package org.hl7.fhir.utilities.xml;

/*
  Copyright (c) 2011+, HL7, Inc.
  All rights reserved.
  
  Redistribution and use in source and binary forms, with or without modification, 
  are permitted provided that the following conditions are met:
    
   * Redistributions of source code must retain the above copyright notice, this 
     list of conditions and the following disclaimer.
   * Redistributions in binary form must reproduce the above copyright notice, 
     this list of conditions and the following disclaimer in the documentation 
     and/or other materials provided with the distribution.
   * Neither the name of HL7 nor the names of its contributors may be used to 
     endorse or promote products derived from this software without specific 
     prior written permission.
  
  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND 
  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 
  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 
  IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 
  INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 
  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 
  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 
  WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
  POSSIBILITY OF SUCH DAMAGE.
  
 */



import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.StringWriter;
import java.io.Writer;

import org.hl7.fhir.exceptions.FHIRException;
import org.hl7.fhir.utilities.MarkDownProcessor;
import org.hl7.fhir.utilities.MarkDownProcessor.Dialect;
import org.hl7.fhir.utilities.Utilities;
import org.hl7.fhir.utilities.xml.XhtmlGeneratorAdorner.XhtmlGeneratorAdornerState;
import org.w3c.dom.Comment;
import org.w3c.dom.DOMException;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.ProcessingInstruction;
import org.w3c.dom.Text;


public class XhtmlGenerator {

	private static final int LINE_LIMIT = 78;
  private XhtmlGeneratorAdorner adorner;
	
  public XhtmlGenerator(XhtmlGeneratorAdorner adorner) {
    super();
    this.adorner = adorner;
  }

  public String generateInsert(Document doc, String name, String desc) throws Exception {
    StringWriter out = new StringWriter();
    
    out.write("<div class=\"example\">\r\n");
    out.write("<p>Example Instance \""+name+"\""+(desc == null ? "" : ": "+Utilities.escapeXml(desc))+"</p>\r\n"); 
    out.write("<pre class=\"xml\" style=\"white-space: pre; overflow: hidden\">\r\n");

    XhtmlGeneratorAdornerState state = null; // adorner == null ? new XhtmlGeneratorAdornerState("", "") : adorner.getState(this, null, null);
    for (int i = 0; i < doc.getChildNodes().getLength(); i++)
      writeNode(out, doc.getChildNodes().item(i), state, 0);
    
    out.write("</pre>\r\n");
    out.write("</div>\r\n");
    out.flush();
    return out.toString();
  }

  public void generate(Document doc, OutputStream xhtml, String name, String desc, int level, boolean adorn, String filename) throws Exception {
    adorn = true; // till the xml trick is working
    
		OutputStreamWriter out = new OutputStreamWriter(xhtml, "UTF-8");
		
    out.write("<div class=\"example\">\r\n");
    out.write("<p>"+Utilities.escapeXml(desc)+"</p>\r\n"); 
    if (adorn) {
      out.write("<pre class=\"xml\" style=\"white-space: pre; overflow: hidden\">\r\n");
      out.write("&lt;?xml version=\"1.0\" encoding=\"UTF-8\"?&gt;\r\n");
      out.write("\r\n");

      XhtmlGeneratorAdornerState state = null; // adorner == null ? new XhtmlGeneratorAdornerState("", "") : adorner.getState(this, null, null);
	  	for (int i = 0; i < doc.getChildNodes().getLength(); i++)
	  		writeNode(out, doc.getChildNodes().item(i), state, level);
      out.write("</pre>\r\n");
    } else {
      out.write("<code class=\"xml\" style=\"white-space: pre; overflow: hidden\">\r\n");
      for (int i = 0; i < doc.getChildNodes().getLength(); i++)
        writeNodePlain(out, doc.getChildNodes().item(i), level);
      
      out.write("</code>\r\n");      
    }
    out.write("</div>\r\n");
		out.flush();
	}

