net.pterodactylus.sone.core.Core.java Source code

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/*
 * Sone - Core.java - Copyright  20102013 David Roden
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package net.pterodactylus.sone.core;

import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;

import java.net.MalformedURLException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
import java.util.logging.Level;
import java.util.logging.Logger;

import net.pterodactylus.sone.core.Options.DefaultOption;
import net.pterodactylus.sone.core.Options.Option;
import net.pterodactylus.sone.core.Options.OptionWatcher;
import net.pterodactylus.sone.core.event.ImageInsertFinishedEvent;
import net.pterodactylus.sone.core.event.MarkPostKnownEvent;
import net.pterodactylus.sone.core.event.MarkPostReplyKnownEvent;
import net.pterodactylus.sone.core.event.MarkSoneKnownEvent;
import net.pterodactylus.sone.core.event.NewPostFoundEvent;
import net.pterodactylus.sone.core.event.NewPostReplyFoundEvent;
import net.pterodactylus.sone.core.event.NewSoneFoundEvent;
import net.pterodactylus.sone.core.event.PostRemovedEvent;
import net.pterodactylus.sone.core.event.PostReplyRemovedEvent;
import net.pterodactylus.sone.core.event.SoneLockedEvent;
import net.pterodactylus.sone.core.event.SoneRemovedEvent;
import net.pterodactylus.sone.core.event.SoneUnlockedEvent;
import net.pterodactylus.sone.data.Album;
import net.pterodactylus.sone.data.Client;
import net.pterodactylus.sone.data.Image;
import net.pterodactylus.sone.data.Post;
import net.pterodactylus.sone.data.PostReply;
import net.pterodactylus.sone.data.Profile;
import net.pterodactylus.sone.data.Profile.Field;
import net.pterodactylus.sone.data.Reply;
import net.pterodactylus.sone.data.Sone;
import net.pterodactylus.sone.data.Sone.ShowCustomAvatars;
import net.pterodactylus.sone.data.Sone.SoneStatus;
import net.pterodactylus.sone.data.SoneImpl;
import net.pterodactylus.sone.data.TemporaryImage;
import net.pterodactylus.sone.database.Database;
import net.pterodactylus.sone.database.DatabaseException;
import net.pterodactylus.sone.database.PostBuilder;
import net.pterodactylus.sone.database.PostProvider;
import net.pterodactylus.sone.database.PostReplyBuilder;
import net.pterodactylus.sone.database.PostReplyProvider;
import net.pterodactylus.sone.database.SoneProvider;
import net.pterodactylus.sone.fcp.FcpInterface;
import net.pterodactylus.sone.fcp.FcpInterface.FullAccessRequired;
import net.pterodactylus.sone.freenet.wot.Identity;
import net.pterodactylus.sone.freenet.wot.IdentityManager;
import net.pterodactylus.sone.freenet.wot.OwnIdentity;
import net.pterodactylus.sone.freenet.wot.event.IdentityAddedEvent;
import net.pterodactylus.sone.freenet.wot.event.IdentityRemovedEvent;
import net.pterodactylus.sone.freenet.wot.event.IdentityUpdatedEvent;
import net.pterodactylus.sone.freenet.wot.event.OwnIdentityAddedEvent;
import net.pterodactylus.sone.freenet.wot.event.OwnIdentityRemovedEvent;
import net.pterodactylus.sone.main.SonePlugin;
import net.pterodactylus.sone.utils.IntegerRangePredicate;
import net.pterodactylus.util.config.Configuration;
import net.pterodactylus.util.config.ConfigurationException;
import net.pterodactylus.util.logging.Logging;
import net.pterodactylus.util.number.Numbers;
import net.pterodactylus.util.service.AbstractService;
import net.pterodactylus.util.thread.NamedThreadFactory;

import com.google.common.base.Optional;
import com.google.common.base.Predicate;
import com.google.common.base.Predicates;
import com.google.common.collect.FluentIterable;
import com.google.common.collect.HashMultimap;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Multimap;
import com.google.common.collect.Multimaps;
import com.google.common.eventbus.EventBus;
import com.google.common.eventbus.Subscribe;
import com.google.inject.Inject;

import freenet.keys.FreenetURI;

/**
 * The Sone core.
 *
 * @author <a href="mailto:bombe@pterodactylus.net">David Bombe Roden</a>
 */
public class Core extends AbstractService implements SoneProvider, PostProvider, PostReplyProvider {

    /** The logger. */
    private static final Logger logger = Logging.getLogger(Core.class);

    /** The start time. */
    private final long startupTime = System.currentTimeMillis();

    /** The options. */
    private final Options options = new Options();

    /** The preferences. */
    private final Preferences preferences = new Preferences(options);

    /** The event bus. */
    private final EventBus eventBus;

    /** The configuration. */
    private Configuration configuration;

    /** Whether were currently saving the configuration. */
    private boolean storingConfiguration = false;

    /** The identity manager. */
    private final IdentityManager identityManager;

    /** Interface to freenet. */
    private final FreenetInterface freenetInterface;

    /** The Sone downloader. */
    private final SoneDownloader soneDownloader;

    /** The image inserter. */
    private final ImageInserter imageInserter;

    /** Sone downloader thread-pool. */
    private final ExecutorService soneDownloaders = Executors.newFixedThreadPool(10,
            new NamedThreadFactory("Sone Downloader %2$d"));

    /** The update checker. */
    private final UpdateChecker updateChecker;

    /** The trust updater. */
    private final WebOfTrustUpdater webOfTrustUpdater;

    /** The FCP interface. */
    private volatile FcpInterface fcpInterface;

    /** The times Sones were followed. */
    private final Map<String, Long> soneFollowingTimes = new HashMap<String, Long>();

    /** Locked local Sones. */
    /* synchronize on itself. */
    private final Set<Sone> lockedSones = new HashSet<Sone>();

    /** Sone inserters. */
    /* synchronize access on this on sones. */
    private final Map<Sone, SoneInserter> soneInserters = new HashMap<Sone, SoneInserter>();

    /** Sone rescuers. */
    /* synchronize access on this on sones. */
    private final Map<Sone, SoneRescuer> soneRescuers = new HashMap<Sone, SoneRescuer>();

    /** All Sones. */
    /* synchronize access on this on itself. */
    private final Map<String, Sone> sones = new HashMap<String, Sone>();

    /** All known Sones. */
    private final Set<String> knownSones = new HashSet<String>();

    /** The post database. */
    private final Database database;

    /** All bookmarked posts. */
    /* synchronize access on itself. */
    private final Set<String> bookmarkedPosts = new HashSet<String>();

    /** Trusted identities, sorted by own identities. */
    private final Multimap<OwnIdentity, Identity> trustedIdentities = Multimaps
            .synchronizedSetMultimap(HashMultimap.<OwnIdentity, Identity>create());

    /** All temporary images. */
    private final Map<String, TemporaryImage> temporaryImages = new HashMap<String, TemporaryImage>();

    /** Ticker for threads that mark own elements as known. */
    private final ScheduledExecutorService localElementTicker = Executors.newScheduledThreadPool(1);

    /** The time the configuration was last touched. */
    private volatile long lastConfigurationUpdate;

    /**
     * Creates a new core.
     *
     * @param configuration
     *            The configuration of the core
     * @param freenetInterface
     *            The freenet interface
     * @param identityManager
     *            The identity manager
     * @param webOfTrustUpdater
     *            The WebOfTrust updater
     * @param eventBus
     *            The event bus
     * @param database
     *            The database
     */
    @Inject
    public Core(Configuration configuration, FreenetInterface freenetInterface, IdentityManager identityManager,
            WebOfTrustUpdater webOfTrustUpdater, EventBus eventBus, Database database) {
        super("Sone Core");
        this.configuration = configuration;
        this.freenetInterface = freenetInterface;
        this.identityManager = identityManager;
        this.soneDownloader = new SoneDownloader(this, freenetInterface);
        this.imageInserter = new ImageInserter(freenetInterface);
        this.updateChecker = new UpdateChecker(eventBus, freenetInterface);
        this.webOfTrustUpdater = webOfTrustUpdater;
        this.eventBus = eventBus;
        this.database = database;
    }

    //
    // ACCESSORS
    //

    /**
     * Returns the time Sone was started.
     *
     * @return The startup time (in milliseconds since Jan 1, 1970 UTC)
     */
    public long getStartupTime() {
        return startupTime;
    }

    /**
     * Sets the configuration to use. This will automatically save the current
     * configuration to the given configuration.
     *
     * @param configuration
     *            The new configuration to use
     */
    public void setConfiguration(Configuration configuration) {
        this.configuration = configuration;
        touchConfiguration();
    }

    /**
     * Returns the options used by the core.
     *
     * @return The options of the core
     */
    public Preferences getPreferences() {
        return preferences;
    }

    /**
     * Returns the identity manager used by the core.
     *
     * @return The identity manager
     */
    public IdentityManager getIdentityManager() {
        return identityManager;
    }

    /**
     * Returns the update checker.
     *
     * @return The update checker
     */
    public UpdateChecker getUpdateChecker() {
        return updateChecker;
    }

    /**
     * Sets the FCP interface to use.
     *
     * @param fcpInterface
     *            The FCP interface to use
     */
    public void setFcpInterface(FcpInterface fcpInterface) {
        this.fcpInterface = fcpInterface;
    }

    /**
     * Returns the Sone rescuer for the given local Sone.
     *
     * @param sone
     *            The local Sone to get the rescuer for
     * @return The Sone rescuer for the given Sone
     */
    public SoneRescuer getSoneRescuer(Sone sone) {
        checkNotNull(sone, "sone must not be null");
        checkArgument(sone.isLocal(), "sone must be local");
        synchronized (sones) {
            SoneRescuer soneRescuer = soneRescuers.get(sone);
            if (soneRescuer == null) {
                soneRescuer = new SoneRescuer(this, soneDownloader, sone);
                soneRescuers.put(sone, soneRescuer);
                soneRescuer.start();
            }
            return soneRescuer;
        }
    }

