package org.apache.maven.shared.utils.xml;

 /*

  * 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.io.PrintWriter;

 import java.io.Writer;

 import java.util.LinkedList;

 import org.apache.maven.shared.utils.Os;

 /**

  * XMLWriter with nice indentation

  */

 public class PrettyPrintXMLWriter

     implements XMLWriter

 {

     private PrintWriter writer;

     private LinkedList<String> elementStack = new LinkedList<String>();

     private boolean processingElement = false;

     private boolean documentStarted = false;

     private boolean endOnSameLine = false;

     private int depth = 0;

     private String lineIndent;

     private String lineSeparator;

     private String encoding;

     private String docType;

     /**

      * @param writer not null

      * @param lineIndent could be null, but the normal way is some spaces.

      */

     public PrettyPrintXMLWriter( PrintWriter writer, String lineIndent )

     {

         this( writer, lineIndent, null, null );

     }

     /**

      * @param writer not null

      * @param lineIndent could be null, but the normal way is some spaces.

      */

     public PrettyPrintXMLWriter( Writer writer, String lineIndent )

     {

         this( new PrintWriter( writer ), lineIndent );

     }

     /**

      * @param writer not null

      */

     public PrettyPrintXMLWriter( PrintWriter writer )

     {

         this( writer, null, null );

     }

     /**

      * @param writer not null

      */

     public PrettyPrintXMLWriter( Writer writer )

     {

         this( new PrintWriter( writer ) );

     }

     /**

      * @param writer not null

      * @param lineIndent could be null, but the normal way is some spaces.

      * @param encoding could be null or invalid.

      * @param doctype could be null.

      */

     public PrettyPrintXMLWriter( PrintWriter writer, String lineIndent, String encoding, String doctype )

     {

         this( writer, lineIndent, Os.LINE_SEP, encoding, doctype );

     }

     /**

      * @param writer not null

      * @param lineIndent could be null, but the normal way is some spaces.

      * @param encoding could be null or invalid.

      * @param doctype could be null.

      */

     public PrettyPrintXMLWriter( Writer writer, String lineIndent, String encoding, String doctype )

     {

         this( new PrintWriter( writer ), lineIndent, encoding, doctype );

     }

     /**

      * @param writer not null

      * @param encoding could be null or invalid.

      * @param doctype could be null.

      */

     public PrettyPrintXMLWriter( PrintWriter writer, String encoding, String doctype )

     {

         this( writer, "  ", encoding, doctype );

     }

     /**

      * @param writer not null

      * @param encoding could be null or invalid.

      * @param doctype could be null.

      */

     public PrettyPrintXMLWriter( Writer writer, String encoding, String doctype )

     {

         this( new PrintWriter( writer ), encoding, doctype );

     }

     /**

      * @param writer not null

      * @param lineIndent could be null, but the normal way is some spaces.

      * @param lineSeparator could be null, but the normal way is valid line separator

      * @param encoding could be null or the encoding to use.

      * @param doctype could be null.

      */

     public PrettyPrintXMLWriter( PrintWriter writer, String lineIndent, String lineSeparator, String encoding,

                                  String doctype )

     {

         this.writer = writer;

         this.lineIndent = lineIndent;

         this.lineSeparator = lineSeparator;

         this.encoding = encoding;

         this.docType = doctype;

         depth = 0;

     }

     public void addAttribute( String key, String value )

     {

         if ( !processingElement )

         {

             throw new IllegalStateException( "currently processing no element" );

         }

         writer.write( ' ' );

         writer.write( key );

         writer.write( '=' );

         writer.write( XMLEncode.xmlEncodeTextForAttribute( value, '"' ) );

     }

     public void setEncoding( String encoding )

     {

         if ( documentStarted )

         {

             throw new IllegalStateException( "Document headers already written!" );

         }

         this.encoding = encoding;

     }

     public void setDocType( String docType )

     {

         if ( documentStarted )

         {

             throw new IllegalStateException( "Document headers already written!" );

         }

         this.docType = docType;

     }

     public void setLineSeparator( String lineSeparator )

     {

         if ( documentStarted )

         {

             throw new IllegalStateException( "Document headers already written!" );

         }

         this.lineSeparator = lineSeparator;

     }

     public void setLineIndenter( String lineIndent )

     {

         if ( documentStarted )

         {

             throw new IllegalStateException( "Document headers already written!" );

         }

         this.lineIndent = lineIndent;

     }

     public void startElement( String elementName )

     {

         boolean firstLine = ensureDocumentStarted();

         completePreviouslyOpenedElement();

         if ( !firstLine )

         {

             newLine();

         }

         writer.write( '<' );

         writer.write( elementName );

         processingElement = true;

         depth++;

         elementStack.addLast( elementName );

     }

     public void writeText( String text )

     {

         ensureDocumentStarted();

         completePreviouslyOpenedElement();

         writer.write( XMLEncode.xmlEncodeText( text ) );

         endOnSameLine = true;

     }

     public void writeMarkup( String markup )

     {

         ensureDocumentStarted();

         completePreviouslyOpenedElement();

         writer.write( markup );

     }

     public void endElement()

     {

         depth--;

         if ( processingElement )

         {

             // this means we don't have any content yet so we just add a />

             writer.write( "/>" );

             elementStack.removeLast();

             processingElement = false;

         }

         else

         {

             if ( !endOnSameLine )

             {

                 newLine();

             }

             // otherwise we need a full closing tag for that element

             writer.write( "</" + elementStack.removeLast() + ">" );

         }

         endOnSameLine = false;

     }

     /**

      * Write the documents if not already done.

      * 

      * @return <code>true</code> if the document headers have freshly been written.

      */

     private boolean ensureDocumentStarted()

     {

         if ( !documentStarted )

         {

             if ( docType != null || encoding != null )

             {

                 writeDocumentHeader();

             }

             documentStarted = true;

             return true;

         }

         return false;

     }

     private void writeDocumentHeader()

     {

         writer.write( "<?xml version=\"1.0\"" );

         if ( encoding != null )

         {

             writer.write( " encoding=\"" + encoding + "\"" );

         }

         writer.write( "?>" );

         newLine();

         if ( docType != null )

         {

             newLine();

             writer.write( "<!DOCTYPE " + docType + ">" );

         }

     }

     private void newLine()

     {

         writer.write( lineSeparator );

         for ( int i = 0; i < depth; i++ )

         {

             writer.write( lineIndent );

         }

     }

     private void completePreviouslyOpenedElement()

     {

         if ( processingElement )

         {

             writer.write( '>' );

             processingElement = false;

         }

     }

 }