package com.trendmicro.grid.acl.ds;
   
   import static net.sf.tinyjee.util.Assert.assertNotNull;
   
   import javax.xml.bind.annotation.*;
   import java.util.*;
   
   /**
    * Is a persitable list of repository selectors.
   *
   * @author juergen_kellerer, 2010-05-05
   * @version 1.0
   */
  @XmlType
  @XmlRootElement(name = "repository-selection")
  @XmlAccessorType(XmlAccessType.FIELD)
  public class RepositorySelectors {
  
  	private static final RepositorySelector EMPTY_SELECTOR = new RepositorySelector() {
  		@Override
  		public Repository getRepository() {
  			return null;
  		}
  
  		@Override
  		public String getSelectedKey() {
  			return null;
  		}
  
  		@Override
  		public List getAvailableKeys() {
  			return Collections.emptyList();
  		}
  	};
  
  	@XmlElement(name = "selector")
  	private List<RepositorySelector<?>> allSelectors = new ArrayList<RepositorySelector<?>>();
  
  	private transient Map<String, RepositorySelector<?>> selectorsMap;
  
  	public List<RepositorySelector<?>> getAllSelectors() {
  		return Collections.unmodifiableList(allSelectors);
  	}
  
  	public long getLastModified() {
  		long lastModified = 0;
  		for (RepositorySelector<?> selector : allSelectors)
  			lastModified = Math.max(lastModified, selector.getLastModified());
  		return lastModified;
  	}
  
  	public void setLastModified(long time) {
  		for (RepositorySelector<?> selector : allSelectors)
  			selector.setLastModified(time);
  	}
  
  	@SuppressWarnings("unchecked")
  	public void addSelector(RepositorySelector selector) {
  		assertNotNull("selector", selector);
  
  		RepositorySelector<?> existing = getSelector(selector.getRepositoryClass());
  		if (existing != null && existing != EMPTY_SELECTOR)
  			existing.initFrom(selector);
  		else {
  			allSelectors.add(selector);
  			selectorsMap = null;
  		}
  	}
  
  
  	/**
  	 * Returns a repository selector for the given class.
  	 *
  	 * @param repositoryClass the repository interface of the selector to return.
  	 * @param <R>             the type of repository interface to return.
  	 * @return a selector for the given class, returns an empty selector instance
  	 *         if no selector exists for a given repository.
  	 */
  	public <R extends Repository> RepositorySelector<R> getSelector(Class<R> repositoryClass) {
  		return getSelector(repositoryClass.getName());
  	}
  
  	/**
  	 * Returns a repository selector for the given class.
  	 *
  	 * @param repositoryClass the repository interface of the selector to return.
  	 * @param <R>             the type of repository interface to return.
  	 * @return a selector for the given class, returns an empty selector instance
  	 *         if no selector exists for a given repository.
  	 */
  	@SuppressWarnings("unchecked")
  	public <R extends Repository> RepositorySelector<R> getSelector(String repositoryClass) {
  		Map<String, RepositorySelector<?>> map = selectorsMap;
  		if (map == null) {
  			map = new HashMap<String, RepositorySelector<?>>();
  			for (RepositorySelector<?> selector : allSelectors)
  				map.put(selector.getRepositoryClass(), selector);
  			selectorsMap = map;
  		}
 
 		RepositorySelector<?> selector = map.get(repositoryClass);
 		return selector == null ? EMPTY_SELECTOR : selector;
 	}
 }