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.theme;
  
  import org.airsonic.player.domain.Theme;
  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.Component;
  import org.springframework.web.servlet.ThemeResolver;
  
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import java.util.HashSet;
  import java.util.Set;
  
  /**
   * Theme resolver implementation which returns the theme selected in the settings.
   *
   * @author Sindre Mehus
   */
  @Component("themeResolver")
  public class CustomThemeResolver implements ThemeResolver {
  
      private SecurityService securityService;
      private SettingsService settingsService;
      private Set<String> themeIds;
  
      /**
      * Resolve the current theme name via the given request.
      *
      * @param request Request to be used for resolution
      * @return The current theme name
      */
      public String resolveThemeName(HttpServletRequest request) {
          String themeId = (String) request.getAttribute("airsonic.theme");
          if (themeId != null) {
              return themeId;
          }
  
          // Optimization: Cache theme in the request.
          themeId = doResolveThemeName(request);
          request.setAttribute("airsonic.theme", themeId);
  
          return themeId;
      }
  
      private String doResolveThemeName(HttpServletRequest request) {
          String themeId = null;
  
          // Look for user-specific theme.
          String username = securityService.getCurrentUsername(request);
          if (username != null) {
              UserSettings userSettings = settingsService.getUserSettings(username);
              if (userSettings != null) {
                  themeId = userSettings.getThemeId();
              }
          }
  
          if (themeId != null && themeExists(themeId)) {
              return themeId;
          }
  
          // Return system theme.
          themeId = settingsService.getThemeId();
          return themeExists(themeId) ? themeId : "default";
      }
  
      /**
       * Returns whether the theme with the given ID exists.
       * @param themeId The theme ID.
       * @return Whether the theme with the given ID exists.
       */
      private synchronized boolean themeExists(String themeId) {
          // Lazily create set of theme IDs.
          if (themeIds == null) {
              Theme[] themes = settingsService.getAvailableThemes();
              themeIds = new HashSet<>(themes.length);
              for (Theme theme : themes) {
                  themeIds.add(theme.getId());
              }
          }
  
          return themeIds.contains(themeId);
      }
  
      /**
       * Set the current theme name to the given one. This method is not supported.
       *
       * @param request   Request to be used for theme name modification
       * @param response  Response to be used for theme name modification
       * @param themeName The new theme name
       * @throws UnsupportedOperationException If the ThemeResolver implementation
       *                                       does not support dynamic changing of the theme
       */
      public void setThemeName(HttpServletRequest request, HttpServletResponse response, String themeName) {
          throw new UnsupportedOperationException("Cannot change theme - use a different theme resolution strategy");
      }
  
      @Autowired
      public void setSecurityService(SecurityService securityService) {
          this.securityService = securityService;
      }
  
      @Autowired
      public void setSettingsService(SettingsService settingsService) {
          this.settingsService = settingsService;
      }
  }
  