package org.apache.maven.plugin;
   
   /*
    * 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.
   */
  
  import java.util.Collection;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  import java.util.Properties;
  
  import org.apache.maven.plugin.descriptor.MojoDescriptor;
  import org.apache.maven.plugin.descriptor.Parameter;
  import org.codehaus.plexus.util.StringUtils;
  
  public class PluginParameterException
      extends PluginConfigurationException
  {
  
      private final List<Parameter> parameters;
  
      private final MojoDescriptor mojo;
  
      public PluginParameterException( MojoDescriptor mojo, List<Parameter> parameters )
      {
          super( mojo.getPluginDescriptor(), "The parameters " + format( parameters ) + " for goal "
              + mojo.getRoleHint() + " are missing or invalid" );
  
          this.mojo = mojo;
  
          this.parameters = parameters;
      }
  
      private static String format( List<Parameter> parameters )
      {
          StringBuilder buffer = new StringBuilder( 128 );
          if ( parameters != null )
          {
              for ( Parameter parameter : parameters )
              {
                  if ( buffer.length() > 0 )
                  {
                      buffer.append( ", " );
                  }
                  buffer.append( '\'' ).append( parameter.getName() ).append( '\'' );
              }
          }
          return buffer.toString();
      }
  
      public MojoDescriptor getMojoDescriptor()
      {
          return mojo;
      }
  
      public List<Parameter> getParameters()
      {
          return parameters;
      }
  
      private static void decomposeParameterIntoUserInstructions( MojoDescriptor mojo, Parameter param,
                                                                  StringBuilder messageBuffer )
      {
          String expression = param.getExpression();
          
          if ( param.isEditable() )
          {
              boolean isArray = param.getType().endsWith( "[]" );
              boolean isCollection = false;
              boolean isMap = false;
              boolean isProperties = false;
              if ( !isArray )
              {
                  try
                  {
                      //assuming Type is available in current ClassLoader
                      isCollection = Collection.class.isAssignableFrom( Class.forName( param.getType() ) );
                      isMap = Map.class.isAssignableFrom( Class.forName( param.getType() ) );
                      isProperties = Properties.class.isAssignableFrom( Class.forName( param.getType() ) );
                  }
                  catch ( ClassNotFoundException e )
                  {
                      // assume it is not assignable from Collection or Map
                 }
             }
             
             messageBuffer.append( "Inside the definition for plugin \'" );
             messageBuffer.append( mojo.getPluginDescriptor().getArtifactId() );
             messageBuffer.append( "\', specify the following:\n\n<configuration>\n  ...\n" );
             messageBuffer.append( "  <" ).append( param.getName() ).append( '>' );
             if ( isArray || isCollection )
             {
                 messageBuffer.append( '\n' );
                 messageBuffer.append( "    <item>" );
             }
             else if ( isProperties )
             {
                 messageBuffer.append( '\n' );
                 messageBuffer.append( "    <property>\n" );
                 messageBuffer.append( "      <name>KEY</name>\n" );
                 messageBuffer.append( "      <value>" );
             }
             else if ( isMap )
             {
                 messageBuffer.append( '\n' );
                 messageBuffer.append( "    <KEY>" );
             }
             messageBuffer.append( "VALUE" );
             if ( isArray || isCollection )
             {
                 messageBuffer.append( "</item>\n" );
                 messageBuffer.append( "  " );
             }
             else if ( isProperties )
             {
                 messageBuffer.append( "</value>\n" );
                 messageBuffer.append( "    </property>\n" );
                 messageBuffer.append( "  " );
             }
             else if ( isMap )
             {
                 messageBuffer.append( "</KEY>\n" );
                 messageBuffer.append( "  " );
             }    
             messageBuffer.append( "</" ).append( param.getName() ).append( ">\n" );
             messageBuffer.append( "</configuration>" );
 
             String alias = param.getAlias();
             if ( StringUtils.isNotEmpty( alias ) && !alias.equals( param.getName() ) )
             {
                 messageBuffer.append( "\n\n-OR-\n\n<configuration>\n  ...\n  <" ).append( alias ).append(
                     ">VALUE</" ).append( alias ).append( ">\n</configuration>\n" );
             }
         }
 
         if ( StringUtils.isEmpty( expression ) )
         {
             messageBuffer.append( "." );
         }
         else
         {
             if ( param.isEditable() )
             {
                 messageBuffer.append( "\n\n-OR-\n\n" );
             }
 
             //addParameterUsageInfo( expression, messageBuffer );
         }
     }
 
     public String buildDiagnosticMessage()
     {
         StringBuilder messageBuffer = new StringBuilder( 256 );
 
         List<Parameter> params = getParameters();
         MojoDescriptor mojo = getMojoDescriptor();
 
         messageBuffer.append( "One or more required plugin parameters are invalid/missing for \'" )
             .append( mojo.getPluginDescriptor().getGoalPrefix() ).append( ":" ).append( mojo.getGoal() )
             .append( "\'\n" );
 
         int idx = 0;
         for ( Iterator<Parameter> it = params.iterator(); it.hasNext(); idx++ )
         {
             Parameter param = it.next();
 
             messageBuffer.append( "\n[" ).append( idx ).append( "] " );
 
             decomposeParameterIntoUserInstructions( mojo, param, messageBuffer );
 
             messageBuffer.append( "\n" );
         }
 
         return messageBuffer.toString();
     }
 }