  private void writeNodePlain(Writer out, Node node, int level) throws FHIRException, DOMException, IOException  {
    if (node.getNodeType() == Node.ELEMENT_NODE)
      writeElementPlain(out, (Element) node, level);
    else if (node.getNodeType() == Node.TEXT_NODE)
      writeTextPlain(out, (Text) node, level);
    else if (node.getNodeType() == Node.COMMENT_NODE)
      writeCommentPlain(out, (Comment) node, level);
    else if (node.getNodeType() == Node.PROCESSING_INSTRUCTION_NODE)
      writeProcessingInstructionPlain(out, (ProcessingInstruction) node);
    else if (node.getNodeType() != Node.ATTRIBUTE_NODE)
      throw new FHIRException("Unhandled node type");
  }

	private void writeNode(Writer out, Node node, XhtmlGeneratorAdornerState state, int level) throws Exception {
		if (node.getNodeType() == Node.ELEMENT_NODE)
			writeElement(out, (Element) node, state, level);
		else if (node.getNodeType() == Node.TEXT_NODE)
			writeText(out, (Text) node, level);
		else if (node.getNodeType() == Node.COMMENT_NODE)
			writeComment(out, (Comment) node, level);
		else if (node.getNodeType() == Node.PROCESSING_INSTRUCTION_NODE)
			writeProcessingInstruction(out, (ProcessingInstruction) node);
		else if (node.getNodeType() != Node.ATTRIBUTE_NODE)
			throw new FHIRException("Unhandled node type");
	}

  private void writeProcessingInstruction(Writer out, ProcessingInstruction node) {
    
    
  }

  private void writeProcessingInstructionPlain(Writer out, ProcessingInstruction node) {
    
    
  }

  private void writeComment(Writer out, Comment node, int level) throws DOMException, IOException {
    String cmt = node.getTextContent();
    if (cmt.contains(":md:"))
      cmt = processMarkdown(cmt.replace(":md:", ""));
    else
      cmt = escapeHtml(cmt, level);
    out.write("<span class=\"xmlcomment\">&lt;!-- "+cmt+" --&gt;</span>");
  }

  private void writeCommentPlain(Writer out, Comment node, int level) throws DOMException, IOException {
    String cmt = node.getTextContent();
    if (cmt.contains(":md:"))
      cmt = processMarkdown(cmt.replace(":md:", ""));
    else
      cmt = Utilities.escapeXml(cmt);
    out.write("<!-- "+cmt+" -->");
  }

  private String processMarkdown(String text) {
    return new MarkDownProcessor(Dialect.COMMON_MARK).process(text, "Xhtml generator");
  }

  private void writeText(Writer out, Text node, int level) throws DOMException, IOException {
    out.write("<b>"+escapeHtml(Utilities.escapeXml(node.getTextContent()), level)+"</b>");
  }

  private void writeTextPlain(Writer out, Text node, int level) throws DOMException, IOException {
    out.write(Utilities.escapeXml(node.getTextContent()));
  }

  private void writeElement(Writer out, Element node, XhtmlGeneratorAdornerState state, int level) throws Exception {
    String link = adorner == null ? null : adorner.getLink(this, state, node);
    if (link != null)
      out.write("<span class=\"xmltag\">&lt;<a href=\""+link+"\" class=\"xmltag\">"+node.getNodeName()+"</a></span>");
    else
      out.write("<span class=\"xmltagred\">&lt;"+node.getNodeName()+"</span>");
    if (node.hasAttributes()) {
      out.write("<span class=\"xmlattr\">");
      out.write("<a name=\""+adorner.getNodeId(state, node)+"\"> </a>");
      
