/*
    * Copyright 2011 FatWire Corporation. All Rights Reserved.
    *
    * 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.fatwire.gst.foundation.controller.support;
  
  import java.util.HashMap;
  import java.util.Map;
  
  import javax.servlet.ServletContext;
  
  import org.apache.commons.lang.StringUtils;
  
  import com.fatwire.gst.foundation.controller.AppContext;
  import com.fatwire.gst.foundation.facade.logging.Log;
  import com.fatwire.gst.foundation.facade.logging.LogUtil;
  
  public class WebAppContext implements AppContext {
      protected static final Log LOG = LogUtil.getLog(WebAppContext.class);
  
      public static final String WEB_CONTEXT_NAME = "gsf/AppContext";
  
      private final ServletContext context;
      private final AppContext parent;
  
      private Map<String, Object> localScope = new HashMap<String, Object>();
  
      /**
       * This constructor is needed for the {@link WebAppContextLoader}.
       * 
       * @param context
       * @param parent
       */
      public WebAppContext(ServletContext context, AppContext parent) {
          super();
          this.context = context;
          this.parent = parent;
      }
  
      /**
       * Constructor with null parent.
       * 
       * @param context
       */
      public WebAppContext(ServletContext context) {
          this(context, null);
      }
  
      @SuppressWarnings("unchecked")
      @Override
      public final <T> T getBean(String name, Class<T> c) {
          if (StringUtils.isBlank(name))
              throw new IllegalArgumentException("name cannot be null or empty");
  
          if (c.isArray()) {
              throw new IllegalArgumentException("Arrays are not supported");
          }
  
          Object o = null;
  
          o = localScope.get(name);
  
          if (o == null) {
              LOG.debug("Asking for bean by name %s of type %s.",name,  c.getName());
              try {
                  // TODO: medium: check for other method signatures
  
                  o = TemplateMethodFactory.createByMethod(this, c);
                  if (o != null && c.isAssignableFrom(o.getClass())) {
                      localScope.put(name, o);
  
                  }
  
              } catch (final NoSuchMethodException e) {
  
                  try {
                      if (parent != null)
                          o = parent.getBean(name, c); // don't register locally
                                                       // if found
                      else {
                          LOG.debug("Could not create  a %s via a Template method, trying via constructor.",c.getName());
                          o = TemplateMethodFactory.createByConstructor(c);
                          if (o != null && c.isAssignableFrom(o.getClass())) {
                              localScope.put(name, o);
                          }
                      }
                  } catch (final RuntimeException e1) {
                      throw e1;
                 } catch (final Exception e1) {
                     throw new RuntimeException(e1);
                 }
             } catch (final RuntimeException e) {
                 throw e;
             } catch (final Exception e) {
                 throw new RuntimeException(e);
             }
 
         }
         return (T) o;
     }
 
     public ServletContext getServletContext() {
         return context;
     }
 
     @Override
     public void init() {
         // TODO Auto-generated method stub
 
     }
 }