/*
 * Created on Apr 2, 2009
 *
 * 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.
 *
 * Copyright @2009 the original author or authors.
 */
package org.fest.swing.junit.ant;

import static org.apache.tools.ant.util.FileUtils.close;
import static org.fest.util.Systems.LINE_SEPARATOR;

import java.io.*;

import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.util.DOMElementWriter;
import org.fest.swing.junit.xml.XmlNode;

/**
 * Understands writing the contents of an XML document to an <code>{@link OutputStream}</code>.
 *
 * @author Alex Ruiz
 */
class XmlOutputWriter {

  private static final String CHARSET = "UTF8";
  private static final String XML_HEADER = "<?xml version=\"1.0\" encoding=\"UTF-8\" ?>";
  private static final String INDENT = "  ";

  private final StandardOutputStreams outputStreams;

  XmlOutputWriter() {
    this(new StandardOutputStreams());
  }

  XmlOutputWriter(StandardOutputStreams outputStreams) {
    this.outputStreams = outputStreams;
  }

  void write(XmlNode xml, OutputStream out) {
    write(xml, out, new DOMElementWriter());
  }

  void write(XmlNode xml, OutputStream out, DOMElementWriter xmlWriter) {
    Writer writer = null;
    try {
      writer = new BufferedWriter(new OutputStreamWriter(out, CHARSET));
      writer.write(XML_HEADER);
      writer.write(LINE_SEPARATOR);
      xmlWriter.write(xml.target(), writer, 0, INDENT);
      writer.flush();
    } catch (IOException ex) {
      throw new BuildException("Unable to write log file", ex);
    } finally {
      if (!outputStreams.isStandardOutOrErr(out)) close(writer);
    }
  }
}