package org.webslinger.commons.vfs.handlers.attributes;

 import org.apache.commons.vfs.FileContent;

 import org.apache.commons.vfs.FileName;

 import org.apache.commons.vfs.FileObject;

 import org.apache.commons.vfs.FileSystemException;

 import org.webslinger.commons.vfs.VFSUtil;

 import org.webslinger.lang.ConcurrentCache;

 import org.webslinger.util.GeneratedResult;

 import org.webslinger.util.TTLObject;

 import org.webslinger.util.TTLCachedObject;

 public class DefaultAttributeMapper implements AttributeMapper {

     static {

         TTLObject.setDefaultTTLForClass(AttributeValueTTLCachedObject.class, 1000);

     }

     protected final FileObject file;

     protected final ConcurrentCache<String, TTLCachedObject<Object>> attributeCache = new ConcurrentCache<String, TTLCachedObject<Object>>(DefaultAttributeMapper.class, "attributeCache", null, ConcurrentCache.HARD) {

         protected TTLCachedObject<Object> createValue(String key) throws Exception {

             return new AttributeValueTTLCachedObject(key);

         }

     };

     protected class AttributeValueTTLCachedObject extends TTLCachedObject<Object> {

         protected final String name;

         protected AttributeValueTTLCachedObject(String name) {

             this.name = name;

         }

         protected long getTimestamp(Object old) throws FileSystemException {

             FileContent content = getContent();

             if (!content.getFile().exists()) return NOT_EXISTANT_TIMESTAMP;

             return content.getLastModifiedTime();

         }

         protected GeneratedResult<Object> generate(Object old) throws FileSystemException {

             FileContent content = getContent();

             if (!content.getFile().exists()) return new GeneratedResult<Object>(NOT_EXISTANT_TIMESTAMP, null);

             return new GeneratedResult<Object>(content.getLastModifiedTime(), content.getAttribute(name));

         }

     }

     public DefaultAttributeMapper(FileObject file) throws FileSystemException {

         this.file = file;

     }

     protected FileContent getContent() throws FileSystemException {

         return file.getContent();

     }

     public void deleteAttributes() throws FileSystemException {

     }

     public void refresh() throws FileSystemException {

         attributeCache.clear();

     }

     public TTLCachedObject<Object> getAttribute(String name) throws FileSystemException {

         try {

             return attributeCache.get(name);

         } catch (Exception e) {

             throw VFSUtil.makeFileSystemException(e);

         }

     }

     public boolean attributeExists(String name) throws FileSystemException {

         return getContent().attributeExists(name);

     }

     public String[] getAttributeNames() throws FileSystemException {

         return getContent().getAttributeNames();

     }

     public void setAttribute(String name, Object value) throws FileSystemException {

         getContent().setAttribute(name, value);

         attributeCache.remove(name);

     }

     public void removeAttribute(String name) throws FileSystemException {

         getContent().removeAttribute(name);

         attributeCache.remove(name);

     }

 }