/*
    * #%L
    * settings4j
    * ===============================================================
    * Copyright (C) 2008 - 2015 Brabenetz Harald, Austria
    * ===============================================================
    * 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.
   * #L%
   */
  package org.settings4j.connector;
  
  import java.nio.charset.Charset;
  
  import org.apache.commons.io.Charsets;
  import org.settings4j.ContentResolver;
  import org.settings4j.contentresolver.ClasspathContentResolver;
  import org.settings4j.contentresolver.UnionContentResolver;
  
  /**
   * Connector implementation to read Settings from the Classpath.
   * <p>
   * Default Charset "UTF-8" is used to read the content from Classpath.
   * </p>
   *
   * @author Harald.Brabenetz
   */
  public class ClasspathConnector extends AbstractConnector {
  
      private final ClasspathContentResolver classpathContentResolver;
      private UnionContentResolver unionContentResolver;
      private Charset charset = Charsets.UTF_8;
  
      /** Default Constructor (e.g. use in settings4j.xml). */
      public ClasspathConnector() {
          this(new ClasspathContentResolver());
      }
  
      /**
       * protected Constructor for extensions and Unit-Tests.
       *
       * @param classpathContentResolver
       *        {@link ClasspathContentResolver}
       */
      protected ClasspathConnector(final ClasspathContentResolver classpathContentResolver) {
          super();
          this.classpathContentResolver = classpathContentResolver;
          this.unionContentResolver = new UnionContentResolver(this.classpathContentResolver);
      }
  
      @Override
      public byte[] getContent(final String key) {
          return this.classpathContentResolver.getContent(key);
      }
  
      @Override
      public Object getObject(final String key) {
          if (getObjectResolver() != null) {
              return getObjectResolver().getObject(key, this.unionContentResolver);
          }
          // else
          return null;
  
      }
  
      @Override
      public String getString(final String key) {
          final byte[] content = getContent(key);
          if (content != null) {
              return new String(this.classpathContentResolver.getContent(key), this.charset);
          }
          return null;
      }
  
      public String getCharset() {
          return this.charset.name();
      }
  
      /**
       * @param charset
       *        a valid {@link Charset}
       * @see Charset#isSupported(String)
       */
      public void setCharset(final String charset) {
          this.charset = Charset.forName(charset);
      }
  
      @Override
      public void setContentResolver(final ContentResolver contentResolver) {
          this.unionContentResolver = new UnionContentResolver(this.classpathContentResolver);
         this.unionContentResolver.addContentResolver(contentResolver);
     }
 
     @Override
     protected ContentResolver getContentResolver() {
         if (hasCustomContentResolver()) {
             return this.unionContentResolver.getContentResolvers()[1];
         }
         return null;
     }
 
     private boolean hasCustomContentResolver() {
         return this.unionContentResolver.getContentResolvers().length > 1;
     }
 }