WeatherPublisher.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.weather.internal.bus;

import java.math.BigDecimal;
import java.util.Calendar;

import org.apache.commons.lang.StringUtils;
import org.apache.commons.lang.WordUtils;
import org.openhab.binding.weather.WeatherBindingProvider;
import org.openhab.binding.weather.internal.common.WeatherContext;
import org.openhab.binding.weather.internal.common.binding.ForecastBindingConfig;
import org.openhab.binding.weather.internal.common.binding.WeatherBindingConfig;
import org.openhab.binding.weather.internal.model.Temperature;
import org.openhab.binding.weather.internal.model.Weather;
import org.openhab.binding.weather.internal.utils.ItemIterator;
import org.openhab.binding.weather.internal.utils.ItemIterator.ItemIteratorCallback;
import org.openhab.binding.weather.internal.utils.PropertyUtils;
import org.openhab.binding.weather.internal.utils.UnitUtils;
import org.openhab.core.library.types.DateTimeType;
import org.openhab.core.library.types.DecimalType;
import org.openhab.core.library.types.StringType;
import org.openhab.core.types.UnDefType;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Publishes object properties to items.
 *
 * @author Gerhard Riegler
 * @since 1.6.0
 */
public class WeatherPublisher {
    private static final Logger logger = LoggerFactory.getLogger(WeatherPublisher.class);
    private WeatherContext context = WeatherContext.getInstance();

    private static WeatherPublisher instance = null;

    private WeatherPublisher() {
    }

    /**
     * Returns the singleton instance of WeatherPublisher.
     */
    public static WeatherPublisher getInstance() {
        if (instance == null) {
            instance = new WeatherPublisher();
        }
        return instance;
    }

    /**
     * Republish the state of the item.
     */
    public void republishItem(String itemName) {
        WeatherBindingConfig bindingConfig = null;
        for (WeatherBindingProvider provider : context.getProviders()) {
            if (bindingConfig == null) {
                bindingConfig = provider.getBindingFor(itemName);
            }
        }
        if (bindingConfig == null) {
            logger.warn("Weather binding for item {} not found", itemName);
        } else {
            publish(bindingConfig.getLocationId());
        }
    }

    /**
     * Iterates through all items and publishes the states for the locationId.
     */
    public void publish(final String locationId) {
        final Weather weather = context.getWeather(locationId);
        if (weather != null) {
            new ItemIterator().iterate(new ItemIteratorCallback() {

                @Override
                public void next(WeatherBindingConfig bindingConfig, String itemName) {
                    if (bindingConfig.getLocationId().equals(locationId)) {
                        try {
                            Weather instance = getInstance(weather, bindingConfig);
                            if (instance != null) {
                                String weatherProperty = bindingConfig.getWeatherProperty();
                                Object value = null;

                                if (Weather.isVirtualProperty(weatherProperty)) {
                                    Temperature temp = instance.getTemperature();
                                    if (Weather.VIRTUAL_TEMP_MINMAX.equals(weatherProperty)) {
                                        Double min = UnitUtils.convertUnit(temp.getMin(), bindingConfig.getUnit(),
                                                bindingConfig.getWeatherProperty());
                                        Double max = UnitUtils.convertUnit(temp.getMax(), bindingConfig.getUnit(),
                                                bindingConfig.getWeatherProperty());
                                        value = getMinMax(min, max, bindingConfig);
                                    }
                                } else {
                                    value = PropertyUtils.getPropertyValue(instance, weatherProperty);
                                    if (bindingConfig.hasUnit()) {
                                        value = UnitUtils.convertUnit((Double) value, bindingConfig.getUnit(),
                                                bindingConfig.getWeatherProperty());
                                    }
                                }

                                publishValue(itemName, value, bindingConfig);
                            }
                        } catch (Exception ex) {
                            logger.warn(ex.getMessage(), ex);
                        }
                    }
                }
            });
        }
    }

    /**
     * Returns the minMax virtual property as a string.
     */
    private String getMinMax(Double min, Double max, WeatherBindingConfig bindingConfig) {
        return toDisplayString(min, bindingConfig) + "/" + toDisplayString(max, bindingConfig);
    }

    /**
     * Returns a rounded double value as string.
     */
    private String toDisplayString(Double value, WeatherBindingConfig bindingConfig) {
        return value == null ? "-" : round(value.toString(), bindingConfig).toString();
    }

    /**
     * Returns the weather or the correct forecast object instance.
     */
    private Weather getInstance(Weather weather, WeatherBindingConfig bindingConfig) {
        Weather instance = weather;
        if (bindingConfig instanceof ForecastBindingConfig) {
            ForecastBindingConfig fcConfig = (ForecastBindingConfig) bindingConfig;
            if (fcConfig.getForecastDay() < weather.getForecast().size()) {
                instance = weather.getForecast().get(fcConfig.getForecastDay());
            } else {
                logger.warn("Weather forecast day {} not available for locationId '{}', only {} available",
                        fcConfig.getForecastDay(), bindingConfig.getLocationId(),
                        Math.max(weather.getForecast().size() - 1, 0));
                instance = null;
            }
        }
        return instance;
    }

    /**
     * Publishes the item with the value.
     */
    private void publishValue(String itemName, Object value, WeatherBindingConfig bindingConfig) {
        if (value == null) {
            context.getEventPublisher().postUpdate(itemName, UnDefType.UNDEF);
        } else if (value instanceof Calendar) {
            Calendar calendar = (Calendar) value;
            context.getEventPublisher().postUpdate(itemName, new DateTimeType(calendar));
        } else if (value instanceof Number) {
            context.getEventPublisher().postUpdate(itemName, new DecimalType(round(value.toString(), bindingConfig)));
        } else if (value instanceof String || value instanceof Enum) {
            if (value instanceof Enum) {
                String enumValue = WordUtils.capitalizeFully(StringUtils.replace(value.toString(), "_", " "));
                context.getEventPublisher().postUpdate(itemName, new StringType(enumValue));
            } else {
                context.getEventPublisher().postUpdate(itemName, new StringType(value.toString()));
            }
        } else {
            logger.warn("Unsupported value type {}", value.getClass().getSimpleName());
        }
    }

    /**
     * Returns a rounded value from the string.
     */
    private BigDecimal round(String value, WeatherBindingConfig bindingConfig) {
        if (bindingConfig.getRoundingMode() == null) {
            return new BigDecimal(value);
        }
        return new BigDecimal(value).setScale(bindingConfig.getScale(), bindingConfig.getRoundingMode());
    }
}