content: package act.db.util;
  
  /*-
   * #%L
   * ACT Framework
   * %%
   * Copyright (C) 2014 - 2017 ActFramework
   * %%
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   * 
   *      http://www.apache.org/licenses/LICENSE-2.0
   * 
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   * #L%
   */
  
  import act.Act;
  import act.app.App;
  import act.app.DbServiceManager;
  import act.cli.Command;
  import act.cli.Required;
  import act.conf.AppConfig;
  import org.osgl.$;
  
  import javax.inject.Inject;
  
  /**
   * Sequence number manipulation utility class
   */
  @SuppressWarnings("unused")
  public class SequenceNumberGenerator {
  
      private static volatile  _SequenceNumberGenerator impl;
  
      public static void registerImpl(_SequenceNumberGenerator impl) {
          SequenceNumberGenerator.impl = $.requireNotNull(impl);
      }
  
      public static long next(String name) {
          return impl.next(name);
      }
  
      public static long get(String name) {
          return impl.get(name);
      }
  
  
      public static class Provider implements javax.inject.Provider<_SequenceNumberGenerator> {
  
          @Inject
          private java.util.List<_SequenceNumberGenerator> generators;
  
          @Override
          public _SequenceNumberGenerator get() {
              if (generators.size() > 1) {
                  App app = Act.app();
                  AppConfig config = app.config();
                  DbServiceManager dbServiceManager = app.dbServiceManager();
                  for (_SequenceNumberGenerator gen: generators) {
                      if (!_SequenceNumberGenerator.InMemorySequenceNumberGenerator.class.isInstance(gen)) {
                          try {
                              gen.configure(config, dbServiceManager);
                          } catch (Exception e) {
                              continue;
                          }
                          return gen;
                      }
                  }
              }
              return generators.get(0);
          }
      }
  
      @SuppressWarnings("unused")
      public static class SequenceAdmin {
  
          @Command(name = "act.seq.next", help = "display the next number in the sequence specified")
          public long generateNext(
                  @Required("specify sequence name") String sequence
          ) {
              return next(sequence);
          }
  
          @Command(name = "act.seq.get", help = "display the current number in the sequence specified")
          public long getCurrent(
                  @Required("Specify sequence name") String sequence
          ) {
              return get(sequence);
          }
  
      }
  
  }
  