    /**
     * Returns whether the given Sone is currently locked.
     *
     * @param sone
     *            The sone to check
     * @return {@code true} if the Sone is locked, {@code false} if it is not
     */
    public boolean isLocked(Sone sone) {
        synchronized (lockedSones) {
            return lockedSones.contains(sone);
        }
    }

    /**
     * {@inheritDocs}
     */
    @Override
    public Collection<Sone> getSones() {
        synchronized (sones) {
            return ImmutableSet.copyOf(sones.values());
        }
    }

    /**
     * Returns the Sone with the given ID, regardless whether its local or
     * remote.
     *
     * @param id
     *            The ID of the Sone to get
     * @return The Sone with the given ID, or {@code null} if there is no such
     *         Sone
     */
    @Override
    public Optional<Sone> getSone(String id) {
        synchronized (sones) {
            return Optional.fromNullable(sones.get(id));
        }
    }

    /**
     * {@inheritDocs}
     */
    @Override
    public Collection<Sone> getLocalSones() {
        synchronized (sones) {
            return FluentIterable.from(sones.values()).filter(new Predicate<Sone>() {

                @Override
                public boolean apply(Sone sone) {
                    return sone.isLocal();
                }
            }).toSet();
        }
    }

    /**
     * Returns the local Sone with the given ID, optionally creating a new Sone.
     *
     * @param id
     *            The ID of the Sone
     * @param create
     *            {@code true} to create a new Sone if none exists,
     *            {@code false} to return null if none exists
     * @return The Sone with the given ID, or {@code null}
     */
    public Sone getLocalSone(String id, boolean create) {
        synchronized (sones) {
            Sone sone = sones.get(id);
            if ((sone == null) && create) {
                sone = new SoneImpl(id, true);
                sones.put(id, sone);
            }
            if ((sone != null) && !sone.isLocal()) {
                sone = new SoneImpl(id, true);
                sones.put(id, sone);
            }
            return sone;
        }
    }

    /**
     * {@inheritDocs}
     */
    @Override
    public Collection<Sone> getRemoteSones() {
        synchronized (sones) {
            return FluentIterable.from(sones.values()).filter(new Predicate<Sone>() {

                @Override
                public boolean apply(Sone sone) {
                    return !sone.isLocal();
                }
            }).toSet();
        }
    }

    /**
     * Returns the remote Sone with the given ID.
     *
     * @param id
     *            The ID of the remote Sone to get
     * @param create
     *            {@code true} to always create a Sone, {@code false} to return
     *            {@code null} if no Sone with the given ID exists
     * @return The Sone with the given ID
     */
    public Sone getRemoteSone(String id, boolean create) {
        synchronized (sones) {
            Sone sone = sones.get(id);
            if ((sone == null) && create && (id != null) && (id.length() == 43)) {
                sone = new SoneImpl(id, false);
                sones.put(id, sone);
            }
            return sone;
        }
    }

    /**
     * Returns whether the given Sone has been modified.
     *
     * @param sone
     *            The Sone to check for modifications
     * @return {@code true} if a modification has been detected in the Sone,
     *         {@code false} otherwise
     */
    public boolean isModifiedSone(Sone sone) {
        return (soneInserters.containsKey(sone)) ? soneInserters.get(sone).isModified() : false;
    }

    /**
     * Returns the time when the given was first followed by any local Sone.
     *
     * @param sone
     *            The Sone to get the time for
     * @return The time (in milliseconds since Jan 1, 1970) the Sone has first
     *         been followed, or {@link Long#MAX_VALUE}
     */
    public long getSoneFollowingTime(Sone sone) {
        synchronized (soneFollowingTimes) {
            return Optional.fromNullable(soneFollowingTimes.get(sone.getId())).or(Long.MAX_VALUE);
        }
    }

    /**
     * Returns whether the target Sone is trusted by the origin Sone.
     *
     * @param origin
     *            The origin Sone
     * @param target
     *            The target Sone
     * @return {@code true} if the target Sone is trusted by the origin Sone
     */
    public boolean isSoneTrusted(Sone origin, Sone target) {
        checkNotNull(origin, "origin must not be null");
        checkNotNull(target, "target must not be null");
        checkArgument(origin.getIdentity() instanceof OwnIdentity, "origins identity must be an OwnIdentity");
        return trustedIdentities.containsEntry(origin.getIdentity(), target.getIdentity());
    }

    /**
     * Returns a post builder.
     *
     * @return A new post builder
     */
    public PostBuilder postBuilder() {
        return database.newPostBuilder();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public Optional<Post> getPost(String postId) {
        return database.getPost(postId);
    }

    /**
     * {@inheritDocs}
     */
    @Override
    public Collection<Post> getPosts(String soneId) {
        return database.getPosts(soneId);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public Collection<Post> getDirectedPosts(final String recipientId) {
        checkNotNull(recipientId, "recipient must not be null");
        return database.getDirectedPosts(recipientId);
    }

    /**
     * Returns a post reply builder.
     *
     * @return A new post reply builder
     */
    public PostReplyBuilder postReplyBuilder() {
        return database.newPostReplyBuilder();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public Optional<PostReply> getPostReply(String replyId) {
        return database.getPostReply(replyId);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public List<PostReply> getReplies(final String postId) {
        return database.getReplies(postId);
    }

    /**
     * Returns all Sones that have liked the given post.
     *
     * @param post
     *            The post to get the liking Sones for
     * @return The Sones that like the given post
     */
    public Set<Sone> getLikes(Post post) {
        Set<Sone> sones = new HashSet<Sone>();
        for (Sone sone : getSones()) {
            if (sone.getLikedPostIds().contains(post.getId())) {
                sones.add(sone);
            }
        }
        return sones;
    }

    /**
     * Returns all Sones that have liked the given reply.
     *
     * @param reply
     *            The reply to get the liking Sones for
     * @return The Sones that like the given reply
     */
    public Set<Sone> getLikes(PostReply reply) {
        Set<Sone> sones = new HashSet<Sone>();
        for (Sone sone : getSones()) {
            if (sone.getLikedReplyIds().contains(reply.getId())) {
                sones.add(sone);
            }
        }
        return sones;
    }

    /**
     * Returns whether the given post is bookmarked.
     *
     * @param post
     *            The post to check
     * @return {@code true} if the given post is bookmarked, {@code false}
     *         otherwise
     */
    public boolean isBookmarked(Post post) {
        return isPostBookmarked(post.getId());
    }

    /**
     * Returns whether the post with the given ID is bookmarked.
     *
     * @param id
     *            The ID of the post to check
     * @return {@code true} if the post with the given ID is bookmarked,
     *         {@code false} otherwise
     */
    public boolean isPostBookmarked(String id) {
        synchronized (bookmarkedPosts) {
            return bookmarkedPosts.contains(id);
        }
    }

    /**
     * Returns all currently known bookmarked posts.
     *
     * @return All bookmarked posts
     */
    public Set<Post> getBookmarkedPosts() {
        Set<Post> posts = new HashSet<Post>();
        synchronized (bookmarkedPosts) {
            for (String bookmarkedPostId : bookmarkedPosts) {
                Optional<Post> post = getPost(bookmarkedPostId);
                if (post.isPresent()) {
                    posts.add(post.get());
                }
            }
        }
        return posts;
    }

    /**
     * Returns the album with the given ID, creating a new album if no album
     * with the given ID can be found.
     *
     * @param albumId
     *            The ID of the album
     * @return The album with the given ID
     */
    public Album getAlbum(String albumId) {
        return getAlbum(albumId, true);
    }

    /**
     * Returns the album with the given ID, optionally creating a new album if
     * an album with the given ID can not be found.
     *
     * @param albumId
     *            The ID of the album
     * @param create
     *            {@code true} to create a new album if none exists for the
     *            given ID
     * @return The album with the given ID, or {@code null} if no album with the
     *         given ID exists and {@code create} is {@code false}
     */
    public Album getAlbum(String albumId, boolean create) {
        Optional<Album> album = database.getAlbum(albumId);
        if (album.isPresent()) {
            return album.get();
        }
        if (!create) {
            return null;
        }
        Album newAlbum = database.newAlbumBuilder().withId(albumId).build();
        database.storeAlbum(newAlbum);
        return newAlbum;
    }

    /**
     * Returns the image with the given ID, creating it if necessary.
     *
     * @param imageId
     *            The ID of the image
     * @return The image with the given ID
     */
    public Image getImage(String imageId) {
        return getImage(imageId, true);
    }

    /**
     * Returns the image with the given ID, optionally creating it if it does
     * not exist.
     *
     * @param imageId
     *            The ID of the image
     * @param create
     *            {@code true} to create an image if none exists with the given
     *            ID
     * @return The image with the given ID, or {@code null} if none exists and
     *         none was created
     */
    public Image getImage(String imageId, boolean create) {
        Optional<Image> image = database.getImage(imageId);
        if (image.isPresent()) {
            return image.get();
        }
        if (!create) {
            return null;
        }
        Image newImage = database.newImageBuilder().withId(imageId).build();
        database.storeImage(newImage);
        return newImage;
    }

    /**
     * Returns the temporary image with the given ID.
     *
     * @param imageId
     *            The ID of the temporary image
     * @return The temporary image, or {@code null} if there is no temporary
     *         image with the given ID
     */
    public TemporaryImage getTemporaryImage(String imageId) {
        synchronized (temporaryImages) {
            return temporaryImages.get(imageId);
        }
    }

