/**
 * Copyright (C) 2009 Google Inc.
 *
 * 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 com.google.inject.internal;

import static com.google.common.collect.Iterables.concat;

import com.google.common.collect.ImmutableList;
import com.google.inject.spi.InjectionPoint;

/**
 * Constructor injectors by type.
 *
 * @author jessewilson@google.com (Jesse Wilson)
 */
final class ConstructorInjectorStore {
  private final InjectorImpl injector;

  private final FailableCache<InjectionPoint, ConstructorInjector<?>>  cache
      = new FailableCache<InjectionPoint, ConstructorInjector<?>> () {
    @Override
    protected ConstructorInjector<?> create(InjectionPoint constructorInjector, Errors errors)
        throws ErrorsException {
      return createConstructor(constructorInjector, errors);
    }
  };

  ConstructorInjectorStore(InjectorImpl injector) {
    this.injector = injector;
  }

  /**
   * Returns a new complete constructor injector with injection listeners registered.
   */
  public ConstructorInjector<?> get(InjectionPoint constructorInjector, Errors errors)
      throws ErrorsException {
    return cache.get(constructorInjector, errors);
  }
  
  /**
   * Purges an injection point from the cache. Use this only if the cache is not actually valid and
   * needs to be purged. (See issue 319 and
   * ImplicitBindingTest#testCircularJitBindingsLeaveNoResidue and
   * #testInstancesRequestingProvidersForThemselvesWithChildInjectors for examples of when this is
   * necessary.)
   * 
   * Returns true if the injector for that point was stored in the cache, false otherwise.
   */
  boolean remove(InjectionPoint ip) {
    return cache.remove(ip);
  }

  private <T> ConstructorInjector<T> createConstructor(InjectionPoint injectionPoint, Errors errors)
      throws ErrorsException {
    int numErrorsBefore = errors.size();

    SingleParameterInjector<?>[] constructorParameterInjectors
        = injector.getParametersInjectors(injectionPoint.getDependencies(), errors);

    @SuppressWarnings("unchecked") // the injector type agrees with the injection point type
    MembersInjectorImpl<T> membersInjector = (MembersInjectorImpl<T>) injector.membersInjectorStore
        .get(injectionPoint.getDeclaringType(), errors);

    /*if[AOP]*/
    ImmutableList<MethodAspect> injectorAspects = injector.state.getMethodAspects();
    ImmutableList<MethodAspect> methodAspects = membersInjector.getAddedAspects().isEmpty()
        ? injectorAspects
        : ImmutableList.copyOf(concat(injectorAspects, membersInjector.getAddedAspects()));
    ConstructionProxyFactory<T> factory = new ProxyFactory<T>(injectionPoint, methodAspects);
    /*end[AOP]*/
    /*if[NO_AOP]
    ConstructionProxyFactory<T> factory = new DefaultConstructionProxyFactory<T>(injectionPoint);
    end[NO_AOP]*/

    errors.throwIfNewErrors(numErrorsBefore);

    return new ConstructorInjector<T>(membersInjector.getInjectionPoints(), factory.create(),
        constructorParameterInjectors, membersInjector);
  }
}