Show timestamp of next connect attempt.
[xudocci.git] / src / main / java / net / pterodactylus / xdcc / core / Core.java
index 248f765..d39ee2b 100644 (file)
 
 package net.pterodactylus.xdcc.core;
 
+import static java.lang.String.format;
+import static net.pterodactylus.irc.event.ChannelNotJoined.Reason.banned;
+import static net.pterodactylus.irc.event.ChannelNotJoined.Reason.inviteOnly;
+import static net.pterodactylus.irc.event.ChannelNotJoined.Reason.registeredNicknamesOnly;
+import static net.pterodactylus.irc.util.MessageCleaner.getDefaultInstance;
+import static net.pterodactylus.xdcc.data.Channel.TO_NETWORK;
+import static net.pterodactylus.xdcc.data.Download.FILTER_RUNNING;
+
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
@@ -24,62 +32,91 @@ import java.io.IOException;
 import java.io.OutputStream;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.HashSet;
+import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
-import java.util.logging.Level;
-import java.util.logging.Logger;
+import java.util.Set;
+import java.util.TreeMap;
+import java.util.concurrent.TimeUnit;
+import java.util.function.Function;
+import java.util.stream.Collectors;
 
 import net.pterodactylus.irc.Connection;
-import net.pterodactylus.irc.ConnectionBuilder;
+import net.pterodactylus.irc.ConnectionFactory;
 import net.pterodactylus.irc.DccReceiver;
+import net.pterodactylus.irc.DefaultConnection;
 import net.pterodactylus.irc.event.ChannelJoined;
+import net.pterodactylus.irc.event.ChannelLeft;
 import net.pterodactylus.irc.event.ChannelMessageReceived;
+import net.pterodactylus.irc.event.ChannelNotJoined;
+import net.pterodactylus.irc.event.ClientQuit;
+import net.pterodactylus.irc.event.ConnectionClosed;
 import net.pterodactylus.irc.event.ConnectionEstablished;
+import net.pterodactylus.irc.event.ConnectionFailed;
+import net.pterodactylus.irc.event.DccAcceptReceived;
 import net.pterodactylus.irc.event.DccDownloadFailed;
 import net.pterodactylus.irc.event.DccDownloadFinished;
 import net.pterodactylus.irc.event.DccSendReceived;
+import net.pterodactylus.irc.event.KickedFromChannel;
+import net.pterodactylus.irc.event.NicknameChanged;
 import net.pterodactylus.irc.event.PrivateMessageReceived;
-import net.pterodactylus.irc.util.MessageCleaner;
+import net.pterodactylus.irc.event.PrivateNoticeReceived;
+import net.pterodactylus.irc.event.ReplyReceived;
 import net.pterodactylus.irc.util.RandomNickname;
 import net.pterodactylus.xdcc.core.event.BotAdded;
 import net.pterodactylus.xdcc.core.event.CoreStarted;
 import net.pterodactylus.xdcc.core.event.DownloadFailed;
 import net.pterodactylus.xdcc.core.event.DownloadFinished;
 import net.pterodactylus.xdcc.core.event.DownloadStarted;
+import net.pterodactylus.xdcc.core.event.GenericError;
+import net.pterodactylus.xdcc.core.event.GenericMessage;
 import net.pterodactylus.xdcc.core.event.MessageReceived;
 import net.pterodactylus.xdcc.data.Bot;
 import net.pterodactylus.xdcc.data.Channel;
+import net.pterodactylus.xdcc.data.ConnectedNetwork;
 import net.pterodactylus.xdcc.data.Download;
 import net.pterodactylus.xdcc.data.Network;
 import net.pterodactylus.xdcc.data.Pack;
 import net.pterodactylus.xdcc.data.Server;
 
 import com.google.common.base.Optional;
+import com.google.common.base.Predicate;
+import com.google.common.collect.FluentIterable;
 import com.google.common.collect.HashBasedTable;
+import com.google.common.collect.HashMultimap;
+import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
+import com.google.common.collect.Multimap;
 import com.google.common.collect.Sets;
 import com.google.common.collect.Table;
 import com.google.common.eventbus.EventBus;
 import com.google.common.eventbus.Subscribe;
 import com.google.common.io.Closeables;
-import com.google.common.util.concurrent.AbstractIdleService;
+import com.google.common.util.concurrent.AbstractExecutionThreadService;
 import com.google.inject.Inject;
+import org.apache.log4j.Logger;
 
 /**
  * The core of XDCC Downloader.
  *
  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  */
-public class Core extends AbstractIdleService {
+public class Core extends AbstractExecutionThreadService {
 
        /** The logger. */
        private static final Logger logger = Logger.getLogger(Core.class.getName());
 
+       private final Object syncObject = new Object();
        /** The event bus. */
        private final EventBus eventBus;
+       private final ConnectionFactory connectionFactory;
+       private final ChannelBanManager channelBanManager =
+                       new ChannelBanManager();
+       private final ConnectionBackoff connectionBackoff = new ConnectionBackoff();
 
        /** The temporary directory to download files to. */
        private final String temporaryDirectory;
@@ -92,6 +129,7 @@ public class Core extends AbstractIdleService {
 
