/*
    * This file is part of ***  M y C o R e  ***
    * See http://www.mycore.de/ for details.
    *
    * MyCoRe is free software: you can redistribute it and/or modify
    * it under the terms of the GNU General Public License as published by
    * the Free Software Foundation, either version 3 of the License, or
    * (at your option) any later version.
    *
   * MyCoRe is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with MyCoRe.  If not, see <http://www.gnu.org/licenses/>.
   */
  
  package org.mycore.common.config;
  
  import java.io.IOException;
  import java.io.OutputStream;
  import java.io.Writer;
  import java.nio.charset.Charset;
  import java.util.Collections;
  import java.util.Enumeration;
  import java.util.Map;
  import java.util.Properties;
  import java.util.Set;
  import java.util.TreeSet;
  
  import org.apache.logging.log4j.LogManager;
  
  /**
   * Like {@link Properties} but with in-place replacement of properties that want to append a value.
   * 
   * Properties for System.getProperties() have always precedence for Properties defined here.
   * 
   * <pre>
   * key=value1
   * key=%key%,value2
   * </pre>
   * 
   * will be resolved to
   * 
   * <pre>
   * key=value1,value2
   * </pre>
   * 
   * @author Thomas Scheffler (yagee)
   * @since 2013.12
   */
  public class MCRProperties extends Properties {
  
      private static final long serialVersionUID = 8801587133852810123L;
  
      @Override
      public synchronized Object put(Object key, Object value) {
          return putString((String) key, (String) value);
      }
  
      private Object putString(String key, String value) {
          String systemProperty = System.getProperties().getProperty(key);
          if (systemProperty != null && !systemProperty.equals(value)) {
              LogManager.getLogger(getClass()).error("Cannot overwrite system property: {}={}", key, value);
              return systemProperty;
          }
          String oldValue = (String) super.get(key);
          String newValue = oldValue == null ? value : value.replaceAll('%' + key + '%', oldValue);
          if (!newValue.equals(value) && newValue.startsWith(",")) {
              //replacement took place, but starts with 'empty' value
              newValue = newValue.substring(1);
          }
          return super.put(key, newValue);
      }
  
      @Override
      public synchronized Object get(Object key) {
          String systemProperty = System.getProperties().getProperty((String) key);
          return systemProperty != null ? systemProperty : super.get(key);
      }
  
      Map<String, String> getAsMap() {
          @SuppressWarnings("rawtypes")
          Map compileFix = this;
          @SuppressWarnings("unchecked")
          Map<String, String> returns = compileFix;
          return returns;
      }
  
      /**
       * Creates a new <code>MCRProperties</code> instance with the values
       * of the given properties.
       */
      public static MCRProperties copy(Properties properties) {
          MCRProperties p = new MCRProperties();
          for (Map.Entry<Object, Object> entry : properties.entrySet()) {
              p.put(entry.getKey(), entry.getValue());
          }
         return p;
     }
 
     @Override
     public void store(OutputStream out, String comments) throws IOException {
         toSortedProperties().store(out, comments);
     }
 
     @Override
     public void store(Writer writer, String comments) throws IOException {
         toSortedProperties().store(writer, comments);
     }
 
     @Override
     public void storeToXML(OutputStream os, String comment, Charset charset) throws IOException {
         toSortedProperties().storeToXML(os, comment, charset);
     }
 
     private Properties toSortedProperties() {
         Properties sortedProps = new Properties() {
             @Override
             public Set<Map.Entry<Object, Object>> entrySet() {
                 Set<Map.Entry<Object, Object>> sortedSet = new TreeSet<>(
                     (o1, o2) -> o1.getKey().toString().compareTo(o2.getKey().toString()));
                 sortedSet.addAll(super.entrySet());
                 return sortedSet;
             }
 
             @Override
             public Set<Object> keySet() {
                 return new TreeSet<Object>(super.keySet());
             }
 
             @Override
             public synchronized Enumeration<Object> keys() {
                 return Collections.enumeration(new TreeSet<Object>(super.keySet()));
             }
 
         };
         sortedProps.putAll(this);
         return sortedProps;
     }
 }