DMDirc-Client/src/main/java/com/dmdirc/Server.java

/*
 * Copyright (c) 2006-2017 DMDirc Developers
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated
 * documentation files (the "Software"), to deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
 * WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS
 * OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

package com.dmdirc;

import com.dmdirc.config.profiles.Profile;
import com.dmdirc.events.FrameClosingEvent;
import com.dmdirc.events.ServerConnectErrorEvent;
import com.dmdirc.events.ServerConnectedEvent;
import com.dmdirc.events.ServerConnectingEvent;
import com.dmdirc.events.ServerDisconnectedEvent;
import com.dmdirc.events.ServerReconnectScheduledEvent;
import com.dmdirc.events.ServerUnknownProtocolEvent;
import com.dmdirc.interfaces.Connection;
import com.dmdirc.interfaces.GroupChatManager;
import com.dmdirc.interfaces.InviteManager;
import com.dmdirc.interfaces.PrivateChat;
import com.dmdirc.interfaces.User;
import com.dmdirc.interfaces.WindowModel;
import com.dmdirc.config.provider.ConfigChangeListener;
import com.dmdirc.config.provider.ConfigProvider;
import com.dmdirc.config.provider.ConfigProviderMigrator;
import com.dmdirc.interfaces.config.IdentityFactory;
import com.dmdirc.parser.common.DefaultStringConverter;
import com.dmdirc.parser.common.IgnoreList;
import com.dmdirc.parser.common.ParserError;
import com.dmdirc.parser.common.ThreadedParser;
import com.dmdirc.parser.interfaces.ClientInfo;
import com.dmdirc.parser.interfaces.EncodingParser;
import com.dmdirc.parser.interfaces.Parser;
import com.dmdirc.parser.interfaces.ProtocolDescription;
import com.dmdirc.parser.interfaces.SecureParser;
import com.dmdirc.parser.interfaces.StringConverter;
import com.dmdirc.tls.CertificateManager;
import com.dmdirc.ui.input.TabCompletionType;
import com.dmdirc.ui.messages.Formatter;
import com.dmdirc.ui.messages.HighlightManager;

import com.google.common.net.InternetDomainName;

import java.net.NoRouteToHostException;
import java.net.SocketException;
import java.net.SocketTimeoutException;
import java.net.URI;
import java.net.UnknownHostException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Map;
import java.util.Optional;
import java.util.concurrent.ConcurrentSkipListMap;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import java.util.function.Function;

import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import javax.net.ssl.SSLException;

import net.engio.mbassy.listener.Handler;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import static com.dmdirc.util.LogUtils.APP_ERROR;
import static com.google.common.base.Preconditions.checkNotNull;

/**
 * The Server class represents the client's view of a server. It maintains a list of all channels,
 * queries, etc, and handles parser callbacks pertaining to the server.
 */
public class Server implements Connection {

    private static final Logger LOG = LoggerFactory.getLogger(Server.class);
    /** The name of the general domain. */
    private static final String DOMAIN_GENERAL = "general";

    /** Manager of group chats. */
    private final GroupChatManagerImpl groupChatManager;
    /** Manager of invites. */
    private final InviteManager inviteManager;
    /** Open query windows on the server. */
    private final Map<String, Query> queries = new ConcurrentSkipListMap<>();
    /** The user manager to retrieve users from. */
    private final UserManager userManager;

    /** The Parser instance handling this server. */
    @Nonnull
    private Optional<Parser> parser = Optional.empty();
    /** The Parser instance that used to be handling this server. */
    @Nonnull
    private Optional<Parser> oldParser = Optional.empty();
    /** The parser-supplied protocol description object. */
    @Nonnull
    private Optional<ProtocolDescription> protocolDescription = Optional.empty();

    /**
     * Object used to synchronise access to parser. This object should be locked by anything
     * requiring that the parser reference remains the same for a duration of time, or by anything
     * which is updating the parser reference.
     *
     * If used in conjunction with myStateLock, the parserLock must always be locked INSIDE the
     * myStateLock to prevent deadlocks.
     */
    private final ReadWriteLock parserLock = new ReentrantReadWriteLock();

    /** Object used to synchronise access to myState. */
    private final Object myStateLock = new Object();
    /** The current state of this server. */
    private final ServerStatus myState = new ServerStatus(this, myStateLock);

