/**
 * Copyright (c) 2013, Redsolution LTD. All rights reserved.
 *
 * This file is part of Xabber project; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License, Version 3.
 *
 * Xabber 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 com.xabber.android.data.roster;

import com.xabber.android.R;
import com.xabber.android.data.Application;
import com.xabber.android.data.NetworkException;
import com.xabber.android.data.OnLoadListener;
import com.xabber.android.data.account.AccountItem;
import com.xabber.android.data.account.AccountManager;
import com.xabber.android.data.account.OnAccountDisabledListener;
import com.xabber.android.data.account.StatusMode;
import com.xabber.android.data.connection.ConnectionItem;
import com.xabber.android.data.connection.ConnectionManager;
import com.xabber.android.data.connection.OnDisconnectListener;
import com.xabber.android.data.connection.OnPacketListener;
import com.xabber.android.data.entity.NestedMap;
import com.xabber.android.data.extension.archive.OnArchiveModificationsReceivedListener;
import com.xabber.android.data.notification.EntityNotificationProvider;
import com.xabber.android.data.notification.NotificationManager;
import com.xabber.xmpp.address.Jid;

import org.jivesoftware.smack.packet.IQ;
import org.jivesoftware.smack.packet.Presence;
import org.jivesoftware.smack.packet.Presence.Type;
import org.jivesoftware.smack.packet.Stanza;
import org.jivesoftware.smack.roster.packet.RosterPacket;
import org.jxmpp.util.XmppStringUtils;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;

/**
 * Process contact's presence information.
 *
 * @author alexander.ivanov
 */
public class PresenceManager implements OnArchiveModificationsReceivedListener,
        OnPacketListener, OnLoadListener, OnAccountDisabledListener,
        OnDisconnectListener {

    private final static PresenceManager instance;

    static {
        instance = new PresenceManager();
        Application.getInstance().addManager(instance);
    }

    private final EntityNotificationProvider<SubscriptionRequest> subscriptionRequestProvider;
    /**
     * List of account with requested subscriptions for auto accept incoming
     * subscription request.
     */
    private final HashMap<String, HashSet<String>> requestedSubscriptions;
    /**
     * Presence container for bare address in account.
     */
    private final NestedMap<ResourceContainer> presenceContainers;
    /**
     * Account ready to send / update its presence information.
     */
    private final ArrayList<String> readyAccounts;

    private PresenceManager() {
        subscriptionRequestProvider = new EntityNotificationProvider<SubscriptionRequest>(
                R.drawable.ic_stat_add_circle);
        requestedSubscriptions = new HashMap<String, HashSet<String>>();
        presenceContainers = new NestedMap<ResourceContainer>();
        readyAccounts = new ArrayList<String>();
    }

    public static PresenceManager getInstance() {
        return instance;
    }

    @Override
    public void onLoad() {
        Application.getInstance().runOnUiThread(new Runnable() {
            @Override
            public void run() {
                onLoaded();
            }
        });
    }

    private void onLoaded() {
        NotificationManager.getInstance().registerNotificationProvider(
                subscriptionRequestProvider);
    }

    /**
     * @param account
     * @param user
     * @return <code>null</code> can be returned.
     */
    public SubscriptionRequest getSubscriptionRequest(String account,
                                                      String user) {
        return subscriptionRequestProvider.get(account, user);
    }

    /**
     * Requests subscription to the contact.
     *
     * @param account
     * @param bareAddress
     * @throws NetworkException
     */
    public void requestSubscription(String account, String bareAddress)
            throws NetworkException {
        Presence packet = new Presence(Presence.Type.subscribe);
        packet.setTo(bareAddress);
        ConnectionManager.getInstance().sendPacket(account, packet);
        HashSet<String> set = requestedSubscriptions.get(account);
        if (set == null) {
            set = new HashSet<String>();
            requestedSubscriptions.put(account, set);
        }
        set.add(bareAddress);
    }

    private void removeRequestedSubscription(String account, String bareAddress) {
        HashSet<String> set = requestedSubscriptions.get(account);
        if (set != null)
            set.remove(bareAddress);
    }

