/*
    * 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.plugins.invoker;
  
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.Map;
  import java.util.Set;
  
  import org.apache.maven.project.MavenProject;
  import org.codehaus.plexus.util.introspection.ReflectionValueExtractor;
  
  /**
   * A map-like source to interpolate expressions.
   *
   * @author Olivier Lamy
   * @since 1.1
   */
  class CompositeMap implements Map<String, Object> {
  
      /**
       * The Maven project from which to extract interpolated values, never <code>null</code>.
       */
      private MavenProject mavenProject;
  
      /**
       * The set of additional properties from which to extract interpolated values, never <code>null</code>.
       */
      private Map<String, Object> properties;
  
      /**
       * Flag indicating to escape XML special characters.
       */
      private final boolean escapeXml;
  
      /**
       * Creates a new interpolation source backed by the specified Maven project and some user-specified properties.
       *
       * @param mavenProject The Maven project from which to extract interpolated values, must not be <code>null</code>.
       * @param properties The set of additional properties from which to extract interpolated values, may be
       *            <code>null</code>.
       * @param escapeXml {@code true}, to escape any XML special characters; {@code false}, to not perform any escaping.
       */
      protected CompositeMap(MavenProject mavenProject, Map<String, Object> properties, boolean escapeXml) {
          if (mavenProject == null) {
              throw new IllegalArgumentException("no project specified");
          }
          this.mavenProject = mavenProject;
          this.properties = properties == null ? new HashMap<String, Object>() : properties;
          this.escapeXml = escapeXml;
      }
  
      /**
       * {@inheritDoc}
       *
       * @see java.util.Map#clear()
       */
      public void clear() {
          // nothing here
      }
  
      /**
       * {@inheritDoc}
       *
       * @see java.util.Map#containsKey(java.lang.Object)
       */
      public boolean containsKey(Object key) {
          if (!(key instanceof String)) {
              return false;
          }
  
          String expression = (String) key;
          if (expression.startsWith("project.") || expression.startsWith("pom.")) {
              try {
                  Object evaluated = ReflectionValueExtractor.evaluate(expression, this.mavenProject);
                  if (evaluated != null) {
                      return true;
                  }
              } catch (Exception e) {
                  // uhm do we have to throw a RuntimeException here ?
              }
          }
  
         return properties.containsKey(key) || mavenProject.getProperties().containsKey(key);
     }
 
     /**
      * {@inheritDoc}
      *
      * @see java.util.Map#containsValue(java.lang.Object)
      */
     public boolean containsValue(Object value) {
         throw new UnsupportedOperationException();
     }
 
     /**
      * {@inheritDoc}
      *
      * @see java.util.Map#entrySet()
      */
     public Set<Entry<String, Object>> entrySet() {
         throw new UnsupportedOperationException();
     }
 
     /**
      * {@inheritDoc}
      *
      * @see java.util.Map#get(java.lang.Object)
      */
     public Object get(Object key) {
         if (!(key instanceof String)) {
             return null;
         }
 
         Object value = null;
         String expression = (String) key;
         if (expression.startsWith("project.") || expression.startsWith("pom.")) {
             try {
                 Object evaluated = ReflectionValueExtractor.evaluate(expression, this.mavenProject);
                 if (evaluated != null) {
                     value = evaluated;
                 }
             } catch (Exception e) {
                 // uhm do we have to throw a RuntimeException here ?
             }
         }
 
         if (value == null) {
             value = properties.get(key);
         }
 
         if (value == null) {
             value = this.mavenProject.getProperties().get(key);
         }
 
         if (value != null && this.escapeXml) {
             value = value.toString()
                     .replaceAll("\"", "&quot;")
                     .replaceAll("<", "&lt;")
                     .replaceAll(">", "&gt;")
                     .replaceAll("&", "&amp;");
         }
 
         return value;
     }
 
     /**
      * {@inheritDoc}
      *
      * @see java.util.Map#isEmpty()
      */
     public boolean isEmpty() {
         return this.mavenProject.getProperties().isEmpty() && this.properties.isEmpty();
     }
 
     /**
      * {@inheritDoc}
      *
      * @see java.util.Map#keySet()
      */
     public Set<String> keySet() {
         throw new UnsupportedOperationException();
     }
 
     /**
      * {@inheritDoc}
      *
      * @see java.util.Map#put(java.lang.Object, java.lang.Object)
      */
     public Object put(String key, Object value) {
         throw new UnsupportedOperationException();
     }
 
     /**
      * {@inheritDoc}
      *
      * @see java.util.Map#putAll(java.util.Map)
      */
     public void putAll(Map<? extends String, ? extends Object> t) {
         throw new UnsupportedOperationException();
     }
 
     /**
      * {@inheritDoc}
      *
      * @see java.util.Map#remove(java.lang.Object)
      */
     public Object remove(Object key) {
         throw new UnsupportedOperationException();
     }
 
     /**
      * {@inheritDoc}
      *
      * @see java.util.Map#size()
      */
     public int size() {
         throw new UnsupportedOperationException();
     }
 
     /**
      * {@inheritDoc}
      *
      * @see java.util.Map#values()
      */
     public Collection<Object> values() {
         throw new UnsupportedOperationException();
     }
 }