/*

  * Licensed to the Apache Software Foundation (ASF) under one

  * or more contributor license agreements.  See the NOTICE file

  * distributed with this work for additional information

  * regarding copyright ownership.  The ASF licenses this file

  * to you 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.apache.shiro.guice;

 import com.google.common.collect.Sets;

 import com.google.inject.Key;

 import com.google.inject.PrivateModule;

 import com.google.inject.TypeLiteral;

 import com.google.inject.binder.AnnotatedBindingBuilder;

 import com.google.inject.binder.LinkedBindingBuilder;

 import com.google.inject.multibindings.Multibinder;

 import com.google.inject.util.Types;

 import org.apache.shiro.config.ConfigurationException;

 import org.apache.shiro.env.Environment;

 import org.apache.shiro.mgt.DefaultSecurityManager;

 import org.apache.shiro.mgt.SecurityManager;

 import org.apache.shiro.realm.Realm;

 import org.apache.shiro.session.mgt.DefaultSessionManager;

 import org.apache.shiro.session.mgt.SessionManager;

 import org.apache.shiro.util.Destroyable;

 import javax.annotation.PreDestroy;

 import java.util.Collection;

 import java.util.Set;

 import java.util.WeakHashMap;

 /**

  * Sets up Shiro lifecycles within Guice, enables the injecting of Shiro objects, and binds a default

  * {@link org.apache.shiro.mgt.SecurityManager} and {@link org.apache.shiro.session.mgt.SessionManager}.  At least one realm must be added by using

  * {@link #bindRealm() bindRealm}.

  */

 public abstract class ShiroModule extends PrivateModule implements Destroyable {

     private Set<Destroyable> destroyables = Sets.newSetFromMap(new WeakHashMap<Destroyable, Boolean>());

     public void configure() {

         // setup security manager

         bindSecurityManager(bind(SecurityManager.class));

         bindSessionManager(bind(SessionManager.class));

         bindEnvironment(bind(Environment.class));

         bindListener(BeanTypeListener.MATCHER, new BeanTypeListener());

         final DestroyableInjectionListener.DestroyableRegistry registry = new DestroyableInjectionListener.DestroyableRegistry() {

             public void add(Destroyable destroyable) {

                 ShiroModule.this.add(destroyable);

             }

             @PreDestroy

             public void destroy() throws Exception {

                 ShiroModule.this.destroy();

             }

         };

         bindListener(LifecycleTypeListener.MATCHER, new LifecycleTypeListener(registry));

         expose(SecurityManager.class);

         configureShiro();

         bind(realmCollectionKey())

                 .to(realmSetKey());

         bind(DestroyableInjectionListener.DestroyableRegistry.class).toInstance(registry);

         BeanTypeListener.ensureBeanTypeMapExists(binder());

     }

     @SuppressWarnings({"unchecked"})

     private Key<Set<Realm>> realmSetKey() {

         return (Key<Set<Realm>>) Key.get(TypeLiteral.get(Types.setOf(Realm.class)));

     }

     @SuppressWarnings({"unchecked"})

     private Key<Collection<Realm>> realmCollectionKey() {

         return (Key<Collection<Realm>>) Key.get(Types.newParameterizedType(Collection.class, Realm.class));

     }

     /**

      * Implement this method in order to configure your realms and any other Shiro customization you may need.

      */

     protected abstract void configureShiro();

     /**

      * This is the preferred manner to bind a realm.  The {@link org.apache.shiro.mgt.SecurityManager} will be injected with any Realm bound

      * with this method.

      *

      * @return a binding builder for a realm

      */

     protected final LinkedBindingBuilder<Realm> bindRealm() {

         Multibinder<Realm> multibinder = Multibinder.newSetBinder(binder(), Realm.class);

         return multibinder.addBinding();

     }

     /**

      * Binds the security manager.  Override this method in order to provide your own security manager binding.

      * <p/>

      * By default, a {@link org.apache.shiro.mgt.DefaultSecurityManager} is bound as an eager singleton.

      *

      * @param bind

      */

     protected void bindSecurityManager(AnnotatedBindingBuilder<? super SecurityManager> bind) {

         try {

             bind.toConstructor(DefaultSecurityManager.class.getConstructor(Collection.class)).asEagerSingleton();

         } catch (NoSuchMethodException e) {

             throw new ConfigurationException("This really shouldn't happen.  Either something has changed in Shiro, or there's a bug in " + ShiroModule.class.getSimpleName(), e);

         }

     }

     /**

      * Binds the session manager.  Override this method in order to provide your own session manager binding.

      * <p/>

      * By default, a {@link org.apache.shiro.session.mgt.DefaultSessionManager} is bound as an eager singleton.

      *

      * @param bind

      */

     protected void bindSessionManager(AnnotatedBindingBuilder<SessionManager> bind) {

         bind.to(DefaultSessionManager.class).asEagerSingleton();

     }

     /**

      * Binds the environment.  Override this method in order to provide your own environment binding.

      * <p/>

      * By default, a {@link GuiceEnvironment} is bound as an eager singleton.

      *

      * @param bind

      */

     protected void bindEnvironment(AnnotatedBindingBuilder<Environment> bind) {

         bind.to(GuiceEnvironment.class).asEagerSingleton();

     }

     /**

      * Binds a key to use for injecting setters in shiro classes.

      * @param typeLiteral the bean property type

      * @param key the key to use to satisfy the bean property dependency

      * @param <T>

      */

     protected final <T> void bindBeanType(TypeLiteral<T> typeLiteral, Key<? extends T> key) {

         BeanTypeListener.bindBeanType(binder(), typeLiteral, key);

     }

     /**

      * Destroys all beans created within this module that implement {@link org.apache.shiro.util.Destroyable}.  Should be called when this

      * module will no longer be used.

      *

      * @throws Exception

      */

     public final void destroy() throws Exception {

         for (Destroyable destroyable : destroyables) {

             destroyable.destroy();

         }

     }

     public void add(Destroyable destroyable) {

         this.destroyables.add(destroyable);

     }

 }