content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You 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.
   */
  package com.alibaba.compileflow.engine.core.builder.generator.script;
  
  import com.alibaba.compileflow.engine.common.CompileFlowException;
  import com.alibaba.compileflow.engine.common.ErrorCode;
  
  import java.util.*;
  
  /**
   * @author yusu
   */
  public class ScriptExecutorProvider {
  
      private List<ScriptExecutor> scriptExecutors = new ArrayList<>();
      private Map<String, ScriptExecutor> scriptExecutorMap = new HashMap<>();
  
      public static ScriptExecutorProvider getInstance() {
          return Holder.INSTANCE;
      }
  
      @SuppressWarnings("unchecked")
      public <T extends ScriptExecutor> T getScriptExecutor(String name) {
          return (T) Optional.ofNullable(scriptExecutorMap.get(name))
                  .orElseThrow(() -> new CompileFlowException.ConfigurationException(
                          ErrorCode.CF_CONFIG_003,
                          "No script executor found, name is " + name
                  ));
      }
  
      public void registerScriptExecutor(ScriptExecutor executor) {
          ScriptExecutor existedExecutor = scriptExecutorMap.get(executor.getName());
          if (existedExecutor != null && !existedExecutor.getClass().equals(executor.getClass())) {
              throw new CompileFlowException.ConfigurationException(
                      ErrorCode.CF_CONFIG_001,
                      "Duplicated executor name[" + executor.getName() + "] found, "
                              + "[" + executor.getClass().getName() + ", " + existedExecutor.getClass().getName() + "]",
                      null
              );
          }
          scriptExecutors.add(executor);
          scriptExecutorMap.put(executor.getName(), executor);
      }
  
      private static class Holder {
          private static final ScriptExecutorProvider INSTANCE = new ScriptExecutorProvider();
      }
  
  }
  