      XhtmlGeneratorAdornerState newstate = adorner == null ? new XhtmlGeneratorAdornerState(null, "", "") : adorner.getState(this, state, node);
      for (int i = 0; i < node.getAttributes().getLength(); i++) {
        if (i > 0)
          out.write(" ");
        if (adorner != null) {
          XhtmlGeneratorAdornerState attrState = adorner.getAttributeMarkup(this, newstate, node, node.getAttributes().item(i).getNodeName(), node.getAttributes().item(i).getTextContent());
          if (attrState.getAltText() != null) {
            out.write(node.getAttributes().item(i).getNodeName()+"=\"<span class=\"xmlattrvalue\">"+attrState.getPrefix()+escapeHtml(Utilities.escapeXml(attrState.getAltText()), level)+attrState.getSuffix()+"</span>\"");
          } else {
            out.write(node.getAttributes().item(i).getNodeName()+"=\"<span class=\"xmlattrvalue\">"+attrState.getPrefix()+escapeHtml(Utilities.escapeXml(node.getAttributes().item(i).getTextContent()), level)+attrState.getSuffix()+"</span>\"");
          }
        } else
          out.write(node.getAttributes().item(i).getNodeName()+"=\"<span class=\"xmlattrvalue\">"+escapeHtml(Utilities.escapeXml(node.getAttributes().item(i).getTextContent()), level)+"</span>\"");
      }
      out.write("</span>");

    }
    if (node.hasChildNodes()) {
      out.write("<span class=\"xmltag\">&gt;</span>");
      if (!node.hasAttributes())
        out.write("<a name=\""+adorner.getNodeId(state, node)+"\"> </a>");
      XhtmlGeneratorAdornerState newstate = adorner == null ? new XhtmlGeneratorAdornerState(null, "", "") : adorner.getState(this, state, node);
      if (newstate.isSuppress())
        out.write("<span class=\"xmlcomment\">&lt;!-- "+escapeHtml(newstate.getSupressionMessage(), level)+" --&gt;</span>");
      else {
        out.write(newstate.getPrefix());
        for (int i = 0; i < node.getChildNodes().getLength(); i++)
          writeNode(out, node.getChildNodes().item(i), newstate, level+2);

        out.write(newstate.getSuffix());
      }
      if (link != null)
        out.write("<span class=\"xmltag\">&lt;/<a href=\""+link+"\" class=\"xmltag\">"+node.getNodeName()+"</a>&gt;</span>");
      else
        out.write("<span class=\"xmltag\">&lt;/"+node.getNodeName()+"&gt;</span>");
    }
    else { 
      out.write("<span class=\"xmltag\">/&gt;</span>");
      if (!node.hasAttributes())
        out.write("<a name=\""+adorner.getNodeId(state, node)+"\"> </a>");
    }
    out.write("<a name=\""+adorner.getNodeId(state, node)+"-end\"> </a>");
	}
	
  private void writeElementPlain(Writer out, Element node, int level) throws IOException, FHIRException  {
    out.write("<"+node.getNodeName());
    if (node.hasAttributes()) {
      for (int i = 0; i < node.getAttributes().getLength(); i++) {
        out.write(" "+node.getAttributes().item(i).getNodeName()+"=\""+Utilities.escapeXml(node.getAttributes().item(i).getTextContent())+"\"");
      }
    }
    if (node.hasChildNodes()) {
      out.write(">");
      for (int i = 0; i < node.getChildNodes().getLength(); i++)
        writeNodePlain(out, node.getChildNodes().item(i), level+2);
      out.write("</"+node.getNodeName()+">");
    }
    else 
      out.write("/>");
  }
  
	private String escapeHtml(String doco, int indent) {
		if (doco == null)
			return "";
		
		int i = 0;
		StringBuilder b = new StringBuilder();
		for (char c : doco.toCharArray()) {
		  i++;
      if (c == '\r' || c == '\n')
        i = 0;
		  if ((i > LINE_LIMIT && c == ' ') || (i > LINE_LIMIT + 15)) {
		    b.append("\r\n");
		    for (int j = 0; j < indent; j++)
	        b.append(" ");
		    i = 0;		    
		  }
		  if (c == '<')
			  b.append("&lt;");
		  else if (c == '>')
			  b.append("&gt;");
		  else if (c == '&')
			  b.append("&amp;");
		  else if (c == '\t')
			  b.append("  ");
		  else if (c == '\'')
			  b.append("&apos;");
		  else if (c == '"')
			  b.append("&quot;");
		  else 
			  b.append(c);
		}		
		return b.toString();
	}	
}