BindingConfigParser.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.astro.internal.bus;

import org.apache.commons.lang.StringUtils;
import org.openhab.binding.astro.internal.common.AstroContext;
import org.openhab.binding.astro.internal.config.AstroBindingConfig;
import org.openhab.binding.astro.internal.model.PlanetName;
import org.openhab.binding.astro.internal.util.PropertyUtils;
import org.openhab.core.items.Item;
import org.openhab.model.item.binding.BindingConfigParseException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Class to parse the key - value base config for an Astro item.
 * <p>
 * Example:
 * </p>
 *
 * <pre>
 * Number   Azimuth        "Azimuth [%.2f]"     {astro="planet=sun, type=position, property=azimuth"}
 * Number   Elevation      "Elevation [%.2f]"   {astro="planet=sun, type=position, property=elevation"}
 *
 * DateTime Sunrise_Time   "Sunrise [%1$tH:%1$tM]"  {astro="planet=sun, type=rise, property=start"}
 * DateTime Noon_Time      "Noon [%1$tH:%1$tM]"     {astro="planet=sun, type=noon, property=start"}
 * DateTime Sunset_Time    "Sunset [%1$tH:%1$tM]"   {astro="planet=sun, type=set, property=end"}
 *
 * Switch   Sunrise_Event                           {astro="planet=sun, type=rise, property=start"}
 * Switch   Sunrise_Event_Delayed                   {astro="planet=sun, type=rise, property=start, offset=10"}
 * Switch   Noon_Event                              {astro="planet=sun, type=noon, property=start"}
 * Switch   Sunset_Event                            {astro="planet=sun, type=set, property=end"}
 *
 * Number   Sunset_Duration                         {astro="planet=sun, type=set, property=duration"}
 * String   Sunset_Duration_Str                     {astro="planet=sun, type=set, property=duration"}
 * </pre>
 *
 * @author Gerhard Riegler
 * @since 1.5.0
 */
public class BindingConfigParser {
    private static final Logger logger = LoggerFactory.getLogger(BindingConfigParser.class);
    protected AstroContext context = AstroContext.getInstance();

    /**
     * Parses the bindingConfig of an item and returns a AstroBindingConfig.
     */
    public AstroBindingConfig parse(Item item, String bindingConfig) throws BindingConfigParseException {
        bindingConfig = StringUtils.trimToEmpty(bindingConfig);
        bindingConfig = StringUtils.removeStart(bindingConfig, "{");
        bindingConfig = StringUtils.removeEnd(bindingConfig, "}");
        String[] entries = bindingConfig.split("[,]");
        AstroBindingConfigHelper helper = new AstroBindingConfigHelper();

        for (String entry : entries) {
            String[] entryParts = StringUtils.trimToEmpty(entry).split("[=]");
            if (entryParts.length != 2) {
                throw new BindingConfigParseException("A bindingConfig must have a key and a value");
            }
            String key = StringUtils.trim(entryParts[0]);

            String value = StringUtils.trim(entryParts[1]);
            value = StringUtils.removeStart(value, "\"");
            value = StringUtils.removeEnd(value, "\"");

            try {
                if ("offset".equalsIgnoreCase(key)) {
                    helper.getClass().getDeclaredField(key).set(helper, Integer.valueOf(value.toString()));
                } else {
                    helper.getClass().getDeclaredField(key).set(helper, value);
                }
            } catch (Exception e) {
                throw new BindingConfigParseException("Could not set value " + value + " for attribute " + key);
            }
        }

        if (helper.isOldStyle()) {
            logger.warn(
                    "Old Astro binding style for item {}, please see Wiki page for new style: https://github.com/openhab/openhab/wiki/Astro-binding",
                    item.getName());
            return getOldAstroBindingConfig(helper);
        }

        if (!helper.isValid()) {
            throw new BindingConfigParseException("Invalid binding: " + bindingConfig);
        }

        PlanetName planetName = getPlanetName(helper);
        if (planetName == null) {
            throw new BindingConfigParseException("Invalid binding, unknown planet: " + bindingConfig);
        }

        AstroBindingConfig astroConfig = new AstroBindingConfig(planetName, helper.type, helper.property,
                helper.offset);

        if (!PropertyUtils.hasProperty(context.getPlanet(astroConfig.getPlanetName()),
                astroConfig.getPlanetProperty())) {
            throw new BindingConfigParseException("Invalid binding, unknown type or property: " + bindingConfig);
        }
        return astroConfig;
    }

    /**
     * Parses the planet name.
     */
    private PlanetName getPlanetName(AstroBindingConfigHelper helper) {
        try {
            return PlanetName.valueOf(StringUtils.upperCase(helper.planet));
        } catch (Exception ex) {
            return null;
        }
    }

    /**
     * Returns the AstroBindingConfig for old binding style.
     */
    private AstroBindingConfig getOldAstroBindingConfig(AstroBindingConfigHelper helper) {
        String type = helper.type.toUpperCase();
        if ("AZIMUTH".equals(type)) {
            return new AstroBindingConfig(PlanetName.SUN, "position", "azimuth");
        } else if ("ELEVATION".equals(type)) {
            return new AstroBindingConfig(PlanetName.SUN, "position", "elevation");
        } else if ("SUNRISE".equals(type)) {
            return new AstroBindingConfig(PlanetName.SUN, "rise", "start");
        } else if ("NOON".equals(type)) {
            return new AstroBindingConfig(PlanetName.SUN, "noon", "start");
        } else if ("SUNSET".equals(type)) {
            return new AstroBindingConfig(PlanetName.SUN, "set", "end");
        } else if ("SUNRISE_TIME".equals(type)) {
            return new AstroBindingConfig(PlanetName.SUN, "rise", "start");
        } else if ("NOON_TIME".equals(type)) {
            return new AstroBindingConfig(PlanetName.SUN, "noon", "start");
        } else if ("SUNSET_TIME".equals(type)) {
            return new AstroBindingConfig(PlanetName.SUN, "set", "end");
        }

        return null;
    }

    /**
     * Helper class for parsing the bindingConfig.
     */
    private class AstroBindingConfigHelper {
        public String planet;
        public String type;
        public String property;
        public int offset = 0;

        protected boolean isValid() {
            return StringUtils.isNotBlank(planet) && StringUtils.isNotBlank(type) && StringUtils.isNotBlank(property);
        }

        protected boolean isOldStyle() {
            return StringUtils.isNotBlank(type) && StringUtils.isBlank(planet) && StringUtils.isBlank(property);
        }
    }

}