/**
    * Copyright (C) 2010 Daniel Manzke <daniel.manzke@googlemail.com>
    *
    * 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 org.apache.onami.autobind.integrations.commons.configuration;
  
  import java.io.File;
  import java.lang.annotation.Annotation;
  import java.net.MalformedURLException;
  import java.net.URL;
  import java.util.Map;
  import java.util.logging.Level;
  import java.util.logging.Logger;
  
  import javax.inject.Named;
  import javax.inject.Singleton;
  
  import org.apache.commons.configuration.ConfigurationException;
  import org.apache.commons.configuration.FileConfiguration;
  import org.apache.onami.autobind.configuration.Configuration;
  import org.apache.onami.autobind.install.BindingStage;
  import org.apache.onami.autobind.scanner.features.BindingScannerFeature;
  
  
  /**
   * This Class will be called for each Class, which is annotated with
   * {@link Configuration} and which needs an Apache Commons-based Configuration.
   * 
   * @author Daniel Manzke
   * 
   */
  @Singleton
  public class CommonsConfigurationFeature extends BindingScannerFeature {
  	private Logger _logger = Logger.getLogger(CommonsConfigurationFeature.class.getName());
  
  	@Override
  	public BindingStage accept(Class<Object> annotatedClass, Map<String, Annotation> annotations) {
  		if (annotations.containsKey(Configuration.class.getName())) {
  			Configuration config = (Configuration) annotations.get(Configuration.class.getName());
  			if (FileConfiguration.class.isAssignableFrom(config.to())) {
  				return BindingStage.BOOT_BEFORE;
  			}
  		}
  		return BindingStage.IGNORE;
  	}
  
  	@SuppressWarnings("unchecked")
  	@Override
  	public void process(Class<Object> annotatedClass, Map<String, Annotation> annotations) {
  		Configuration config = (Configuration) annotations.get(Configuration.class.getName());
  		Named name = config.name();
  
  		// TODO Implement Location overriding
  		URL url;
  		switch (config.location().type()) {
  		case FILE:
  			File file = new File(config.location().value());
  			if (!file.exists()) {
  				_logger.log(Level.WARNING, "Ignoring Configuration " + name + " in "
  						+ config.location() + ". In the Path " + file.getAbsolutePath()
  						+ " no Configuration was found.");
  				return;
  			}
  			try {
  				url = file.toURI().toURL();
  			} catch (MalformedURLException e) {
  				_logger.log(Level.WARNING, "Ignoring Configuration " + name + " in "
  						+ config.location() + ". It has an illegal URL-Format.", e);
  				return;
  			}
  			break;
  		case URL:
  			try {
  				url = new URL(config.location().value());
  			} catch (MalformedURLException e) {
  				_logger.log(Level.WARNING, "Ignoring Configuration " + name + " in "
  						+ config.location() + ". It has an illegal URL-Format.", e);
  				return;
  			}
  			break;
  		case CLASSPATH:
  		default:
  			url = this.getClass().getResource(config.location().value());
  			break;
  		}
 
 		if (url == null) {
 			_logger.log(Level.WARNING, "Ignoring Configuration " + name + " in "
 					+ config.location() + ", because is couldn't be found in the Classpath.");
 			// TODO Throw an exception if config doesn't exist?
 			return;
 		}
 
 		Named named = null;
 		if (name.value().length() > 0) {
 			named = name;
 		}
 
 		FileConfiguration configuration;
 		try {
 			// Class<? extends FileConfiguration> interf =
 			// config.to().asSubclass(FileConfiguration.class);
 			Class<FileConfiguration> interf = (Class<FileConfiguration>) config.to();
 			configuration = (FileConfiguration) injector.getInstance(interf);
 			configuration.load(url);
 
 			bindInstance(configuration, interf, named, null);
 			bindInstance(configuration, FileConfiguration.class, named, null);
 			bindInstance(configuration, org.apache.commons.configuration.Configuration.class,
 				named, null);
 		} catch (ConfigurationException e) {
 			_logger.log(Level.WARNING, "Configuration " + name + " couldn't be loaded/bound: "
 					+ e.getMessage(), e);
 		}
 	}
 }