+package net.pterodactylus.irc.connection;
+
+import static com.google.common.base.Optional.absent;
+import static com.google.common.base.Optional.fromNullable;
+import static com.google.common.base.Optional.of;
+import static java.lang.String.format;
+import static java.net.InetAddress.getByName;
+import static org.apache.log4j.Logger.getLogger;
+
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+import java.util.List;
+
+import net.pterodactylus.irc.Connection;
+import net.pterodactylus.irc.Reply;
+import net.pterodactylus.irc.Source;
+import net.pterodactylus.irc.event.DccAcceptReceived;
+import net.pterodactylus.irc.event.DccSendReceived;
+
+import com.google.common.base.Optional;
+import com.google.common.eventbus.EventBus;
+import com.google.common.primitives.Ints;
+import com.google.common.primitives.Longs;
+import org.apache.log4j.Logger;
+
+/**
+ * Handles all CTCP messages relevant to DCC transfers.
+ *
+ * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
+ */
+public class CtcpHandler implements Handler {
+
+ private static final Logger logger = getLogger(CtcpHandler.class);
+ private final EventBus eventBus;
+ private final Connection connection;
+
+ public CtcpHandler(EventBus eventBus, Connection connection) {
+ this.eventBus = eventBus;
+ this.connection = connection;
+ }
+
+ @Override
+ public boolean willHandle(Reply reply) {
+ return (commandIs(reply, "PRIVMSG") || commandIs(reply, "NOTICE"))
+ && messageIsCtcp(reply.parameters().get(1));
+ }
+
+ private boolean commandIs(Reply reply, String command) {
+ return reply.command().equalsIgnoreCase(command);
+ }
+
+ private boolean messageIsCtcp(String message) {
+ return message.startsWith("\u0001") && message.endsWith("\u0001");
+ }
+
+ @Override
+ public void handleReply(Reply reply) {
+ List<String> parameters = reply.parameters();
+ String message = parameters.get(1);
+ Source source = reply.source().get();
+ handleCtcp(source, message);
+ }
+
+ private void handleCtcp(Source client, String message) {
+ String[] messageWords = message.substring(1, message.length() - 1).split(" +");
+ String ctcpCommand = messageWords[0];
+ if (ctcpCommand.equalsIgnoreCase("DCC")) {
+ if (messageWords[1].equalsIgnoreCase("SEND")) {
+ Optional<InetAddress> inetAddress = parseInetAddress(messageWords[3]);
+ Optional<Integer> port = fromNullable(Ints.tryParse(messageWords[4]));
+ long fileSize = fromNullable(Longs.tryParse(messageWords[5])).or(-1L);
+ if (inetAddress.isPresent() && port.isPresent()) {
+ eventBus.post(new DccSendReceived(connection, client, messageWords[2], inetAddress.get(), port.get(), fileSize));
+ } else {
+ logger.warn(format("Received malformed DCC SEND: “%s”", message));
+ }
+ } else if (messageWords[1].equalsIgnoreCase("ACCEPT")) {
+ Optional<Integer> port = fromNullable(Ints.tryParse(messageWords[3]));
+ long position = (messageWords.length > 4) ? fromNullable(Longs.tryParse(messageWords[4])).or(-1L) : -1;
+ if (port.isPresent()) {
+ eventBus.post(new DccAcceptReceived(connection, client, messageWords[2], port.get(), position));
+ } else {
+ logger.warn(format("Received malformed DCC ACCEPT: “%s”", message));
+ }
+ }
+ }
+ }
+
+ private Optional<InetAddress> parseInetAddress(String ip) {
+ Long ipNumber = Longs.tryParse(ip);
+ if (ipNumber == null) {
+ return absent();
+ }
+
+ StringBuilder hostname = new StringBuilder(15);
+ hostname.append((ipNumber >>> 24) & 0xff).append('.');
+ hostname.append((ipNumber >>> 16) & 0xff).append('.');
+ hostname.append((ipNumber >>> 8) & 0xff).append('.');
+ hostname.append(ipNumber & 0xff);
+ try {
+ return of(getByName(hostname.toString()));
+ } catch (UnknownHostException uhe1) {
+ return absent();
+ }
+ }
+
+}