package org.trails.io;

 import org.apache.commons.logging.Log;

 import org.apache.commons.logging.LogFactory;

 import org.apache.tapestry.services.DataSqueezer;

 import org.apache.tapestry.util.io.SqueezeAdaptor;

 import org.trails.util.Utils;

 import org.trails.descriptor.DescriptorService;

 import org.trails.descriptor.IClassDescriptor;

 import org.trails.engine.encoders.abbreviator.EntityNameAbbreviator;

 /**

  * Squeezes a {@link IClassDescriptor}

  */

 public class ClassDescriptorSqueezerStrategy implements SqueezeAdaptor

 {

         private static final Log LOG = LogFactory.getLog(ClassDescriptorSqueezerStrategy.class);

         public static final String PREFIX = "Y";

         private DescriptorService descriptorService;

         private EntityNameAbbreviator entityNameAbbreviator;

         private boolean shouldAbbreviate = false;

         public Class getDataClass()

         {

                 return IClassDescriptor.class;

         }

         public String getPrefix()

         {

                 return PREFIX;

         }

         public void setDescriptorService(DescriptorService descriptorService)

         {

                 this.descriptorService = descriptorService;

         }

         public String squeeze(DataSqueezer squeezer, Object object)

         {

                 IClassDescriptor classDescriptor = (IClassDescriptor) object;

                 final String squeezed = abbreviate(classDescriptor.getType());

                 if (LOG.isDebugEnabled())

                 {

                         LOG.debug("squeezing descriptor for: " + squeezed);

                 }

                 return PREFIX + squeezed;

         }

         public Object unsqueeze(DataSqueezer squeezer, String string)

         {

                 if (LOG.isDebugEnabled())

                 {

                         LOG.debug("unsqueezing: " + string);

                 }

                 final String squeezed = string.substring(PREFIX.length());

                 return descriptorService.getClassDescriptor(unabbreviate(squeezed));

         }

         public void setEntityNameAbbreviator(EntityNameAbbreviator entityNameAbbreviator)

         {

                 this.entityNameAbbreviator = entityNameAbbreviator;

                 shouldAbbreviate = entityNameAbbreviator != null;

         }

         private String abbreviate(Class clazz)

         {

                 return shouldAbbreviate ? entityNameAbbreviator.abbreviate(clazz) : clazz.getName();

         }

         private Class unabbreviate(String abbreviation)

         {

                 return shouldAbbreviate ? entityNameAbbreviator.unabbreviate(abbreviation) : Utils.classForName(abbreviation);

         }

 }