InboxUseCase

package com.productify.urge.usecase;

import android.os.Handler;
import android.util.Log;

import com.google.gson.Gson;
import com.productify.urge.common.UseCase;
import com.productify.urge.model.Message;
import com.productify.urge.model.Profile;
import com.pubnub.api.PubNub;
import com.pubnub.api.callbacks.SubscribeCallback;
import com.pubnub.api.enums.PNStatusCategory;
import com.pubnub.api.models.consumer.PNStatus;
import com.pubnub.api.models.consumer.pubsub.PNMessageResult;
import com.pubnub.api.models.consumer.pubsub.PNPresenceEventResult;

import java.util.Collections;

import javax.inject.Inject;

/**
 * Created by feresr on 8/08/16.
 * This use case connects to the PubNub server and informs its listener of incoming messages.
 * Usage: Simply setting a listener will start the PunNub subscription. Setting the listener to null will cancel it.
 */
public class InboxUseCase extends UseCase<InboxUseCase.InboxCallbackListener> {

    private final static String TAG = InboxUseCase.class.getSimpleName();
    private PubNub pubnub;
    private Profile profile;
    private Handler handler;

    @Inject
    public InboxUseCase(PubNub pubnub, Profile profile) {
        this.pubnub = pubnub;
        this.profile = profile;
        this.handler = new Handler();

        pubnub.addListener(new SubscribeCallback() {
            @Override
            public void status(PubNub pubnub, PNStatus status) {
                Log.e(TAG, "pubnub status: " + status.getCategory().toString());
                if (status.getCategory() == PNStatusCategory.PNTimeoutCategory) {
                    pubnub.reconnect();
                } else {
                    if (status.isError()) {
                        Log.d(TAG, status.getErrorData().toString());
                    }
                }
            }

            @Override
            public void message(PubNub pubnub, PNMessageResult m) {
                try {
                    Log.d(TAG, "pubnub message: " + m.getMessage().toString());
                    final Message message = new Gson().fromJson(m.getMessage().toString(), Message.class);
                    message.setTimeToken(m.getTimetoken());
                    if (listener != null) {
                        handler.post(new Runnable() {
                            @Override
                            public void run() {
                                listener.onNewMessageReceived(message);
                            }
                        });
                    }
                } catch (final Exception e) {
                    e.printStackTrace();
                    if (listener != null) {
                        handler.post(new Runnable() {
                            @Override
                            public void run() {
                                listener.onErrorReceivingMessage(e.getMessage());
                            }
                        });
                    }
                }
            }

            @Override
            public void presence(PubNub pubnub, PNPresenceEventResult presence) {

            }
        });
    }

    @Override
    public void setListener(final InboxCallbackListener listener) {
        super.setListener(listener);

        String channel = profile.isMerchant() ? profile.getStore().getUrgeUid() : profile.getUrgeUid();

        if (listener != null) {
            pubnub.subscribe().withPresence()
                    .channels(Collections.singletonList(channel)) // subscribe to channels
                    .execute();
        } else {
            pubnub.unsubscribe()
                    .channels(Collections.singletonList(channel)) // subscribe to channels
                    .execute();
        }
    }

    /**
     * This interface must be implemented by those interested in receiving new messages
     */
    public interface InboxCallbackListener {
        void onNewMessageReceived(Message message);

        void onErrorReceivingMessage(String error);
    }
}