    //
    // ACTIONS
    //

    /**
     * Locks the given Sone. A locked Sone will not be inserted by
     * {@link SoneInserter} until it is {@link #unlockSone(Sone) unlocked}
     * again.
     *
     * @param sone
     *            The sone to lock
     */
    public void lockSone(Sone sone) {
        synchronized (lockedSones) {
            if (lockedSones.add(sone)) {
                eventBus.post(new SoneLockedEvent(sone));
            }
        }
    }

    /**
     * Unlocks the given Sone.
     *
     * @see #lockSone(Sone)
     * @param sone
     *            The sone to unlock
     */
    public void unlockSone(Sone sone) {
        synchronized (lockedSones) {
            if (lockedSones.remove(sone)) {
                eventBus.post(new SoneUnlockedEvent(sone));
            }
        }
    }

    /**
     * Adds a local Sone from the given own identity.
     *
     * @param ownIdentity
     *            The own identity to create a Sone from
     * @return The added (or already existing) Sone
     */
    public Sone addLocalSone(OwnIdentity ownIdentity) {
        if (ownIdentity == null) {
            logger.log(Level.WARNING, "Given OwnIdentity is null!");
            return null;
        }
        logger.info(String.format("Adding Sone from OwnIdentity: %s", ownIdentity));
        synchronized (sones) {
            final Sone sone;
            try {
                sone = getLocalSone(ownIdentity.getId(), true).setIdentity(ownIdentity)
                        .setInsertUri(new FreenetURI(ownIdentity.getInsertUri()))
                        .setRequestUri(new FreenetURI(ownIdentity.getRequestUri()));
            } catch (MalformedURLException mue1) {
                logger.log(Level.SEVERE,
                        String.format("Could not convert the Identitys URIs to Freenet URIs: %s, %s",
                                ownIdentity.getInsertUri(), ownIdentity.getRequestUri()),
                        mue1);
                return null;
            }
            sone.setLatestEdition(Numbers.safeParseLong(ownIdentity.getProperty("Sone.LatestEdition"), (long) 0));
            sone.setClient(new Client("Sone", SonePlugin.VERSION.toString()));
            sone.setKnown(true);
            /* TODO - load posts n stuff */
            sones.put(ownIdentity.getId(), sone);
            final SoneInserter soneInserter = new SoneInserter(this, eventBus, freenetInterface, sone);
            soneInserters.put(sone, soneInserter);
            sone.setStatus(SoneStatus.idle);
            loadSone(sone);
            soneInserter.start();
            return sone;
        }
    }

    /**
     * Creates a new Sone for the given own identity.
     *
     * @param ownIdentity
     *            The own identity to create a Sone for
     * @return The created Sone
     */
    public Sone createSone(OwnIdentity ownIdentity) {
        if (!webOfTrustUpdater.addContextWait(ownIdentity, "Sone")) {
            logger.log(Level.SEVERE,
                    String.format("Could not add Sone? context to own identity: %s", ownIdentity));
            return null;
        }
        Sone sone = addLocalSone(ownIdentity);
        sone.getOptions().addBooleanOption("AutoFollow", new DefaultOption<Boolean>(false));
        sone.getOptions().addBooleanOption("EnableSoneInsertNotifications", new DefaultOption<Boolean>(false));
        sone.getOptions().addBooleanOption("ShowNotification/NewSones", new DefaultOption<Boolean>(true));
        sone.getOptions().addBooleanOption("ShowNotification/NewPosts", new DefaultOption<Boolean>(true));
        sone.getOptions().addBooleanOption("ShowNotification/NewReplies", new DefaultOption<Boolean>(true));
        sone.getOptions().addEnumOption("ShowCustomAvatars",
                new DefaultOption<ShowCustomAvatars>(ShowCustomAvatars.NEVER));

        followSone(sone, "nwa8lHa271k2QvJ8aa0Ov7IHAV-DFOCFgmDt3X6BpCI");
        touchConfiguration();
        return sone;
    }

    /**
     * Adds the Sone of the given identity.
     *
     * @param identity
     *            The identity whose Sone to add
     * @return The added or already existing Sone
     */
    public Sone addRemoteSone(Identity identity) {
        if (identity == null) {
            logger.log(Level.WARNING, "Given Identity is null!");
            return null;
        }
        synchronized (sones) {
            final Sone sone = getRemoteSone(identity.getId(), true);
            if (sone.isLocal()) {
                return sone;
            }
            sone.setIdentity(identity);
            boolean newSone = sone.getRequestUri() == null;
            sone.setRequestUri(SoneUri.create(identity.getRequestUri()));
            sone.setLatestEdition(Numbers.safeParseLong(identity.getProperty("Sone.LatestEdition"), (long) 0));
            if (newSone) {
                synchronized (knownSones) {
                    newSone = !knownSones.contains(sone.getId());
                }
                sone.setKnown(!newSone);
                if (newSone) {
                    eventBus.post(new NewSoneFoundEvent(sone));
                    for (Sone localSone : getLocalSones()) {
                        if (localSone.getOptions().getBooleanOption("AutoFollow").get()) {
                            followSone(localSone, sone.getId());
                        }
                    }
                }
            }
            soneDownloader.addSone(sone);
            soneDownloaders.execute(new Runnable() {

                @Override
                @SuppressWarnings("synthetic-access")
                public void run() {
                    soneDownloader.fetchSone(sone, sone.getRequestUri());
                }

            });
            return sone;
        }
    }

    /**
     * Lets the given local Sone follow the Sone with the given ID.
     *
     * @param sone
     *            The local Sone that should follow another Sone
     * @param soneId
     *            The ID of the Sone to follow
     */
    public void followSone(Sone sone, String soneId) {
        checkNotNull(sone, "sone must not be null");
        checkNotNull(soneId, "soneId must not be null");
        sone.addFriend(soneId);
        synchronized (soneFollowingTimes) {
            if (!soneFollowingTimes.containsKey(soneId)) {
                long now = System.currentTimeMillis();
                soneFollowingTimes.put(soneId, now);
                Optional<Sone> followedSone = getSone(soneId);
                if (!followedSone.isPresent()) {
                    return;
                }
                for (Post post : followedSone.get().getPosts()) {
                    if (post.getTime() < now) {
                        markPostKnown(post);
                    }
                }
                for (PostReply reply : followedSone.get().getReplies()) {
                    if (reply.getTime() < now) {
                        markReplyKnown(reply);
                    }
                }
            }
        }
        touchConfiguration();
    }

    /**
     * Lets the given local Sone unfollow the Sone with the given ID.
     *
     * @param sone
     *            The local Sone that should unfollow another Sone
     * @param soneId
     *            The ID of the Sone being unfollowed
     */
    public void unfollowSone(Sone sone, String soneId) {
        checkNotNull(sone, "sone must not be null");
        checkNotNull(soneId, "soneId must not be null");
        sone.removeFriend(soneId);
        boolean unfollowedSoneStillFollowed = false;
        for (Sone localSone : getLocalSones()) {
            unfollowedSoneStillFollowed |= localSone.hasFriend(soneId);
        }
        if (!unfollowedSoneStillFollowed) {
            synchronized (soneFollowingTimes) {
                soneFollowingTimes.remove(soneId);
            }
        }
        touchConfiguration();
    }

    /**
     * Sets the trust value of the given origin Sone for the target Sone.
     *
     * @param origin
     *            The origin Sone
     * @param target
     *            The target Sone
     * @param trustValue
     *            The trust value (from {@code -100} to {@code 100})
     */
    public void setTrust(Sone origin, Sone target, int trustValue) {
        checkNotNull(origin, "origin must not be null");
        checkArgument(origin.getIdentity() instanceof OwnIdentity, "origin must be a local Sone");
        checkNotNull(target, "target must not be null");
        checkArgument((trustValue >= -100) && (trustValue <= 100), "trustValue must be within [-100, 100]");
        webOfTrustUpdater.setTrust((OwnIdentity) origin.getIdentity(), target.getIdentity(), trustValue,
                preferences.getTrustComment());
    }

    /**
     * Removes any trust assignment for the given target Sone.
     *
     * @param origin
     *            The trust origin
     * @param target
     *            The trust target
     */
    public void removeTrust(Sone origin, Sone target) {
        checkNotNull(origin, "origin must not be null");
        checkNotNull(target, "target must not be null");
        checkArgument(origin.getIdentity() instanceof OwnIdentity, "origin must be a local Sone");
        webOfTrustUpdater.setTrust((OwnIdentity) origin.getIdentity(), target.getIdentity(), null, null);
    }

    /**
     * Assigns the configured positive trust value for the given target.
     *
     * @param origin
     *            The trust origin
     * @param target
     *            The trust target
     */
    public void trustSone(Sone origin, Sone target) {
        setTrust(origin, target, preferences.getPositiveTrust());
    }

    /**
     * Assigns the configured negative trust value for the given target.
     *
     * @param origin
     *            The trust origin
     * @param target
     *            The trust target
     */
    public void distrustSone(Sone origin, Sone target) {
        setTrust(origin, target, preferences.getNegativeTrust());
    }

    /**
     * Removes the trust assignment for the given target.
     *
     * @param origin
     *            The trust origin
     * @param target
     *            The trust target
     */
    public void untrustSone(Sone origin, Sone target) {
        removeTrust(origin, target);
    }

    /**
     * Updates the stored Sone with the given Sone.
     *
     * @param sone
     *            The updated Sone
     */
    public void updateSone(Sone sone) {
        updateSone(sone, false);
    }

