/**
    * This file Copyright (c) 2011 Magnolia International
    * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
    *
    *
    * This file is dual-licensed under both the Magnolia
    * Network Agreement and the GNU General Public License.
    * You may elect to use one or the other of these licenses.
    *
   * This file is distributed in the hope that it will be
   * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
   * implied warranty of MERCHANTABILITY or FITNESS FOR A
   * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
   * Redistribution, except as permitted by whichever of the GPL
   * or MNA you select, is prohibited.
   *
   * 1. For the GPL license (GPL), you can redistribute and/or
   * modify this file under the terms of the GNU General
   * Public License, Version 3, as published by the Free Software
   * Foundation.  You should have received a copy of the GNU
   * General Public License, Version 3 along with this program;
   * if not, write to the Free Software Foundation, Inc., 51
   * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * 2. For the Magnolia Network Agreement (MNA), this file
   * and the accompanying materials are made available under the
   * terms of the MNA which accompanies this distribution, and
   * is available at http://www.magnolia-cms.com/mna.html
   *
   * Any modifications to this file must keep this entire header
   * intact.
   *
   */
  package info.magnolia.objectfactory.guice;
  
  import java.lang.reflect.InvocationTargetException;
  import java.util.Set;
  import javax.inject.Inject;
  import javax.inject.Provider;
  
  import com.google.common.collect.ImmutableSet;
  import com.google.common.collect.Sets;
  import com.google.inject.Injector;
  import com.google.inject.Key;
  import com.google.inject.spi.Dependency;
  import com.google.inject.spi.InjectionPoint;
  import com.google.inject.spi.ProviderWithDependencies;
  
  import info.magnolia.objectfactory.ComponentFactory;
  import info.magnolia.objectfactory.ComponentFactoryUtil;
  import info.magnolia.objectfactory.ComponentProvider;
  
  /**
   * Utilities for guice.
   *
   * @version $Id$
   */
  public class GuiceUtils {
  
      public static <T> Provider<T> providerForInstance(final T instance) {
          return new Provider<T>() {
              @Override
              public T get() {
                  return instance;
              }
  
              @Override
              public String toString() {
                  return "Provider for: " + instance.toString();
              }
          };
      }
  
      public static <T> Provider<T> providerForComponentFactory(final Class<? extends ComponentFactory<T>> componentFactoryClass) {
          return new Provider<T>() {
  
              @Inject
              private ComponentProvider componentProvider;
  
              @Override
              public T get() {
                  try {
                      ComponentFactory<T> componentFactory = ComponentFactoryUtil.createFactory(componentFactoryClass, componentProvider);
                      ((GuiceComponentProvider) componentProvider).injectMembers(componentFactory);
                      T instance = componentFactory.newInstance();
                      return instance;
                  } catch (InstantiationException e) {
                      throw new IllegalStateException("Failed to create ComponentFactory [" + componentFactoryClass + "]", e);
                  } catch (IllegalAccessException e) {
                      throw new IllegalStateException("Failed to create ComponentFactory [" + componentFactoryClass + "]", e);
                  } catch (InvocationTargetException e) {
                      throw new IllegalStateException("Failed to create ComponentFactory [" + componentFactoryClass + "]", e);
                  }
              }
  
              @Override
              public String toString() {
                  return "ComponentFactory: " + componentFactoryClass.toString();
              }
         };
     }
 
     public static <T> Provider<T> providerForComponentFactory(final ComponentFactory<T> componentFactory) {
 
         // This method does exactly the same as com.google.inject.util.Providers#guicify
 
         // Ensure that we inject all injection points from the delegate provider.
         Set<InjectionPoint> injectionPoints =
                 InjectionPoint.forInstanceMethodsAndFields(componentFactory.getClass());
         if(injectionPoints.isEmpty()) {
             return new com.google.inject.Provider<T>() {
                 @Override
                 public T get() {
                     return componentFactory.newInstance();
                 }
 
                 @Override
                 public String toString() {
                     return "ComponentFactory: " + componentFactory.toString();
                 }
             };
         } else {
             Set<Dependency<?>> mutableDeps = Sets.newHashSet();
             for(InjectionPoint ip : injectionPoints) {
                 mutableDeps.addAll(ip.getDependencies());
             }
             final Set<Dependency<?>> dependencies = ImmutableSet.copyOf(mutableDeps);
             return new ProviderWithDependencies<T>() {
                 @SuppressWarnings("unused")
                 @com.google.inject.Inject
                 void initialize(Injector injector) {
                     injector.injectMembers(componentFactory);
                 }
 
                 @Override
                 public Set<Dependency<?>> getDependencies() {
                     return dependencies;
                 }
 
                 @Override
                 public T get() {
                     return componentFactory.newInstance();
                 }
 
                 @Override
                 public String toString() {
                     return "ComponentFactory: " + componentFactory.toString();
                 }
             };
         }
     }
 
     public static boolean hasExplicitBindingFor(Injector injector, Class<?> type) {
         Key<?> key = Key.get(type);
         Injector target = injector;
         do {
             if (target.getBindings().containsKey(key)) {
                 return true;
             }
             target = target.getParent();
         } while (target != null);
         return false;
     }
 }