package org.andromda.core.translation.library;
   
   import java.util.LinkedHashMap;
   import java.util.Map;
   import org.andromda.core.common.ComponentContainer;
   import org.andromda.core.common.ExceptionUtils;
   import org.apache.log4j.Logger;
   
   /**
   * Finds LibraryTranslations by <code>translation</code> (i.e. library and name).
   *
   * @author Chad Brandon
   */
  public class LibraryTranslationFinder
  {
      /**
       * The logger instance.
       */
      private static final Logger logger = Logger.getLogger(LibraryTranslationFinder.class);
  
      /**
       * Stores the found library translations.
       */
      protected static final Map libraryTranslations = new LinkedHashMap();
  
      /**
       * Finds the library with the specified libraryName.
       *
       * @param libraryName
       * @return the Library found or null if none is found.
       */
      protected static Library findLibrary(final String libraryName)
      {
          return (Library)ComponentContainer.instance().findComponentByNamespace(libraryName, Library.class);
      }
  
      /**
       * Finds the LibraryTranslation with the specified translationName.
       *
       * @param translation the name of the translation to find.
       * @return the LibraryTranslation found or null if none is found.
       */
      public static LibraryTranslation findLibraryTranslation(final String translation)
      {
          ExceptionUtils.checkEmpty("translation", translation);
  
          LibraryTranslation libraryTranslation = (LibraryTranslation)libraryTranslations.get(translation);
  
          if (libraryTranslation == null)
          {
              char libSeparator = '.';
              int index = translation.indexOf(libSeparator);
              if (index == -1)
              {
                  throw new IllegalArgumentException(
                      "libraryTranslation '" + translation + "' must contain the character '" +
                      libSeparator + "' in order to separate the library name from the translation" +
                      " name (must be in the form: <library name>.<translation name>)");
              }
              final String libraryName = translation.substring(0, index);
              final Library library = findLibrary(libraryName);
              final int translationLength = translation.length();
  
              final String translationName = translation.substring(index + 1, translationLength);
  
              if (library != null)
              {
                  libraryTranslation = library.getLibraryTranslation(translationName);
                  if (libraryTranslation == null)
                  {
                      logger.error(
                          "ERROR! no translation '" + translationName + "' found within library --> '" + libraryName +
                                  '\'');
                  }
              }
          }
          return libraryTranslation;
      }
  }