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 org.apache.camel.language.groovy;
  
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.Map;
  import java.util.Set;
  
  import groovy.lang.Binding;
  import groovy.lang.GroovyShell;
  import groovy.lang.Script;
  import org.apache.camel.Exchange;
  import org.apache.camel.attachment.AttachmentMessage;
  import org.apache.camel.attachment.DefaultAttachmentMessage;
  import org.apache.camel.support.ExchangeHelper;
  import org.apache.camel.support.ExpressionSupport;
  import org.apache.camel.support.ObjectHelper;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  public class GroovyExpression extends ExpressionSupport {
  
      private static final Logger LOG = LoggerFactory.getLogger(GroovyExpression.class);
  
      private final String text;
  
      public GroovyExpression(String text) {
          this.text = text;
      }
  
      @Override
      public String toString() {
          return "groovy: " + text;
      }
  
      @Override
      protected String assertionFailureMessage(Exchange exchange) {
          return "groovy: " + text;
      }
  
      @Override
      public <T> T evaluate(Exchange exchange, Class<T> type) {
          Map<String, Object> globalVariables = new HashMap<>();
          Script script = instantiateScript(exchange, globalVariables);
          script.setBinding(createBinding(exchange, globalVariables));
  
          Object value = script.run();
  
          return exchange.getContext().getTypeConverter().convertTo(type, value);
      }
  
      @SuppressWarnings("unchecked")
      protected Script instantiateScript(Exchange exchange, Map<String, Object> globalVariables) {
          // Get the script from the cache, or create a new instance
          GroovyLanguage language = (GroovyLanguage) exchange.getContext().resolveLanguage("groovy");
          Set<GroovyShellFactory> shellFactories = exchange.getContext().getRegistry().findByType(GroovyShellFactory.class);
          GroovyShellFactory shellFactory = null;
          String fileName = null;
          if (shellFactories.size() == 1) {
              shellFactory = shellFactories.iterator().next();
              fileName = shellFactory.getFileName(exchange);
              globalVariables.putAll(shellFactory.getVariables(exchange));
          }
          final String key = fileName != null ? fileName + text : text;
          Class<Script> scriptClass = language.getScriptFromCache(key);
          if (scriptClass == null) {
              // prefer to use classloader from groovy script compiler, and if not fallback to app context
              ClassLoader cl = exchange.getContext().getCamelContextExtension().getContextPlugin(GroovyScriptClassLoader.class);
              GroovyShell shell = shellFactory != null ? shellFactory.createGroovyShell(exchange)
                      : cl != null ? new GroovyShell(cl) : new GroovyShell();
              scriptClass = fileName != null
                      ? shell.getClassLoader().parseClass(text, fileName) : shell.getClassLoader().parseClass(text);
              language.addScriptToCache(key, scriptClass);
          }
          // New instance of the script
          return ObjectHelper.newInstance(scriptClass, Script.class);
      }
  
      protected Binding createBinding(Exchange exchange, Map<String, Object> globalVariables) {
          Map<String, Object> map = new HashMap<>(globalVariables);
          ExchangeHelper.populateVariableMap(exchange, map, true);
          AttachmentMessage am = new DefaultAttachmentMessage(exchange.getMessage());
          if (am.hasAttachments()) {
              map.put("attachments", am.getAttachments());
          } else {
              map.put("attachments", Collections.EMPTY_MAP);
          }
          map.put("log", LOG);
          return new Binding(map);
      }
  }
  