content: /*
   This file is part of Airsonic.
  
   Airsonic is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
  
   Airsonic is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
  
   You should have received a copy of the GNU General Public License
   along with Airsonic.  If not, see <http://www.gnu.org/licenses/>.
  
   Copyright 2016 (C) Airsonic Authors
   Based upon Subsonic, Copyright 2009 (C) Sindre Mehus
   */
  package org.airsonic.player.i18n;
  
  import org.airsonic.player.domain.UserSettings;
  import org.airsonic.player.service.SecurityService;
  import org.airsonic.player.service.SettingsService;
  import org.springframework.beans.factory.annotation.Autowired;
  import org.springframework.stereotype.Service;
  
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import java.util.Arrays;
  import java.util.HashSet;
  import java.util.Locale;
  import java.util.Set;
  
  /**
   * Locale resolver implementation which returns the locale selected in the settings.
   *
   * @author Sindre Mehus
   */
  @Service
  public class LocaleResolver implements org.springframework.web.servlet.LocaleResolver {
  
      @Autowired
      private SecurityService securityService;
      @Autowired
      private SettingsService settingsService;
      private Set<Locale> locales;
  
      /**
      * Resolve the current locale via the given request.
      *
      * @param request Request to be used for resolution.
      * @return The current locale.
      */
      public Locale resolveLocale(HttpServletRequest request) {
          Locale locale = (Locale) request.getAttribute("airsonic.locale");
          if (locale != null) {
              return locale;
          }
  
          // Optimization: Cache locale in the request.
          locale = doResolveLocale(request);
          request.setAttribute("airsonic.locale", locale);
  
          return locale;
      }
  
      private Locale doResolveLocale(HttpServletRequest request) {
          Locale locale = null;
  
          // Look for user-specific locale.
          String username = securityService.getCurrentUsername(request);
          if (username != null) {
              UserSettings userSettings = settingsService.getUserSettings(username);
              if (userSettings != null) {
                  locale = userSettings.getLocale();
              }
          }
  
          if (locale != null && localeExists(locale)) {
              return locale;
          }
  
          // Return system locale.
          locale = settingsService.getLocale();
          return localeExists(locale) ? locale : Locale.ENGLISH;
      }
  
      /**
       * Returns whether the given locale exists.
       * @param locale The locale.
       * @return Whether the locale exists.
       */
      private synchronized boolean localeExists(Locale locale) {
          // Lazily create set of locales.
          if (locales == null) {
              locales = new HashSet<Locale>(Arrays.asList(settingsService.getAvailableLocales()));
          }
  
          return locales.contains(locale);
      }
  
      public void setLocale(HttpServletRequest request, HttpServletResponse response, Locale locale) {
          throw new UnsupportedOperationException("Cannot change locale - use a different locale resolution strategy");
      }
  
      public void setSecurityService(SecurityService securityService) {
          this.securityService = securityService;
      }
  
      public void setSettingsService(SettingsService settingsService) {
          this.settingsService = settingsService;
      }
  }
  