/**
    * Copyright 2005-2013 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 edu.samplu.common;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.util.ArrayList;
  import java.util.Enumeration;
  import java.util.HashMap;
  import java.util.Iterator;
  import java.util.LinkedList;
  import java.util.List;
  import java.util.Map;
  import java.util.Properties;
  
  /**
   * @author Kuali Rice Team (rice.collab@kuali.org)
   */
  
  public class PropertiesUtils {
  
  
      public static Properties loadPropertiesWithSystemOverrides(InputStream inputStream) throws IOException {
          Properties props = PropertiesUtils.loadProperties(inputStream);
          PropertiesUtils.systemPropertiesOverride(props);
          return props;
      }
  
      public static Properties loadPropertiesWithSystemOverridesAndNumberedPropertiesToList(InputStream inputStream) throws IOException {
          Properties props = PropertiesUtils.loadProperties(inputStream);
          PropertiesUtils.systemPropertiesOverride(props);
          PropertiesUtils.transformNumberedPropertiesToList(props);
          return props;
      }
  
      public static Properties loadProperties(InputStream inputStream) throws IOException {
          Properties props = new Properties();
  
          if(inputStream != null) {
              props.load(inputStream);
          }
  
          return props;
      }
  
      public static String removeNumber(final String numberedKey) {
          String unnumberedKey = numberedKey;
          int firstNumberIndex = unnumberedKey.length() - 1;
          while (Character.isDigit(unnumberedKey.charAt(firstNumberIndex))) {
              firstNumberIndex--;
          }
          unnumberedKey = unnumberedKey.substring(0, firstNumberIndex + 1);
  
          return unnumberedKey;
      }
  
      public static void systemPropertiesOverride(Properties props) {
          PropertiesUtils.systemPropertiesOverride(props, null);
      }
  
      /**
       * -Dkey.propertyname= to override the property value for propertyname.
       * @param props properties to update with System.getProperty overrides.
       * @param key optional value that the property names will be appended to.
       */
      public static void systemPropertiesOverride(Properties props, String key) {
          Enumeration<?> names = props.propertyNames();
          Object nameObject;
          String name;
          while (names.hasMoreElements()) {
  
              nameObject = names.nextElement();
              if (nameObject instanceof String) {
  
                  name = (String)nameObject;
                  if (key == null || key.isEmpty()) {
                      props.setProperty(name, System.getProperty(name, props.getProperty(name)));
                  } else {
                      props.setProperty(name, System.getProperty(key + "." + name, props.getProperty(name)));
                  }
              }
          }
      }
  
      public static void transformNumberedPropertiesToList(Properties props) {
          String key = null;
         String unnumberedKey = null;
         List<String> keyList = null;
         List<String> removeKeys = new LinkedList<String>();
 
         // unnumber keys and place their values in a list
         Iterator keys = props.keySet().iterator();
         Map<String, List<String>> keysLists = new HashMap<String, List<String>>();
         while (keys.hasNext()) {
             key = (String)keys.next();
             if (Character.isDigit(key.charAt(key.length()-1))) {
                 unnumberedKey = removeNumber(key);
                 if (keysLists.get(unnumberedKey) == null) {
                     keyList = new ArrayList<String>();
                     keyList.add(props.getProperty(key));
                     keysLists.put(unnumberedKey, keyList);
                     removeKeys.add(key);
                 } else {
                     keyList = keysLists.get(unnumberedKey);
                     keyList.add(props.getProperty(key));
                     keysLists.put(unnumberedKey, keyList);
                     removeKeys.add(key);
                 }
             }
         }
 
         // remove keys that where unnumbered
         Iterator removeKey = removeKeys.iterator();
         while (removeKey.hasNext()) {
             key = (String)removeKey.next();
             props.remove(key);
         }
 
         // put new unnumbered key values mapped by unnumber key with an s appended to it.
         Iterator newKeys = keysLists.keySet().iterator();
         String newKey = null;
         while (newKeys.hasNext()) {
             newKey = (String)newKeys.next();
             props.put(newKey + "s", keysLists.get(newKey));
         }
     }
 }