    /** The address of the server we're connecting to. */
    @Nonnull
    private URI address;
    /** The profile we're using. */
    @Nonnull
    private Profile profile;

    /** Our reason for being away, if any. */
    private Optional<String> awayMessage;
    /** Our event handler. */
    private final ServerEventHandler eventHandler;
    /** Our ignore list. */
    private final IgnoreList ignoreList = new IgnoreList();
    /** Our string converter. */
    private StringConverter converter = new DefaultStringConverter();
    /** ParserFactory we use for creating parsers. */
    private final ParserFactory parserFactory;
    /** Factory to use to create new identities. */
    private final IdentityFactory identityFactory;
    /** The migrator to use to change our config provider. */
    private final ConfigProviderMigrator configMigrator;
    /** Factory to use for creating queries. */
    private final QueryFactory queryFactory;
    /** The config provider to write user settings to. */
    private final ConfigProvider userSettings;
    /** Executor service to use to schedule repeated events. */
    private final ScheduledExecutorService executorService;
    /** The message encoder factory to create a message encoder with. */
    private final MessageEncoderFactory messageEncoderFactory;
    /** The manager to use for highlighting. */
    private final HighlightManager highlightManager;
    /** Listener to use for config changes. */
    private final ConfigChangeListener configListener = (domain, key) -> updateTitle();
    private final WindowModel windowModel;
    /** The future used when a reconnect timer is scheduled. */
    private ScheduledFuture<?> reconnectTimerFuture;

    /**
     * Creates a new server which will connect to the specified URL with the specified profile.
     */
    public Server(
            final WindowModel windowModel,
            final ConfigProviderMigrator configMigrator,
            final ParserFactory parserFactory,
            final IdentityFactory identityFactory,
            final QueryFactory queryFactory,
            final MessageEncoderFactory messageEncoderFactory,
            final ConfigProvider userSettings,
            final GroupChatManagerImplFactory groupChatManagerFactory,
            final ScheduledExecutorService executorService,
            @Nonnull final URI uri,
            @Nonnull final Profile profile,
            final UserManager userManager) {
        this.windowModel = windowModel;
        this.parserFactory = parserFactory;
        this.identityFactory = identityFactory;
        this.configMigrator = configMigrator;
        this.queryFactory = queryFactory;
        this.executorService = executorService;
        this.userSettings = userSettings;
        this.messageEncoderFactory = messageEncoderFactory;
        this.userManager = userManager;
        this.groupChatManager = groupChatManagerFactory.create(this);
        this.inviteManager = new InviteManagerImpl(this);

        awayMessage = Optional.empty();
        eventHandler = new ServerEventHandler(this, groupChatManager, windowModel.getEventBus());

        this.address = uri;
        this.profile = profile;
        setConnectionDetails(uri, profile);

        updateIcon();

        windowModel.getConfigManager().addChangeListener("formatter", "serverName", configListener);
        windowModel.getConfigManager().addChangeListener("formatter", "serverTitle", configListener);

        highlightManager = new HighlightManager(windowModel);
        windowModel.getEventBus().subscribe(highlightManager);
        windowModel.getEventBus().subscribe(this);
    }

    /**
     * Updates the connection details for this server.
     *
     * @param uri     The new URI that this server should connect to
     * @param profile The profile that this server should use
     */
    private void setConnectionDetails(final URI uri, final Profile profile) {
        this.address = checkNotNull(uri);
        this.protocolDescription = Optional.ofNullable(parserFactory.getDescription(uri));
        this.profile = profile;
    }

    @Override
    public void connect() {
        connect(address, profile);
    }

    @Override
    @Precondition({
        "The current parser is null or not connected",
        "The specified profile is not null"
    })
    @SuppressWarnings("fallthrough")
    public void connect(final URI address, final Profile profile) {
        checkNotNull(address);
        checkNotNull(profile);

        synchronized (myStateLock) {
            LOG.info("Connecting to {}, current state is {}", address, myState.getState());