    /**
     * Updates the stored Sone with the given Sone. If {@code soneRescueMode} is
     * {@code true}, an older Sone than the current Sone can be given to restore
     * an old state.
     *
     * @param sone
     *            The Sone to update
     * @param soneRescueMode
     *            {@code true} if the stored Sone should be updated regardless
     *            of the age of the given Sone
     */
    public void updateSone(Sone sone, boolean soneRescueMode) {
        Optional<Sone> storedSone = getSone(sone.getId());
        if (storedSone.isPresent()) {
            if (!soneRescueMode && !(sone.getTime() > storedSone.get().getTime())) {
                logger.log(Level.FINE,
                        String.format("Downloaded Sone %s is not newer than stored Sone %s.", sone, storedSone));
                return;
            }
            /* find removed posts. */
            Collection<Post> existingPosts = database.getPosts(sone.getId());
            for (Post oldPost : existingPosts) {
                if (!sone.getPosts().contains(oldPost)) {
                    eventBus.post(new PostRemovedEvent(oldPost));
                }
            }
            /* find new posts. */
            for (Post newPost : sone.getPosts()) {
                if (existingPosts.contains(newPost)) {
                    continue;
                }
                if (newPost.getTime() < getSoneFollowingTime(sone)) {
                    newPost.setKnown(true);
                } else if (!newPost.isKnown()) {
                    eventBus.post(new NewPostFoundEvent(newPost));
                }
            }
            /* store posts. */
            database.storePosts(sone, sone.getPosts());
            if (!soneRescueMode) {
                for (PostReply reply : storedSone.get().getReplies()) {
                    if (!sone.getReplies().contains(reply)) {
                        eventBus.post(new PostReplyRemovedEvent(reply));
                    }
                }
            }
            Set<PostReply> storedReplies = storedSone.get().getReplies();
            for (PostReply reply : sone.getReplies()) {
                if (storedReplies.contains(reply)) {
                    continue;
                }
                if (reply.getTime() < getSoneFollowingTime(sone)) {
                    reply.setKnown(true);
                } else if (!reply.isKnown()) {
                    eventBus.post(new NewPostReplyFoundEvent(reply));
                }
            }
            database.storePostReplies(sone, sone.getReplies());
            for (Album album : storedSone.get().getRootAlbum().getAlbums()) {
                database.removeAlbum(album);
                for (Image image : album.getImages()) {
                    database.removeImage(image);
                }
            }
            for (Album album : sone.getRootAlbum().getAlbums()) {
                database.storeAlbum(album);
                for (Image image : album.getImages()) {
                    database.storeImage(image);
                }
            }
            synchronized (sones) {
                sone.setOptions(storedSone.get().getOptions());
                sone.setKnown(storedSone.get().isKnown());
                sone.setStatus((sone.getTime() == 0) ? SoneStatus.unknown : SoneStatus.idle);
                if (sone.isLocal()) {
                    soneInserters.get(storedSone.get()).setSone(sone);
                    touchConfiguration();
                }
                sones.put(sone.getId(), sone);
            }
        }
    }

    /**
     * Deletes the given Sone. This will remove the Sone from the
     * {@link #getLocalSones() local Sones}, stop its {@link SoneInserter} and
     * remove the context from its identity.
     *
     * @param sone
     *            The Sone to delete
     */
    public void deleteSone(Sone sone) {
        if (!(sone.getIdentity() instanceof OwnIdentity)) {
            logger.log(Level.WARNING, String.format("Tried to delete Sone of non-own identity: %s", sone));
            return;
        }
        synchronized (sones) {
            if (!getLocalSones().contains(sone)) {
                logger.log(Level.WARNING, String.format("Tried to delete non-local Sone: %s", sone));
                return;
            }
            sones.remove(sone.getId());
            SoneInserter soneInserter = soneInserters.remove(sone);
            soneInserter.stop();
        }
        webOfTrustUpdater.removeContext((OwnIdentity) sone.getIdentity(), "Sone");
        webOfTrustUpdater.removeProperty((OwnIdentity) sone.getIdentity(), "Sone.LatestEdition");
        try {
            configuration.getLongValue("Sone/" + sone.getId() + "/Time").setValue(null);
        } catch (ConfigurationException ce1) {
            logger.log(Level.WARNING, "Could not remove Sone from configuration!", ce1);
        }
    }

    /**
     * Marks the given Sone as known. If the Sone was not {@link Post#isKnown()
     * known} before, a {@link MarkSoneKnownEvent} is fired.
     *
     * @param sone
     *            The Sone to mark as known
     */
    public void markSoneKnown(Sone sone) {
        if (!sone.isKnown()) {
            sone.setKnown(true);
            synchronized (knownSones) {
                knownSones.add(sone.getId());
            }
            eventBus.post(new MarkSoneKnownEvent(sone));
            touchConfiguration();
        }
    }

    /**
     * Loads and updates the given Sone from the configuration. If any error is
     * encountered, loading is aborted and the given Sone is not changed.
     *
     * @param sone
     *            The Sone to load and update
     */
    public void loadSone(Sone sone) {
        if (!sone.isLocal()) {
            logger.log(Level.FINE, String.format("Tried to load non-local Sone: %s", sone));
            return;
        }
        logger.info(String.format("Loading local Sone: %s", sone));

        /* initialize options. */
        sone.getOptions().addBooleanOption("AutoFollow", new DefaultOption<Boolean>(false));
        sone.getOptions().addBooleanOption("EnableSoneInsertNotifications", new DefaultOption<Boolean>(false));
        sone.getOptions().addBooleanOption("ShowNotification/NewSones", new DefaultOption<Boolean>(true));
        sone.getOptions().addBooleanOption("ShowNotification/NewPosts", new DefaultOption<Boolean>(true));
        sone.getOptions().addBooleanOption("ShowNotification/NewReplies", new DefaultOption<Boolean>(true));
        sone.getOptions().addEnumOption("ShowCustomAvatars",
                new DefaultOption<ShowCustomAvatars>(ShowCustomAvatars.NEVER));

        /* load Sone. */
        String sonePrefix = "Sone/" + sone.getId();
        Long soneTime = configuration.getLongValue(sonePrefix + "/Time").getValue(null);
        if (soneTime == null) {
            logger.log(Level.INFO, "Could not load Sone because no Sone has been saved.");
            return;
        }
        String lastInsertFingerprint = configuration.getStringValue(sonePrefix + "/LastInsertFingerprint")
                .getValue("");

        /* load profile. */
        Profile profile = new Profile(sone);
        profile.setFirstName(configuration.getStringValue(sonePrefix + "/Profile/FirstName").getValue(null));
        profile.setMiddleName(configuration.getStringValue(sonePrefix + "/Profile/MiddleName").getValue(null));
        profile.setLastName(configuration.getStringValue(sonePrefix + "/Profile/LastName").getValue(null));
        profile.setBirthDay(configuration.getIntValue(sonePrefix + "/Profile/BirthDay").getValue(null));
        profile.setBirthMonth(configuration.getIntValue(sonePrefix + "/Profile/BirthMonth").getValue(null));
        profile.setBirthYear(configuration.getIntValue(sonePrefix + "/Profile/BirthYear").getValue(null));

        /* load profile fields. */
        while (true) {
            String fieldPrefix = sonePrefix + "/Profile/Fields/" + profile.getFields().size();
            String fieldName = configuration.getStringValue(fieldPrefix + "/Name").getValue(null);
            if (fieldName == null) {
                break;
            }
            String fieldValue = configuration.getStringValue(fieldPrefix + "/Value").getValue("");
            profile.addField(fieldName).setValue(fieldValue);
        }

        /* load posts. */
        Set<Post> posts = new HashSet<Post>();
        while (true) {
            String postPrefix = sonePrefix + "/Posts/" + posts.size();
            String postId = configuration.getStringValue(postPrefix + "/ID").getValue(null);
            if (postId == null) {
                break;
            }
            String postRecipientId = configuration.getStringValue(postPrefix + "/Recipient").getValue(null);
            long postTime = configuration.getLongValue(postPrefix + "/Time").getValue((long) 0);
            String postText = configuration.getStringValue(postPrefix + "/Text").getValue(null);
            if ((postTime == 0) || (postText == null)) {
                logger.log(Level.WARNING, "Invalid post found, aborting load!");
                return;
            }
            PostBuilder postBuilder = postBuilder().withId(postId).from(sone.getId()).withTime(postTime)
                    .withText(postText);
            if ((postRecipientId != null) && (postRecipientId.length() == 43)) {
                postBuilder.to(postRecipientId);
            }
            posts.add(postBuilder.build());
        }

        /* load replies. */
        Set<PostReply> replies = new HashSet<PostReply>();
        while (true) {
            String replyPrefix = sonePrefix + "/Replies/" + replies.size();
            String replyId = configuration.getStringValue(replyPrefix + "/ID").getValue(null);
            if (replyId == null) {
                break;
            }
            String postId = configuration.getStringValue(replyPrefix + "/Post/ID").getValue(null);
            long replyTime = configuration.getLongValue(replyPrefix + "/Time").getValue((long) 0);
            String replyText = configuration.getStringValue(replyPrefix + "/Text").getValue(null);
            if ((postId == null) || (replyTime == 0) || (replyText == null)) {
                logger.log(Level.WARNING, "Invalid reply found, aborting load!");
                return;
            }
            PostReplyBuilder postReplyBuilder = postReplyBuilder().withId(replyId).from(sone.getId()).to(postId)
                    .withTime(replyTime).withText(replyText);
            replies.add(postReplyBuilder.build());
        }

        /* load post likes. */
        Set<String> likedPostIds = new HashSet<String>();
        while (true) {
            String likedPostId = configuration
                    .getStringValue(sonePrefix + "/Likes/Post/" + likedPostIds.size() + "/ID").getValue(null);
            if (likedPostId == null) {
                break;
            }
            likedPostIds.add(likedPostId);
        }

        /* load reply likes. */
        Set<String> likedReplyIds = new HashSet<String>();
        while (true) {
            String likedReplyId = configuration
                    .getStringValue(sonePrefix + "/Likes/Reply/" + likedReplyIds.size() + "/ID").getValue(null);
            if (likedReplyId == null) {
                break;
            }
            likedReplyIds.add(likedReplyId);
        }

