/**

  * Copyright 2010 The Kuali Foundation Licensed under the

  * Educational Community 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.osedu.org/licenses/ECL-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 org.kuali.student.common.util;

 import java.util.HashSet;

 import java.util.Properties;

 import org.springframework.beans.BeansException;

 import org.springframework.beans.factory.BeanDefinitionStoreException;

 import org.springframework.beans.factory.BeanFactory;

 import org.springframework.beans.factory.InitializingBean;

 import org.springframework.beans.factory.config.BeanDefinition;

 import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;

 import org.springframework.beans.factory.config.PropertyPlaceholderConfigurer;

 import org.springframework.core.io.DefaultResourceLoader;

 import org.springframework.core.io.Resource;

 import org.springframework.util.StringValueResolver;

 public class ModPropertyPlaceholderConfigurer extends

                 PropertyPlaceholderConfigurer implements InitializingBean  {

         private String customConfigSystemProperty;

         private String customConfigFileLocation;

         private Resource[] locations;        

         private String beanName;

         private BeanFactory beanFactory;

         private String nullValue;

         public String getCustomConfigSystemProperty() {

                 return customConfigSystemProperty;

         }

         public void setCustomConfigSystemProperty(String customConfigSystemProperty) {

                 this.customConfigSystemProperty = customConfigSystemProperty;

         }

         @Override

         public void setLocations(Resource[] locations) {

                 this.locations=locations;

                 super.setLocations(locations);

         }

         @Override

         public void afterPropertiesSet() throws Exception {

                 if(customConfigSystemProperty!=null){

                         String customConfigLocation = System.getProperty(customConfigSystemProperty);

                         try{

                                 customConfigLocation = this.parseStringValue(customConfigLocation, System.getProperties(), new HashSet<String>());

                                 Resource customConfigResource = new DefaultResourceLoader().getResource(customConfigLocation);

                                 if(customConfigResource.exists()){

                                         Resource[] finalLocations = new Resource[locations.length+1];

                                         int i=0;

                                         for(Resource resource:locations){

                                                 finalLocations[i]=resource;

                                                 i++;

                                         }

                                         finalLocations[i]=customConfigResource;

                                         super.setLocations(finalLocations);

                                 }else{

                                         logger.warn("File does not exist:"+customConfigLocation);

                                 }

                         }catch(Exception e){

                                 logger.warn("Could not load custom properties from property:"+customConfigSystemProperty+" location:"+customConfigLocation);

                         }

                 }

                 if(customConfigFileLocation!=null){

                         String location = this.parseStringValue(customConfigFileLocation, System.getProperties(), new HashSet<String>());

                         try{

                                 Resource customConfigResource = new DefaultResourceLoader().getResource(location);

                                 if(customConfigResource.exists()){

                                         Resource[] finalLocations = new Resource[locations.length+1];

                                         int i=0;

                                         for(Resource resource:locations){

                                                 finalLocations[i] = resource;

                                                 i++;

                                         }

                                         finalLocations[i] = customConfigResource;

                                         super.setLocations(finalLocations);

                                 }else{

                                         logger.warn("File does not exist:"+location);

                                 }

                         }catch(Exception e){

                                 logger.warn("Could not load custom properties from file:"+location);

                         }

                 }

         }

         @Override

         public void setBeanName(String beanName) {

                 this.beanName = beanName;

                 super.setBeanName(beanName);

         }

         @Override

         public void setBeanFactory(BeanFactory beanFactory) {

                 this.beanFactory = beanFactory;

                 super.setBeanFactory(beanFactory);

         }

         @Override

         public void setNullValue(String nullValue) {

                 this.nullValue = nullValue;

                 super.setNullValue(nullValue);

         }

         @Override

         protected void processProperties(ConfigurableListableBeanFactory beanFactoryToProcess, Properties props)

                         throws BeansException {

                 StringValueResolver valueResolver = new PlaceholderResolvingStringValueResolver(props);

                 ModBeanDefinitionVisitor visitor = new ModBeanDefinitionVisitor(valueResolver);

                 String[] beanNames = beanFactoryToProcess.getBeanDefinitionNames();

                 for (int i = 0; i < beanNames.length; i++) {

                         // Check that we're not parsing our own bean definition,

                         // to avoid failing on unresolvable placeholders in properties file locations.

                         if (!(beanNames[i].equals(this.beanName) && beanFactoryToProcess.equals(this.beanFactory))) {

                                 BeanDefinition bd = beanFactoryToProcess.getBeanDefinition(beanNames[i]);

                                 try {

                                         visitor.visitBeanDefinition(bd);

                                 }

                                 catch (BeanDefinitionStoreException ex) {

                                         throw new BeanDefinitionStoreException(bd.getResourceDescription(), beanNames[i], ex.getMessage());

                                 }

                         }

                 }

                 // New in Spring 2.5: resolve placeholders in alias target names and aliases as well.

                 beanFactoryToProcess.resolveAliases(valueResolver);

         }

         /**

          * BeanDefinitionVisitor that resolves placeholders in String values,

          * delegating to the <code>parseStringValue</code> method of the

          * containing class.

          */

         public class PlaceholderResolvingStringValueResolver implements StringValueResolver {

                 private final Properties props;

                 public PlaceholderResolvingStringValueResolver(Properties props) {

                         this.props = props;

                 }

                 public String resolveStringValue(String strVal) throws BeansException {

                         String value = parseStringValue(strVal, this.props, new HashSet<String>());

                         return (value.equals(nullValue) ? null : value);

                 }

                 public Properties resolvePropertyValue(String strVal){

                         Properties prefixedProps = new Properties();

                         for(Object key:props.keySet()){

                                 String keyStr = (String)key; 

                                 if(keyStr.startsWith(strVal)){

                                         String newKeyStr = keyStr.substring(strVal.length()+1);

                                         prefixedProps.put(newKeyStr, resolveStringValue((String)props.get(key)));

                                 }

                         }

                         return prefixedProps;

                 }

         }

         public String getCustomConfigFileLocation() {

                 return customConfigFileLocation;

         }

         public void setCustomConfigFileLocation(String customConfigFileLocation) {

                 this.customConfigFileLocation = customConfigFileLocation;

         }

 }