            switch (myState.getState()) {
                case RECONNECT_WAIT:
                    LOG.debug("Cancelling reconnection timer");
                    if (reconnectTimerFuture != null) {
                        reconnectTimerFuture.cancel(false);
                    }
                    break;
                case CLOSING:
                    // Ignore the connection attempt
                    return;
                case CONNECTED:
                case CONNECTING:
                    disconnect(windowModel.getConfigManager()
                            .getOption(DOMAIN_GENERAL, "quitmessage"));
                case DISCONNECTING:
                    while (!myState.getState().isDisconnected()) {
                        try {
                            myStateLock.wait();
                        } catch (InterruptedException ex) {
                            return;
                        }
                    }
                    break;
                default:
                    // Do nothing
                    break;
            }

            final URI connectAddress;
            final Parser newParser;

            try {
                parserLock.writeLock().lock();
                if (parser.isPresent()) {
                    throw new IllegalArgumentException("Connection attempt while parser "
                            + "is still connected.\n\nMy state:" + getState());
                }

                configMigrator.migrate(address.getScheme(), "", "", address.getHost());

                setConnectionDetails(address, profile);

                updateTitle();
                updateIcon();

                parser = Optional.ofNullable(buildParser());

                if (!parser.isPresent()) {
                    windowModel.getEventBus().publishAsync(
                            new ServerUnknownProtocolEvent(this, address.getScheme()));
                    return;
                }

                newParser = parser.get();
                connectAddress = newParser.getURI();
            } finally {
                parserLock.writeLock().unlock();
            }

            myState.transition(ServerState.CONNECTING);

            doCallbacks();

            updateAwayState(Optional.empty());
            inviteManager.removeInvites();

            newParser.connect();
            if (newParser instanceof ThreadedParser) {
                ((ThreadedParser) newParser).getControlThread()
                        .setName("Parser - " + connectAddress.getHost());
            }
        }

        windowModel.getEventBus().publish(new ServerConnectingEvent(this, address));
    }

    @Override
    public void reconnect(final String reason) {
        synchronized (myStateLock) {
            if (myState.getState() == ServerState.CLOSING) {
                return;
            }

            disconnect(reason);

            connect(address, profile);
        }
    }

    @Override
    public void reconnect() {
        reconnect(windowModel.getConfigManager().getOption(DOMAIN_GENERAL, "reconnectmessage"));
    }

    @Override
    public void disconnect() {
        disconnect(windowModel.getConfigManager().getOption(DOMAIN_GENERAL, "quitmessage"));
    }

    @Override
    public void disconnect(final String reason) {
        synchronized (myStateLock) {
            LOG.info("Disconnecting. Current state: {}", myState.getState());

            switch (myState.getState()) {
                case CLOSING:
                case DISCONNECTING:
                case DISCONNECTED:
                case TRANSIENTLY_DISCONNECTED:
                    return;
                case RECONNECT_WAIT:
                    LOG.debug("Cancelling reconnection timer");
                    if (reconnectTimerFuture != null) {
                        reconnectTimerFuture.cancel(false);
                    }
                    break;
                default:
                    break;
            }

            groupChatManager.handleDisconnect();

            try {
                parserLock.readLock().lock();
                if (parser.isPresent()) {
                    myState.transition(ServerState.DISCONNECTING);

                    inviteManager.removeInvites();
                    updateIcon();

                    parser.get().disconnect(reason);
                } else {
                    myState.transition(ServerState.DISCONNECTED);
                }
            } finally {
                parserLock.readLock().unlock();
            }

            if (windowModel.getConfigManager()
                    .getOptionBool(DOMAIN_GENERAL, "closequeriesonquit")) {
                closeQueries();
            }
        }
    }

    /**
     * Schedules a reconnect attempt to be performed after a user-defined delay.
     */
    @Precondition("The server state is transiently disconnected")
    private void doDelayedReconnect() {
        synchronized (myStateLock) {
            LOG.info("Performing delayed reconnect. State: {}", myState.getState());

            if (myState.getState() != ServerState.TRANSIENTLY_DISCONNECTED) {
                throw new IllegalStateException("doDelayedReconnect when not "
                        + "transiently disconnected\n\nState: " + myState);
            }

            final int delay = Math.max(1000,
                    windowModel.getConfigManager().getOptionInt(DOMAIN_GENERAL, "reconnectdelay"));

            windowModel.getEventBus().publishAsync(
                    new ServerReconnectScheduledEvent(this, delay / 1000));

            reconnectTimerFuture = executorService.schedule(() -> {
                synchronized (myStateLock) {
                    LOG.debug("Reconnect task executing, state: {}", myState.getState());
                    if (myState.getState() == ServerState.RECONNECT_WAIT) {
                        myState.transition(ServerState.TRANSIENTLY_DISCONNECTED);
                        reconnect();
                    }
                }
            }, delay, TimeUnit.MILLISECONDS);

