MqttitudeBinding.java

/**
 * Copyright (c) 2010-2016 by the respective copyright holders.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 */
package org.openhab.binding.mqttitude.internal;

import java.util.ArrayList;
import java.util.Dictionary;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.commons.lang.StringUtils;
import org.openhab.binding.mqttitude.MqttitudeBindingProvider;
import org.openhab.core.binding.AbstractBinding;
import org.openhab.core.binding.BindingProvider;
import org.openhab.io.transport.mqtt.MqttService;
import org.osgi.service.cm.ConfigurationException;
import org.osgi.service.cm.ManagedService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Binding for Mqttitude location detection.
 *
 * Install the Mqttitude app on your phone and configure it to publish location
 * updates to a specified broker. This binding will subscribe to that broker
 * and listen for location updates (to a specified topic).
 *
 * There are two types of binding, one just listens for any location updates and
 * calculates the distance relative to 'home' (specified in binding config).
 * The other listens for enter/leave events published by the Mqttitude app for a
 * specific region meaning we can detect presence in any number of areas.
 *
 * @author Ben Jones
 * @since 1.4.0
 */
public class MqttitudeBinding extends AbstractBinding<MqttitudeBindingProvider>implements ManagedService {

    private static final Logger logger = LoggerFactory.getLogger(MqttitudeBinding.class);

    private MqttService mqttService;

    // optional home location and geofence (only used if no 'regions' defined in the Mqttitude app)
    private Location homeLocation = null;
    private float geoFence = 0;

    // list of consumers (grouped by broker)
    private Map<String, List<MqttitudeConsumer>> consumers = new HashMap<String, List<MqttitudeConsumer>>();

    /**
     * @{inheritDoc}
     */
    @Override
    public void bindingChanged(BindingProvider provider, String itemName) {
        if (provider instanceof MqttitudeBindingProvider) {
            MqttitudeBindingProvider mqttitudeProvider = (MqttitudeBindingProvider) provider;
            registerItemConfig(mqttitudeProvider.getItemConfig(itemName));
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void allBindingsChanged(BindingProvider provider) {
        if (provider instanceof MqttitudeBindingProvider) {
            MqttitudeBindingProvider mqttitudeProvider = (MqttitudeBindingProvider) provider;
            for (String itemName : mqttitudeProvider.getItemNames()) {
                registerItemConfig(mqttitudeProvider.getItemConfig(itemName));
            }
        }
    }

    /**
     * Start the binding service.
     */
    @Override
    public void activate() {
        logger.debug("Activating Mqttitude binding");
        super.activate();
        registerAll();
    }

    /**
     * Shut down the binding service.
     */
    @Override
    public void deactivate() {
        logger.debug("Deactivating Mqttitude binding");
        super.deactivate();
        unregisterAll();
    }

    protected void addBindingProvider(MqttitudeBindingProvider bindingProvider) {
        super.addBindingProvider(bindingProvider);
    }

    protected void removeBindingProvider(MqttitudeBindingProvider bindingProvider) {
        super.removeBindingProvider(bindingProvider);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void updated(Dictionary<String, ?> properties) throws ConfigurationException {
        // no mandatory binding properties - so fine to get nothing here
        if (properties == null || properties.size() == 0) {
            return;
        }

        float homeLat = Float.parseFloat(getOptionalProperty(properties, "home.lat", "0"));
        float homeLon = Float.parseFloat(getOptionalProperty(properties, "home.lon", "0"));

        if (homeLat == 0 || homeLon == 0) {
            homeLocation = null;
            geoFence = 0;
            logger.debug(
                    "Mqttitude binding configuration updated, no 'home' location specified. All item bindings must be configured with a <region>.");
        } else {
            homeLocation = new Location(homeLat, homeLon);
            geoFence = Float.parseFloat(getOptionalProperty(properties, "geofence", "100"));
            logger.debug(
                    "Mqttitude binding configuration updated, 'home' location specified ({}) with a geofence of {}m.",
                    homeLocation.toString(), geoFence);
        }

        // need to re-register all the consumers/topics if the home location has changed
        unregisterAll();
        registerAll();
    }

    private String getOptionalProperty(Dictionary<String, ?> properties, String name, String defaultValue) {
        if (properties == null) {
            return defaultValue;
        }

        String value = (String) properties.get(name);

        if (StringUtils.isBlank(value)) {
            return defaultValue;
        }

        return value.trim();
    }

    private void registerAll() {
        for (BindingProvider provider : providers) {
            if (provider instanceof MqttitudeBindingProvider) {
                MqttitudeBindingProvider mqttitudeProvider = (MqttitudeBindingProvider) provider;
                for (String itemName : mqttitudeProvider.getItemNames()) {
                    registerItemConfig(mqttitudeProvider.getItemConfig(itemName));
                }
            }
        }
    }

    private void unregisterAll() {
        for (String broker : consumers.keySet()) {
            for (MqttitudeConsumer consumer : consumers.get(broker)) {
                logger.debug("Unregistering Mqttitude consumer for {} (on {})", consumer.getTopic(), broker);
                mqttService.unregisterMessageConsumer(broker, consumer);
            }
        }
        consumers.clear();
    }

    private void registerItemConfig(MqttitudeItemConfig itemConfig) {
        if (itemConfig == null) {
            return;
        }

        String broker = itemConfig.getBroker();
        String topic = itemConfig.getTopic();

        // get the consumer for this broker/topic (might not exist)
        MqttitudeConsumer consumer = getConsumer(broker, topic);

        // NOTE: we only create a single consumer for each topic, but a topic may
        // have multiple item bindings - i.e. monitoring multiple regions
        if (consumer == null) {
            // create a new consumer for this topic
            consumer = new MqttitudeConsumer(homeLocation, geoFence);
            consumer.setTopic(topic);

            // register the new consumer
            logger.debug("Registering Mqttitude consumer for {} (on {})", topic, broker);
            mqttService.registerMessageConsumer(broker, consumer);

            if (!consumers.containsKey(broker)) {
                consumers.put(broker, new ArrayList<MqttitudeConsumer>());
            }

            consumers.get(broker).add(consumer);
        }

        // add this item to our consumer (will replace any existing config for the same item name)
        consumer.addItemConfig(itemConfig);
    }

    private MqttitudeConsumer getConsumer(String broker, String topic) {
        if (consumers.containsKey(broker)) {
            for (MqttitudeConsumer consumer : consumers.get(broker)) {
                if (consumer.getTopic().equals(topic)) {
                    return consumer;
                }
            }
        }
        return null;
    }

    /**
     * Setter for Declarative Services. Adds the MqttService instance.
     *
     * @param mqttService to set.
     */
    public void setMqttService(MqttService mqttService) {
        this.mqttService = mqttService;
    }

    /**
     * Unsetter for Declarative Services.
     *
     * @param mqttService to remove.
     */
    public void unsetMqttService(MqttService mqttService) {
        this.mqttService = null;
    }
}