        /** The channels that are currentlymonitored. */
        private final Collection<Channel> joinedChannels = Sets.newHashSet();
+       private final Set<Channel> channelsBeingJoined = new HashSet<>();
 
        /** The channels that are joined but not configured. */
        private final Collection<Channel> extraChannels = Sets.newHashSet();
@@ -103,10 +141,10 @@ public class Core extends AbstractIdleService {
        private final Table<Network, String, Bot> networkBots = HashBasedTable.create();
 
        /** The current downloads. */
-       private final Map<String, Download> downloads = Maps.newHashMap();
+       private final Multimap<String, Download> downloads = HashMultimap.create();
 
        /** The current DCC receivers. */
-       private final Collection<DccReceiver> dccReceivers = Sets.newHashSet();
+       private final Collection<DccReceiver> dccReceivers = Lists.newArrayList();
 
        /**
         * Creates a new core.
@@ -119,8 +157,9 @@ public class Core extends AbstractIdleService {
         *              The directory to move finished files to
         */
        @Inject
-       public Core(EventBus eventBus, String temporaryDirectory, String finalDirectory) {
+       public Core(EventBus eventBus, ConnectionFactory connectionFactory, String temporaryDirectory, String finalDirectory) {
                this.eventBus = eventBus;
+               this.connectionFactory = connectionFactory;
                this.temporaryDirectory = temporaryDirectory;
                this.finalDirectory = finalDirectory;
        }
@@ -130,6 +169,50 @@ public class Core extends AbstractIdleService {
        //
 
        /**
+        * Returns all currently known connections.
+        *
+        * @return All currently known connections
+        */
+       public Collection<Connection> connections() {
+               return networkConnections.values();
+       }
+
+       /**
+        * Returns all defined networks.
+        *
+        * @return All defined networks
+        */
+       public Collection<Network> networks() {
+               return FluentIterable.from(channels).transform(TO_NETWORK).toSet();
+       }
+
+       /**
+        * Returns all connected networks.
+        *
+        * @return All connected networks
+        */
+       public Collection<ConnectedNetwork> connectedNetworks() {
+               return networkConnections.entrySet().stream().map((entry) -> {
+                       Network network = entry.getKey();
+                       Collection<Bot> bots = networkBots.row(network).values();
+                       int packCount = bots.stream().mapToInt((bot) -> bot.packs().size()).reduce((a, b) -> a + b).orElse(0);
+                       return new ConnectedNetwork(network, entry.getValue().hostname(),
+                                       entry.getValue().port(), entry.getValue().nickname(),
+                                       channels.stream()
+                                                       .filter((channel) -> channel.network()
+                                                                       .equals(network))
+                                                       .map(Channel::name)
+                                                       .collect(Collectors.<String>toList()),
+                                       extraChannels.stream()
+                                                       .filter((channel) -> channel.network()
+                                                                       .equals(network))
+                                                       .map(Channel::name)
+                                                       .collect(Collectors.<String>toList()),
+                                       bots.size(), packCount);
+               }).collect(Collectors.<ConnectedNetwork>toList());
+       }
+
+       /**
         * Returns all configured channels. Due to various circumstances, configured
         * channels might not actually be joined.
         *
@@ -167,12 +250,12 @@ public class Core extends AbstractIdleService {
        }
 
        /**
-        * Returns the currently active DCC receivers.
+        * Returns all currently running downloads.
         *
-        * @return The currently active DCC receivers
+        * @return All currently running downloads
         */
-       public Collection<DccReceiver> dccReceivers() {
-               return dccReceivers;
+       public Collection<Download> downloads() {
+               return downloads.values();
        }
 
        //
@@ -203,13 +286,83 @@ public class Core extends AbstractIdleService {
                        return;
                }
 
+               /* check if we are already downloading the file? */
+               if (downloads.containsKey(pack.name())) {
+                       Collection<Download> packDownloads = downloads.get(pack.name());
+                       Collection<Download> runningDownloads = FluentIterable.from(packDownloads).filter(FILTER_RUNNING).toSet();
+                       if (!runningDownloads.isEmpty()) {
+                               Download download = runningDownloads.iterator().next();
+                               eventBus.post(new GenericMessage(String.format("File %s is already downloading from %s (%s).", pack.name(), download.bot().name(), download.bot().network().name())));
+                               return;
+                       }
+                       StringBuilder bots = new StringBuilder();
+                       for (Download download : packDownloads) {
+                               if (bots.length() > 0) {
+                                       bots.append(", ");
+                               }
+                               bots.append(download.bot().name()).append(" (").append(download.bot().network().name()).append(')');
+                       }
+                       eventBus.post(new GenericMessage(String.format("File %s is already requested from %d bots (%s).", pack.name(), packDownloads.size(), bots.toString())));
+               }
+
                Download download = new Download(bot, pack);
                downloads.put(pack.name(), download);
 
