package com.atlassian.sal.core.message;
   
   import com.atlassian.sal.api.message.I18nResolver;
   import com.atlassian.sal.api.message.Message;
   import com.atlassian.sal.api.message.MessageCollection;
   
   import java.io.Serializable;
   import java.util.Locale;
   
  import static com.google.common.base.Preconditions.checkNotNull;
  
  /**
   * Basic skeleton of an implementation of {@link I18nResolver}, which host applications can use to get started.
   * Subclasses should only need to implement the abstract methods {@link #resolveText(String, java.io.Serializable[])}
   * and {@link #resolveText(Locale, String, Serializable[])}.
   */
  public abstract class AbstractI18nResolver implements I18nResolver
  {
      private static final Serializable[] EMPTY_SERIALIZABLE = new Serializable[0];
  
      public String getText(String key, Serializable... arguments)
      {
          Serializable[] resolvedArguments = new Serializable[arguments.length];
          for (int i = 0; i < arguments.length; i++)
          {
              Serializable argument = arguments[i];
              if (argument instanceof Message)
              {
                  resolvedArguments[i] = getText((Message) argument);
              }
              else
              {
                  resolvedArguments[i] = arguments[i];
              }
          }
          return resolveText(key, resolvedArguments);
      }
  
      public String getText(Locale locale, String key, Serializable... arguments)
      {
          checkNotNull(locale);
          Serializable[] resolvedArguments = new Serializable[arguments.length];
          for (int i = 0; i < arguments.length; i++)
          {
              Serializable argument = arguments[i];
              if (argument instanceof Message)
              {
                  resolvedArguments[i] = getText(locale, (Message) argument);
              }
              else
              {
                  resolvedArguments[i] = arguments[i];
              }
          }
          return resolveText(locale, key, resolvedArguments);
      }
  
      public String getText(String key)
      {
          return resolveText(key, EMPTY_SERIALIZABLE);
      }
  
      public String getText(Locale locale, String key)
      {
          checkNotNull(locale);
          return resolveText(locale, key, EMPTY_SERIALIZABLE);
      }
  
      public String getText(Message message)
      {
          return getText(message.getKey(), message.getArguments());
      }
  
      public String getText(Locale locale, Message message)
      {
          return getText(locale, message.getKey(), message.getArguments());
      }
  
      /**
       * Subclasses should implement this method to dispatch to a matching language in (in order of preference):
       * <ul>
       *     <li>the user's locale</li>
       *     <li>the application's configured locale, or</li>
       *     <li>the system default locale</li>
       * </ul>
       * @param key the key to translate.
       * @param arguments the arguments to be inserted into the translated string.
       * @return the translated string.
       */
      public abstract String resolveText(String key, Serializable[] arguments);
  
      /**
       * Subclasses should implement this method to dispatch to a matching language in the given locale.
       * @param locale the locale to translate into.
       * @param key the key to translate.
       * @param arguments the arguments to be inserted into the translated string.
       * @return the translated string.
       */
      public abstract String resolveText(Locale locale, String key, Serializable[] arguments);
 
 	public Message createMessage(String key, Serializable... arguments)
 	{
 		return new DefaultMessage(key, arguments);
 	}
 
 	public MessageCollection createMessageCollection()
 	{
 		return new DefaultMessageCollection();
 	}
 }