/**

  * Copyright 2012 Sven Diedrichsen 

  * 

  * Licensed under the Apache License, Version 2.0 (the "License"); 

  * you may not use this file except in compliance with the License. 

  * You may obtain a copy of the License at 

  * 

  * http://www.apache.org/licenses/LICENSE-2.0 

  * 

  * Unless required by applicable law or agreed to in writing, software 

  * distributed under the License is distributed on an 

  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either 

  * express or implied. See the License for the specific language 

  * governing permissions and limitations under the License. 

  */

 package de.jollyday.configuration;

 import java.util.Properties;

 import java.util.logging.Logger;

 import de.jollyday.ManagerParameter;

 import de.jollyday.configuration.impl.DefaultConfigurationProvider;

 import de.jollyday.configuration.impl.URLConfigurationProvider;

 import de.jollyday.util.ClassLoadingUtil;

 /**

  * Manages the configuration provider implementations and thus delivering the

  * jollyday configuration.

  * 

  * @author sven

  */

 public class ConfigurationProviderManager {

         private static final Logger LOG = Logger.getLogger(ConfigurationProviderManager.class.getName());

         private ConfigurationProvider defaultConfigurationProvider = new DefaultConfigurationProvider();

         private ConfigurationProvider urlConfigurationProvider = new URLConfigurationProvider();

         private transient ClassLoadingUtil classLoadingUtil = new ClassLoadingUtil();

         /**

          * Constructs an instance

          */

         public ConfigurationProviderManager() {

         }

         /**

          * Reads the jollyday configuration from the

          * {@link DefaultConfigurationProvider}, the

          * {@link URLConfigurationProvider} and any configuration provider specified

          * by the system property 'de.jollyday.config.provider'.

          * 

          * @param parameter

          *            the configuration {@link ManagerParameter} to use

          */

         public void mergeConfigurationProperties(ManagerParameter parameter) {

                 addInternalConfigurationProviderProperies(parameter);

                 addCustomConfigurationProviderProperties(parameter);

         }

         private void addInternalConfigurationProviderProperies(ManagerParameter parameter) {

                 parameter.mergeProperties(urlConfigurationProvider.getProperties());

                 parameter.mergeProperties(defaultConfigurationProvider.getProperties());

         }

         private void addCustomConfigurationProviderProperties(ManagerParameter parameter) {

                 Properties systemProps = System.getProperties();

                 String providersStrList = systemProps.getProperty(ConfigurationProvider.CONFIG_PROVIDERS_PROPERTY);

                 if (providersStrList != null) {

                         String[] providersClassNames = providersStrList.split(",");

                         if (providersClassNames != null) {

                                 for (String providerClassName : providersClassNames) {

                                         if (providerClassName == null || "".equals(providerClassName))

                                                 continue;

                                         try {

                                                 Class<?> providerClass = Class.forName(providerClassName.trim(), true,

                                                                 classLoadingUtil.getClassloader());

                                                 ConfigurationProvider configurationProvider = ConfigurationProvider.class.cast(providerClass

                                                                 .newInstance());

                                                 parameter.mergeProperties(configurationProvider.getProperties());

                                         } catch (Exception e) {

                                                 LOG.warning("Cannot load configuration from provider class '" + providerClassName + "'. "

                                                                 + e.getClass().getSimpleName() + " (" + e.getMessage() + ").");

                                         }

                                 }

                         }

                 }

         }

 }