/*

  * 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.primitives.Primitives;

 import com.google.inject.*;

 import com.google.inject.matcher.Matcher;

 import com.google.inject.matcher.Matchers;

 import com.google.inject.multibindings.MapBinder;

 import com.google.inject.name.Names;

 import com.google.inject.spi.TypeEncounter;

 import com.google.inject.spi.TypeListener;

 import com.google.inject.util.Types;

 import org.apache.commons.beanutils.PropertyUtils;

 import org.apache.shiro.SecurityUtils;

 import java.beans.PropertyDescriptor;

 import java.lang.reflect.InvocationTargetException;

 import java.lang.reflect.Modifier;

 import java.lang.reflect.Type;

 import java.util.HashMap;

 import java.util.Map;

 /**

  * TypeListener that injects setter methods on Shiro objects.

  */

 class BeanTypeListener implements TypeListener {

     public static final Package SHIRO_GUICE_PACKAGE = ShiroModule.class.getPackage();

     public static final Package SHIRO_PACKAGE = SecurityUtils.class.getPackage();

     private static Matcher<Class> shiroMatcher = Matchers.inSubpackage(SHIRO_PACKAGE.getName());

     private static Matcher<Class> shiroGuiceMatcher = Matchers.inSubpackage(SHIRO_GUICE_PACKAGE.getName());

     private static Matcher<Class> classMatcher = ShiroMatchers.ANY_PACKAGE.and(shiroMatcher.and(Matchers.not(shiroGuiceMatcher)));

     public static final Matcher<TypeLiteral> MATCHER = ShiroMatchers.typeLiteral(classMatcher);

     private static final String BEAN_TYPE_MAP_NAME = "__SHIRO_BEAN_TYPES__";

     static final Key<?> MAP_KEY = Key.get(Types.mapOf(TypeLiteral.class, BeanTypeKey.class), Names.named(BEAN_TYPE_MAP_NAME));

     public <I> void hear(TypeLiteral<I> type, final TypeEncounter<I> encounter) {

         PropertyDescriptor propertyDescriptors[] = PropertyUtils.getPropertyDescriptors(type.getRawType());

         final Map<PropertyDescriptor, Key<?>> propertyDependencies = new HashMap<PropertyDescriptor, Key<?>>(propertyDescriptors.length);

         final Provider<Injector> injectorProvider = encounter.getProvider(Injector.class);

         for (PropertyDescriptor propertyDescriptor : propertyDescriptors) {

             if (propertyDescriptor.getWriteMethod() != null && Modifier.isPublic(propertyDescriptor.getWriteMethod().getModifiers())) {

                 Type propertyType = propertyDescriptor.getWriteMethod().getGenericParameterTypes()[0];

                 propertyDependencies.put(propertyDescriptor, createDependencyKey(propertyDescriptor, propertyType));

             }

         }

         encounter.register(new MembersInjector<I>() {

             public void injectMembers(I instance) {

                 for (Map.Entry<PropertyDescriptor, Key<?>> dependency : propertyDependencies.entrySet()) {

                     try {

                         final Injector injector = injectorProvider.get();

                         Object value = injector.getInstance(getMappedKey(injector, dependency.getValue()));

                         dependency.getKey().getWriteMethod().invoke(instance, value);

                     } catch (ConfigurationException e) {

                         // This is ok, it simply means that we can't fulfill this dependency.

                         // Is there a better way to do this?

                     } catch (InvocationTargetException e) {

                         throw new RuntimeException("Couldn't set property " + dependency.getKey().getDisplayName(), e);

                     } catch (IllegalAccessException e) {

                         throw new RuntimeException("We shouldn't have ever reached this point, we don't try to inject to non-accessible methods.", e);

                     }

                 }

             }

         });

     }

     private static Key<?> getMappedKey(Injector injector, Key<?> key) {

         Map<TypeLiteral, BeanTypeKey> beanTypeMap = getBeanTypeMap(injector);

         if(key.getAnnotation() == null && beanTypeMap.containsKey(key.getTypeLiteral())) {

             return beanTypeMap.get(key.getTypeLiteral()).key;

         } else {

             return key;

         }

     }

     @SuppressWarnings({"unchecked"})

     private static Map<TypeLiteral, BeanTypeKey> getBeanTypeMap(Injector injector) {

         return (Map<TypeLiteral, BeanTypeKey>) injector.getInstance(MAP_KEY);

     }

     private static Key<?> createDependencyKey(PropertyDescriptor propertyDescriptor, Type propertyType) {

         if(requiresName(propertyType)) {

             return Key.get(propertyType, Names.named("shiro." + propertyDescriptor.getName()));

         } else {

             return Key.get(propertyType);

         }

     }

     private static boolean requiresName(Type propertyType) {

         if (propertyType instanceof Class) {

             Class<?> aClass = (Class<?>) propertyType;

             return aClass.isPrimitive() || aClass.isEnum() || Primitives.isWrapperType(aClass) || CharSequence.class.isAssignableFrom(aClass);

         } else {

             return false;

         }

     }

     static void ensureBeanTypeMapExists(Binder binder) {

         beanTypeMapBinding(binder).addBinding(TypeLiteral.get(BeanTypeKey.class)).toInstance(new BeanTypeKey(null));

     }

     static <T> void bindBeanType(Binder binder, TypeLiteral<T> typeLiteral, Key<? extends T> key) {

         beanTypeMapBinding(binder).addBinding(typeLiteral).toInstance(new BeanTypeKey(key));

     }

     private static MapBinder<TypeLiteral, BeanTypeKey> beanTypeMapBinding(Binder binder) {

         return MapBinder.newMapBinder(binder, TypeLiteral.class, BeanTypeKey.class, Names.named(BEAN_TYPE_MAP_NAME));

     }

     private static class BeanTypeKey {

         Key<?> key;

         private BeanTypeKey(Key<?> key) {

             this.key = key;

         }

     }

 }