package com.atlassian.plugin;
   
   import com.google.common.collect.ImmutableSet;
   
   import java.util.Set;
   
   import static com.google.common.base.Preconditions.checkNotNull;
   import static java.util.Optional.ofNullable;
   
  /**
   * @since 3.0
   */
  public final class Permissions {
      /**
       * <p>Represents all the permissions in one. This is useful for plugins before version 3 which by default require all
       * permissions.
       * <p>It is not a good idea to use this as a plugin developer, as this is a way internally to define permissions for
       * legacy plugins.
       */
      public static final String ALL_PERMISSIONS = "all_permissions";
  
      /**
       * A permission to execute java code. You will need this permission if as a plugin developers you write your own
       * java components for your plugin, be it a simple service, a servlet, etc.
       */
      public static final String EXECUTE_JAVA = "execute_java";
  
      /**
       * A permission to create system modules.
       */
      public static final String CREATE_SYSTEM_MODULES = "create_system_modules";
  
      /**
       * <p>A permission to generate arbitrary HTML.
       * <p>Generating arbitrary HTML can be a security threat hence why it would require such permission.
       */
      public static final String GENERATE_ANY_HTML = "generate_any_html";
  
      private Permissions() {
      }
  
      public static Set<String> getRequiredPermissions(Class<?> type) {
          final Class<RequirePermission> annotation = RequirePermission.class;
          if (type != null && type.isAnnotationPresent(annotation)) {
              return ImmutableSet.copyOf(type.getAnnotation(annotation).value());
          }
          return ImmutableSet.of();
      }
  
      public static Plugin addPermission(Plugin plugin, String permission, InstallationMode mode) {
          checkNotNull(plugin);
  
          getPluginInformation(plugin).setPermissions(
                  ImmutableSet.<PluginPermission>builder()
                          .addAll(getPluginInformation(plugin).getPermissions())
                          .add(new PluginPermission(permission, mode))
                          .build());
          return plugin;
      }
  
      private static PluginInformation getPluginInformation(Plugin plugin) {
          return ofNullable(plugin.getPluginInformation()).orElseGet(PluginInformation::new);
      }
  }