network) && (channel.name().equalsIgnoreCase(channelName))) {
 693                                 return Optional.of(channel);
 694                         }
 695                 }
 696                 return Optional.absent();
 697         }
 698
 699         /**
 700          * Parses {@link Pack} information from the given message.
 701          *
 702          * @param message
 703          *              The message to parse pack information from
 704          * @return The parsed pack, or {@link Optional#absent()} if the message could
 705          *         not be parsed into a pack
 706          */
 707         private Optional<Pack> parsePack(String message) {
 708                 int squareOpen = message.indexOf('[');
 709                 int squareClose = message.indexOf(']', squareOpen);
 710                 if ((squareOpen == -1) && (squareClose == -1)) {
 711                         return Optional.absent();
 712                 }
 713                 String packSize = message.substring(squareOpen + 1, squareClose);
 714                 String packName = message.substring(message.lastIndexOf(' ') + 1);
 715                 String packIndex = message.substring(0, message.indexOf(' ')).substring(1);
 716                 return Optional.of(new Pack(packIndex, packSize, packName));
 717         }
 718
 719 }