        /* load friends. */
        Set<String> friends = new HashSet<String>();
        while (true) {
            String friendId = configuration.getStringValue(sonePrefix + "/Friends/" + friends.size() + "/ID")
                    .getValue(null);
            if (friendId == null) {
                break;
            }
            friends.add(friendId);
        }

        /* load albums. */
        List<Album> topLevelAlbums = new ArrayList<Album>();
        int albumCounter = 0;
        while (true) {
            String albumPrefix = sonePrefix + "/Albums/" + albumCounter++;
            String albumId = configuration.getStringValue(albumPrefix + "/ID").getValue(null);
            if (albumId == null) {
                break;
            }
            String albumTitle = configuration.getStringValue(albumPrefix + "/Title").getValue(null);
            String albumDescription = configuration.getStringValue(albumPrefix + "/Description").getValue(null);
            String albumParentId = configuration.getStringValue(albumPrefix + "/Parent").getValue(null);
            String albumImageId = configuration.getStringValue(albumPrefix + "/AlbumImage").getValue(null);
            if ((albumTitle == null) || (albumDescription == null)) {
                logger.log(Level.WARNING, "Invalid album found, aborting load!");
                return;
            }
            Album album = getAlbum(albumId).setSone(sone).modify().setTitle(albumTitle)
                    .setDescription(albumDescription).setAlbumImage(albumImageId).update();
            if (albumParentId != null) {
                Album parentAlbum = getAlbum(albumParentId, false);
                if (parentAlbum == null) {
                    logger.log(Level.WARNING, String.format("Invalid parent album ID: %s", albumParentId));
                    return;
                }
                parentAlbum.addAlbum(album);
            } else {
                if (!topLevelAlbums.contains(album)) {
                    topLevelAlbums.add(album);
                }
            }
        }

        /* load images. */
        int imageCounter = 0;
        while (true) {
            String imagePrefix = sonePrefix + "/Images/" + imageCounter++;
            String imageId = configuration.getStringValue(imagePrefix + "/ID").getValue(null);
            if (imageId == null) {
                break;
            }
            String albumId = configuration.getStringValue(imagePrefix + "/Album").getValue(null);
            String key = configuration.getStringValue(imagePrefix + "/Key").getValue(null);
            String title = configuration.getStringValue(imagePrefix + "/Title").getValue(null);
            String description = configuration.getStringValue(imagePrefix + "/Description").getValue(null);
            Long creationTime = configuration.getLongValue(imagePrefix + "/CreationTime").getValue(null);
            Integer width = configuration.getIntValue(imagePrefix + "/Width").getValue(null);
            Integer height = configuration.getIntValue(imagePrefix + "/Height").getValue(null);
            if ((albumId == null) || (key == null) || (title == null) || (description == null)
                    || (creationTime == null) || (width == null) || (height == null)) {
                logger.log(Level.WARNING, "Invalid image found, aborting load!");
                return;
            }
            Album album = getAlbum(albumId, false);
            if (album == null) {
                logger.log(Level.WARNING, "Invalid album image encountered, aborting load!");
                return;
            }
            Image image = getImage(imageId).modify().setSone(sone).setCreationTime(creationTime).setKey(key)
                    .setTitle(title).setDescription(description).setWidth(width).setHeight(height).update();
            album.addImage(image);
        }

        /* load avatar. */
        String avatarId = configuration.getStringValue(sonePrefix + "/Profile/Avatar").getValue(null);
        if (avatarId != null) {
            profile.setAvatar(getImage(avatarId, false));
        }

        /* load options. */
        sone.getOptions().getBooleanOption("AutoFollow")
                .set(configuration.getBooleanValue(sonePrefix + "/Options/AutoFollow").getValue(null));
        sone.getOptions().getBooleanOption("EnableSoneInsertNotifications").set(configuration
                .getBooleanValue(sonePrefix + "/Options/EnableSoneInsertNotifications").getValue(null));
        sone.getOptions().getBooleanOption("ShowNotification/NewSones").set(
                configuration.getBooleanValue(sonePrefix + "/Options/ShowNotification/NewSones").getValue(null));
        sone.getOptions().getBooleanOption("ShowNotification/NewPosts").set(
                configuration.getBooleanValue(sonePrefix + "/Options/ShowNotification/NewPosts").getValue(null));
        sone.getOptions().getBooleanOption("ShowNotification/NewReplies").set(
                configuration.getBooleanValue(sonePrefix + "/Options/ShowNotification/NewReplies").getValue(null));
        sone.getOptions().<ShowCustomAvatars>getEnumOption("ShowCustomAvatars").set(
                ShowCustomAvatars.valueOf(configuration.getStringValue(sonePrefix + "/Options/ShowCustomAvatars")
                        .getValue(ShowCustomAvatars.NEVER.name())));

        /* if were still here, Sone was loaded successfully. */
        synchronized (sone) {
            sone.setTime(soneTime);
            sone.setProfile(profile);
            sone.setPosts(posts);
            sone.setReplies(replies);
            sone.setLikePostIds(likedPostIds);
            sone.setLikeReplyIds(likedReplyIds);
            for (String friendId : friends) {
                followSone(sone, friendId);
            }
            for (Album album : sone.getRootAlbum().getAlbums()) {
                sone.getRootAlbum().removeAlbum(album);
            }
            for (Album album : topLevelAlbums) {
                sone.getRootAlbum().addAlbum(album);
            }
            soneInserters.get(sone).setLastInsertFingerprint(lastInsertFingerprint);
        }
        synchronized (knownSones) {
            for (String friend : friends) {
                knownSones.add(friend);
            }
        }
        database.storePosts(sone, posts);
        for (Post post : posts) {
            post.setKnown(true);
        }
        database.storePostReplies(sone, replies);
        for (PostReply reply : replies) {
            reply.setKnown(true);
        }

        logger.info(String.format("Sone loaded successfully: %s", sone));
    }

    /**
     * Creates a new post.
     *
     * @param sone
     *            The Sone that creates the post
     * @param text
     *            The text of the post
     * @return The created post
     */
    public Post createPost(Sone sone, String text) {
        return createPost(sone, System.currentTimeMillis(), text);
    }

    /**
     * Creates a new post.
     *
     * @param sone
     *            The Sone that creates the post
     * @param time
     *            The time of the post
     * @param text
     *            The text of the post
     * @return The created post
     */
    public Post createPost(Sone sone, long time, String text) {
        return createPost(sone, null, time, text);
    }

    /**
     * Creates a new post.
     *
     * @param sone
     *            The Sone that creates the post
     * @param recipient
     *            The recipient Sone, or {@code null} if this post does not have
     *            a recipient
     * @param text
     *            The text of the post
     * @return The created post
     */
    public Post createPost(Sone sone, Optional<Sone> recipient, String text) {
        return createPost(sone, recipient, System.currentTimeMillis(), text);
    }

    /**
     * Creates a new post.
     *
     * @param sone
     *            The Sone that creates the post
     * @param recipient
     *            The recipient Sone, or {@code null} if this post does not have
     *            a recipient
     * @param time
     *            The time of the post
     * @param text
     *            The text of the post
     * @return The created post
     */
    public Post createPost(Sone sone, Optional<Sone> recipient, long time, String text) {
        checkNotNull(text, "text must not be null");
        checkArgument(text.trim().length() > 0, "text must not be empty");
        if (!sone.isLocal()) {
            logger.log(Level.FINE, String.format("Tried to create post for non-local Sone: %s", sone));
            return null;
        }
        PostBuilder postBuilder = database.newPostBuilder();
        postBuilder.from(sone.getId()).randomId().withTime(time).withText(text.trim());
        if (recipient.isPresent()) {
            postBuilder.to(recipient.get().getId());
        }
        final Post post = postBuilder.build();
        database.storePost(post);
        eventBus.post(new NewPostFoundEvent(post));
        sone.addPost(post);
        touchConfiguration();
        localElementTicker.schedule(new Runnable() {

            /**
             * {@inheritDoc}
             */
            @Override
            public void run() {
                markPostKnown(post);
            }
        }, 10, TimeUnit.SECONDS);
        return post;
    }

    /**
     * Deletes the given post.
     *
     * @param post
     *            The post to delete
     */
    public void deletePost(Post post) {
        if (!post.getSone().isLocal()) {
            logger.log(Level.WARNING, String.format("Tried to delete post of non-local Sone: %s", post.getSone()));
            return;
        }
        database.removePost(post);
        eventBus.post(new PostRemovedEvent(post));
        markPostKnown(post);
        touchConfiguration();
    }

    /**
     * Marks the given post as known, if it is currently not a known post
     * (according to {@link Post#isKnown()}).
     *
     * @param post
     *            The post to mark as known
     */
    public void markPostKnown(Post post) {
        post.setKnown(true);
        eventBus.post(new MarkPostKnownEvent(post));
        touchConfiguration();
        for (PostReply reply : getReplies(post.getId())) {
            markReplyKnown(reply);
        }
    }

    /**
     * Bookmarks the given post.
     *
     * @param post
     *            The post to bookmark
     */
    public void bookmark(Post post) {
        bookmarkPost(post.getId());
    }

    /**
     * Bookmarks the post with the given ID.
     *
     * @param id
     *            The ID of the post to bookmark
     */
    public void bookmarkPost(String id) {
        synchronized (bookmarkedPosts) {
            bookmarkedPosts.add(id);
        }
    }

    /**
     * Removes the given post from the bookmarks.
     *
     * @param post
     *            The post to unbookmark
     */
    public void unbookmark(Post post) {
        unbookmarkPost(post.getId());
    }

    /**
     * Removes the post with the given ID from the bookmarks.
     *
     * @param id
     *            The ID of the post to unbookmark
     */
    public void unbookmarkPost(String id) {
        synchronized (bookmarkedPosts) {
            bookmarkedPosts.remove(id);
        }
    }

