/**
    * Logback: the reliable, generic, fast and flexible logging framework.
    * Copyright (C) 1999-2009, QOS.ch. All rights reserved.
    *
    * This program and the accompanying materials are dual-licensed under
    * either the terms of the Eclipse Public License v1.0 as published by
    * the Eclipse Foundation
    *
    *   or (per the licensee's choosing)
   *
   * under the terms of the GNU Lesser General Public License version 2.1
   * as published by the Free Software Foundation.
   */
  package ch.qos.logback.core.joran.action;
  
  import java.util.Stack;
  
  import org.xml.sax.Attributes;
  
  import ch.qos.logback.core.joran.spi.InterpretationContext;
  import ch.qos.logback.core.joran.spi.NoAutoStartUtil;
  import ch.qos.logback.core.joran.spi.Pattern;
  import ch.qos.logback.core.joran.util.PropertySetter;
  import ch.qos.logback.core.spi.ContextAware;
  import ch.qos.logback.core.spi.LifeCycle;
  import ch.qos.logback.core.util.AggregationType;
  import ch.qos.logback.core.util.Loader;
  import ch.qos.logback.core.util.OptionHelper;
  
  /**
   * This action is responsible for tying together a parent object with a child
   * element for which there is no explicit rule.
   * 
   * @author Ceki Gülcü
   */
  public class NestedComplexPropertyIA extends ImplicitAction {
  
    // actionDataStack contains ActionData instances
    // We use a stack of ActionData objects in order to support nested
    // elements which are handled by the same NestedComplexPropertyIA instance.
    // We push a ActionData instance in the isApplicable method (if the
    // action is applicable) and pop it in the end() method.
    // The XML well-formedness property will guarantee that a push will eventually
    // be followed by a corresponding pop.
    Stack<IADataForComplexProperty> actionDataStack = new Stack<IADataForComplexProperty>();
  
    public boolean isApplicable(Pattern pattern, Attributes attributes,
        InterpretationContext ic) {
  
      String nestedElementTagName = pattern.peekLast();
  
      // calling ic.peekObject with an empty stack will throw an exception
      if (ic.isEmpty()) {
        return false;
      }
  
      Object o = ic.peekObject();
      PropertySetter parentBean = new PropertySetter(o);
      parentBean.setContext(context);
  
      AggregationType aggregationType = parentBean
          .computeAggregationType(nestedElementTagName);
  
      switch (aggregationType) {
      case NOT_FOUND:
      case AS_BASIC_PROPERTY:
      case AS_BASIC_PROPERTY_COLLECTION:
        return false;
  
        // we only push action data if NestComponentIA is applicable
      case AS_COMPLEX_PROPERTY_COLLECTION:
      case AS_COMPLEX_PROPERTY:
        IADataForComplexProperty ad = new IADataForComplexProperty(parentBean,
            aggregationType, nestedElementTagName);
        actionDataStack.push(ad);
  
        return true;
      default:
        addError("PropertySetter.computeAggregationType returned "
            + aggregationType);
        return false;
      }
    }
  
    public void begin(InterpretationContext ec, String localName,
        Attributes attributes) {
      // LogLog.debug("in NestComponentIA begin method");
      // get the action data object pushed in isApplicable() method call
      IADataForComplexProperty actionData = (IADataForComplexProperty) actionDataStack
          .peek();
  
      String className = attributes.getValue(CLASS_ATTRIBUTE);
      // perform variable name substitution
      className = ec.subst(className);
  
      Class componentClass = null;
      try {
  
        if (!OptionHelper.isEmpty(className)) {
         componentClass = Loader.loadClass(className, context);
       } else {
         // guess class name via implicit rules
         PropertySetter parentBean = actionData.parentBean;
         componentClass = parentBean.getClassNameViaImplicitRules(actionData
             .getComplexPropertyName(), actionData.getAggregationType(), ec
             .getDefaultNestedComponentRegistry());
       }
 
       if (componentClass == null) {
         actionData.inError = true;
         String errMsg = "Could not find an appropriate class for property ["
             + localName + "]";
         addError(errMsg);
         return;
       }
 
       if (OptionHelper.isEmpty(className)) {
         addInfo("Assuming default type [" + componentClass.getName()
             + "] for [" + localName + "] property");
       }
 
       actionData.setNestedComplexProperty(componentClass.newInstance());
 
       // pass along the repository
       if (actionData.getNestedComplexProperty() instanceof ContextAware) {
         ((ContextAware) actionData.getNestedComplexProperty())
             .setContext(this.context);
       }
       // getLogger().debug(
       addInfo("Pushing component [" + localName
           + "] on top of the object stack.");
       ec.pushObject(actionData.getNestedComplexProperty());
 
     } catch (Exception oops) {
       actionData.inError = true;
       String msg = "Could not create component [" + localName + "] of type ["
           + className + "]";
       addError(msg, oops);
     }
 
   }
 
   public void end(InterpretationContext ec, String tagName) {
 
     // pop the action data object pushed in isApplicable() method call
     // we assume that each this begin
     IADataForComplexProperty actionData = (IADataForComplexProperty) actionDataStack
         .pop();
 
     if (actionData.inError) {
       return;
     }
 
     PropertySetter nestedBean = new PropertySetter(actionData
         .getNestedComplexProperty());
     nestedBean.setContext(context);
 
     // have the nested element point to its parent if possible
     if (nestedBean.computeAggregationType("parent") == AggregationType.AS_COMPLEX_PROPERTY) {
       nestedBean.setComplexProperty("parent", actionData.parentBean.getObj());
     }
 
     // start the nested complex property if it implements LifeCycle and is not
     // marked with a @NoAutoStart annotation
     Object nestedComplexProperty = actionData.getNestedComplexProperty();
     if (nestedComplexProperty instanceof LifeCycle
         && NoAutoStartUtil.notMarkedWithNoAutoStart(nestedComplexProperty)) {
       ((LifeCycle) nestedComplexProperty).start();
     }
 
     Object o = ec.peekObject();
 
     if (o != actionData.getNestedComplexProperty()) {
       addError("The object on the top the of the stack is not the component pushed earlier.");
     } else {
       ec.popObject();
       // Now let us attach the component
       switch (actionData.aggregationType) {
       case AS_COMPLEX_PROPERTY:
         actionData.parentBean.setComplexProperty(tagName, actionData
             .getNestedComplexProperty());
 
         break;
       case AS_COMPLEX_PROPERTY_COLLECTION:
         actionData.parentBean.addComplexProperty(tagName, actionData
             .getNestedComplexProperty());
 
         break;
       }
     }
   }
 
 }