Mercury-IM/core/src/main/java/org/mercury_im/messenger/core/centers/ConnectionCenter.java

package org.mercury_im.messenger.core.centers;

import org.jivesoftware.smack.AbstractXMPPConnection;
import org.jivesoftware.smack.tcp.XMPPTCPConnection;
import org.jivesoftware.smack.tcp.XMPPTCPConnectionConfiguration;
import org.jivesoftware.smackx.caps.EntityCapsManager;
import org.mercury_im.messenger.core.stores.EntityCapsStore;
import org.mercury_im.messenger.core.connection.MercuryConfiguration;
import org.mercury_im.messenger.core.connection.MercuryConnection;
import org.mercury_im.messenger.core.stores.PlainMessageStore;
import org.mercury_im.messenger.core.stores.RosterStore;
import org.mercury_im.messenger.persistence.model.AccountModel;
import org.mercury_im.messenger.persistence.repository.AccountRepository;
import org.mercury_im.messenger.persistence.repository.RosterRepository;

import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.logging.Level;
import java.util.logging.Logger;

import javax.inject.Inject;
import javax.inject.Singleton;

import io.reactivex.disposables.CompositeDisposable;
import io.reactivex.functions.Consumer;
import io.reactivex.schedulers.Schedulers;

@Singleton
public class ConnectionCenter {

    private static final Logger LOGGER = Logger.getLogger(ConnectionCenter.class.getName());

    // Injected
    private final AccountRepository accountRepository;
    private final PlainMessageStore messageStore;
    private final EntityCapsStore entityCapsStore;
    private final RosterRepository rosterRepository;

    // Connections
    private final Map<Long, MercuryConnection> connectionMap =
            Collections.synchronizedMap(new HashMap<>());

    // Disposable for rx
    private final CompositeDisposable disposable = new CompositeDisposable();

    private final AtomicBoolean isConnectionCenterStarted = new AtomicBoolean(false);

    @Inject
    public ConnectionCenter(EntityCapsStore capsStore,
                            PlainMessageStore messageStore,
                            AccountRepository accountRepository,
                            RosterRepository rosterRepository) {
        LOGGER.log(Level.INFO, "ConnectionCenter initialized");
        this.entityCapsStore = capsStore;
        this.messageStore = messageStore;
        this.accountRepository = accountRepository;
        this.rosterRepository = rosterRepository;

        EntityCapsManager.setPersistentCache(capsStore);
        startUp();
    }

    /**
     * Start up the center by subscribing to changes of the {@link AccountModel accounts} in the
     * database. For each new {@link AccountModel} it creates a {@link MercuryConnection} and
     * stores it in the {@link #connectionMap}.
     */
    @SuppressWarnings("unchecked")
    public synchronized void startUp() {

        if (isConnectionCenterStarted.getAndSet(true)) {
            // already started.
            return;
        }

        // otherwise subscribe to accounts and create connections.
        disposable.add(
                accountRepository.getAllAccounts()
                        .observeOn(Schedulers.io())
                        .subscribeOn(Schedulers.computation())
                        .subscribe((Consumer<List<? extends AccountModel>>) accounts -> {
                            LOGGER.log(Level.INFO, "Accounts changed.");
                            Set<Long> accountIds = new HashSet<>();
                            // Add missing connections to the map
                            for (AccountModel account : accounts) {
                                accountIds.add(account.getId());
                                if (connectionMap.get(account.getId()) != null) {
                                    continue;
                                }

                                LOGGER.log(Level.INFO, "Add new connection " + account.getJid().toString() + " to ConnectionCenter list.");
                                MercuryConnection connection = createConnection(account);
                                connectionMap.put(account.getId(), connection);

                                RosterStore rosterStore = new RosterStore(rosterRepository);
                                rosterStore.setAccountId(account.getId());
                                rosterStore.subscribe();
                                connection.getRoster().setRosterStore(rosterStore);

                                messageStore.registerForMercuryConnection(connection);

                                if (account.getEnabled()) {
                                    LOGGER.log(Level.INFO, "Connecting...");
                                    connection.connect();
                                    LOGGER.log(Level.INFO, "Connected!");
                                } else {
                                    LOGGER.log(Level.INFO, "Account not enabled. Skip.");
                                }
                            }

                            // Remove unwanted connections from the map
                            for (long connectionId : connectionMap.keySet()) {
                                if (!accountIds.contains(connectionId)) {
                                    AbstractXMPPConnection con =
                                            (AbstractXMPPConnection) connectionMap.get(connectionId).getConnection();
                                    con.disconnect();
                                    connectionMap.remove(connectionId);
                                }
                            }
                        }));
    }

    public MercuryConnection getConnection(AccountModel account) {
        return getConnection(account.getId());
    }

    public MercuryConnection getConnection(long accountId) {
        return connectionMap.get(accountId);
    }

    public void putConnection(MercuryConnection connection) {
        connectionMap.put(connection.getAccountId(), connection);
    }

    public MercuryConnection createConnection(AccountModel accountModel) {
        LOGGER.log(Level.INFO, "Create Connection for " + accountModel.getJid().toString());
        XMPPTCPConnectionConfiguration configuration = XMPPTCPConnectionConfiguration.builder()
                .setHost(accountModel.getJid().getDomain().toString())
                .setXmppAddressAndPassword(accountModel.getJid(), accountModel.getPassword())
                .setConnectTimeout(2 * 60 * 1000)
                .setEnabledSSLCiphers(MercuryConfiguration.enabledCiphers)
                .setEnabledSSLProtocols(MercuryConfiguration.enabledProtocols)
                .build();

        AbstractXMPPConnection tcpConnection = new XMPPTCPConnection(configuration);
        return new MercuryConnection(tcpConnection, accountModel.getId());
    }
}