    /**
     * Creates a new reply.
     *
     * @param sone
     *            The Sone that creates the reply
     * @param post
     *            The post that this reply refers to
     * @param text
     *            The text of the reply
     * @return The created reply
     */
    public PostReply createReply(Sone sone, Post post, String text) {
        checkNotNull(text, "text must not be null");
        checkArgument(text.trim().length() > 0, "text must not be empty");
        if (!sone.isLocal()) {
            logger.log(Level.FINE, String.format("Tried to create reply for non-local Sone: %s", sone));
            return null;
        }
        PostReplyBuilder postReplyBuilder = postReplyBuilder();
        postReplyBuilder.randomId().from(sone.getId()).to(post.getId()).currentTime().withText(text.trim());
        final PostReply reply = postReplyBuilder.build();
        database.storePostReply(reply);
        eventBus.post(new NewPostReplyFoundEvent(reply));
        sone.addReply(reply);
        touchConfiguration();
        localElementTicker.schedule(new Runnable() {

            /**
             * {@inheritDoc}
             */
            @Override
            public void run() {
                markReplyKnown(reply);
            }
        }, 10, TimeUnit.SECONDS);
        return reply;
    }

    /**
     * Deletes the given reply.
     *
     * @param reply
     *            The reply to delete
     */
    public void deleteReply(PostReply reply) {
        Sone sone = reply.getSone();
        if (!sone.isLocal()) {
            logger.log(Level.FINE, String.format("Tried to delete non-local reply: %s", reply));
            return;
        }
        database.removePostReply(reply);
        markReplyKnown(reply);
        sone.removeReply(reply);
        touchConfiguration();
    }

    /**
     * Marks the given reply as known, if it is currently not a known reply
     * (according to {@link Reply#isKnown()}).
     *
     * @param reply
     *            The reply to mark as known
     */
    public void markReplyKnown(PostReply reply) {
        boolean previouslyKnown = reply.isKnown();
        reply.setKnown(true);
        eventBus.post(new MarkPostReplyKnownEvent(reply));
        if (!previouslyKnown) {
            touchConfiguration();
        }
    }

    /**
     * Creates a new top-level album for the given Sone.
     *
     * @param sone
     *            The Sone to create the album for
     * @return The new album
     */
    public Album createAlbum(Sone sone) {
        return createAlbum(sone, sone.getRootAlbum());
    }

    /**
     * Creates a new album for the given Sone.
     *
     * @param sone
     *            The Sone to create the album for
     * @param parent
     *            The parent of the album (may be {@code null} to create a
     *            top-level album)
     * @return The new album
     */
    public Album createAlbum(Sone sone, Album parent) {
        Album album = database.newAlbumBuilder().randomId().build();
        database.storeAlbum(album);
        album.setSone(sone);
        parent.addAlbum(album);
        return album;
    }

    /**
     * Deletes the given album. The owner of the album has to be a local Sone,
     * and the album has to be {@link Album#isEmpty() empty} to be deleted.
     *
     * @param album
     *            The album to remove
     */
    public void deleteAlbum(Album album) {
        checkNotNull(album, "album must not be null");
        checkArgument(album.getSone().isLocal(), "albums Sone must be a local Sone");
        if (!album.isEmpty()) {
            return;
        }
        album.getParent().removeAlbum(album);
        database.removeAlbum(album);
        touchConfiguration();
    }

    /**
     * Creates a new image.
     *
     * @param sone
     *            The Sone creating the image
     * @param album
     *            The album the image will be inserted into
     * @param temporaryImage
     *            The temporary image to create the image from
     * @return The newly created image
     */
    public Image createImage(Sone sone, Album album, TemporaryImage temporaryImage) {
        checkNotNull(sone, "sone must not be null");
        checkNotNull(album, "album must not be null");
        checkNotNull(temporaryImage, "temporaryImage must not be null");
        checkArgument(sone.isLocal(), "sone must be a local Sone");
        checkArgument(sone.equals(album.getSone()), "album must belong to the given Sone");
        Image image = database.newImageBuilder().withId(temporaryImage.getId()).build().modify().setSone(sone)
                .setCreationTime(System.currentTimeMillis()).update();
        album.addImage(image);
        database.storeImage(image);
        imageInserter.insertImage(temporaryImage, image);
        return image;
    }

    /**
     * Deletes the given image. This method will also delete a matching
     * temporary image.
     *
     * @see #deleteTemporaryImage(TemporaryImage)
     * @param image
     *            The image to delete
     */
    public void deleteImage(Image image) {
        checkNotNull(image, "image must not be null");
        checkArgument(image.getSone().isLocal(), "image must belong to a local Sone");
        deleteTemporaryImage(image.getId());
        image.getAlbum().removeImage(image);
        database.removeImage(image);
        touchConfiguration();
    }

    /**
     * Creates a new temporary image.
     *
     * @param mimeType
     *            The MIME type of the temporary image
     * @param imageData
     *            The encoded data of the image
     * @return The temporary image
     */
    public TemporaryImage createTemporaryImage(String mimeType, byte[] imageData) {
        TemporaryImage temporaryImage = new TemporaryImage();
        temporaryImage.setMimeType(mimeType).setImageData(imageData);
        synchronized (temporaryImages) {
            temporaryImages.put(temporaryImage.getId(), temporaryImage);
        }
        return temporaryImage;
    }

    /**
     * Deletes the given temporary image.
     *
     * @param temporaryImage
     *            The temporary image to delete
     */
    public void deleteTemporaryImage(TemporaryImage temporaryImage) {
        checkNotNull(temporaryImage, "temporaryImage must not be null");
        deleteTemporaryImage(temporaryImage.getId());
    }

    /**
     * Deletes the temporary image with the given ID.
     *
     * @param imageId
     *            The ID of the temporary image to delete
     */
    public void deleteTemporaryImage(String imageId) {
        checkNotNull(imageId, "imageId must not be null");
        synchronized (temporaryImages) {
            temporaryImages.remove(imageId);
        }
        Image image = getImage(imageId, false);
        if (image != null) {
            imageInserter.cancelImageInsert(image);
        }
    }

    /**
     * Notifies the core that the configuration, either of the core or of a
     * single local Sone, has changed, and that the configuration should be
     * saved.
     */
    public void touchConfiguration() {
        lastConfigurationUpdate = System.currentTimeMillis();
    }

    //
    // SERVICE METHODS
    //

    /**
     * Starts the core.
     */
    @Override
    public void serviceStart() {
        loadConfiguration();
        updateChecker.start();
        identityManager.start();
        webOfTrustUpdater.init();
        webOfTrustUpdater.start();
        database.start();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void serviceRun() {
        long lastSaved = System.currentTimeMillis();
        while (!shouldStop()) {
            sleep(1000);
            long now = System.currentTimeMillis();
            if (shouldStop()
                    || ((lastConfigurationUpdate > lastSaved) && ((now - lastConfigurationUpdate) > 5000))) {
                for (Sone localSone : getLocalSones()) {
                    saveSone(localSone);
                }
                saveConfiguration();
                lastSaved = now;
            }
        }
    }

    /**
     * Stops the core.
     */
    @Override
    public void serviceStop() {
        localElementTicker.shutdownNow();
        synchronized (sones) {
            for (Entry<Sone, SoneInserter> soneInserter : soneInserters.entrySet()) {
                soneInserter.getValue().stop();
                saveSone(getLocalSone(soneInserter.getKey().getId(), false));
            }
        }
        saveConfiguration();
        database.stop();
        webOfTrustUpdater.stop();
        updateChecker.stop();
        soneDownloader.stop();
        soneDownloaders.shutdown();
        identityManager.stop();
    }

    //
    // PRIVATE METHODS
    //

    /**
     * Saves the given Sone. This will persist all local settings for the given
     * Sone, such as the friends list and similar, private options.
     *
     * @param sone
     *            The Sone to save
     */
    private synchronized void saveSone(Sone sone) {
        if (!sone.isLocal()) {
            logger.log(Level.FINE, String.format("Tried to save non-local Sone: %s", sone));
            return;
        }
        if (!(sone.getIdentity() instanceof OwnIdentity)) {
            logger.log(Level.WARNING,
                    String.format("Local Sone without OwnIdentity found, refusing to save: %s", sone));
            return;
        }

        logger.log(Level.INFO, String.format("Saving Sone: %s", sone));
        try {
            /* save Sone into configuration. */
            String sonePrefix = "Sone/" + sone.getId();
            configuration.getLongValue(sonePrefix + "/Time").setValue(sone.getTime());
            configuration.getStringValue(sonePrefix + "/LastInsertFingerprint")
                    .setValue(soneInserters.get(sone).getLastInsertFingerprint());

            /* save profile. */
            Profile profile = sone.getProfile();
            configuration.getStringValue(sonePrefix + "/Profile/FirstName").setValue(profile.getFirstName());
            configuration.getStringValue(sonePrefix + "/Profile/MiddleName").setValue(profile.getMiddleName());
            configuration.getStringValue(sonePrefix + "/Profile/LastName").setValue(profile.getLastName());
            configuration.getIntValue(sonePrefix + "/Profile/BirthDay").setValue(profile.getBirthDay());
            configuration.getIntValue(sonePrefix + "/Profile/BirthMonth").setValue(profile.getBirthMonth());
            configuration.getIntValue(sonePrefix + "/Profile/BirthYear").setValue(profile.getBirthYear());
            configuration.getStringValue(sonePrefix + "/Profile/Avatar").setValue(profile.getAvatar());

            /* save profile fields. */
            int fieldCounter = 0;
            for (Field profileField : profile.getFields()) {
                String fieldPrefix = sonePrefix + "/Profile/Fields/" + fieldCounter++;
                configuration.getStringValue(fieldPrefix + "/Name").setValue(profileField.getName());
                configuration.getStringValue(fieldPrefix + "/Value").setValue(profileField.getValue());
            }
            configuration.getStringValue(sonePrefix + "/Profile/Fields/" + fieldCounter + "/Name").setValue(null);

