package ca.uhn.fhir.util;
   
   /*
    * #%L
    * HAPI FHIR - Core Library
    * %%
    * Copyright (C) 2014 University Health Network
    * %%
    * 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.
   * #L%
   */
  
  import java.util.HashMap;
  import java.util.Map;
  
  import javax.xml.namespace.NamespaceContext;
  import javax.xml.stream.XMLStreamException;
  import javax.xml.stream.XMLStreamWriter;
  
  import org.apache.commons.lang3.StringUtils;
  
  public class PrettyPrintWriterWrapper implements XMLStreamWriter {
  
  	private static final String INDENT_CHAR = " ";
  	private static final String LINEFEED_CHAR = "\n";
  	private static final String PRE = "pre";
  	private int depth = 0;
  	private Map<Integer, Boolean> hasChildElement = new HashMap<Integer, Boolean>();
  
  	private int myInsidePre = 0;
  	private XMLStreamWriter myTarget;
  	private boolean myFirstIndent=true;
  
  	public PrettyPrintWriterWrapper(XMLStreamWriter target) {
  		myTarget = target;
  	}
  
  	@Override
  	public void close() throws XMLStreamException {
  		myTarget.close();
  	}
  
  	@Override
  	public void flush() throws XMLStreamException {
  		myTarget.flush();
  	}
  
  	@Override
  	public NamespaceContext getNamespaceContext() {
  		return myTarget.getNamespaceContext();
  	}
  
  	@Override
  	public String getPrefix(String theUri) throws XMLStreamException {
  		return myTarget.getPrefix(theUri);
  	}
  
  	@Override
  	public Object getProperty(String theName) throws IllegalArgumentException {
  		return myTarget.getProperty(theName);
  	}
  
  	@Override
  	public void setDefaultNamespace(String theUri) throws XMLStreamException {
  		myTarget.setDefaultNamespace(theUri);
  	}
  
  	@Override
  	public void setNamespaceContext(NamespaceContext theContext) throws XMLStreamException {
  		myTarget.setNamespaceContext(theContext);
  	}
  
  	@Override
  	public void setPrefix(String thePrefix, String theUri) throws XMLStreamException {
  		myTarget.setPrefix(thePrefix, theUri);
  	}
  
  	@Override
  	public void writeAttribute(String theLocalName, String theValue) throws XMLStreamException {
  		myTarget.writeAttribute(theLocalName, theValue);
  	}
  
  	@Override
  	public void writeAttribute(String theNamespaceURI, String theLocalName, String theValue) throws XMLStreamException {
  		myTarget.writeAttribute(theNamespaceURI, theLocalName, theValue);
  	}
  
  	@Override
  	public void writeAttribute(String thePrefix, String theNamespaceURI, String theLocalName, String theValue) throws XMLStreamException {
 		myTarget.writeAttribute(thePrefix, theNamespaceURI, theLocalName, theValue);
 	}
 
 	@Override
 	public void writeCData(String theData) throws XMLStreamException {
 		myTarget.writeCData(theData);
 	}
 
 	@Override
 	public void writeCharacters(char[] theText, int theStart, int theLen) throws XMLStreamException {
 		NonPrettyPrintWriterWrapper.writeCharacters(theText, theStart, theLen, myTarget, myInsidePre);
 	}
 
 	@Override
 	public void writeCharacters(String theText) throws XMLStreamException {
 		if (myInsidePre > 0) {
 			myTarget.writeCharacters(theText);
 		} else {
 			writeCharacters(theText.toCharArray(), 0, theText.length());
 		}
 	}
 
 	@Override
 	public void writeComment(String theData) throws XMLStreamException {
 		myTarget.writeComment(theData);
 	}
 
 	@Override
 	public void writeDefaultNamespace(String theNamespaceURI) throws XMLStreamException {
 		myTarget.writeDefaultNamespace(theNamespaceURI);
 	}
 
 	@Override
 	public void writeDTD(String theDtd) throws XMLStreamException {
 		myTarget.writeDTD(theDtd);
 	}
 
 	@Override
 	public void writeEmptyElement(String theLocalName) throws XMLStreamException {
 		indent();
 		myTarget.writeEmptyElement(theLocalName);
 	}
 