                try {
                        connection.sendMessage(bot.name(), "XDCC SEND " + pack.id());
                } catch (IOException ioe1) {
-                       logger.log(Level.WARNING, "Could not send message to bot!", ioe1);
+                       logger.warn("Could not send message to bot!", ioe1);
+               }
+       }
+
+       /**
+        * Cancels the download of the given pack from the given bot.
+        *
+        * @param bot
+        *              The bot the pack is being downloaded from
+        * @param pack
+        *              The pack being downloaded
+        */
+       public void cancelDownload(Bot bot, Pack pack) {
+               Optional<Download> download = getDownload(pack, bot);
+               if (!download.isPresent()) {
+                       return;
+               }
+
+               /* get connection. */
+               Connection connection = networkConnections.get(bot.network());
+               if (connection == null) {
+                       /* request for unknown network? */
+                       return;
+               }
+
+               /* stop the DCC receiver. */
+               if (download.get().dccReceiver() != null) {
+                       download.get().dccReceiver().stop();
+               } else {
+                       /* remove download if it hasn’t started yet. */
+                       downloads.remove(pack.name(), download.get());
+               }
+
+               /* remove the request from the bot, too. */
+               try {
+                       connection.sendMessage(bot.name(), String.format("XDCC %s", (download.get().dccReceiver() != null) ? "CANCEL" : "REMOVE"));
+               } catch (IOException ioe1) {
+                       logger.warn(String.format("Could not cancel DCC from %s (%s)!", bot.name(), bot.network().name()), ioe1);
+               }
+       }
+
+       /**
+        * Closes the given connection.
+        *
+        * @param connection
+        *              The connection to close
+        */
+       public void closeConnection(Connection connection) {
+               try {
+                       connection.close();
+               } catch (IOException ioe1) {
+                       /* TODO */
                }
        }
 
@@ -221,15 +374,7 @@ public class Core extends AbstractIdleService {
        protected void startUp() {
                for (Channel channel : channels) {
                        logger.info(String.format("Connecting to Channel %s on Network %s…", channel.name(), channel.network().name()));
-                       if (!networkConnections.containsKey(channel.network())) {
-                               /* select a random server. */
-                               List<Server> servers = Lists.newArrayList(channel.network().servers());
-                               Server server = servers.get((int) (Math.random() * servers.size()));
-                               Connection connection = new ConnectionBuilder(eventBus).connect(server.hostname()).port(server.unencryptedPorts().iterator().next()).build();
-                               connection.username(RandomNickname.get()).realName(RandomNickname.get());
-                               networkConnections.put(channel.network(), connection);
-                               connection.start();
-                       }
+                       connectNetwork(channel.network());
                }
 
                /* notify listeners. */
@@ -237,7 +382,152 @@ public class Core extends AbstractIdleService {
        }
 
