package org.kuali.student.ap.i18n;
   
   
   import org.slf4j.Logger;
   import org.slf4j.LoggerFactory;
   
   import java.util.Collections;
   import java.util.Enumeration;
   import java.util.HashSet;
  import java.util.List;
  import java.util.Locale;
  import java.util.MissingResourceException;
  import java.util.ResourceBundle;
  import java.util.Set;
  
  /**
   * Created with IntelliJ IDEA.
   * User: chmaurer
   * Date: 2/12/14
   * Time: 10:08 AM
   * To change this template use File | Settings | File Templates.
   */
  public class MergedPropertiesResourceBundleImpl extends ResourceBundle {
  
      List<ResourceBundle> bundles;
      private Locale locale;
  
      private static final Logger LOG = LoggerFactory.getLogger(MergedPropertiesResourceBundleImpl.class);
  
      public MergedPropertiesResourceBundleImpl(List<ResourceBundle> bundles, Locale locale) {
          this.bundles = bundles;
          this.locale = locale;
          validateKeys();
          validateLocales();
          LOG.debug("MergedPropertiesResourceBundleImpl({}, {})", bundles.size(), locale);
      }
  
      @Override
      public Locale getLocale() {
          return locale;
      }
  
      @Override
      protected Object handleGetObject(String key) {
          Object retVal = null;
          for (ResourceBundle bundle : bundles) {
              validateLocale(this.locale.toString(), bundle);
              try {
                  retVal = bundle.getObject(key);
              }
              catch (MissingResourceException mre) {
                  //Swallowing this for now since we are looping through multiple bundles...
              }
              if (retVal != null) {
                  LOG.debug("Key({}) found in bundle with locale:'{}'", key, bundle.getLocale());
                  break;
              }
          }
          if (retVal == null) {
              throw new MissingResourceException("Can't find resource for bundle "
                      +this.getClass().getName()
                      +", key "+key,
                      this.getClass().getName(),
                      key);
          }
          return retVal;
      }
  
      @Override
      public Enumeration<String> getKeys() {
          Set<String> keys = new HashSet<String>();
          for (ResourceBundle bundle : bundles) {
              List<String> bundleKeys = Collections.list(bundle.getKeys());
              keys.addAll(bundleKeys);
          }
          return Collections.enumeration(keys);
      }
  
      /**
       * Make sure that the number of keys match up after combining the properties files
       */
      private void validateKeys() {
          int totalCount = 0;
  
          Set<String> keys = new HashSet<String>();
          for (ResourceBundle bundle : bundles) {
              boolean doValidate = true;
              List<String> bundleKeys = Collections.list(bundle.getKeys());
  
              if (bundle instanceof DBResourceBundleImpl) {
                  //Don't include a bundle
                  doValidate = false;
              }
              if (doValidate) {
                  keys.addAll(bundleKeys);
                  totalCount+=bundleKeys.size();
              }
          }
          if (totalCount != keys.size())
             throw new RuntimeException("Duplicate keys found.  Expected: " + totalCount + "; Found: " + keys.size());
     }
 
     /**
      * Make sure that the locales match up after combining the properties files
      */
     private void validateLocales() {
         String the_locale = this.getLocale().toString();
         for (ResourceBundle bundle : bundles) {
             validateLocale(the_locale, bundle);
         }
     }
 
     private void validateLocale(String expected, ResourceBundle bundle) {
         String bundle_locale = bundle.getLocale().toString();
         if (!expected.equals(bundle_locale) && !bundle_locale.equals("")) {
             //throw new RuntimeException("Mismatched locales.  Expected '" + the_locale + "' but got '" + bundle_locale + "' from " + bundle);
             LOG.warn("Mismatched locales.  Expected '{}' but got '{}' from {}", expected, bundle_locale, bundle);
         }
         else {
             LOG.debug("Expected '{}' and got '{}' from {}", expected, bundle_locale, bundle);
         }
     }
 }