WikisImpl.java

package comeon.wikis;

import com.google.common.eventbus.EventBus;
import com.google.inject.Inject;
import com.google.inject.Singleton;
import comeon.ComeOn;
import comeon.core.WithPreferences;
import comeon.model.User;
import comeon.model.Wiki;

import java.util.ArrayList;
import java.util.List;
import java.util.prefs.BackingStoreException;
import java.util.prefs.Preferences;

@Singleton
public final class WikisImpl implements Wikis, WithPreferences {

    private static final String DEFAULT_ACTIVE_WIKI_NAME = "Commons";

    private final ArrayList<Wiki> wikis;

    private final Preferences preferences;

    private final EventBus bus;

    private Wiki activeWiki;

    @Inject
    public WikisImpl(final EventBus bus) {
        this.bus = bus;
        this.wikis = new ArrayList<>(0);
        preferences = Preferences.userNodeForPackage(ComeOn.class).node("wikis");
    }

    @Override
    public void loadPreferences() throws BackingStoreException {
        final String activeWikiName = preferences.get(WikiPreferencesKeys.ACTIVE.name(), DEFAULT_ACTIVE_WIKI_NAME);
        final String[] wikiNames = preferences.childrenNames();
        this.wikis.ensureCapacity(wikiNames.length);
        for (final String name : wikiNames) {
            final Wiki wiki = this.readWiki(name);
            if (activeWikiName.equals(name)) {
                activeWiki = wiki;
            }
        }
    }

    @Override
    public List<Wiki> getWikis() {
        return new ArrayList<>(wikis);
    }

    @Override
    public void setWikis(final List<Wiki> wikis) {
        this.wikis.clear();
        this.wikis.ensureCapacity(wikis.size());
        this.wikis.addAll(wikis);
    }

    @Override
    public void save() throws BackingStoreException {
        for (final String name : preferences.childrenNames()) {
            preferences.node(name).removeNode();
        }
        for (final Wiki wiki : wikis) {
            final Preferences node = preferences.node(wiki.getName());
            node.put(WikiPreferencesKeys.URL.name(), wiki.getUrl());
            final Preferences userNode = node.node("user");
            userNode.put(UserPreferencesKeys.LOGIN.name(), wiki.getUser().getLogin());
            userNode.put(UserPreferencesKeys.PASSWORD.name(), wiki.getUser().getPassword());
            userNode.put(UserPreferencesKeys.DISPLAY_NAME.name(), wiki.getUser().getDisplayName());
        }
    }

    @Override
    public Wiki getActiveWiki() {
        return activeWiki;
    }

    @Override
    public void setActiveWiki(final Wiki wiki) {
        final ActiveWikiChangeEvent event = new ActiveWikiChangeEvent(this.activeWiki, wiki);
        this.activeWiki = wiki;
        preferences.put(WikiPreferencesKeys.ACTIVE.name(), wiki.getName());
        bus.post(event);
    }

    private Wiki readWiki(final String name) throws BackingStoreException {
        final Preferences node = preferences.node(name);
        final String url = node.get(WikiPreferencesKeys.URL.name(), null);
        final Wiki wiki = new Wiki(name, url, this.readUser(node));
        wikis.add(wiki);
        return wiki;
    }

    private User readUser(final Preferences wikiNode) throws BackingStoreException {
        final Preferences userNode = wikiNode.node("user");
        final String login = userNode.get(UserPreferencesKeys.LOGIN.name(), null);
        final String password = userNode.get(UserPreferencesKeys.PASSWORD.name(), null);
        final String displayName = userNode.get(UserPreferencesKeys.DISPLAY_NAME.name(), null);
        return new User(login, password, displayName);
    }

    private enum WikiPreferencesKeys {
        URL, ACTIVE
    }

    private enum UserPreferencesKeys {
        LOGIN, PASSWORD, DISPLAY_NAME
    }
}