package org.kuali.rice.krad.data.provider.spring;
   
   import org.kuali.rice.core.api.util.ClassLoaderUtils;
   import org.kuali.rice.krad.data.metadata.DataObjectMetadata;
   import org.kuali.rice.krad.data.metadata.impl.DataObjectMetadataImpl;
   import org.kuali.rice.krad.data.provider.impl.MetadataProviderBase;
   import org.springframework.beans.factory.support.DefaultListableBeanFactory;
   import org.springframework.beans.factory.xml.XmlBeanDefinitionReader;
   import org.springframework.core.io.DefaultResourceLoader;
  
  import java.util.Collection;
  import java.util.List;
  import java.util.Map;
  
  /**
   * Metadata provider which can be configured via the standard spring mechanisms. The bean locations are listed as part
   * of the metadata provider service definition. The beans in this provider are loaded into a separate context from all
   * other beans in Rice.
   * 
   * @author jonathan
   * 
   */
  public class SpringMetadataProviderImpl extends MetadataProviderBase {
  	private static final org.apache.log4j.Logger LOG = org.apache.log4j.Logger
  			.getLogger(SpringMetadataProviderImpl.class);
  
  	protected List<String> resourceLocations;
  	protected DefaultResourceLoader resourceLoader = new DefaultResourceLoader(ClassLoaderUtils.getDefaultClassLoader());
  	protected DefaultListableBeanFactory beanFactory = new DefaultListableBeanFactory();
  
  	public SpringMetadataProviderImpl() {
  		LOG.debug("Building SpringMetadataProviderImpl");
  	}
  
  	@Override
  	public synchronized void initializeMetadata(Collection<Class<?>> types) {
  		// First, extract the data from the spring configuration into a form usable by the Spring XML parser
  		if (LOG.isDebugEnabled()) {
  			LOG.debug("Loading Metadata Bean Definitions from Locations:");
  			for (String loc : resourceLocations) {
  				LOG.debug(loc);
  			}
  		}
  		// Now, parse the beans and load them into the bean factory
  		XmlBeanDefinitionReader xmlReader = new XmlBeanDefinitionReader(beanFactory);
  		String configFileLocationsArray[] = new String[resourceLocations.size()];
  		configFileLocationsArray = resourceLocations.toArray(configFileLocationsArray);
  		xmlReader.loadBeanDefinitions(configFileLocationsArray);
  
  		// extract the objects from the bean factory, by pulling all the DataObjectMetadata objects
  		Map<String, DataObjectMetadata> metadataObjects = beanFactory.getBeansOfType(DataObjectMetadata.class);
  		if (LOG.isInfoEnabled()) {
  			LOG.info(metadataObjects.size() + " DataObjectMetadata objects in Spring configuration files");
  		}
  		// populate the map
  		masterMetadataMap.clear();
  		for (DataObjectMetadata metadata : metadataObjects.values()) {
  			if (metadata.getType() != null) {
  				if (metadata instanceof DataObjectMetadataImpl) {
  					((DataObjectMetadataImpl) metadata).setProvider(this);
  				}
  				masterMetadataMap.put(metadata.getType(), metadata);
  			} else {
  				LOG.error("Configuration Error.  MetadataObject in the Spring context contained a null DataObjectType reference: "
  						+ metadata);
  			}
  		}
  	}
  
  	public List<String> getResourceLocations() {
  		return resourceLocations;
  	}
  
  	public void setResourceLocations(List<String> resourceLocations) {
  		if (LOG.isDebugEnabled()) {
  			LOG.debug("Resource locations set to: " + resourceLocations);
  		}
  		this.resourceLocations = resourceLocations;
  	}
  
  	@Override
  	public String toString() {
  		return getClass().getName() + " : " + resourceLocations;
  	}
  }