        @Override
-       protected void shutDown() {
+       protected void run() throws Exception {
+               while (isRunning()) {
+
+                       Set<Channel> missingChannels = new HashSet<>();
+                       for (Channel channel : channels) {
+                               if (joinedChannels.contains(channel) || channelsBeingJoined.contains(channel)) {
+                                       continue;
+                               }
+                               if (channelBanManager.isBanned(channel)) {
+                                       continue;
+                               }
+                               if (!networkConnections.containsKey(channel.network()) || networkConnections.get(channel.network()).established()) {
+                                       missingChannels.add(channel);
+                               }
+                       }
+                       Set<Network> missingNetworks = missingChannels.stream()
+                                       .map(Channel::network)
+                                       .distinct()
+                                       .filter((network) -> !networkConnections.containsKey(network))
+                                       .collect(Collectors.toSet());
+
+                       if (missingNetworks.isEmpty()) {
+                               if (!missingChannels.isEmpty()) {
+                                       for (Channel missingChannel : missingChannels) {
+                                               Network network = missingChannel.network();
+                                               eventBus.post(new GenericMessage(String.format("Trying to join %s on %s...", missingChannel.name(), network)));
+                                               try {
+                                                       channelsBeingJoined.add(missingChannel);
+                                                       networkConnections.get(network).joinChannel(missingChannel.name());
+                                               } catch (IOException ioe1) {
+                                                       logger.warn(String.format("Could not join %s on %s!", missingChannel.name(), network.name()), ioe1);
+                                               }
+                                       }
+                               } else {
+                                       synchronized (syncObject) {
+                                               try {
+                                                       syncObject.wait(TimeUnit.MINUTES.toMillis(1));
+                                               } catch (InterruptedException ie1) {
+                                               /* ignore. */
+                                               }
+                                       }
+                               }
+                               continue;
+                       }
+
+                       Map<Long, Network> timesForNextConnects = new TreeMap<>(missingNetworks.stream()
+                                       .collect(Collectors.toMap(connectionBackoff::getConnectionTime, Function.identity(), (network, ignore) -> network)));
+
+                       Optional<Entry<Long, Network>> firstNetwork = Optional.fromNullable(timesForNextConnects.entrySet().stream().findFirst().orElse(null));
+                       if (!firstNetwork.isPresent()) {
+                               continue;
+                       }
+                       if (firstNetwork.get().getKey() > System.currentTimeMillis()) {
+                               eventBus.post(new GenericMessage(String.format("Will connect to %2$s at %1$tH:%1$tM...", firstNetwork.get().getKey(), firstNetwork.get().getValue().name())));
+                               synchronized (syncObject) {
+                                       try {
+                                               syncObject.wait(firstNetwork.get().getKey() - System.currentTimeMillis());
+                                       } catch (InterruptedException ie1) {
+                                               /* ignore. */
+                                       }
+                               }
+                               if (!isRunning()) {
+                                       break;
+                               }
+                               if (firstNetwork.get().getKey() > System.currentTimeMillis()) {
+                                       continue;
+                               }
+                       }
+
+                       connectNetwork(firstNetwork.get().getValue());
+               }
+       }
+
+       @Override
+       protected void triggerShutdown() {
+               synchronized (syncObject) {
+                       syncObject.notifyAll();
+               }
+       }
+
+       //
+       // PRIVATE METHODS
+       //
+
+       /**
+        * Starts a new connection for the given network if no such connection exists
+        * already.
+        *
+        * @param network
+        *              The network to connect to
+        */
+       private void connectNetwork(Network network) {
+               if (!networkConnections.containsKey(network)) {
+                               /* select a random server. */
+                       List<Server> servers = Lists.newArrayList(network.servers());
+                       if (servers.isEmpty()) {
+                               eventBus.post(new GenericError(String.format("Network %s does not have any servers.", network.name())));
+                               return;
+                       }
+                       Server server = servers.get((int) (Math.random() * servers.size()));
+                       eventBus.post(new GenericMessage(String.format("Connecting to %s on %s...", network.name(), server.hostname())));
+                       Connection connection = connectionFactory.createConnection(server.hostname(),
+                                       server.unencryptedPorts().iterator().next());
+                       connection.username(RandomNickname.get()).realName(RandomNickname.get());
+                       networkConnections.put(network, connection);
+                       connection.open();
+               }
+       }
+
+       /**
+        * Removes the given connection and all its channels and bots.
+        *
+        * @param connection
+        *              The connection to remove
+        */
+       private void removeConnection(Connection connection) {
+               Optional<Network> network = getNetwork(connection);
+               if (!network.isPresent()) {
+                       return;
+               }
+               networkConnections.remove(network.get());
+               if (!connection.established()) {
+                       return;
+               }
+
+               /* find all channels that need to be removed. */
+               for (Collection<Channel> channels : ImmutableList.of(joinedChannels, extraChannels)) {
+                       for (Iterator<Channel> channelIterator = channels.iterator(); channelIterator.hasNext(); ) {
+                               Channel joinedChannel = channelIterator.next();
+                               if (!joinedChannel.network().equals(network.get())) {
+                                       continue;
+                               }
+
+                               channelIterator.remove();
+                       }
+               }
+
+               /* now remove all bots for that network. */
+               Map<String, Bot> bots = networkBots.row(network.get());
+               int botCount = bots.size();
+               int packCount = 0;
+               for (Bot bot : bots.values()) {
+                       packCount += bot.packs().size();
+               }
+               bots.clear();
+               eventBus.post(new GenericMessage(String.format("Network %s disconnected, %d bots removed, %d packs removed.", network.get().name(), botCount, packCount)));
        }
 
        //
@@ -259,22 +549,59 @@ public class Core extends AbstractIdleService {
 
                /* found network? */
                if (!network.isPresent()) {
+                       eventBus.post(new GenericMessage(String.format("Connected to unknown network: %s", connectionEstablished.connection().hostname())));
                        return;
                }
 
+               connectionBackoff.connectionSuccessful(network.get());
+               eventBus.post(new GenericMessage(String.format("Connected to network %s.", network.get().name())));
+
                /* join all channels on this network. */
                for (Channel channel : channels) {
                        if (channel.network().equals(network.get())) {
                                try {
+                                       eventBus.post(new GenericMessage(String.format("Trying to join %s on %s...", channel.name(), network.get().name())));
                                        connectionEstablished.connection().joinChannel(channel.name());
                                } catch (IOException ioe1) {
-                                       logger.log(Level.WARNING, String.format("Could not join %s on %s!", channel.name(), network.get().name()), ioe1);
+                                       logger.warn(String.format("Could not join %s on %s!", channel.name(), network.get().name()), ioe1);
                                }
                        }
                }
        }
 
        /**
+        * Remove all data stored for a network if the connection is closed.
+        *
+        * @param connectionClosed
+        *              The connection closed event
+        */
+       @Subscribe
+       public void connectionClosed(ConnectionClosed connectionClosed) {
+               connectionBackoff.connectionFailed(getNetwork(connectionClosed.connection()).get());
+               removeConnection(connectionClosed.connection());
+               synchronized (syncObject) {
+                       syncObject.notifyAll();
+               }
+               eventBus.post(new GenericMessage(String.format("Connection closed by %s.", connectionClosed.connection().hostname())));
+       }
+
+       /**
+        * Remove all data stored for a network if the connection fails.
+        *
+        * @param connectionFailed
+        *              The connection failed event
+        */
+       @Subscribe
+       public void connectionFailed(ConnectionFailed connectionFailed) {
+               connectionBackoff.connectionFailed(getNetwork(connectionFailed.connection()).get());
+               removeConnection(connectionFailed.connection());
+               synchronized (syncObject) {
+                       syncObject.notifyAll();
+               }
+               eventBus.post(new GenericMessage(String.format("Could not connect to %s: %s.", connectionFailed.connection().hostname(), connectionFailed.cause())));
+       }
+
+       /**
         * Shows a message when a channel was joined by us.
         *
         * @param channelJoined
@@ -296,11 +623,179 @@ public class Core extends AbstractIdleService {
                                return;
                        }
 
