/*
    * Grapht, an open source dependency injector.
    * Copyright 2014-2015 various contributors (see CONTRIBUTORS.txt)
    * Copyright 2010-2014 Regents of the University of Minnesota
    *
    * This program is free software; you can redistribute it and/or modify
    * it under the terms of the GNU Lesser General Public License as
    * published by the Free Software Foundation; either version 2.1 of the
    * License, or (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
   * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
   * details.
   *
   * You should have received a copy of the GNU General Public License along with
   * this program; if not, write to the Free Software Foundation, Inc., 51
   * Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
   */
  package org.grouplens.grapht.reflect.internal;
  
  import org.grouplens.grapht.*;
  import org.grouplens.grapht.reflect.*;
  import org.grouplens.grapht.util.ClassProxy;
  import org.grouplens.grapht.util.Preconditions;
  import org.grouplens.grapht.util.Types;
  
  import javax.inject.Provider;
  import javax.inject.Singleton;
  import java.io.InvalidObjectException;
  import java.io.ObjectInputStream;
  import java.io.ObjectStreamException;
  import java.io.Serializable;
  import java.lang.reflect.Modifier;
  import java.lang.reflect.Type;
  import java.util.List;
  import java.util.Map;
  
  /**
   * ProviderClassSatisfaction is a satisfaction implementation that satisfies a
   * type given a {@link Provider} class capable of providing that type.
   * 
   * @author <a href="http://grouplens.org">GroupLens Research</a>
   */
  public class ProviderClassSatisfaction implements Satisfaction, Serializable {
      private static final long serialVersionUID = -1L;
      private final transient Class<? extends Provider<?>> providerType;
  
      /**
       * Create a ProviderClassSatisfaction that wraps a given provider type.
       * 
       * @param providerType The provider class type
       * @throws NullPointerException if providerType is null
       * @throws IllegalArgumentException if the class is not a Provider, or is not instantiable
       */
      public ProviderClassSatisfaction(Class<? extends Provider<?>> providerType) {
          Preconditions.notNull("provider type", providerType);
          Preconditions.isAssignable(Provider.class, providerType);
          int mods = providerType.getModifiers();
          if (Modifier.isAbstract(mods) || Modifier.isInterface(mods)) {
              throw new IllegalArgumentException("Provider satisfaction " + providerType + " is abstract");
          }
          if (!Types.isInstantiable(providerType)) {
              throw new IllegalArgumentException("Provider satisfaction " + providerType + " is not instantiable");
          }
          
          this.providerType = providerType;
      }
      
      @Override
      public CachePolicy getDefaultCachePolicy() {
          return (getErasedType().getAnnotation(Singleton.class) != null ? CachePolicy.MEMOIZE : CachePolicy.NO_PREFERENCE);
      }
      
      /**
       * @return The Provider class that provides instances satisfying this
       *         satisfaction
       */
      public Class<? extends Provider<?>> getProviderType() {
          return providerType;
      }
      
      @Override
      public List<Desire> getDependencies() {
          return ReflectionDesire.getDesires(providerType);
      }
  
      @Override
      public Type getType() {
          return Types.getProvidedType(providerType);
      }
  
      @Override
      public Class<?> getErasedType() {
          return Types.erase(getType());
      }
  
      @Override
      public boolean hasInstance() {
         return false;
     }
 
     @Override
     public <T> T visit(SatisfactionVisitor<T> visitor) {
         return visitor.visitProviderClass(providerType);
     }
 
     @Override
     @SuppressWarnings({ "unchecked", "rawtypes" })
     public Instantiator makeInstantiator(Map<Desire,Instantiator> dependencies,
                                          LifecycleManager lm) {
         // we have to use the raw type because we don't have enough information,
         // but we can assume correctly that it will build a provider
         ClassInstantiator providerBuilder = new ClassInstantiator(providerType, getDependencies(),
                                                                   dependencies, lm);
         return Instantiators.ofProviderInstantiator(providerBuilder);
     }
     
     @Override
     public boolean equals(Object o) {
         if (!(o instanceof ProviderClassSatisfaction)) {
             return false;
         }
         return ((ProviderClassSatisfaction) o).providerType.equals(providerType);
     }
     
     @Override
     public int hashCode() {
         return providerType.hashCode();
     }
     
     @Override
     public String toString() {
         return "Provider(" + providerType.getName() + ")";
     }
 
     private Object writeReplace() {
         return new SerialProxy(providerType);
     }
 
     private void readObject(ObjectInputStream stream) throws ObjectStreamException {
         throw new InvalidObjectException("must use serialization proxy");
     }
 
     private static class SerialProxy implements Serializable {
         private static final long serialVersionUID = 1L;
 
         private final ClassProxy providerType;
 
         public SerialProxy(Class<?> cls) {
             providerType = ClassProxy.of(cls);
         }
 
         @SuppressWarnings("unchecked")
         private Object readResolve() throws ObjectStreamException {
             try {
                 return new ProviderClassSatisfaction((Class<? extends Provider<?>>) providerType.resolve().asSubclass(Provider.class));
             } catch (ClassNotFoundException e) {
                 InvalidObjectException ex = new InvalidObjectException("cannot resolve " + providerType);
                 ex.initCause(e);
                 throw ex;
             } catch (ClassCastException e) {
                 InvalidObjectException ex = new InvalidObjectException("class " + providerType + " is not a provider");
                 ex.initCause(e);
                 throw ex;
             }
         }
     }
 }