            LOG.info("Scheduling reconnect task for delay of {}", delay);

            myState.transition(ServerState.RECONNECT_WAIT);
            updateIcon();
        }
    }

    @Override
    public boolean hasQuery(final String host) {
        return queries.containsKey(converter.toLowerCase(getUser(host).getNickname()));
    }

    @Override
    public Optional<User> getLocalUser() {
        return parser.map(Parser::getLocalClient)
                .map(client -> userManager.getUserFromClientInfo(client, this));
    }

    @Override
    public User getUser(final String details) {
        return parser.map(p -> p.getClient(details))
                .map(client -> userManager.getUserFromClientInfo(client, this)).get();
    }

    @Override
    public PrivateChat getQuery(final String host) {
        return getQuery(host, false);
    }

    @Override
    public PrivateChat getQuery(final String host, final boolean focus) {
        synchronized (myStateLock) {
            if (myState.getState() == ServerState.CLOSING) {
                // Can't open queries while the server is closing
                return null;
            }
        }

        final String nick = getUser(host).getNickname();
        final String lnick = converter.toLowerCase(nick);

        if (!queries.containsKey(lnick)) {
            final Query newQuery = queryFactory.getQuery(this, getUser(host));
            if (!getState().isDisconnected()) {
                newQuery.reregister();
            }
            windowModel.getInputModel().get().getTabCompleter()
                    .addEntry(TabCompletionType.QUERY_NICK, nick);
            queries.put(lnick, newQuery);
        }

        return queries.get(lnick);
    }

    /**
     * Updates tab completer and queries after a user changes their nickname.
     *
     * @param client The client that changed nickname
     * @param oldNick The old nickname they used.
     */
    void handleNickChange(final ClientInfo client, final String oldNick) {
        if (queries.containsKey(converter.toLowerCase(oldNick))) {
            windowModel.getInputModel().get().getTabCompleter()
                    .removeEntry(TabCompletionType.QUERY_NICK, oldNick);
            windowModel.getInputModel().get().getTabCompleter()
                    .addEntry(TabCompletionType.QUERY_NICK, client.getNickname());

            queries.put(
                    converter.toLowerCase(client.getNickname()),
                    queries.remove(converter.toLowerCase(oldNick)));
        }
    }

    @Override
    public Collection<PrivateChat> getQueries() {
        return Collections.unmodifiableCollection(queries.values());
    }

    @Override
    public void delQuery(final PrivateChat query) {
        windowModel.getInputModel().get().getTabCompleter().removeEntry(
                TabCompletionType.QUERY_NICK, query.getNickname());
        queries.remove(converter.toLowerCase(query.getNickname()));
    }

    /**
     * Closes all open query windows associated with this server.
     */
    private void closeQueries() {
        new ArrayList<>(queries.values()).forEach(Query::close);
    }

    /**
     * Builds an appropriately configured {@link Parser} for this server.
     *
     * @return A configured parser.
     */
    @Nullable
    private Parser buildParser() {
        final Parser myParser = parserFactory
                .getParser(profile, address, windowModel.getConfigManager())
                .orElse(null);

        if (myParser != null) {
            myParser.setIgnoreList(ignoreList);
        }

        if (myParser instanceof SecureParser) {
            final CertificateManager certificateManager =
                    new CertificateManager(this, address.getHost(), windowModel.getConfigManager(),
                            userSettings, windowModel.getEventBus());
            final SecureParser secureParser = (SecureParser) myParser;
            secureParser.setTrustManagers(certificateManager);
            secureParser.setKeyManagers(certificateManager.getKeyManager());
        }

        if (myParser instanceof EncodingParser) {
            final EncodingParser encodingParser = (EncodingParser) myParser;
            encodingParser.setEncoder(messageEncoderFactory.getMessageEncoder(this, myParser));
        }

        return myParser;
    }

    @Override
    public boolean compareURI(final URI uri) {
        return parser.map(p -> p.compareURI(uri)).orElse(
                oldParser.map(op -> op.compareURI(uri)).orElse(false));
    }