+                       channelBanManager.unban(channel.get());
                        joinedChannels.add(channel.get());
+                       channelsBeingJoined.remove(channel.get());
                        logger.info(String.format("Joined Channel %s on %s.", channelJoined.channel(), network.get().name()));
                }
        }
 
+       @Subscribe
+       public void channelNotJoined(ChannelNotJoined channelNotJoined) {
+               Optional<Network> network = getNetwork(channelNotJoined.connection());
+               if (!network.isPresent()) {
+                       return;
+               }
+
+               Optional<Channel> channel = getChannel(network.get(), channelNotJoined.channel());
+               synchronized (syncObject) {
+                       syncObject.notifyAll();
+               }
+               if (!channel.isPresent()) {
+                       eventBus.post(new GenericMessage(format("Could not join %s but didn’t try to join, either.", channelNotJoined.channel())));
+                       return;
+               }
+               channelsBeingJoined.remove(channel.get());
+
+
+               /* remove all bots for this channel, we might have been kicked. */
+               Collection<Bot> botsToRemove = networkBots.row(network.get())
+                               .values().stream()
+                               .filter(bot -> bot.channel()
+                                               .equalsIgnoreCase(channel.get().name()))
+                               .collect(Collectors.toSet());
+               botsToRemove.stream()
+                               .forEach(bot -> networkBots.row(network.get())
+                                               .remove(bot.name()));
+
+               channelBanManager.ban(channel.get());
+               if (channelNotJoined.reason() == registeredNicknamesOnly) {
+                       eventBus.post(new GenericMessage(
+                                       format("Not trying to join %s anymore.", channel.get())));
+               } else if (channelNotJoined.reason() == inviteOnly) {
+                       eventBus.post(new GenericMessage(
+                                       format("%s is invite-only, suspending join for a day.",
+                                                       channel.get())));
+               } else if (channelNotJoined.reason() == banned) {
+                       eventBus.post(new GenericMessage(
+                                       format("Banned from %s, suspending join for a day.",
+                                                       channel.get())));
+               } else {
+                       eventBus.post(new GenericMessage(
+                                       format("Could not join %s: %s", channelNotJoined.channel(),
+                                                       channelNotJoined.reason())));
+               }
+       }
+
+       /**
+        * Removes bots that leave a channel, or channels when it’s us that’s leaving.
+        *
+        * @param channelLeft
+        *              The channel left event
+        */
+       @Subscribe
+       public void channelLeft(ChannelLeft channelLeft) {
+               Optional<Network> network = getNetwork(channelLeft.connection());
+               if (!network.isPresent()) {
+                       return;
+               }
+
+               Bot bot = networkBots.get(network.get(), channelLeft.client().nick().get());
+               if (bot == null) {
+                       /* maybe it was us? */
+                       if (channelLeft.connection().isSource(channelLeft.client())) {
+                               Optional<Channel> channel = getChannel(network.get(), channelLeft.channel());
+                               if (!channel.isPresent()) {
+                                       /* maybe it was an extra channel? */
+                                       channel = getExtraChannel(network.get(), channelLeft.channel());
+                                       if (!channel.isPresent()) {
+                                               /* okay, whatever. */
+                                               return;
+                                       }
+
+                                       extraChannels.remove(channel);
+                               } else {
+                                       channels.remove(channel.get());
+                               }
+                               synchronized (syncObject) {
+                                       syncObject.notifyAll();
+                               }
+
+                               eventBus.post(new GenericMessage(String.format("Left Channel %s on %s.", channel.get().name(), channel.get().network().name())));
+                       }
+
+                       return;
+               }
+
+               networkBots.remove(network.get(), channelLeft.client().nick().get());
+       }
+
+       @Subscribe
+       public void kickedFromChannel(KickedFromChannel kickedFromChannel) {
+               Optional<Network> network = getNetwork(kickedFromChannel.connection());
+               if (!network.isPresent()) {
+                       return;
+               }
+
+               /* have we been kicked? */
+               if (nicknameMatchesConnection(kickedFromChannel.connection(), kickedFromChannel.kickee())) {
+                       Optional<Channel> channel = getChannel(network.get(), kickedFromChannel.channel());
+                       if (!channel.isPresent()) {
+                               /* maybe it was an extra channel? */
+                               channel = getExtraChannel(network.get(), kickedFromChannel.channel());
+                               if (!channel.isPresent()) {
+                                       /* okay, whatever. */
+                                       return;
+                               }
+
+                               extraChannels.remove(channel.get());
+                       } else {
+                               joinedChannels.remove(channel.get());
+                       }
+                       synchronized (syncObject) {
+                               syncObject.notifyAll();
+                       }
+                       eventBus.post(new GenericMessage(format(
+                                       "Kicked from %s by %s: %s",
+                                       kickedFromChannel.channel(),
+                                       kickedFromChannel.kicker(),
+                                       kickedFromChannel.reason().or("<unknown>")
+                       )));
+               }
+       }
+
+       private boolean nicknameMatchesConnection(Connection connection, String nickname) {
+               return connection.nickname().equalsIgnoreCase(nickname);
+       }
+
+       /**
+        * Removes a client (which may be a bot) from the table of known bots.
+        *
+        * @param clientQuit
+        *              The client quit event
+        */
+       @Subscribe
+       public void clientQuit(ClientQuit clientQuit) {
+               Optional<Network> network = getNetwork(clientQuit.connection());
+               if (!network.isPresent()) {
+                       return;
+               }
+
+               networkBots.remove(network.get(), clientQuit.client().nick().get());
+       }
+
+       /**
+        * If the nickname of a bit changes, remove it from the old name and store it
+        * under the new name.
+        *
+        * @param nicknameChanged
+        *              The nickname changed event
+        */
+       @Subscribe
+       public void nicknameChanged(NicknameChanged nicknameChanged) {
+               Optional<Network> network = getNetwork(nicknameChanged.connection());
+               if (!network.isPresent()) {
+                       return;
+               }
+
+               Bot bot = networkBots.remove(network.get(), nicknameChanged.client().nick().get());
+               if (bot == null) {
+                       return;
+               }
+
+               networkBots.put(network.get(), nicknameChanged.newNickname(), bot);
+       }
+
        /**
         * If a message on a channel is received, it is parsed for pack information
         * with is then added to a bot.
@@ -310,7 +805,7 @@ public class Core extends AbstractIdleService {
         */
        @Subscribe
        public void channelMessageReceived(ChannelMessageReceived channelMessageReceived) {
-               String message = MessageCleaner.getDefaultInstance().clean(channelMessageReceived.message());
+               String message = getDefaultInstance().clean(channelMessageReceived.message());
                if (!message.startsWith("#")) {
                        /* most probably not a pack announcement. */
                        return;
@@ -331,7 +826,8 @@ public class Core extends AbstractIdleService {
                Bot bot;
                synchronized (networkBots) {
                        if (!networkBots.contains(network.get(), channelMessageReceived.source().nick().get())) {
-                               bot = new Bot(network.get()).name(channelMessageReceived.source().nick().get());
+                               bot = new Bot(network.get(), channelMessageReceived.channel(),
+                                               channelMessageReceived.source().nick().get());
                                networkBots.put(network.get(), channelMessageReceived.source().nick().get(), bot);
                                eventBus.post(new BotAdded(bot));
                        } else {
@@ -341,7 +837,7 @@ public class Core extends AbstractIdleService {
 
