/*
    * Copyright 2011 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.opensource.org/licenses/ecl2.php
    * 
   * 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.ole.docstore.discovery.util;
  
  import com.thoughtworks.xstream.XStream;
  import com.thoughtworks.xstream.converters.Converter;
  import com.thoughtworks.xstream.converters.MarshallingContext;
  import com.thoughtworks.xstream.converters.UnmarshallingContext;
  import com.thoughtworks.xstream.io.HierarchicalStreamReader;
  import com.thoughtworks.xstream.io.HierarchicalStreamWriter;
  import org.apache.commons.io.IOUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.io.InputStream;
  import java.net.URL;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  
  public class Languages {
  
      private List<Language> languages = new ArrayList<Language>();
      private static Languages soLanguagesISO639_1_cc = null;
      private static Languages soLanguagesISO639_3 = null;
      protected final Logger LOG = LoggerFactory.getLogger(Languages.class);
      public static final String ISO_639_1_CC = "ISO_639_1_CC";
      public static final String ISO_639_3 = "ISO_639_3";
  
      private Languages(String encoding) {
          try {
              String file = null;
              if (ISO_639_1_CC.equals(encoding)) {
                  file = "languages-iso-639-1-cc.xml";
              } else if (ISO_639_3.equals(encoding)) {
                  file = "languages-iso-639-3.xml";
              }
              URL url = this.getClass().getClassLoader().getResource(file);
              XStream xStream = new XStream();
              xStream.alias("languages", Languages.class);
              xStream.alias("lang", Language.class);
              xStream.addImplicitCollection(Languages.class, "languages", Language.class);
              xStream.registerConverter(new LanguageConverter());
              Languages langs = (Languages) xStream.fromXML(IOUtils.toString((InputStream) url.getContent()));
              this.setLanguages(Collections.unmodifiableList(langs.getLanguages()));
          } catch (Exception e) {
              LOG.error(e.getMessage(), e);
          }
      }
  
      /**
       * Method to give out the Single Instance of Languages.
       *
       * @param encoding - Specify the encoding type of the languages expected.
       * @return
       */
      public static Languages getInstance(String encoding) {
          if (ISO_639_1_CC.equals(encoding)) {
              if (soLanguagesISO639_1_cc == null) {
                  soLanguagesISO639_1_cc = new Languages(encoding);
              }
              return soLanguagesISO639_1_cc;
          } else if (ISO_639_3.equals(encoding)) {
              if (soLanguagesISO639_3 == null) {
                  soLanguagesISO639_3 = new Languages(encoding);
              }
              return soLanguagesISO639_3;
          } else {
              return null;
          }
      }
  
      /**
       * Method to give language. If not a valid language gives null.
       *
       * @param code
       * @return
       */
      public Language getLanguage(String code) {
          int indx = getLanguages().indexOf(new Language(code));
          if (indx != -1) {
              return this.getLanguages().get(indx);
          } else {
              return null;
          }
      }
 
     /**
      * Method to give language description. If not a valid language gives null.
      *
      * @param code
      * @return
      */
     public String getLanguageDescription(String code) {
         int indx = getLanguages().indexOf(new Language(code));
         if (indx != -1) {
             return this.getLanguages().get(indx).getValue();
         } else {
             return null;
         }
     }
 
     public List<Language> getLanguages() {
         return languages;
     }
 
     private void setLanguages(List<Language> languages) {
         this.languages = languages;
     }
 
     private void addLanguage(Language language) {
         this.languages.add(language);
     }
 
     /**
      * Class Language.
      *
      * @author Rajesh Chowdary K
      */
     class Language {
         public Language() {
         }
 
         public Language(String code) {
             this.code = code;
         }
 
         private String code = null;
         private String value = null;
 
         public String getCode() {
             return code;
         }
 
         public void setCode(String code) {
             this.code = code;
         }
 
         public String getValue() {
             return value;
         }
 
         public void setValue(String value) {
             this.value = value;
         }
 
         @Override
         public boolean equals(Object obj) {
             if (obj instanceof Language) {
                 if (((Language) obj).getCode().equals(code)) {
                     return true;
                 } else {
                     return false;
                 }
             } else {
                 return false;
             }
         }
     }
 
     private class LanguageConverter
             implements Converter {
         @Override
         public void marshal(Object o, HierarchicalStreamWriter streamWriter, MarshallingContext marshallingContext) {
         }
 
         @Override
         public Object unmarshal(HierarchicalStreamReader streamReader, UnmarshallingContext unmarshallingContext) {
             Language language = new Language();
             language.setCode(streamReader.getAttribute("code"));
             language.setValue(streamReader.getValue());
             return language;
         }
 
         @Override
         public boolean canConvert(Class aClass) {
             return aClass.equals(Language.class);
         }
     }
 }