package com.atlassian.plugins.rest.common.interceptor.impl;
   
   import com.atlassian.plugin.AutowireCapablePlugin;
   import com.atlassian.plugins.rest.common.interceptor.InterceptorChain;
   import com.atlassian.plugins.rest.common.interceptor.ResourceInterceptor;
   
   import java.lang.reflect.Method;
   import java.util.ArrayList;
   import java.util.LinkedHashMap;
  import java.util.List;
  
  /**
   * Builds the interceptor chain for the resource method.  Uses the {@link InterceptorChain} resource by building the
   * chain from the method then class then package, then default interceptors passed into the constructor.
   *
   * This is a private class and used by the  {@link EntityParamDispatchProviderWrapper}
   * and {@link com.atlassian.plugins.rest.common.multipart.jersey.MultipartFormDispatchProvider}
   * which both will use this helper class to wrap calls to rest methods with interceptors.
   *
   * @since 2.0
   */
  public class InterceptorChainBuilder
  {
      private final LinkedHashMap<Class<? extends ResourceInterceptor>, ResourceInterceptor> defaultResourceInterceptors;
      private final AutowireCapablePlugin plugin;
  
      public InterceptorChainBuilder(AutowireCapablePlugin plugin, ResourceInterceptor... resourceInterceptors)
      {
          defaultResourceInterceptors = new LinkedHashMap<Class<? extends ResourceInterceptor>, ResourceInterceptor>();
          for (ResourceInterceptor resourceInterceptor : resourceInterceptors)
          {
              defaultResourceInterceptors.put(resourceInterceptor.getClass(), resourceInterceptor);
          }
          this.plugin = plugin;
      }
  
      public List<ResourceInterceptor> getResourceInterceptorsForMethod(Method m)
      {
          // First check the method
          InterceptorChain chain = m.getAnnotation(InterceptorChain.class);
          if (chain == null)
          {
              // Next check the class
              chain = m.getDeclaringClass().getAnnotation(InterceptorChain.class);
              if (chain == null)
              {
                  // Finally, check the package
                  chain = m.getDeclaringClass().getPackage().getAnnotation(InterceptorChain.class);
              }
          }
  
          if (chain != null)
          {
              return buildFromClass(chain.value());
          }
          else
          {
              // Return default interceptor list
              return new ArrayList<ResourceInterceptor>(defaultResourceInterceptors.values());
          }
      }
  
      private List<ResourceInterceptor> buildFromClass(Class<? extends ResourceInterceptor>[] resourceInterceptorClasses)
      {
          List<ResourceInterceptor> resourceInterceptors = new ArrayList<ResourceInterceptor>();
          for (Class<? extends ResourceInterceptor> resourceInterceptorClass : resourceInterceptorClasses)
          {
              if (defaultResourceInterceptors.containsKey(resourceInterceptorClass))
              {
                  resourceInterceptors.add(defaultResourceInterceptors.get(resourceInterceptorClass));
              }
              else
              {
                  resourceInterceptors.add(plugin.autowire(resourceInterceptorClass));
  
                  // todo: we should find a way to autowire from jersey injectables
              }
          }
          return resourceInterceptors;
      }
  }