                /* add pack. */
                bot.addPack(pack.get());
-               logger.fine(String.format("Bot %s now has %d packs.", bot, bot.packs().size()));
+               logger.debug(String.format("Bot %s now has %d packs.", bot, bot.packs().size()));
        }
 
        /**
@@ -356,27 +852,95 @@ public class Core extends AbstractIdleService {
        }
 
        /**
+        * Sends a message to all console when a notice was received.
+        *
+        * @param privateNoticeReceived
+        *              The notice received event
+        */
+       @Subscribe
+       public void privateNoticeReceived(PrivateNoticeReceived privateNoticeReceived) {
+               Optional<Network> network = getNetwork(privateNoticeReceived.connection());
+               if (!network.isPresent()) {
+                       return;
+               }
+
+               eventBus.post(new GenericMessage(String.format("Notice from %s (%s): %s", privateNoticeReceived.source(), network.get(), privateNoticeReceived.text())));
+       }
+
+       /**
         * Starts a DCC download.
         *
         * @param dccSendReceived
         *              The DCC SEND event
         */
        @Subscribe
-       public void dccSendReceived(DccSendReceived dccSendReceived) {
-               Optional<Network> network = getNetwork(dccSendReceived.connection());
+       public void dccSendReceived(final DccSendReceived dccSendReceived) {
+               final Optional<Network> network = getNetwork(dccSendReceived.connection());
                if (!network.isPresent()) {
                        return;
                }
 
-               Download download = downloads.get(dccSendReceived.filename());
-               if (download == null) {
+               Collection<Download> packDownloads = downloads.get(dccSendReceived.filename());
+               if (packDownloads.isEmpty()) {
                        /* unknown download, ignore. */
                        return;
                }
 
