pzalejko.iot.hardware.home.core.task.LedAlertTask.java Source code

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Here is the source code for pzalejko.iot.hardware.home.core.task.LedAlertTask.java

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/*******************************************************************************
 * Copyright (c) 2015 Pawel Zalejko(p.zalejko@gmail.com).
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Apache License Version 2.0
 * which accompanies this distribution, and is available at
 * http://www.apache.org/licenses/
 *******************************************************************************/

package pzalejko.iot.hardware.home.core.task;

import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import javax.inject.Inject;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

import pzalejko.iot.common.home.api.TemperatureAlertEntity;
import pzalejko.iot.common.home.api.TemperatureEntity;
import pzalejko.iot.common.home.api.event.Event;
import pzalejko.iot.common.home.api.event.EventBus;
import pzalejko.iot.common.home.api.event.EventListener;
import pzalejko.iot.common.home.api.event.EventType;
import pzalejko.iot.hardware.home.api.config.ConfigurationService;
import pzalejko.iot.hardware.home.api.config.LedConfiguration;
import pzalejko.iot.hardware.home.api.led.LedService;
import pzalejko.iot.hardware.home.core.util.LogMessages;

/**
 * The {@link LedAlertTask} is responsible for switching on the LED when a temperature value reaches the alert level.
 */
@Component
public class LedAlertTask extends AbstractLedTask implements EventListener {

    private static final Logger LOG = LoggerFactory.getLogger(LedAlertTask.class);

    private double maxTemperature;
    private final ConfigurationService configurationService;

    @Inject
    public LedAlertTask(EventBus eventBus, ConfigurationService configurationService, LedService ledService) {
        super(eventBus, ledService);
        this.configurationService = configurationService;
    }

    @Override
    @PostConstruct
    public void init() {
        super.init();

        final LedConfiguration ledSettings = configurationService.getLedSettings();
        maxTemperature = ledSettings.getTemperatureAlert();
    }

    @Override
    protected int getLedID() {
        final LedConfiguration ledSettings = configurationService.getLedSettings();
        return ledSettings.getLedId();
    }

    @Override
    public void run() {
        LOG.debug(LogMessages.STARTING_TASK);
        eventBus.register(this);
    }

    @Override
    @PreDestroy
    public void destroy() {
        eventBus.unregister(this);
        super.destroy();
    }

    @Override
    public void handle(Event event) {
        if (isLedToUpdateEvent(event)) {
            updateLed(event);
        } else if (isAlertTemperatureToUpdateEvent(event)) {
            updateAlertTemperature(event);
        } else if (isGetAlertTemperatureEvent(event)) {
            publishCurrentAlertValue();
        }
    }

    /**
     * Updates a LED's state according to the payload provided by the given event. An expected payload is an instance of the
     * {@link TemperatureEntity}.
     * 
     * @param event the event.
     */
    private void updateLed(Event event) {
        LOG.debug(LogMessages.UPDATING_LED_FOR, event);

        final Object payload = event.getPayload();
        if (payload instanceof TemperatureEntity) {
            updateLed(((TemperatureEntity) payload).getTemperature() >= maxTemperature);
        } else {
            LOG.error(LogMessages.PAYLOAD_NOT_SUPPORTED, payload);
        }
    }

    /**
     * Updates an alert value according to the payload provided by the given event. An expected payload is an instance of the
     * {@link TemperatureAlertEntity}.
     * 
     * @param event the event.
     */
    private void updateAlertTemperature(Event event) {
        final Object payload = event.getPayload();
        if (payload instanceof TemperatureAlertEntity) {
            try {
                maxTemperature = ((TemperatureAlertEntity) payload).getAlert();
                LOG.info(LogMessages.UPDATED_AN_ALERT_TEMPERATURE_TO, maxTemperature);
                publishCurrentAlertValue();
            } catch (final NumberFormatException e) {
                LOG.error(LogMessages.COULD_NOT_UPDATE_TEMPERATURE_ALERT, e.getMessage(), e);
            }
        } else {
            LOG.error(LogMessages.PAYLOAD_NOT_SUPPORTED, payload);
        }
    }

    private void publishCurrentAlertValue() {
        final TemperatureAlertEntity alertEntity = new TemperatureAlertEntity(maxTemperature);
        eventBus.postLocal(alertEntity, EventType.TEMPERATURE_ALERT_VALUE);
    }

    private boolean isLedToUpdateEvent(Event event) {
        return event.getType() == EventType.TEMPERATURE_VALUE;
    }

    private boolean isAlertTemperatureToUpdateEvent(Event event) {
        return event.getType() == EventType.UPDATE_TEMPERATURE_ALERT;
    }

    private boolean isGetAlertTemperatureEvent(Event event) {
        return event.getType() == EventType.PUBLISH_TEMPERATURE_ALERT_REQUEST;
    }
}