package org.andromda.core.common;
   
   import java.net.URL;
   import java.util.ArrayList;
   import java.util.Collection;
   import java.util.HashMap;
   import java.util.Map;
   import org.andromda.core.configuration.Namespaces;
   import org.apache.commons.lang.StringUtils;
  import org.apache.commons.lang.builder.ToStringBuilder;
  import org.apache.log4j.Logger;
  
  /**
   * Contains the configuration of a template object which are objects that are
   * made available to the cartridge templates.
   *
   * @author Chad Brandon
   * @author Bob Fields
   */
  public class TemplateObject
  {
      private static final Logger logger = Logger.getLogger(TemplateObject.class);
  
      /**
       * The name of this template object made available to the
       * template.
       */
      private String name;
  
      /**
       * Gets the current name of this TemplateObject.
       *
       * @return String
       */
      public String getName()
      {
          final String methodName = "TemplateObject.getName";
          if (StringUtils.isEmpty(this.name))
          {
              throw new TemplateObjectException(methodName + " - templateObject '" + this + "' has no name defined");
          }
          return this.name;
      }
  
      /**
       * Caches the template objects.
       */
      private final Map<String, Object> objectCache = new HashMap<String, Object>();
  
      /**
       * Defines the class should be used in a static way
       */
      private static final String STATIC_SUFFIX = ".class";
      
      /**
       * Returns the actuall object instance described by this
       * template object.
       *
       * @return the actual object instance.
       */
      public Object getObject()
      {
          final String methodName = "TemplateObject.getTemplateObject";
          if (StringUtils.isEmpty(this.className))
          {
              throw new TemplateObjectException(methodName + " - templateObject '" + this + "' has no className defined");
          }
          Object templateObject = this.objectCache.get(this.className);
          try
          {
              if (templateObject == null)
              {
                  final Class templateObjectClass;
                  if(this.className.endsWith(STATIC_SUFFIX))
                  {
                      templateObjectClass = ClassUtils.loadClass(StringUtils.substringBefore(this.className, STATIC_SUFFIX));
                      templateObject = templateObjectClass; 
                  }
                  else
                  {
                      templateObjectClass = ClassUtils.loadClass(this.className);
                      templateObject = templateObjectClass.newInstance();
                  }
                  this.objectCache.put(this.className, templateObject);
              }
  
              // - we want to set the properties each time we retrieve (in case they've changed)
              this.setProperties(templateObject);
          }
          catch (final Throwable throwable)
          {
              throw new TemplateObjectException(throwable);
          }
          return templateObject;
      }
  
      /**
       * Sets all the nested properties on the templateObject object.
       *
      * @param templateObject the template object on which to populate properties.
      */
     protected void setProperties(final Object templateObject)
     {
         for (final String reference : propertyReferences)
         {
             String value = Namespaces.instance().getPropertyValue(
                     this.getNamespace(),
                     reference);
             if (value != null)
             {
                 if (this.getLogger().isDebugEnabled())
                 {
                     this.getLogger().debug(
                         "populating template object '" + this.name + "' property '" + reference + "' with value '" +
                         value + "' for namespace '" + namespace + '\'');
                 }
                 try
                 {
                     Introspector.instance().setProperty(templateObject, reference, value);
                 }
                 catch (final Exception exception)
                 {
                     // - don't throw the exception
                     final String message =
                         "Error setting property '" + reference + "' with '" + value + "' on templateObject --> '" +
                         templateObject + '\'';
                     logger.warn(message);
                 }
             }
         }
     }
 
     /**
      * Sets the name of the template object (this name will be what the template class is stored under in the template)
      *
      * @param name the name of the template object.
      */
     public void setName(final String name)
     {
         this.name = StringUtils.trimToEmpty(name);
     }
 
     /**
      * The name of the class for this template object.
      */
     private String className;
 
     /**
      * Sets the class of the transformation object.
      *
      * @param className the name of the template object class.
      */
     public void setClassName(final String className)
     {
         ExceptionUtils.checkEmpty("className", className);
         this.className = className;
     }
 
     /**
      * The property references that configure this template object.
      */
     private final Collection<String> propertyReferences = new ArrayList<String>();
 
     /**
      * Adds a templateObject property reference (used to customize templateObjects). Property references are used to
      * populate bean like properties of template objects.
      *
      * @param reference the name of the property reference.
      */
     public void addPropertyReference(final String reference)
     {
         this.propertyReferences.add(reference);
     }
 
     /**
      * The resource in which the template object was found.
      */
     private URL resource;
 
     /**
      * The resource in which the templateObject was found.
      *
      * @return the resource as a URL.
      */
     public URL getResource()
     {
         return resource;
     }
 
     /**
      * Sets the resource in which the templateObject was defined.
      *
      * @param resource the resource on which this template object was defined.
      */
     public void setResource(final URL resource)
     {
         this.resource = resource;
     }
 
     /**
      * The namespace to which this template object belongs.
      */
     private String namespace;
 
     /**
      * Gets the namespace to which this template object belongs.
      *
      * @return Returns the namespace.
      */
     public String getNamespace()
     {
         return namespace;
     }
 
     /**
      * Sets the namespace to which this template object belongs.
      *
      * @param namespace The namespace to set.
      */
     public void setNamespace(final String namespace)
     {
         this.namespace = StringUtils.trimToEmpty(namespace);
     }
 
     /**
      * Gets the namespace logger (the logger under which output for this
      * template object should be written).
      *
      * @return the logger instance.
      */
     protected Logger getLogger()
     {
         return AndroMDALogger.getNamespaceLogger(this.namespace);
     }
 
     /**
      * @see Object#toString()
      */
     public String toString()
     {
         return ToStringBuilder.reflectionToString(this);
     }
 }