-               logger.info(String.format("Starting download of %s.", dccSendReceived.filename()));
+               /* check if it’s already downloading. */
+               Collection<Download> runningDownloads = FluentIterable.from(packDownloads).filter(FILTER_RUNNING).toSet();
+               if (!runningDownloads.isEmpty()) {
+                       eventBus.post(new GenericMessage(String.format("Ignoring offer for %s, it’s already being downloaded.", dccSendReceived.filename())));
+                       return;
+               }
+
+               /* locate the correct download. */
+               Collection<Download> requestedDownload = FluentIterable.from(packDownloads).filter(new Predicate<Download>() {
+
+                       @Override
+                       public boolean apply(Download download) {
+                               return download.bot().network().equals(network.get()) && download.bot().name().equalsIgnoreCase(dccSendReceived.source().nick().get());
+                       }
+               }).toSet();
+
+               /* we did not request this download. */
+               if (requestedDownload.isEmpty()) {
+                       return;
+               }
+
+               Download download = requestedDownload.iterator().next();
+
+               /* check if the file already exists. */
+               File outputFile = new File(temporaryDirectory, dccSendReceived.filename());
+               if (outputFile.exists()) {
+                       long existingFileSize = outputFile.length();
+
+                       /* file already complete? */
+                       if ((dccSendReceived.filesize() > -1) && (existingFileSize >= dccSendReceived.filesize())) {
+                               /* file is apparently already complete. just move it. */
+                               if (outputFile.renameTo(new File(finalDirectory, download.pack().name()))) {
+                                       eventBus.post(new GenericMessage(String.format("File %s already downloaded.", download.pack().name())));
+                               } else {
+                                       eventBus.post(new GenericMessage(String.format("File %s already downloaded but not moved to %s.", download.pack().name(), finalDirectory)));
+                               }
+
+                               /* remove download. */
+                               downloads.removeAll(download.pack().name());
+                               return;
+                       }
+
+                       /* file not complete yet, DCC resume it. */
+                       try {
+                               download.remoteAddress(dccSendReceived.inetAddress()).filesize(dccSendReceived.filesize());
+                               dccSendReceived.connection().sendDccResume(dccSendReceived.source().nick().get(), dccSendReceived.filename(), dccSendReceived.port(), existingFileSize);
+                       } catch (IOException ioe1) {
+                               eventBus.post(new GenericError(String.format("Could not send DCC RESUME %s to %s (%s).", dccSendReceived.filename(), dccSendReceived.source().nick().get(), ioe1.getMessage())));
+                       }
+
+                       return;
+               }
+
+               /* file does not exist, start the download. */
                try {
-                       File outputFile = new File(temporaryDirectory, dccSendReceived.filename());
                        OutputStream fileOutputStream = new FileOutputStream(outputFile);
                        DccReceiver dccReceiver = new DccReceiver(eventBus, dccSendReceived.inetAddress(), dccSendReceived.port(), dccSendReceived.filename(), dccSendReceived.filesize(), fileOutputStream);
                        download.filename(outputFile.getPath()).outputStream(fileOutputStream).dccReceiver(dccReceiver);
@@ -384,7 +948,62 @@ public class Core extends AbstractIdleService {
                        dccReceiver.start();
                        eventBus.post(new DownloadStarted(download));
                } catch (FileNotFoundException fnfe1) {
-                       logger.log(Level.WARNING, "Could not open file for download!", fnfe1);
+                       eventBus.post(new GenericError(String.format("Could not start download of %s from %s (%s).", dccSendReceived.filename(), dccSendReceived.source().nick().get(), fnfe1.getMessage())));
+               }
+       }
+
+       @Subscribe
+       public void dccAcceptReceived(final DccAcceptReceived dccAcceptReceived) {
+               final Optional<Network> network = getNetwork(dccAcceptReceived.connection());
+               if (!network.isPresent()) {
+                       return;
+               }
+
+               Collection<Download> packDownloads = downloads.get(dccAcceptReceived.filename());
+               if (packDownloads.isEmpty()) {
+                       /* unknown download, ignore. */
+                       return;
+               }
+
+               /* check if it’s already downloading. */
+               Collection<Download> runningDownloads = FluentIterable.from(packDownloads).filter(FILTER_RUNNING).toSet();
+               if (!runningDownloads.isEmpty()) {
+                       eventBus.post(new GenericMessage(String.format("Ignoring offer for %s, it’s already being downloaded.", dccAcceptReceived.filename())));
+                       return;
+               }
+
+               /* locate the correct download. */
+               Collection<Download> requestedDownload = FluentIterable.from(packDownloads).filter(new Predicate<Download>() {
+
+                       @Override
+                       public boolean apply(Download download) {
+                               return download.bot().network().equals(network.get()) && download.bot().name().equalsIgnoreCase(dccAcceptReceived.source().nick().get());
+                       }
+               }).toSet();
+
+               /* we did not request this download. */
+               if (requestedDownload.isEmpty()) {
+                       return;
+               }
+
+               Download download = requestedDownload.iterator().next();
+
+               try {
+                       File outputFile = new File(temporaryDirectory, dccAcceptReceived.filename());
+                       if (outputFile.length() != dccAcceptReceived.position()) {
+                               eventBus.post(new GenericError(String.format("Download %s from %s does not start at the right position!")));
+                               logger.warn(String.format("Download %s from %s: have %d bytes but wants to resume from %d!", dccAcceptReceived.filename(), dccAcceptReceived.source(), outputFile.length(), dccAcceptReceived.position()));
+
+                               downloads.removeAll(download.pack().name());
+                               return;
+                       }
+                       OutputStream outputStream = new FileOutputStream(outputFile, true);
+                       DccReceiver dccReceiver = new DccReceiver(eventBus, download.remoteAddress(), dccAcceptReceived.port(), dccAcceptReceived.filename(), dccAcceptReceived.position(), download.filesize(), outputStream);
+                       download.filename(outputFile.getPath()).outputStream(outputStream).dccReceiver(dccReceiver);
+                       dccReceivers.add(dccReceiver);
+                       dccReceiver.start();
+                       eventBus.post(new DownloadStarted(download));
+               } catch (FileNotFoundException fnfe1) {
                }
        }
 
