/*
    * 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.model.interpolation;
  
  import java.util.List;
  
  import org.apache.maven.model.building.ModelProblem.Severity;
  import org.apache.maven.model.building.ModelProblem.Version;
  import org.apache.maven.model.building.ModelProblemCollector;
  import org.apache.maven.model.building.ModelProblemCollectorRequest;
  import org.codehaus.plexus.interpolation.ValueSource;
  
  /**
   * Wraps another value source and intercepts interpolated expressions, checking for problems.
   *
   * @author Benjamin Bentmann
   */
  class ProblemDetectingValueSource implements ValueSource {
  
      private final ValueSource valueSource;
  
      private final String bannedPrefix;
  
      private final String newPrefix;
  
      private final ModelProblemCollector problems;
  
      ProblemDetectingValueSource(
              ValueSource valueSource, String bannedPrefix, String newPrefix, ModelProblemCollector problems) {
          this.valueSource = valueSource;
          this.bannedPrefix = bannedPrefix;
          this.newPrefix = newPrefix;
          this.problems = problems;
      }
  
      @Override
      public Object getValue(String expression) {
          Object value = valueSource.getValue(expression);
  
          if (value != null && expression.startsWith(bannedPrefix)) {
              String msg = "The expression ${" + expression + "} is deprecated.";
              if (newPrefix != null && newPrefix.length() > 0) {
                  msg += " Please use ${" + newPrefix + expression.substring(bannedPrefix.length()) + "} instead.";
              }
              problems.add(new ModelProblemCollectorRequest(Severity.WARNING, Version.V20).setMessage(msg));
          }
  
          return value;
      }
  
      @Override
      public List getFeedback() {
          return valueSource.getFeedback();
      }
  
      @Override
      public void clearFeedback() {
          valueSource.clearFeedback();
      }
  }