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