package com.atlassian.plugin.webresource;
   
   import com.atlassian.plugin.Plugin;
   import com.atlassian.plugin.PluginParseException;
   import com.atlassian.plugin.descriptors.AbstractModuleDescriptor;
   import com.atlassian.plugin.hostcontainer.HostContainer;
   import com.atlassian.plugin.web.Condition;
   import com.atlassian.plugin.web.conditions.ConditionLoadingException;
   import com.atlassian.plugin.web.descriptors.ConditionElementParser;
  import com.atlassian.plugin.web.descriptors.ConditionalDescriptor;
  import org.dom4j.Attribute;
  import org.dom4j.Element;
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Set;
  
  /**
   * A way of linking to web 'resources', such as javascript or css.  This allows us to include resources once
   * on any given page, as well as ensuring that plugins can declare resources, even if they are included
   * at the bottom of a page.
   */
  public class WebResourceModuleDescriptor extends AbstractModuleDescriptor<Void> implements ConditionalDescriptor
  {
      private List<String> dependencies = Collections.emptyList();
      private boolean disableMinification;
      private Set<String> contexts = Collections.emptySet();
      private List<WebResourceTransformation> webResourceTransformations = Collections.emptyList();
      private ConditionElementParser conditionElementParser;
      private Element element;
      private Condition condition;
  
      public WebResourceModuleDescriptor(final HostContainer hostContainer)
      {
          this.conditionElementParser = new ConditionElementParser(new ConditionElementParser.ConditionFactory()
          {
              public Condition create(String className, Plugin plugin) throws ConditionLoadingException
              {
                  try
                  {
                      Class<Condition> conditionClass = plugin.loadClass(className, this.getClass());
                      return hostContainer.create(conditionClass);
                  }
                  catch (ClassNotFoundException e)
                  {
                      throw new ConditionLoadingException("Cannot load condition class: " + className, e);
                  }
              }
          });
      }
  
      @Override
      public void init(final Plugin plugin, final Element element) throws PluginParseException
      {
          super.init(plugin, element);
  
          final List<String> deps = new ArrayList<String>();
          for (Element dependency : (List<Element>) element.elements("dependency"))
          {
              deps.add(dependency.getTextTrim());
          }
          dependencies = Collections.unmodifiableList(deps);
  
          final Set<String> ctxs = new HashSet<String>();
          for (Element contextElement : (List<Element>) element.elements("context"))
          {
              ctxs.add(contextElement.getTextTrim());
          }
          contexts = Collections.unmodifiableSet(ctxs);
  
          final List<WebResourceTransformation> trans = new ArrayList<WebResourceTransformation>();
          for (Element e : (List<Element>) element.elements("transformation"))
          {
              trans.add(new WebResourceTransformation(e));
          }
          webResourceTransformations = Collections.unmodifiableList(trans);
  
          final Attribute minifiedAttribute = element.attribute("disable-minification");
          disableMinification = minifiedAttribute == null ? false : Boolean.valueOf(minifiedAttribute.getValue());
          this.element = element;
      }
  
      /**
       * As this descriptor just handles resources, you should never call this
       */
      @Override
      public Void getModule()
      {
          throw new UnsupportedOperationException("There is no module for Web Resources");
      }
  
      @Override
      public void enabled()
      {
          super.enabled();
          try
          {
             condition = conditionElementParser.makeConditions(plugin, element, ConditionElementParser.CompositeType.AND);
         }
         catch (final PluginParseException e)
         {
             // is there a better exception to throw?
             throw new RuntimeException("Unable to enable web resource due to issue processing condition", e);
         }
     }
 
     @Override
     public void disabled()
     {
         super.disabled();
         condition = null;
     }
 
     /**
      * Returns the web resource contexts this resource is associated with.
      *
      * @return  the web resource contexts this resource is associated with.
      * @since 2.5.0
      */
     public Set<String> getContexts()
     {
         return contexts;
     }
 
     /**
      * Returns a list of dependencies on other web resources.
      * @return a list of module complete keys
      */
     public List<String> getDependencies()
     {
         return dependencies;
     }
 
     public List<WebResourceTransformation> getTransformations()
     {
         return webResourceTransformations;
     }
 
     /**
      * @return <code>true</code> if resource minification should be skipped, <code>false</code> otherwise.
      */
     public boolean isDisableMinification()
     {
         return disableMinification;
     }
 
     /**
      * @return The condition to determine if it should be displayed or not
      * @since 2.7.0
      */
     public Condition getCondition()
     {
         return condition;
     }
 
     /**
      * @return True if this web resource should be displayed based on the optional condition
      * @since 2.7.0
      */
     public boolean shouldDisplay()
     {
         return condition != null ? condition.shouldDisplay(Collections.<String, Object>emptyMap()) : true;
     }
 }