/*
    * #%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.io.File;
  import java.io.IOException;
  import java.io.UnsupportedEncodingException;
  import java.nio.charset.Charset;
  
  import org.apache.commons.io.Charsets;
  import org.settings4j.ContentResolver;
  import org.settings4j.contentresolver.FSContentResolver;
  import org.settings4j.contentresolver.UnionContentResolver;
  
  /**
   * The FileSystem implementation of an {@link org.settings4j.Connector}.
   *
   * @author Harald.Brabenetz
   */
  public class FSConnector extends AbstractConnector {
  
      private final FSContentResolver fsContentResolver;
      private UnionContentResolver unionContentResolver;
      private Charset charset = Charsets.UTF_8;
  
      /** Default Constructor (e.g. use in settings4j.xml). */
      public FSConnector() {
          this(new FSContentResolver());
      }
  
      /**
       * protected Constructor for extensions and Unit-Tests.
       *
       * @param fsContentResolver
       *        {@link FSContentResolver}
       */
      protected FSConnector(final FSContentResolver fsContentResolver) {
          super();
          this.fsContentResolver = fsContentResolver;
          this.unionContentResolver = new UnionContentResolver(this.fsContentResolver);
      }
  
      @Override
      public byte[] getContent(final String key) {
          return this.fsContentResolver.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.fsContentResolver.getContent(key), this.charset);
          }
          // else
          return null;
      }
  
      /**
       * @param key The Settings4j Key.
       * @param value The value to Store.
       * @throws IOException if an error occured.
       */
      public void setContent(final String key, final byte[] value) throws IOException {
          this.fsContentResolver.setContent(key, value);
      }
  
      /**
       * @param key The Settings4j Key.
       * @param value The value to Store.
       * @throws IOException if an error occured.
       */
      public void setString(final String key, final String value) throws IOException {
          try {
             setContent(key, value.getBytes(this.charset));
         } catch (final UnsupportedEncodingException e) {
             throw new UnsupportedOperationException(String.format("Charset not found: %s", this.charset), e);
         }
     }
 
     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);
     }
 
     /**
      * Delegate the rootFolderPath to the {@link FSContentResolver#setRootFolderPath(String)}.
      *
      * @param rootFolderPath The root Folder Path where the settings could be stored.
      */
     public void setRootFolderPath(final String rootFolderPath) {
         this.fsContentResolver.setRootFolderPath(rootFolderPath);
     }
 
     @Override
     public void setContentResolver(final ContentResolver contentResolver) {
         this.unionContentResolver = new UnionContentResolver(this.fsContentResolver);
         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;
     }
     /**
      * return the root of this FileSystem ContenResolver.
      * <p>
      * if no one is set, the "." will be returned.
      * </p>
      *
      * @return the root of this FileSystem ContenResolver.
      */
     public File getRootFolder() {
         return this.fsContentResolver.getRootFolder();
     }
 }