package com.atlassian.sal.core.pluginsettings;
   
   import java.io.*;
   import java.util.*;
   import java.util.Map.Entry;
   
   import com.atlassian.sal.api.pluginsettings.PluginSettings;
   import com.google.common.collect.Lists;
   import com.google.common.base.Function;
  import org.apache.commons.lang.Validate;
  import org.apache.log4j.Logger;
  
  /**
   * PluginSettings implementation for datastores that only support Strings.  Handles converting Strings into Lists and
   * Properties objects using a '#TYPE_IDENTIFIER' header on the string.
   */
  public abstract class AbstractStringPluginSettings implements PluginSettings
  {
      private static final Logger log = Logger.getLogger(AbstractStringPluginSettings.class);
  
      private static final String PROPERTIES_ENCODING = "ISO8859_1";
      private static final String PROPERTIES_IDENTIFIER = "java.util.Properties";
      private static final String LIST_IDENTIFIER = "#java.util.List";
      private static final String MAP_IDENTIFIER = "#java.util.Map";
  
      /**
       * Puts a setting value.
       *
       * @param key Setting key.  Cannot be null
       * @param value Setting value.  Must be one of {@link String}, {@link List<String>}, {@link Properties}, {@link
       * Map<String, String>}, or null. null will remove the item from the settings.
       * @return The setting value that was over ridden. Null if none existed.
       * @throws IllegalArgumentException if value is not {@link String}, {@link List<String>}, {@link Properties}, {@link
       * Map<String, String>}, or null.
       */
      public Object put(String key, Object value)
      {
          Validate.notNull(key, "The plugin settings key cannot be null");
          if (value == null)
          {
              return remove(key);
          }
  
          final Object oldValue = get(key);
          if (value instanceof Properties)
          {
              final ByteArrayOutputStream bout = new ByteArrayOutputStream();
              try
              {
  
                  final Properties properties = (Properties) value;
                  properties.store(bout, PROPERTIES_IDENTIFIER);
                  putActual(key, new String(bout.toByteArray(), PROPERTIES_ENCODING));
              }
              catch (final IOException e)
              {
                  throw new IllegalArgumentException("Unable to serialize properties", e);
              }
          }
          else if (value instanceof String)
          {
              putActual(key, (String) value);
          }
          else if (value instanceof List)
          {
              final StringBuilder sb = new StringBuilder();
              sb.append(LIST_IDENTIFIER).append(EscapeUtils.NEW_LINE);
              for (final Iterator i = ((List) value).iterator(); i.hasNext();)
              {
                  sb.append(EscapeUtils.escape(i.next().toString()));
                  if (i.hasNext())
                      sb.append(EscapeUtils.NEW_LINE);
              }
              putActual(key, sb.toString());
          }
          else if (value instanceof Map)
          {
              final StringBuilder sb = new StringBuilder();
              sb.append(MAP_IDENTIFIER).append(EscapeUtils.NEW_LINE);
              for (final Iterator<Entry> i = ((Map) value).entrySet().iterator(); i.hasNext();)
              {
                  final Entry entry = i.next();
                  sb.append(EscapeUtils.escape(entry.getKey().toString()));
                  sb.append(EscapeUtils.VERTICAL_TAB);
                  sb.append(EscapeUtils.escape(entry.getValue().toString()));
                  if (i.hasNext())
                      sb.append(EscapeUtils.NEW_LINE);
              }
              putActual(key, sb.toString());
          }
          else
          {
              throw new IllegalArgumentException("Property type: " + value.getClass() + " not supported");
          }
          return oldValue;
      }
  
      /**
       * Gets a setting value. The setting returned should be specific to this context settings object and not cascade the
      * value to a global context.
      *
      * @param key The setting key.  Cannot be null
      * @return The setting value. May be null
      */
     public Object get(String key)
     {
         Validate.notNull(key, "The plugin settings key cannot be null");
         final String val = getActual(key);
         if (val != null && val.startsWith("#" + PROPERTIES_IDENTIFIER))
         {
             final Properties p = new Properties();
             try
             {
                 p.load(new ByteArrayInputStream(val.getBytes(PROPERTIES_ENCODING)));
             }
             catch (final IOException e)
             {
                 throw new IllegalArgumentException("Unable to deserialize properties", e);
             }
             return p;
         }
         else if (val != null && val.startsWith(LIST_IDENTIFIER))
         {
             final String[] lines = val.split(EscapeUtils.NEW_LINE + "");
 
             // remove the first item since it's the list identifier.
             final List<String> rawItems = Arrays.asList(lines).subList(1, lines.length);
 
             // unescape each of the items.
             final List<String> items = Lists.transform(rawItems, new Function<String, String>()
                                                                  {
                                                                         public String apply(String from)
                                                                         {
                                                                             return EscapeUtils.unescape(from);
                                                                         }
                                                                  });
             return new ArrayList<String>(items);
         }
         else if (val != null && val.startsWith(MAP_IDENTIFIER))
         {
             String nval = val.substring(MAP_IDENTIFIER.length() + 1);
             final HashMap<String, String> map = new HashMap<String, String>();
             final String[] items = nval.split(EscapeUtils.NEW_LINE + "");
             for (String item : items)
             {
                 if (item.length() > 0)
                 {
                     String[] pair = item.split(EscapeUtils.VERTICAL_TAB + "");
                     if (pair.length != 2)
                     {
                         log.error("Could not parse map element: << " + item + " >> \n" +
                             "Full list: \n" + nval);
                     }
                     else
                     {
                         map.put(EscapeUtils.unescape(pair[0]),
                                 EscapeUtils.unescape(pair[1]));
                     }    
                 }
             }
 
             return map;
         }
         else
         {
             return val;
         }
     }
 
     /**
      * Removes a setting value
      *
      * @param key The setting key
      * @return The setting value that was removed. Null if nothing was removed.
      */
     public Object remove(String key)
     {
         Validate.notNull(key, "The plugin settings key cannot be null");
         Object oldValue = get(key);
         if (oldValue != null)
         {
             removeActual(key);
         }
         return oldValue;
     }
 
     /**
      * Put the actual value.
      *
      * @param key The key to put it at.
      * @param val The value
      */
     protected abstract void putActual(String key, String val);
 
     /**
      * Get the actual value
      *
      * @param key The key to get
      * @return The value
      */
     protected abstract String getActual(String key);
 
     /**
      * Do the actual remove.  This will only be called if the value already exists.
      *
      * @param key The key to remove
      */
     protected abstract void removeActual(String key);
 
 }