/**
 * Copyright (C) 2006 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.opensymphony.xwork2.inject;

import java.util.HashMap;
import java.util.Map;

/**
 * Internal context. Used to coordinate injections and support circular
 * dependencies.
 *
 * @author crazybob@google.com (Bob Lee)
 */
class InternalContext {

  final ContainerImpl container;
  final Map<Object, ConstructionContext<?>> constructionContexts =
      new HashMap<Object, ConstructionContext<?>>();
  Scope.Strategy scopeStrategy;
  ExternalContext<?> externalContext;

  InternalContext(ContainerImpl container) {
    this.container = container;
  }

  public Container getContainer() {
    return container;
  }

  ContainerImpl getContainerImpl() {
    return container;
  }

  Scope.Strategy getScopeStrategy() {
    if (scopeStrategy == null) {
      scopeStrategy = (Scope.Strategy) container.localScopeStrategy.get();

      if (scopeStrategy == null) {
        throw new IllegalStateException("Scope strategy not set. "
            + "Please call Container.setScopeStrategy().");
      }
    }

    return scopeStrategy;
  }

  @SuppressWarnings("unchecked")
  <T> ConstructionContext<T> getConstructionContext(Object key) {
    ConstructionContext<T> constructionContext =
        (ConstructionContext<T>) constructionContexts.get(key);
    if (constructionContext == null) {
      constructionContext = new ConstructionContext<T>();
      constructionContexts.put(key, constructionContext);
    }
    return constructionContext;
  }

  @SuppressWarnings("unchecked")
  <T> ExternalContext<T> getExternalContext() {
    return (ExternalContext<T>) externalContext;
  }

  void setExternalContext(ExternalContext<?> externalContext) {
    this.externalContext = externalContext;
  }
}