    /**
     * Updates this server's icon.
     */
    private void updateIcon() {
        final String icon = myState.getState() == ServerState.CONNECTED
                ? protocolDescription.get().isSecure(address)
                ? "secure-server" : "server" : "server-disconnected";
        windowModel.setIcon(icon);
    }

    /**
     * Registers callbacks.
     */
    private void doCallbacks() {
        eventHandler.registerCallbacks();
        queries.values().forEach(Query::reregister);
    }

    @Override
    public void sendLine(final String line) {
        synchronized (myStateLock) {
            try {
                parserLock.readLock().lock();
                parser.ifPresent(p -> {
                    if (!line.isEmpty() && myState.getState() == ServerState.CONNECTED) {
                        p.sendRawMessage(line);
                    }
                });
            } finally {
                parserLock.readLock().unlock();
            }
        }
    }

    @Override
    public void sendMessage(final String target, final String message) {
        if (!message.isEmpty()) {
            parser.ifPresent(p -> p.sendMessage(target, message));
        }
    }

    public int getMaxLineLength() {
        return withParserReadLock(Parser::getMaxLength, -1);
    }

    @Override
    @Nonnull
    public Optional<Parser> getParser() {
        return parser;
    }

    @Nonnull
    @Override
    public Profile getProfile() {
        return profile;
    }

    @Override
    public String getAddress() {
        return withParserReadLock(Parser::getServerName, address.getHost());
    }

    @Override
    public String getNetwork() {
        try {
            parserLock.readLock().lock();
            return parser.map(p -> p.getNetworkName().isEmpty()
                            ? getNetworkFromServerName(p.getServerName()) : p.getNetworkName())
                    .orElseThrow(() -> new IllegalStateException(
                            "getNetwork called when parser is null (state: " + getState() + ')'));
        } finally {
            parserLock.readLock().unlock();
        }
    }

    @Override
    public boolean isNetwork(final String target) {
        synchronized (myStateLock) {
            return withParserReadLock(p -> getNetwork().equalsIgnoreCase(target), false);
        }
    }

    /**
     * Calculates a network name from the specified server name.
     *
     * @param serverName The server name to parse
     * @return A network name for the specified server
     */
    protected static String getNetworkFromServerName(final String serverName) {
        try {
            return InternetDomainName.from(serverName).topPrivateDomain().toString();
        } catch (IllegalArgumentException | IllegalStateException ex) {
            // Either couldn't parse it as a domain name, or it didn't have a public suffix.
            // Just use the server name as-is.
            return serverName;
        }
    }

    @Override
    public String getIrcd() {
        return parser.get().getServerSoftwareType();
    }

    @Override
    public String getProtocol() {
        return address.getScheme();
    }

    @Override
    public boolean isAway() {
        return awayMessage.isPresent();
    }

    @Override
    public String getAwayMessage() {
        return awayMessage.orElse(null);
    }

    @Override
    public ServerState getState() {
        return myState.getState();
    }

    public ServerStatus getStatus() {
        return myState;
    }

    @Handler
    private void handleClose(final FrameClosingEvent event) {
        if (event.getSource().equals(windowModel)) {
            synchronized (myStateLock) {
                eventHandler.unregisterCallbacks();
                windowModel.getConfigManager().removeListener(configListener);
                windowModel.getEventBus().unsubscribe(highlightManager);
                executorService.shutdown();

                disconnect();

                myState.transition(ServerState.CLOSING);
            }

            groupChatManager.closeAll();
            closeQueries();
            inviteManager.removeInvites();
            windowModel.getEventBus().unsubscribe(this);
        }
    }

    @Override
    public WindowModel getWindowModel() {
        return windowModel;
    }

    @Override
    public void sendCTCPReply(final String source, final String type, final String args) {
        if ("VERSION".equalsIgnoreCase(type)) {
            parser.get().sendCTCPReply(source, "VERSION",
                    "DMDirc " + windowModel.getConfigManager().getOption("version", "version") +
                            " - https://www.dmdirc.com/");
        } else if ("PING".equalsIgnoreCase(type)) {
            parser.get().sendCTCPReply(source, "PING", args);
        } else if ("CLIENTINFO".equalsIgnoreCase(type)) {
            parser.get().sendCTCPReply(source, "CLIENTINFO", "VERSION PING CLIENTINFO");
        }
    }