    /**
     * Accepts subscription request from the entity (share own presence).
     *
     * @param account
     * @param bareAddress
     * @throws NetworkException
     */
    public void acceptSubscription(String account, String bareAddress)
            throws NetworkException {
        Presence packet = new Presence(Presence.Type.subscribed);
        packet.setTo(bareAddress);
        ConnectionManager.getInstance().sendPacket(account, packet);
        subscriptionRequestProvider.remove(account, bareAddress);
        removeRequestedSubscription(account, bareAddress);
    }

    /**
     * Discards subscription request from the entity (deny own presence
     * sharing).
     *
     * @param account
     * @param bareAddress
     * @throws NetworkException
     */
    public void discardSubscription(String account, String bareAddress)
            throws NetworkException {
        Presence packet = new Presence(Presence.Type.unsubscribed);
        packet.setTo(bareAddress);
        ConnectionManager.getInstance().sendPacket(account, packet);
        subscriptionRequestProvider.remove(account, bareAddress);
        removeRequestedSubscription(account, bareAddress);
    }

    public boolean hasSubscriptionRequest(String account, String bareAddress) {
        return getSubscriptionRequest(account, bareAddress) != null;
    }

    /**
     * @param account
     * @param bareAddress
     * @return Best resource item for specified user. <code>null</code> if there
     * is no such user or user has no available resource.
     */
    public ResourceItem getResourceItem(String account, String bareAddress) {
        ResourceContainer resourceContainer = presenceContainers.get(account,
                bareAddress);
        if (resourceContainer == null)
            return null;
        return resourceContainer.getBest();
    }

    /**
     * @return Collection with available resources.
     */
    public Collection<ResourceItem> getResourceItems(String account,
                                                     String bareAddress) {
        ResourceContainer container = presenceContainers.get(account,
                bareAddress);
        if (container == null)
            return Collections.emptyList();
        return container.getResourceItems();
    }

    public StatusMode getStatusMode(String account, String bareAddress) {
        ResourceItem resourceItem = getResourceItem(account, bareAddress);
        if (resourceItem == null)
            return StatusMode.unavailable;
        return resourceItem.getStatusMode();
    }

    public String getStatusText(String account, String bareAddress) {
        ResourceItem resourceItem = getResourceItem(account, bareAddress);
        if (resourceItem == null)
            return "";
        return resourceItem.getStatusText();
    }

    @Override
    public void onPacket(ConnectionItem connection, String bareAddress, Stanza packet) {
        if (!(connection instanceof AccountItem))
            return;
        String account = ((AccountItem) connection).getAccount();
        if (packet instanceof Presence) {
            if (bareAddress == null)
                return;
            Presence presence = (Presence) packet;
            if (presence.getType() == Presence.Type.subscribe) {
                // Subscription request
                HashSet<String> set = requestedSubscriptions.get(account);
                if (set != null && set.contains(bareAddress)) {
                    try {
                        acceptSubscription(account, bareAddress);
                    } catch (NetworkException e) {
                    }
                    subscriptionRequestProvider.remove(account, bareAddress);
                } else {
                    subscriptionRequestProvider.add(new SubscriptionRequest(
                            account, bareAddress), null);
                }
                return;
            }
            String verbose = XmppStringUtils.parseResource(presence.getFrom());
            String resource = Jid.getResource(presence.getFrom());
            ResourceContainer resourceContainer = presenceContainers.get(
                    account, bareAddress);
            ResourceItem resourceItem;
            if (resourceContainer == null)
                resourceItem = null;
            else
                resourceItem = resourceContainer.get(resource);
            StatusMode previousStatusMode = getStatusMode(account, bareAddress);
            String previousStatusText = getStatusText(account, bareAddress);
            if (presence.getType() == Type.available) {
                StatusMode statusMode = StatusMode.createStatusMode(presence);
                String statusText = presence.getStatus();
                int priority = presence.getPriority();
                if (statusText == null)
                    statusText = "";
                if (priority == Integer.MIN_VALUE)
                    priority = 0;
                if (resourceItem == null) {
                    if (resourceContainer == null) {
                        resourceContainer = new ResourceContainer();
                        presenceContainers.put(account, bareAddress,
                                resourceContainer);
                    }
                    resourceContainer.put(resource, new ResourceItem(verbose,
                            statusMode, statusText, priority));
                    resourceContainer.updateBest();
                } else {
                    resourceItem.setVerbose(verbose);
                    resourceItem.setStatusMode(statusMode);
                    resourceItem.setStatusText(statusText);
                    resourceItem.setPriority(priority);
                    resourceContainer.updateBest();
                }
            } else if (presence.getType() == Presence.Type.error
                    || presence.getType() == Type.unavailable) {
                if (presence.getType() == Presence.Type.error
                        && "".equals(resource) && resourceContainer != null)
                    presenceContainers.remove(account, bareAddress);
                else if (resourceItem != null) {
                    resourceContainer.remove(resource);
                    resourceContainer.updateBest();
                }
            }