@@ -397,11 +1016,15 @@ public class Core extends AbstractIdleService {
         */
        @Subscribe
        public void dccDownloadFinished(DccDownloadFinished dccDownloadFinished) {
-               Download download = downloads.get(dccDownloadFinished.dccReceiver().filename());
-               if (download == null) {
-                       /* probably shouldn’t happen. */
+
+               /* locate the correct download. */
+               Collection<Download> requestedDownload = FluentIterable.from(downloads.get(dccDownloadFinished.dccReceiver().filename())).filter(FILTER_RUNNING).toSet();
+               if (requestedDownload.isEmpty()) {
+                       /* this seems wrong. */
+                       logger.warn("Download finished but could not be located.");
                        return;
                }
+               Download download = requestedDownload.iterator().next();
 
                try {
                        download.outputStream().close();
@@ -409,9 +1032,10 @@ public class Core extends AbstractIdleService {
                        file.renameTo(new File(finalDirectory, download.pack().name()));
                        eventBus.post(new DownloadFinished(download));
                        dccReceivers.remove(dccDownloadFinished.dccReceiver());
+                       downloads.removeAll(download.pack().name());
                } catch (IOException ioe1) {
                        /* TODO - handle all the errors. */
-                       logger.log(Level.WARNING, String.format("Could not move file %s to directory %s.", download.filename(), finalDirectory), ioe1);
+                       logger.warn(String.format("Could not move file %s to directory %s.", download.filename(), finalDirectory), ioe1);
                }
        }
 
@@ -423,26 +1047,58 @@ public class Core extends AbstractIdleService {
         */
        @Subscribe
        public void dccDownloadFailed(DccDownloadFailed dccDownloadFailed) {
-               Download download = downloads.get(dccDownloadFailed.dccReceiver().filename());
-               if (download == null) {
-                       /* probably shouldn’t happen. */
+
+               /* locate the correct download. */
+               Collection<Download> requestedDownload = FluentIterable.from(downloads.get(dccDownloadFailed.dccReceiver().filename())).filter(FILTER_RUNNING).toSet();
+               if (requestedDownload.isEmpty()) {
+                       /* this seems wrong. */
+                       logger.warn("Download finished but could not be located.");
                        return;
                }
+               Download download = requestedDownload.iterator().next();
 
                try {
                        Closeables.close(download.outputStream(), true);
                        eventBus.post(new DownloadFailed(download));
                        dccReceivers.remove(dccDownloadFailed.dccReceiver());
+                       downloads.removeAll(download.pack().name());
                } catch (IOException ioe1) {
                        /* swallow silently. */
                }
        }
 
+       @Subscribe
+       public void replyReceived(ReplyReceived replyReceived) {
+               logger.trace(String.format("%s: %s", replyReceived.connection().hostname(), replyReceived.reply()));
+       }
+
        //
        // PRIVATE METHODS
        //
 
        /**
+        * Returns the download of the given pack from the given bot.
+        *
+        * @param pack
+        *              The pack being downloaded
+        * @param bot
+        *              The bot the pack is being downloaded from
+        * @return The download, or {@link Optional#absent()} if the download could not
+        *         be found
+        */
+       private Optional<Download> getDownload(Pack pack, Bot bot) {
+               if (!downloads.containsKey(pack.name())) {
+                       return Optional.absent();
+               }
+               for (Download download : Lists.newArrayList(downloads.get(pack.name()))) {
+                       if (download.bot().equals(bot)) {
+                               return Optional.of(download);
+                       }
+               }
+               return Optional.absent();
+       }
+
+       /**
         * Searches all current connections for the given connection, returning the
         * associated network.
         *
@@ -480,6 +1136,25 @@ public class Core extends AbstractIdleService {
        }
 
        /**
+        * Returns the extra channel for the given network and name.
+        *
+        * @param network
+        *              The network the channel is located on
+        * @param channelName
+        *              The name of the channel
+        * @return The extra channel, or {@link Optional#absent()} if no extra channel
+        *         matching the given network and name was found
+        */
+       public Optional<Channel> getExtraChannel(Network network, String channelName) {
+               for (Channel channel : extraChannels) {
+                       if (channel.network().equals(network) && (channel.name().equalsIgnoreCase(channelName))) {
+                               return Optional.of(channel);
+                       }
+               }
+               return Optional.absent();
+       }
+
+       /**
         * Parses {@link Pack} information from the given message.
         *
         * @param message