/*
    * Copyright 2006-2012 smartics, Kronseder & Reiner GmbH
    *
    * 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 de.smartics.maven.io;
  
  import java.io.File;
  import java.io.IOException;
  import java.io.OutputStream;
  
  import javax.xml.transform.OutputKeys;
  import javax.xml.transform.Transformer;
  import javax.xml.transform.TransformerException;
  import javax.xml.transform.TransformerFactory;
  import javax.xml.transform.dom.DOMSource;
  import javax.xml.transform.stream.StreamResult;
  
  import org.apache.maven.plugin.MojoExecutionException;
  import org.apache.maven.reporting.MavenReportException;
  import org.w3c.dom.Document;
  
  /**
   * Utilities for Mojos working with IO.
   *
   * @author <a href="mailto:robert.reiner@smartics.de">Robert Reiner</a>
   * @version $Revision:591 $
   */
  public final class MojoIoUtils
  {
    // ********************************* Fields *********************************
  
    // --- constants ------------------------------------------------------------
  
    // --- members --------------------------------------------------------------
  
    // ****************************** Initializer *******************************
  
    // ****************************** Constructors ******************************
  
    /**
     * Utility class pattern.
     */
    private MojoIoUtils()
    {
    }
  
    // ****************************** Inner Classes *****************************
  
    // ********************************* Methods ********************************
  
    // --- init -----------------------------------------------------------------
  
    // --- get&set --------------------------------------------------------------
  
    // --- business -------------------------------------------------------------
  
    /**
     * Ensures that the directory with the given name is present and if not,
     * creates it.
     *
     * @param dirName the name of the directory to be created.
     * @throws MojoExecutionException if the directory is not present and cannot
     *           be created.
     */
    public static File provideMojoDirectory(final String dirName)
      throws MojoExecutionException
    {
      final File dir = new File(dirName);
      provideMojoDirectory(dir);
      return dir;
    }
  
    /**
     * Ensures that the given directory is present and if not, creates it.
     *
     * @param directory the directory to be created.
     * @throws IOException if the directory is not present and cannot be created.
     */
    public static void provideDirectory(final File directory) throws IOException
    {
      if (!directory.exists())
      {
        final boolean created = directory.mkdirs();
        if (!created && !directory.exists())
        {
          throw new IOException("Cannot create directory: " // NOPMD
                                + directory.getAbsolutePath());
        }
     }
   }
 
   /**
    * Ensures that the given directory is present and if not, creates it.
    *
    * @param directory the directory to be created.
    * @throws MojoExecutionException if the directory is not present and cannot
    *           be created.
    */
   public static void provideMojoDirectory(final File directory)
     throws MojoExecutionException
   {
     if (!directory.exists())
     {
       final boolean created = directory.mkdirs();
       if (!created && !directory.exists())
       {
         throw new MojoExecutionException("Cannot create directory: "
                                          + directory.getAbsolutePath());
       }
     }
   }
 
   /**
    * Ensures that the given directory is present and if not, creates it.
    *
    * @param directory the directory to be created.
    * @throws MavenReportException if the directory is not present and cannot be
    *           created.
    */
   public static void provideReportDirectory(final File directory)
     throws MavenReportException
   {
     if (!directory.exists())
     {
       final boolean created = directory.mkdirs();
       if (!created && !directory.exists())
       {
         throw new MavenReportException("Cannot create directory: "
                                        + directory.getAbsolutePath());
       }
     }
   }
 
   /**
    * Normalises the file name to be used as a URL name.
    *
    * @impl Any character that is not a letter between A-Z (upper or lower case),
    *       a number or a dash, an underscore or a dot, will be mapped to an
    *       underscore. This algorithm is not part of the public API and stated
    *       here for informal reason. Any valid URL character may be added at a
    *       latter time. Client can be sure that the returned value contains only
    *       characters valid in an URL.
    * @param input the file name to be normalised.
    * @return the normalised filename.
    */
   public static String normalizeFileName(final String input)
   {
     final int length = input.length();
     final StringBuilder buffer = new StringBuilder(length);
     for (int i = 0; i < length; i++)
     {
       final char c = input.charAt(i);
       if (isValidUrlChar(c))
       {
         buffer.append(c);
       }
       else
       {
         buffer.append('_');
       }
     }
 
     return buffer.toString();
   }
 
   private static boolean isValidUrlChar(final char c)
   {
     return isUrlLetter(c) || isDigit(c) || c == '_' || c == '-' || c == '.';
   }
 
   private static boolean isUrlLetter(final char c)
   {
     return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
   }
 
   private static boolean isDigit(final char c)
   {
     return c >= '0' && c <= '9';
   }
 
   /**
    * Writes the DOM document to the given stream.
    *
    * @param document the document to write.
    * @param out the stream to write to.
    * @throws TransformerException on any problem writing to the stream.
    */
   public static void serialize(final Document document, final OutputStream out)
     throws TransformerException
   {
     serialize(document, out, false);
   }
 
   /**
    * Writes the DOM document to the given stream.
    *
    * @param document the document to write.
    * @param out the stream to write to.
    * @throws TransformerException on any problem writing to the stream.
    */
   public static void serialize(final Document document, final OutputStream out,
       final boolean prettyPrint) throws TransformerException
   {
     final TransformerFactory factory = TransformerFactory.newInstance();
     final Transformer serializer = factory.newTransformer();
     if (prettyPrint)
     {
       serializer.setOutputProperty(OutputKeys.INDENT, "yes");
       serializer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount",
           "2");
     }
 
     serializer.transform(new DOMSource(document), new StreamResult(out));
   }
 
   // --- object basics --------------------------------------------------------
 
 }