    @Override
    public void updateTitle() {
        synchronized (myStateLock) {
            if (myState.getState() == ServerState.CLOSING) {
                return;
            }

            try {
                parserLock.readLock().lock();
                final Object[] arguments = {
                    address.getHost(), parser.map(Parser::getServerName).orElse("Unknown"),
                    address.getPort(), parser.map(p -> getNetwork()).orElse("Unknown"),
                    getLocalUser().map(User::getNickname).orElse("Unknown")
                };

                windowModel.setName(Formatter.formatMessage(windowModel.getConfigManager(),
                        "serverName", arguments));
                windowModel.setTitle(Formatter.formatMessage(windowModel.getConfigManager(),
                        "serverTitle", arguments));
            } finally {
                parserLock.readLock().unlock();
            }
        }
    }

    /**
     * Called when the socket has been closed.
     */
    public void onSocketClosed() {
        LOG.info("Received socket closed event, state: {}", myState.getState());

        if (Thread.holdsLock(myStateLock)) {
            LOG.info("State lock contended: rerunning on a new thread");

            executorService.schedule(this::onSocketClosed, 0, TimeUnit.SECONDS);
            return;
        }

        windowModel.getEventBus().publish(new ServerDisconnectedEvent(this));

        eventHandler.unregisterCallbacks();

        synchronized (myStateLock) {
            if (myState.getState() == ServerState.CLOSING
                    || myState.getState() == ServerState.DISCONNECTED) {
                // This has been triggered via .disconnect()
                return;
            }

            if (myState.getState() == ServerState.DISCONNECTING) {
                myState.transition(ServerState.DISCONNECTED);
            } else {
                myState.transition(ServerState.TRANSIENTLY_DISCONNECTED);
            }

            groupChatManager.handleSocketClosed();

            try {
                parserLock.writeLock().lock();
                oldParser = parser;
                parser = Optional.empty();
            } finally {
                parserLock.writeLock().unlock();
            }

            updateIcon();

            if (windowModel.getConfigManager()
                    .getOptionBool(DOMAIN_GENERAL, "closequeriesondisconnect")) {
                closeQueries();
            }

            inviteManager.removeInvites();
            updateAwayState(Optional.empty());

            if (windowModel.getConfigManager()
                    .getOptionBool(DOMAIN_GENERAL, "reconnectondisconnect")
                    && myState.getState() == ServerState.TRANSIENTLY_DISCONNECTED) {
                doDelayedReconnect();
            }
        }
    }

    /**
     * Called when an error was encountered while connecting.
     *
     * @param errorInfo The parser's error information
     */
    @Precondition("The current server state is CONNECTING")
    public void onConnectError(final ParserError errorInfo) {
        synchronized (myStateLock) {
            LOG.info("Received connect error event, state: {}; error: {}", myState.getState(),
                    errorInfo);

            if (myState.getState() == ServerState.CLOSING
                    || myState.getState() == ServerState.DISCONNECTING) {
                // Do nothing
                return;
            } else if (myState.getState() != ServerState.CONNECTING) {
                // Shouldn't happen
                throw new IllegalStateException("Connect error when not "
                        + "connecting\n\n" + getStatus().getTransitionHistory());
            }

            myState.transition(ServerState.TRANSIENTLY_DISCONNECTED);

            try {
                parserLock.writeLock().lock();
                oldParser = parser;
                parser = Optional.empty();
            } finally {
                parserLock.writeLock().unlock();
            }

            updateIcon();

            windowModel.getEventBus().publish(new ServerConnectErrorEvent(this,
                    getErrorDescription(errorInfo)));

            if (windowModel.getConfigManager()
                    .getOptionBool(DOMAIN_GENERAL, "reconnectonconnectfailure")) {
                doDelayedReconnect();
            }
        }
    }

