package com.atlassian.plugin.webresource;
   
   import static com.atlassian.plugin.servlet.AbstractFileServerServlet.PATH_SEPARATOR;
   import static com.atlassian.plugin.servlet.AbstractFileServerServlet.RESOURCE_URL_PREFIX;
   import static com.atlassian.plugin.servlet.AbstractFileServerServlet.SERVLET_PATH;
   import com.atlassian.plugin.Plugin;
   import com.atlassian.util.concurrent.LazyReference;
   import com.google.common.collect.ImmutableMap;
   
  import java.util.Collections;
  import java.util.HashSet;
  import java.util.Map;
  import java.util.Set;
  
  /**
   * Represents a single plugin resource.
   *
   * It provides methods to parse and generate urls to locate a single plugin resource.
   *
   * Note: This PluginResource does not use it's parameters in generating the url. 
   *
   * @since 2.2
   */
  public class SinglePluginResource implements PluginResource
  {
      /**
       * The url prefix to a single plugin resource: "/download/resources/"
       */
      static final String URL_PREFIX = PATH_SEPARATOR + SERVLET_PATH + PATH_SEPARATOR + RESOURCE_URL_PREFIX;
  
      private final String resourceName;
      private final String moduleCompleteKey;
      private final boolean cached;
      private final Map<String, String> params;
      private final LazyReference<String> type;
      
      public SinglePluginResource(final String resourceName, final String moduleCompleteKey, final boolean cached)
      {
          this(resourceName, moduleCompleteKey, cached, Collections.<String, String>emptyMap());
      }
  
      public SinglePluginResource(final String resourceName, final String moduleCompleteKey, final boolean cached, final Map<String, String> params)
      {
          this.resourceName = resourceName;
          this.moduleCompleteKey = moduleCompleteKey;
          this.cached = cached;
          this.params = ImmutableMap.copyOf(params);
          this.type = new LazyReference<String>() {
              @Override
              protected String create() throws Exception
              {
                  return ResourceUtils.getType(resourceName);
              }
          };
      }
  
      public String getResourceName()
      {
          return resourceName;
      }
  
      public String getModuleCompleteKey()
      {
          return moduleCompleteKey;
      }
  
      public Map<String, String> getParams()
      {
          return params;
      }
  
      public String getVersion(WebResourceIntegration integration)
      {
          final Plugin plugin = integration.getPluginAccessor().getEnabledPluginModule(getModuleCompleteKey()).getPlugin();
          return plugin.getPluginInformation().getVersion();
      }
  
      public boolean isCacheSupported()
      {
          return cached;
      }
      
      @Override
      public Set<BatchedWebResourceDescriptor> getBatchedWebResourceDescriptors()
      {
          return Collections.emptySet();
      }
      
      /**
       * Returns a url string in the format: /download/resources/MODULE_COMPLETE_KEY/RESOURCE_NAME
       *
       * e.g. /download/resources/example.plugin:webresources/foo.css
       */
      public String getUrl()
      {
          return URL_PREFIX + PATH_SEPARATOR + moduleCompleteKey + PATH_SEPARATOR + resourceName;
      }
  
      @Override
     public String getType()
     {
         return type.get();
     }
 }