 	@Override
 	public void writeEmptyElement(String theNamespaceURI, String theLocalName) throws XMLStreamException {
 		indent();
 		myTarget.writeEmptyElement(theNamespaceURI, theLocalName);
 	}
 
 	@Override
 	public void writeEmptyElement(String thePrefix, String theLocalName, String theNamespaceURI) throws XMLStreamException {
 		indent();
 		myTarget.writeEmptyElement(thePrefix, theLocalName, theNamespaceURI);
 	}
 
 	@Override
 	public void writeEndDocument() throws XMLStreamException {
 		decrementAndIndent();
 		myTarget.writeEndDocument();
 	}
 
 	@Override
 	public void writeEndElement() throws XMLStreamException {
 		if (myInsidePre > 0) {
 			myInsidePre--;
 		}
 		decrementAndIndent();
 
 		myTarget.writeEndElement();
 
 	}
 
 	@Override
 	public void writeEntityRef(String theName) throws XMLStreamException {
 		myTarget.writeEntityRef(theName);
 	}
 
 	@Override
 	public void writeNamespace(String thePrefix, String theNamespaceURI) throws XMLStreamException {
 		myTarget.writeNamespace(thePrefix, theNamespaceURI);
 	}
 
 	@Override
 	public void writeProcessingInstruction(String theTarget) throws XMLStreamException {
 		myTarget.writeProcessingInstruction(theTarget);
 	}
 
 	@Override
 	public void writeProcessingInstruction(String theTarget, String theData) throws XMLStreamException {
 		myTarget.writeProcessingInstruction(theTarget, theData);
 	}
 
 	@Override
 	public void writeStartDocument() throws XMLStreamException {
 		myFirstIndent=true;
 		myTarget.writeStartDocument();
 	}
 
 	@Override
 	public void writeStartDocument(String theVersion) throws XMLStreamException {
 		myFirstIndent=true;
 		myTarget.writeStartDocument(theVersion);
 	}
 
 	@Override
 	public void writeStartDocument(String theEncoding, String theVersion) throws XMLStreamException {
 		myFirstIndent=true;
 		myTarget.writeStartDocument(theEncoding, theVersion);
 	}
 
 	@Override
 	public void writeStartElement(String theLocalName) throws XMLStreamException {
 		indentAndAdd();
 		myTarget.writeStartElement(theLocalName);
 		if (PRE.equals(theLocalName) || myInsidePre > 0) {
 			myInsidePre++;
 		}
 	}
 
 	@Override
 	public void writeStartElement(String theNamespaceURI, String theLocalName) throws XMLStreamException {
 		indentAndAdd();
 		myTarget.writeStartElement(theNamespaceURI, theLocalName);
 		if (PRE.equals(theLocalName) || myInsidePre > 0) {
 			myInsidePre++;
 		}
 	}
 
 	@Override
 	public void writeStartElement(String thePrefix, String theLocalName, String theNamespaceURI) throws XMLStreamException {
 		indentAndAdd();
 		myTarget.writeStartElement(thePrefix, theLocalName, theNamespaceURI);
 		if (PRE.equals(theLocalName) || myInsidePre > 0) {
 			myInsidePre++;
 		}
 	}
 
 	private void decrementAndIndent() throws XMLStreamException {
 		if (myInsidePre > 0) {
 			return;
 		}
 		depth--;
 
 		if (hasChildElement.get(depth) == true) {
 			// indent for current depth
 			myTarget.writeCharacters(LINEFEED_CHAR + repeat(depth, INDENT_CHAR));
 		}
 	}
 
 	private void indent() throws XMLStreamException {
 		if (myFirstIndent) {
 			myFirstIndent = false;
 			return;
 		}
 		myTarget.writeCharacters(LINEFEED_CHAR + repeat(depth, INDENT_CHAR));
 	}
 
 	private void indentAndAdd() throws XMLStreamException {
 		if (myInsidePre > 0) {
 			return;
 		}
 		indent();
 
 		// update state of parent node
 		if (depth > 0) {
 			hasChildElement.put(depth - 1, true);
 		}
 
 		// reset state of current node
 		hasChildElement.put(depth, false);
 
 		depth++;
 	}
 
 	private String repeat(int d, String s) {
 		return StringUtils.repeat(s, d * 3);
 	}
 
 }