            // Notify about changes
            StatusMode newStatusMode = getStatusMode(account, bareAddress);
            String newStatusText = getStatusText(account, bareAddress);
            if (previousStatusMode != newStatusMode
                    || !previousStatusText.equals(newStatusText))
                for (OnStatusChangeListener listener : Application
                        .getInstance()
                        .getManagers(OnStatusChangeListener.class))
                    if (previousStatusMode == newStatusMode)
                        listener.onStatusChanged(account, bareAddress,
                                resource, newStatusText);
                    else
                        listener.onStatusChanged(account, bareAddress,
                                resource, newStatusMode, newStatusText);

            RosterContact rosterContact = RosterManager.getInstance()
                    .getRosterContact(account, bareAddress);
            if (rosterContact != null) {
                ArrayList<RosterContact> rosterContacts = new ArrayList<RosterContact>();
                rosterContacts.add(rosterContact);
                for (OnRosterChangedListener listener : Application
                        .getInstance().getManagers(
                                OnRosterChangedListener.class))
                    listener.onPresenceChanged(rosterContacts);
            }

            RosterManager.getInstance().onContactChanged(account, bareAddress);
        } else if (packet instanceof RosterPacket
                && ((RosterPacket) packet).getType() != IQ.Type.error) {
            RosterPacket rosterPacket = (RosterPacket) packet;
            for (RosterPacket.Item item : rosterPacket.getRosterItems()) {
                if (item.getItemType() == RosterPacket.ItemType.both
                        || item.getItemType() == RosterPacket.ItemType.from) {
                    String user = Jid.getBareAddress(item.getUser());
                    if (user == null)
                        continue;
                    // Contact can be subscribed or unsubscribed from
                    // another IM.
                    subscriptionRequestProvider.remove(account, user);
                }
            }
        }
    }

    @Override
    public void onArchiveModificationsReceived(ConnectionItem connection) {
        if (!(connection instanceof AccountItem))
            return;
        // Send presence information only when server side archive modifications
        // received.
        String account = ((AccountItem) connection).getAccount();
        readyAccounts.add(account);
        Collection<String> previous = new HashSet<String>();
        for (NestedMap.Entry<ResourceContainer> entry : presenceContainers)
            previous.add(entry.getSecond());
        presenceContainers.clear(account);
        ArrayList<RosterContact> rosterContacts = new ArrayList<RosterContact>();
        for (String bareAddress : previous) {
            RosterContact rosterContact = RosterManager.getInstance()
                    .getRosterContact(account, bareAddress);
            if (rosterContact != null)
                rosterContacts.add(rosterContact);
        }
        for (OnRosterChangedListener listener : Application.getInstance()
                .getManagers(OnRosterChangedListener.class))
            listener.onPresenceChanged(rosterContacts);
        try {
            resendPresence(account);
        } catch (NetworkException e) {
        }
    }

    @Override
    public void onDisconnect(ConnectionItem connection) {
        if (!(connection instanceof AccountItem))
            return;
        String account = ((AccountItem) connection).getAccount();
        readyAccounts.remove(account);
    }

    @Override
    public void onAccountDisabled(AccountItem accountItem) {
        requestedSubscriptions.remove(accountItem.getAccount());
        presenceContainers.clear(accountItem.getAccount());
    }

    /**
     * Sends new presence information.
     *
     * @param account
     * @throws NetworkException
     */
    public void resendPresence(String account) throws NetworkException {
        if (!readyAccounts.contains(account))
            throw new NetworkException(R.string.NOT_CONNECTED);
        ConnectionManager.getInstance().sendPacket(account,
                AccountManager.getInstance().getAccount(account).getPresence());
    }

}
