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[])},
   * {@link #resolveText(Locale, String, Serializable[])}, {@link #getRawText(String)} and
   * {@link #getRawText(java.util.Locale, String)}.
   */
  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();
      }
  }