    /**
     * Gets a user-readable description of the specified error.
     *
     * @param errorInfo The parser error to get a description for.
     * @return A user-readable error description.
     */
    private static String getErrorDescription(final ParserError errorInfo) {
        final String description;
        if (errorInfo.getException() == null) {
            description = errorInfo.getData();
        } else {
            final Exception exception = errorInfo.getException();

            if (exception instanceof UnknownHostException) {
                description = "Unknown host (unable to resolve)";
            } else if (exception instanceof NoRouteToHostException) {
                description = "No route to host";
            } else if (exception instanceof SocketTimeoutException) {
                description = "Connection attempt timed out";
            } else if (exception instanceof SocketException
                    || exception instanceof SSLException) {
                description = exception.getMessage();
            } else {
                LOG.info(APP_ERROR, "Unknown socket error: {}",
                        exception.getClass().getCanonicalName(), exception);
                description = "Unknown error: " + exception.getMessage();
            }
        }
        return description;
    }

    /**
     * Called after the parser receives the 005 headers from the server.
     */
    @Precondition("State is CONNECTING")
    public void onPost005() {
        synchronized (myStateLock) {
            if (myState.getState() != ServerState.CONNECTING) {
                // Shouldn't happen
                throw new IllegalStateException("Received onPost005 while not "
                        + "connecting\n\n" + myState.getTransitionHistory());
            }

            myState.transition(ServerState.CONNECTED);

            configMigrator.migrate(address.getScheme(),
                    parser.get().getServerSoftwareType(), getNetwork(), parser.get().getServerName());

            updateIcon();
            updateTitle();
            updateIgnoreList();

            converter = parser.get().getStringConverter();
            groupChatManager.handleConnected();
        }

        windowModel.getEventBus().publish(new ServerConnectedEvent(this));
    }

    @Override
    public IgnoreList getIgnoreList() {
        return ignoreList;
    }

    @Override
    public void updateIgnoreList() {
        ignoreList.clear();
        ignoreList.addAll(windowModel.getConfigManager().getOptionList("network", "ignorelist"));
    }

    @Override
    public void saveIgnoreList() {
        getNetworkIdentity().setOption("network", "ignorelist", ignoreList.getRegexList());
    }

    @Override
    public ConfigProvider getServerIdentity() {
        return identityFactory.createServerConfig(parser.get().getServerName());
    }

    @Override
    public ConfigProvider getNetworkIdentity() {
        return identityFactory.createNetworkConfig(getNetwork());
    }

    @Override
    public void updateAwayState(final Optional<String> message) {
        checkNotNull(message);
        if (awayMessage.equals(message)) {
            return;
        }

        awayMessage = message;
    }

    @Override
    public String getUserModes() {
        return getParser().map(Parser::getChannelUserModes).orElse("");
    }

    @Override
    public String getBooleanModes() {
        return getParser().map(Parser::getBooleanChannelModes).orElse("");
    }

    @Override
    public String getListModes() {
        return getParser().map(Parser::getListChannelModes).orElse("");
    }

    @Override
    public String getParameterModes() {
        return getParser().map(Parser::getParameterChannelModes).orElse("");
    }

    @Override
    public String getDoubleParameterModes() {
        return getParser().map(Parser::getDoubleParameterChannelModes).orElse("");
    }

    @Override
    public int getMaxListModes(final char mode) {
        return getParser().map(p -> p.getMaxListModes(mode)).orElse(-1);
    }

    @Override
    public GroupChatManager getGroupChatManager() {
        return groupChatManager;
    }

    @Override
    public InviteManager getInviteManager() {
        return inviteManager;
    }

    @Override
    public void setNickname(final String nickname) {
        parser.map(Parser::getLocalClient).ifPresent(c -> c.setNickname(nickname));
    }

    @Override
    public Optional<String> getNickname() {
        return parser.map(Parser::getLocalClient).map(ClientInfo::getNickname);
    }

    @Override
    public void requestUserInfo(final User user) {
        parser.ifPresent(p -> p.sendWhois(user.getNickname()));
    }

    /**
     * Utility method to get a result from the parser while holding the {@link #parserLock}
     * read lock.
     *
     * @param func The function to use to retrieve information from the parser.
     * @param orElse The value to return if the parser is otherwise not present.
     * @param <T> The type of result returned.
     * @return The value returned by {@code func}, if the parser is present, otherwise the
     * {@code orElse} value.
     */
    private <T> T withParserReadLock(
            final Function<Parser, T> func,
            final T orElse) {
        try {
            parserLock.readLock().lock();
            return parser.map(func).orElse(orElse);
        } finally {
            parserLock.readLock().unlock();
        }
    }

}