/**
    * Copyright (C) 2011-2012 Indiana University
    *
    * Licensed 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 edu.iu.ul.maven.plugins.fileweaver;
  
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileNotFoundException;
  import java.io.InputStreamReader;
  import java.io.Reader;
  import java.io.StringReader;
  import java.io.UnsupportedEncodingException;
  import java.nio.charset.Charset;
  import org.apache.maven.plugin.MojoExecutionException;
  
  /**
   * Represent a portion of an output file:  literal text, or an input file.
   * It is an error to specify both, or neither.
   * @author mwood
   */
  public class Part
  {
      /**
       * Text of a literal part.
       * @parameter
       */
      private String text;
  
      public void setText(String text) throws MojoExecutionException
      {
          if (null != path)
              throw new MojoExecutionException("Part cannot have text and path.");
          else
              this.text = text;
      }
  
      /**
       * Path to an external file part.
       * @parameter
       */
      private File path;
  
      public void setPath(File path) throws MojoExecutionException
      {
          if (null != text)
              throw new MojoExecutionException("Part cannot have text and path.");
          else
              this.path = path;
      }
  
      /**
       * Do not append a newline.
       * @parameter default-value="false"
       * @required
       */
      private Boolean nonl = Boolean.FALSE;
  
      /**
       * @parameter default-value="${{project.build.encoding}"
       * @readonly
       * @required
       */
      private String encoding;
  
      /**
       * Get a Reader on whatever kind of content we have.
       * @return
       * @throws FileNotFoundException 
       */
      Reader getReader()
              throws FileNotFoundException, MojoExecutionException,
              UnsupportedEncodingException
      {
          Charset charset;
          if (null == encoding)
              charset = Charset.defaultCharset();
          else
              charset = Charset.forName(encoding);
  
          if (null != text)
              if (nonl)
                  return new StringReader(text);
              else
                  return new StringReader(text + "\n");
          else if (null != path)
              return new InputStreamReader(new FileInputStream(path),charset);
          else
             throw new MojoExecutionException("Part has neither text nor path.");
     }
 
     @Override
     public String toString()
     {
         if (null != text)
             return "literal part:  " + text;
         else if (null != path)
             return "file part:  " + path;
         else
             return "unknown part";
     }
 }