            /* save posts. */
            int postCounter = 0;
            for (Post post : sone.getPosts()) {
                String postPrefix = sonePrefix + "/Posts/" + postCounter++;
                configuration.getStringValue(postPrefix + "/ID").setValue(post.getId());
                configuration.getStringValue(postPrefix + "/Recipient").setValue(post.getRecipientId().orNull());
                configuration.getLongValue(postPrefix + "/Time").setValue(post.getTime());
                configuration.getStringValue(postPrefix + "/Text").setValue(post.getText());
            }
            configuration.getStringValue(sonePrefix + "/Posts/" + postCounter + "/ID").setValue(null);

            /* save replies. */
            int replyCounter = 0;
            for (PostReply reply : sone.getReplies()) {
                String replyPrefix = sonePrefix + "/Replies/" + replyCounter++;
                configuration.getStringValue(replyPrefix + "/ID").setValue(reply.getId());
                configuration.getStringValue(replyPrefix + "/Post/ID").setValue(reply.getPostId());
                configuration.getLongValue(replyPrefix + "/Time").setValue(reply.getTime());
                configuration.getStringValue(replyPrefix + "/Text").setValue(reply.getText());
            }
            configuration.getStringValue(sonePrefix + "/Replies/" + replyCounter + "/ID").setValue(null);

            /* save post likes. */
            int postLikeCounter = 0;
            for (String postId : sone.getLikedPostIds()) {
                configuration.getStringValue(sonePrefix + "/Likes/Post/" + postLikeCounter++ + "/ID")
                        .setValue(postId);
            }
            configuration.getStringValue(sonePrefix + "/Likes/Post/" + postLikeCounter + "/ID").setValue(null);

            /* save reply likes. */
            int replyLikeCounter = 0;
            for (String replyId : sone.getLikedReplyIds()) {
                configuration.getStringValue(sonePrefix + "/Likes/Reply/" + replyLikeCounter++ + "/ID")
                        .setValue(replyId);
            }
            configuration.getStringValue(sonePrefix + "/Likes/Reply/" + replyLikeCounter + "/ID").setValue(null);

            /* save friends. */
            int friendCounter = 0;
            for (String friendId : sone.getFriends()) {
                configuration.getStringValue(sonePrefix + "/Friends/" + friendCounter++ + "/ID").setValue(friendId);
            }
            configuration.getStringValue(sonePrefix + "/Friends/" + friendCounter + "/ID").setValue(null);

            /* save albums. first, collect in a flat structure, top-level first. */
            List<Album> albums = FluentIterable.from(sone.getRootAlbum().getAlbums())
                    .transformAndConcat(Album.FLATTENER).toList();

            int albumCounter = 0;
            for (Album album : albums) {
                String albumPrefix = sonePrefix + "/Albums/" + albumCounter++;
                configuration.getStringValue(albumPrefix + "/ID").setValue(album.getId());
                configuration.getStringValue(albumPrefix + "/Title").setValue(album.getTitle());
                configuration.getStringValue(albumPrefix + "/Description").setValue(album.getDescription());
                configuration.getStringValue(albumPrefix + "/Parent")
                        .setValue(album.getParent().equals(sone.getRootAlbum()) ? null : album.getParent().getId());
                configuration.getStringValue(albumPrefix + "/AlbumImage")
                        .setValue(album.getAlbumImage() == null ? null : album.getAlbumImage().getId());
            }
            configuration.getStringValue(sonePrefix + "/Albums/" + albumCounter + "/ID").setValue(null);

            /* save images. */
            int imageCounter = 0;
            for (Album album : albums) {
                for (Image image : album.getImages()) {
                    if (!image.isInserted()) {
                        continue;
                    }
                    String imagePrefix = sonePrefix + "/Images/" + imageCounter++;
                    configuration.getStringValue(imagePrefix + "/ID").setValue(image.getId());
                    configuration.getStringValue(imagePrefix + "/Album").setValue(album.getId());
                    configuration.getStringValue(imagePrefix + "/Key").setValue(image.getKey());
                    configuration.getStringValue(imagePrefix + "/Title").setValue(image.getTitle());
                    configuration.getStringValue(imagePrefix + "/Description").setValue(image.getDescription());
                    configuration.getLongValue(imagePrefix + "/CreationTime").setValue(image.getCreationTime());
                    configuration.getIntValue(imagePrefix + "/Width").setValue(image.getWidth());
                    configuration.getIntValue(imagePrefix + "/Height").setValue(image.getHeight());
                }
            }
            configuration.getStringValue(sonePrefix + "/Images/" + imageCounter + "/ID").setValue(null);

            /* save options. */
            configuration.getBooleanValue(sonePrefix + "/Options/AutoFollow")
                    .setValue(sone.getOptions().getBooleanOption("AutoFollow").getReal());
            configuration.getBooleanValue(sonePrefix + "/Options/ShowNotification/NewSones")
                    .setValue(sone.getOptions().getBooleanOption("ShowNotification/NewSones").getReal());
            configuration.getBooleanValue(sonePrefix + "/Options/ShowNotification/NewPosts")
                    .setValue(sone.getOptions().getBooleanOption("ShowNotification/NewPosts").getReal());
            configuration.getBooleanValue(sonePrefix + "/Options/ShowNotification/NewReplies")
                    .setValue(sone.getOptions().getBooleanOption("ShowNotification/NewReplies").getReal());
            configuration.getBooleanValue(sonePrefix + "/Options/EnableSoneInsertNotifications")
                    .setValue(sone.getOptions().getBooleanOption("EnableSoneInsertNotifications").getReal());
            configuration.getStringValue(sonePrefix + "/Options/ShowCustomAvatars")
                    .setValue(sone.getOptions().<ShowCustomAvatars>getEnumOption("ShowCustomAvatars").get().name());

            configuration.save();

            webOfTrustUpdater.setProperty((OwnIdentity) sone.getIdentity(), "Sone.LatestEdition",
                    String.valueOf(sone.getLatestEdition()));

            logger.log(Level.INFO, String.format("Sone %s saved.", sone));
        } catch (ConfigurationException ce1) {
            logger.log(Level.WARNING, String.format("Could not save Sone: %s", sone), ce1);
        }
    }

    /**
     * Saves the current options.
     */
    private void saveConfiguration() {
        synchronized (configuration) {
            if (storingConfiguration) {
                logger.log(Level.FINE, "Already storing configuration");
                return;
            }
            storingConfiguration = true;
        }

        /* store the options first. */
        try {
            configuration.getIntValue("Option/ConfigurationVersion").setValue(0);
            configuration.getIntValue("Option/InsertionDelay")
                    .setValue(options.getIntegerOption("InsertionDelay").getReal());
            configuration.getIntValue("Option/PostsPerPage")
                    .setValue(options.getIntegerOption("PostsPerPage").getReal());
            configuration.getIntValue("Option/ImagesPerPage")
                    .setValue(options.getIntegerOption("ImagesPerPage").getReal());
            configuration.getIntValue("Option/CharactersPerPost")
                    .setValue(options.getIntegerOption("CharactersPerPost").getReal());
            configuration.getIntValue("Option/PostCutOffLength")
                    .setValue(options.getIntegerOption("PostCutOffLength").getReal());
            configuration.getBooleanValue("Option/RequireFullAccess")
                    .setValue(options.getBooleanOption("RequireFullAccess").getReal());
            configuration.getIntValue("Option/PositiveTrust")
                    .setValue(options.getIntegerOption("PositiveTrust").getReal());
            configuration.getIntValue("Option/NegativeTrust")
                    .setValue(options.getIntegerOption("NegativeTrust").getReal());
            configuration.getStringValue("Option/TrustComment")
                    .setValue(options.getStringOption("TrustComment").getReal());
            configuration.getBooleanValue("Option/ActivateFcpInterface")
                    .setValue(options.getBooleanOption("ActivateFcpInterface").getReal());
            configuration.getIntValue("Option/FcpFullAccessRequired")
                    .setValue(options.getIntegerOption("FcpFullAccessRequired").getReal());

            /* save known Sones. */
            int soneCounter = 0;
            synchronized (knownSones) {
                for (String knownSoneId : knownSones) {
                    configuration.getStringValue("KnownSone/" + soneCounter++ + "/ID").setValue(knownSoneId);
                }
                configuration.getStringValue("KnownSone/" + soneCounter + "/ID").setValue(null);
            }

            /* save Sone following times. */
            soneCounter = 0;
            synchronized (soneFollowingTimes) {
                for (Entry<String, Long> soneFollowingTime : soneFollowingTimes.entrySet()) {
                    configuration.getStringValue("SoneFollowingTimes/" + soneCounter + "/Sone")
                            .setValue(soneFollowingTime.getKey());
                    configuration.getLongValue("SoneFollowingTimes/" + soneCounter + "/Time")
                            .setValue(soneFollowingTime.getValue());
                    ++soneCounter;
                }
                configuration.getStringValue("SoneFollowingTimes/" + soneCounter + "/Sone").setValue(null);
            }

            /* save known posts. */
            database.save();

            /* save bookmarked posts. */
            int bookmarkedPostCounter = 0;
            synchronized (bookmarkedPosts) {
                for (String bookmarkedPostId : bookmarkedPosts) {
                    configuration.getStringValue("Bookmarks/Post/" + bookmarkedPostCounter++ + "/ID")
                            .setValue(bookmarkedPostId);
                }
            }
            configuration.getStringValue("Bookmarks/Post/" + bookmarkedPostCounter++ + "/ID").setValue(null);

            /* now save it. */
            configuration.save();

        } catch (ConfigurationException ce1) {
            logger.log(Level.SEVERE, "Could not store configuration!", ce1);
        } catch (DatabaseException de1) {
            logger.log(Level.SEVERE, "Could not save database!", de1);
        } finally {
            synchronized (configuration) {
                storingConfiguration = false;
            }
        }
    }

