package fi.internetix.smvc.i18n;

import java.text.MessageFormat;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import java.util.ResourceBundle;

/** A repository for localized messages.
 */
public class Messages {

  /** Returns the message repository singleton instance.
   * 
   * @return The message repository singleton instance.
   */
  public static Messages getInstance() {
    return instance;
  }
  
  private static Messages instance;
  
  /** Returns the string whose key is <code>key</code>, localized to <code>locale</code>.
   * 
   * @param locale The target locale.
   * @param key The key of the string to be localized.
   * @return The string whose key is <code>key</code>, localized to <code>locale</code>.
   */
  public String getText(Locale locale, String key) {
    return getResourceBundle(locale).getString(key);
  }
  
  /** Returns the format string whose key is <code>key</code>, localized to <code>locale</code>,
   * formatted with <code>params</code>.
   * 
   * @see MessageFormat
   * @param locale The target locale.
   * @param key The key of the string to be localized.
   * @param params The formatting parameters, to be passed to <code>MessageFormat</code>.
   * @return The string whose key is <code>key</code>, localized to <code>locale</code>.
   */
  public String getText(Locale locale, String key, Object[] params) {
    return MessageFormat.format(getText(locale, key), params);
  }
  
  /** Returns the resource bundle that contains the strings of the specified locale.
   * 
   * @param locale The locale whose bundle is returned.
   * @return The bundle that contains the strings of the specified locale.
   */
  public ResourceBundle getResourceBundle(Locale locale) {
    if (!bundles.containsKey(locale)) {
      ResourceBundle localeBundle = ResourceBundle.getBundle("fi.internetix.smvc.i18n.locale", locale); 
      bundles.put(locale, localeBundle);
    }

    return bundles.get(locale);
  }
  
  private Map<Locale, ResourceBundle> bundles = new HashMap<>();
  
  static {
    instance = new Messages();
  }
}