// Copyright 2006 Daniel Gredler

 //

 // 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 net.sf.beanform.integration;

 import java.util.ArrayList;

 import java.util.Collections;

 import java.util.HashMap;

 import java.util.Iterator;

 import java.util.List;

 import java.util.Map;

 import org.apache.commons.logging.Log;

 import org.apache.commons.logging.LogFactory;

 import net.sf.beanform.prop.BeanProperty;

 /**

  * Represents a chain of integration elements, the makeup of which will vary according to

  * the execution environment.

  *

  * Note: If <a href="http://jcp.org/en/jsr/detail?id=303">JSR 303: Bean Validation</a> ever

  * gets added to Java SE, add it to the integration chain.

  *

  * @author Daniel Gredler

  */

 public final class IntegratorChain {

     private final static Log LOG = LogFactory.getLog( IntegratorChain.class );

     private final static List<Integrator> INTEGRATORS;

     static {

         // Important note: The methods below are coded such that in the case of

         // conflicting contributions, the last of the contributions is used.

         List<Integrator> list = new ArrayList<Integrator>();

         if( isSupported( "Hibernate", "org.hibernate.validator.Max" ) ) {

             list.add( new HibernateIntegrator() );

         }

         if( isSupported( "EJB3", "javax.persistence.Column" ) ) {

             list.add( new Ejb3Integrator() );

         }

         INTEGRATORS = Collections.unmodifiableList( list );

     }

     static boolean isSupported( String featureName, String className ) {

         Class c;

         try {

             c = Class.forName( className );

         }

         catch( ClassNotFoundException e ) {

             c = null;

         }

         catch( NoClassDefFoundError e ) {

             c = null;

         }

         boolean supported = ( c != null );

         if( supported ) LOG.debug( featureName + " support detected." );

         return supported;

     }

     IntegratorChain() {

         // Empty.

     }

     public static String getValidation( BeanProperty prop ) {

         Map<String, String> validations = new HashMap<String, String>();

         for( Integrator integrator : INTEGRATORS ) {

             Map<String, String> temp = integrator.getValidation( prop );

             validations.putAll( temp );

         }

         StringBuilder sb = new StringBuilder();

         for( Iterator<String> i = validations.values().iterator(); i.hasNext(); ) {

             sb.append( i.next() );

             if( i.hasNext() ) sb.append( "," );

         }

         if( sb.length() == 0 ) return null;

         else return sb.toString();

     }

     public static Integer getMaxLength( BeanProperty prop ) {

         Integer maxLength = null;

         for( Integrator integrator : INTEGRATORS ) {

             Integer temp = integrator.getMaxLength( prop );

             if( temp != null ) maxLength = temp;

         }

         return maxLength;

     }

     public static boolean isNullable( BeanProperty prop ) {

         boolean nullable = true;

         for( Integrator integrator : INTEGRATORS ) {

             boolean temp = integrator.isNullable( prop );

             nullable = nullable && temp;

         }

         return nullable;

     }

 }