CommonIdHandler.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.parser;

import java.io.InputStream;
import java.util.HashMap;
import java.util.Map;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.Unmarshaller;

import org.apache.commons.lang.StringUtils;
import org.apache.commons.lang.builder.ToStringBuilder;
import org.apache.commons.lang.builder.ToStringStyle;
import org.openhab.binding.weather.internal.model.Condition;
import org.openhab.binding.weather.internal.model.ProviderName;
import org.openhab.binding.weather.internal.model.Weather;
import org.openhab.binding.weather.internal.model.common.CommonId;
import org.openhab.binding.weather.internal.model.common.CommonIdList;
import org.openhab.binding.weather.internal.model.common.CommonIdProvider;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Handles all the weather ids and icons of the differnet providers and map them
 * to a common weather id.
 *
 * @author Gerhard Riegler
 * @since 1.6.0
 */
public class CommonIdHandler {
    private static final Logger logger = LoggerFactory.getLogger(CommonIdHandler.class);
    private static CommonIdHandler instance;

    private Map<ProviderName, Map<String, CommonId>> providerCommonIds = new HashMap<ProviderName, Map<String, CommonId>>();

    private CommonIdHandler() {
    }

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

    /**
     * Load predefined common id mappings from an XML file.
     */
    public void loadMapping() throws Exception {
        Unmarshaller um = JAXBContext.newInstance(CommonIdList.class).createUnmarshaller();
        InputStream stream = Thread.currentThread().getContextClassLoader()
                .getResourceAsStream("weather/common-id-mappings.xml");
        CommonIdList mappings = (CommonIdList) um.unmarshal(stream);

        for (CommonId commonId : mappings.getCommonIds()) {
            for (CommonIdProvider commonIdProvider : commonId.getProviders()) {
                Map<String, CommonId> commonIds = providerCommonIds.get(commonIdProvider.getName());
                if (commonIds == null) {
                    commonIds = new HashMap<String, CommonId>();
                    providerCommonIds.put(commonIdProvider.getName(), commonIds);
                }

                addCommonId(commonIdProvider.getIds(), "id", commonIdProvider, commonIds, commonId);
                addCommonId(commonIdProvider.getIcons(), "icon", commonIdProvider, commonIds, commonId);
            }
        }
    }

    private void addCommonId(String[] keys, String keyType, CommonIdProvider providerMapping,
            Map<String, CommonId> commonIds, CommonId commonCondition) {
        if (keys != null) {
            for (String key : keys) {
                key = StringUtils.trim(key);
                if (commonIds.containsKey(key)) {
                    throw new IllegalArgumentException("CommonId for provider " + providerMapping.getName() + " with "
                            + keyType + " " + key + " already exists");
                }
                commonIds.put(key, commonCondition);
            }
        }
    }

    /**
     * Sets the common condition id into the weather object.
     */
    public void setCommonId(Weather weather) {
        Map<String, CommonId> commonIds = providerCommonIds.get(weather.getProvider());
        if (commonIds == null) {
            throw new RuntimeException("No common ids for provider " + weather.getProvider() + " declared");
        }

        Condition cond = weather.getCondition();

        CommonId cid = commonIds.get(cond.getId());
        if (cid == null) {
            cid = commonIds.get(cond.getIcon());
        }

        if (cid != null) {
            cond.setCommonId(cid.getId());
        } else {
            ToStringBuilder tsb = new ToStringBuilder(this, ToStringStyle.SHORT_PREFIX_STYLE)
                    .append("provider", weather.getProvider()).append("id", cond.getId())
                    .append("icon", cond.getIcon());
            logger.warn("CommonId not found: {}", tsb.toString());
        }
    }
}