/*
    * 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.maven.enforcer.rules;
  
  import javax.inject.Inject;
  import javax.inject.Named;
  
  import java.util.Objects;
  
  import bsh.EvalError;
  import bsh.Interpreter;
  import org.apache.maven.enforcer.rule.api.EnforcerRuleException;
  import org.codehaus.plexus.component.configurator.expression.ExpressionEvaluationException;
  import org.codehaus.plexus.component.configurator.expression.ExpressionEvaluator;
  
  /**
   * Rule for Maven Enforcer using Beanshell to evaluate a conditional expression.
   *
   * @author hugonnem
   */
  @Named("evaluateBeanshell")
  public final class EvaluateBeanshell extends AbstractStandardEnforcerRule {
  
      /** Beanshell interpreter. */
      private final Interpreter interpreter = new Interpreter();
  
      /** The condition to be evaluated.
       * */
      private String condition;
  
      private final ExpressionEvaluator evaluator;
  
      @Inject
      public EvaluateBeanshell(ExpressionEvaluator evaluator) {
          this.evaluator = Objects.requireNonNull(evaluator);
      }
  
      public void setCondition(String condition) {
          this.condition = condition;
      }
  
      public String getCondition() {
          return condition;
      }
  
      @Override
      public void execute() throws EnforcerRuleException {
  
          try {
              getLog().debug("Echo condition : " + condition);
              // Evaluate condition within Plexus Container
              String script = (String) evaluator.evaluate(condition);
              getLog().debug("Echo script : " + script);
              if (!evaluateCondition(script)) {
                  String message = getMessage();
                  if (message == null || message.isEmpty()) {
                      message = "The expression \"" + condition + "\" is not true.";
                  }
                  throw new EnforcerRuleException(message);
              }
          } catch (ExpressionEvaluationException e) {
              throw new EnforcerRuleException("Unable to evaluate an expression '" + condition + "'", e);
          }
      }
  
      /**
       * Evaluate expression using Beanshell.
       *
       * @param script the expression to be evaluated
       * @return boolean the evaluation of the expression
       * @throws EnforcerRuleException if the script could not be evaluated
       */
      private boolean evaluateCondition(String script) throws EnforcerRuleException {
          Boolean evaluation;
          try {
              evaluation = (Boolean) interpreter.eval(script);
              getLog().debug("Echo evaluating : " + evaluation);
          } catch (EvalError ex) {
              throw new EnforcerRuleException("Couldn't evaluate condition: " + script, ex);
          }
          return evaluation;
      }
  
     @Override
     public String toString() {
         return String.format("EvaluateBeanshell[message=%s, condition=%s]", getMessage(), condition);
     }
 }