    /**
     * Loads the configuration.
     */
    private void loadConfiguration() {
        /* create options. */
        options.addIntegerOption("InsertionDelay", new DefaultOption<Integer>(60,
                new IntegerRangePredicate(0, Integer.MAX_VALUE), new OptionWatcher<Integer>() {

                    @Override
                    public void optionChanged(Option<Integer> option, Integer oldValue, Integer newValue) {
                        SoneInserter.setInsertionDelay(newValue);
                    }

                }));
        options.addIntegerOption("PostsPerPage",
                new DefaultOption<Integer>(10, new IntegerRangePredicate(1, Integer.MAX_VALUE)));
        options.addIntegerOption("ImagesPerPage",
                new DefaultOption<Integer>(9, new IntegerRangePredicate(1, Integer.MAX_VALUE)));
        options.addIntegerOption("CharactersPerPost", new DefaultOption<Integer>(400,
                Predicates.<Integer>or(new IntegerRangePredicate(50, Integer.MAX_VALUE), Predicates.equalTo(-1))));
        options.addIntegerOption("PostCutOffLength", new DefaultOption<Integer>(200,
                Predicates.<Integer>or(new IntegerRangePredicate(50, Integer.MAX_VALUE), Predicates.equalTo(-1))));
        options.addBooleanOption("RequireFullAccess", new DefaultOption<Boolean>(false));
        options.addIntegerOption("PositiveTrust",
                new DefaultOption<Integer>(75, new IntegerRangePredicate(0, 100)));
        options.addIntegerOption("NegativeTrust",
                new DefaultOption<Integer>(-25, new IntegerRangePredicate(-100, 100)));
        options.addStringOption("TrustComment", new DefaultOption<String>("Set from Sone Web Interface"));
        options.addBooleanOption("ActivateFcpInterface",
                new DefaultOption<Boolean>(false, new OptionWatcher<Boolean>() {

                    @Override
                    @SuppressWarnings("synthetic-access")
                    public void optionChanged(Option<Boolean> option, Boolean oldValue, Boolean newValue) {
                        fcpInterface.setActive(newValue);
                    }
                }));
        options.addIntegerOption("FcpFullAccessRequired",
                new DefaultOption<Integer>(2, new OptionWatcher<Integer>() {

                    @Override
                    @SuppressWarnings("synthetic-access")
                    public void optionChanged(Option<Integer> option, Integer oldValue, Integer newValue) {
                        fcpInterface.setFullAccessRequired(FullAccessRequired.values()[newValue]);
                    }

                }));

        loadConfigurationValue("InsertionDelay");
        loadConfigurationValue("PostsPerPage");
        loadConfigurationValue("ImagesPerPage");
        loadConfigurationValue("CharactersPerPost");
        loadConfigurationValue("PostCutOffLength");
        options.getBooleanOption("RequireFullAccess")
                .set(configuration.getBooleanValue("Option/RequireFullAccess").getValue(null));
        loadConfigurationValue("PositiveTrust");
        loadConfigurationValue("NegativeTrust");
        options.getStringOption("TrustComment")
                .set(configuration.getStringValue("Option/TrustComment").getValue(null));
        options.getBooleanOption("ActivateFcpInterface")
                .set(configuration.getBooleanValue("Option/ActivateFcpInterface").getValue(null));
        options.getIntegerOption("FcpFullAccessRequired")
                .set(configuration.getIntValue("Option/FcpFullAccessRequired").getValue(null));

        /* load known Sones. */
        int soneCounter = 0;
        while (true) {
            String knownSoneId = configuration.getStringValue("KnownSone/" + soneCounter++ + "/ID").getValue(null);
            if (knownSoneId == null) {
                break;
            }
            synchronized (knownSones) {
                knownSones.add(knownSoneId);
            }
        }

        /* load Sone following times. */
        soneCounter = 0;
        while (true) {
            String soneId = configuration.getStringValue("SoneFollowingTimes/" + soneCounter + "/Sone")
                    .getValue(null);
            if (soneId == null) {
                break;
            }
            long time = configuration.getLongValue("SoneFollowingTimes/" + soneCounter + "/Time")
                    .getValue(Long.MAX_VALUE);
            synchronized (soneFollowingTimes) {
                soneFollowingTimes.put(soneId, time);
            }
            ++soneCounter;
        }

        /* load bookmarked posts. */
        int bookmarkedPostCounter = 0;
        while (true) {
            String bookmarkedPostId = configuration
                    .getStringValue("Bookmarks/Post/" + bookmarkedPostCounter++ + "/ID").getValue(null);
            if (bookmarkedPostId == null) {
                break;
            }
            synchronized (bookmarkedPosts) {
                bookmarkedPosts.add(bookmarkedPostId);
            }
        }

    }

    /**
     * Loads an {@link Integer} configuration value for the option with the
     * given name, logging validation failures.
     *
     * @param optionName
     *            The name of the option to load
     */
    private void loadConfigurationValue(String optionName) {
        try {
            options.getIntegerOption(optionName)
                    .set(configuration.getIntValue("Option/" + optionName).getValue(null));
        } catch (IllegalArgumentException iae1) {
            logger.log(Level.WARNING,
                    String.format("Invalid value for %s in configuration, using default.", optionName));
        }
    }

    /**
     * Notifies the core that a new {@link OwnIdentity} was added.
     *
     * @param ownIdentityAddedEvent
     *            The event
     */
    @Subscribe
    public void ownIdentityAdded(OwnIdentityAddedEvent ownIdentityAddedEvent) {
        OwnIdentity ownIdentity = ownIdentityAddedEvent.ownIdentity();
        logger.log(Level.FINEST, String.format("Adding OwnIdentity: %s", ownIdentity));
        if (ownIdentity.hasContext("Sone")) {
            addLocalSone(ownIdentity);
        }
    }

    /**
     * Notifies the core that an {@link OwnIdentity} was removed.
     *
     * @param ownIdentityRemovedEvent
     *            The event
     */
    @Subscribe
    public void ownIdentityRemoved(OwnIdentityRemovedEvent ownIdentityRemovedEvent) {
        OwnIdentity ownIdentity = ownIdentityRemovedEvent.ownIdentity();
        logger.log(Level.FINEST, String.format("Removing OwnIdentity: %s", ownIdentity));
        trustedIdentities.removeAll(ownIdentity);
    }

    /**
     * Notifies the core that a new {@link Identity} was added.
     *
     * @param identityAddedEvent
     *            The event
     */
    @Subscribe
    public void identityAdded(IdentityAddedEvent identityAddedEvent) {
        Identity identity = identityAddedEvent.identity();
        logger.log(Level.FINEST, String.format("Adding Identity: %s", identity));
        trustedIdentities.put(identityAddedEvent.ownIdentity(), identity);
        addRemoteSone(identity);
    }

    /**
     * Notifies the core that an {@link Identity} was updated.
     *
     * @param identityUpdatedEvent
     *            The event
     */
    @Subscribe
    public void identityUpdated(IdentityUpdatedEvent identityUpdatedEvent) {
        final Identity identity = identityUpdatedEvent.identity();
        soneDownloaders.execute(new Runnable() {

            @Override
            @SuppressWarnings("synthetic-access")
            public void run() {
                Sone sone = getRemoteSone(identity.getId(), false);
                if (sone.isLocal()) {
                    return;
                }
                sone.setIdentity(identity);
                sone.setLatestEdition(
                        Numbers.safeParseLong(identity.getProperty("Sone.LatestEdition"), sone.getLatestEdition()));
                soneDownloader.addSone(sone);
                soneDownloader.fetchSone(sone);
            }
        });
    }

    /**
     * Notifies the core that an {@link Identity} was removed.
     *
     * @param identityRemovedEvent
     *            The event
     */
    @Subscribe
    public void identityRemoved(IdentityRemovedEvent identityRemovedEvent) {
        OwnIdentity ownIdentity = identityRemovedEvent.ownIdentity();
        Identity identity = identityRemovedEvent.identity();
        trustedIdentities.remove(ownIdentity, identity);
        boolean foundIdentity = false;
        for (Entry<OwnIdentity, Collection<Identity>> trustedIdentity : trustedIdentities.asMap().entrySet()) {
            if (trustedIdentity.getKey().equals(ownIdentity)) {
                continue;
            }
            if (trustedIdentity.getValue().contains(identity)) {
                foundIdentity = true;
            }
        }
        if (foundIdentity) {
            /* some local identity still trusts this identity, dont remove. */
            return;
        }
        Optional<Sone> sone = getSone(identity.getId());
        if (!sone.isPresent()) {
            /* TODO - we dont have the Sone anymore. should this happen? */
            return;
        }
        database.removePosts(sone.get());
        for (Post post : sone.get().getPosts()) {
            eventBus.post(new PostRemovedEvent(post));
        }
        database.removePostReplies(sone.get());
        for (PostReply reply : sone.get().getReplies()) {
            eventBus.post(new PostReplyRemovedEvent(reply));
        }
        synchronized (sones) {
            sones.remove(identity.getId());
        }
        eventBus.post(new SoneRemovedEvent(sone.get()));
    }

    /**
     * Deletes the temporary image.
     *
     * @param imageInsertFinishedEvent
     *            The event
     */
    @Subscribe
    public void imageInsertFinished(ImageInsertFinishedEvent imageInsertFinishedEvent) {
        logger.log(Level.WARNING, String.format("Image insert finished for %s: %s",
                imageInsertFinishedEvent.image(), imageInsertFinishedEvent.resultingUri()));
        imageInsertFinishedEvent.image().modify().setKey(imageInsertFinishedEvent.resultingUri().toString())
                .update();
        deleteTemporaryImage(imageInsertFinishedEvent.image().getId());
        touchConfiguration();
    }

}