/*
    *    Copyright 2012 The 99 Software Foundation
    *
    *    Licensed under the Apache License, Version 2.0 (the "License");
    *    you may not use this file except in compliance with the License.
    *    You may obtain a copy of the License at
    *
    *       http://www.apache.org/licenses/LICENSE-2.0
    *
   *    Unless required by applicable law or agreed to in writing, software
   *    distributed under the License is distributed on an "AS IS" BASIS,
   *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   *    See the License for the specific language governing permissions and
   *    limitations under the License.
   */
  package org.nnsoft.guice.junice.handler;
  
  import java.lang.reflect.Method;
  import java.lang.reflect.Modifier;
  import java.util.ArrayList;
  import java.util.List;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.nnsoft.guice.junice.annotation.GuiceProvidedModules;
  import org.nnsoft.guice.junice.reflection.ClassVisitor;
  import org.nnsoft.guice.junice.reflection.HandleException;
  import org.nnsoft.guice.junice.reflection.MethodHandler;
  
  import com.google.inject.Module;
  import com.google.inject.TypeLiteral;
  import com.google.inject.internal.MoreTypes;
  
  /**
   * Handler class to handle all {@link GuiceProvidedModules} annotations.
   * 
   * @see ClassVisitor
   * @see GuiceProvidedModules
   * @author Marco Speranza
   * @version $Id: GuiceProviderHandler.java 000 2009-12-01 00:00:00Z marco.speranza79 $
   */
  public final class GuiceProvidedModuleHandler implements MethodHandler<GuiceProvidedModules> {
  
      private static Log logger = LogFactory.getLog(GuiceProvidedModuleHandler.class);
  
      final private List<Module> modules = new ArrayList<Module>();
  
      /**
       * @return the guiceProviderModuleRegistry
       */
      public List<Module> getModules() {
          return this.modules;
      }
  
      /**
       * {@inheritDoc}
       */
      @SuppressWarnings("unchecked")
      public void handle(GuiceProvidedModules annotation, Method method) throws HandleException {
          final Class<?> returnType = method.getReturnType();
  
          if (logger.isDebugEnabled()) {
              logger.debug("  Found " 
                      + GuiceProvidedModules.class.getSimpleName()
                      + " annotated method, checking if return type '"
                      + returnType.getName()
                      + "' is one of (''|''|'')...");
          }
  
          if (!Modifier.isPublic(method.getModifiers())
                  || !Modifier.isStatic(method.getModifiers())) {
              throw new HandleException("Impossible to invoke method: "
                      + method
                      + ", it has to be static and public");
          }
  
          final Class<?> type = method.getDeclaringClass();
  
          try {
              if (Module.class.isAssignableFrom(returnType)) {
                  this.modules.add((Module) method.invoke(type));
              } else if (MoreTypes
                      .getRawType(new TypeLiteral<Iterable<Module>>() {}.getType())
                      .isAssignableFrom(returnType)) {
                  this.addModules((Iterable<Module>) method.invoke(type));
              } else if (MoreTypes
                      .getRawType(new TypeLiteral<Module[]>() {}.getType())
                      .isAssignableFrom(returnType)) {
                  this.addModules((Module[]) method.invoke(type));
              }
          } catch (Exception e) {
              throw new HandleException("Error invoking method: "
                      + method
                      + "please make sure it is static and public", e);
          }
  
          if (logger.isDebugEnabled()) {
              logger.debug("  Invoked method: "
                      + method.toGenericString());
         }
     }
 
     private void addModules(Iterable<Module> modules) {
         for (Module module : modules) {
             this.modules.add(module);
         }
     }
 
     private void addModules(Module... modules) {
         for (Module module : modules) {
             this.modules.add(module);
         }
     }
 
 }