/*
 *
 */
package xid;
import java.util.*;
import java.io.*;
import javax.xml.parsers.*;
import javax.xml.validation.Schema;
import org.xml.sax.*;
import org.w3c.dom.*;
/**
 *
 */
public class Presenter
{
  static protected org.apache.log4j.Logger log;

  static
  { 
    log = org.apache.log4j.Logger.getLogger (Presenter.class.getName ());
  }

  protected String webappPath;
  protected String sourceFileName;
  protected long sourceFileTime;
  protected Document doc;

  /*
   *
   */
  public Presenter ()
  {
    this.webappPath = null;
    this.sourceFileName = null;
    this.sourceFileTime = 0;
    this.doc = null;
  }


  /*
   *
   */
  public Presenter (String webappPath, String fileName)
  {
    this.webappPath = webappPath;
    this.sourceFileName = fileName;
    this.sourceFileTime = 0;
    this.doc = null;
  }


  /*
   *
   */
  public String getWebappPath ()
  {
    String result;

    result = this.webappPath;

    //
    return (result);
  }


  /*
   *
   */
  public void setSource (String fileName)
  {
    this.sourceFileName = fileName;
    this.sourceFileTime = 0;
    this.doc = null;
  }


  /*
   *
   */
  public String getSource ()
  {
    String result;

    result = this.sourceFileName;

    //
    return (result);
  }


  /*
   *
   */
  public StringBuffer doXid (TagsData datas, StringBuffer errorOutput)
  {
    StringBuffer result;

    String sourceFilePath = this.webappPath + File.separator + this.sourceFileName;

    // Get the good tree.
    File source = new File (sourceFilePath);

    if (source == null)
      {
	String errorMessage = "source file not defined";
	errorOutput.append (errorMessage);
	log.error (errorMessage);
	result = null;
      }
    else if (!source.exists ())
      {
	String errorMessage = "source file defined but not found (" + sourceFilePath + ")";
	errorOutput.append (errorMessage);
	log.error (errorMessage);
	result = null;
      }
    else if ((this.doc == null) ||
	     (this.sourceFileTime != source.lastModified ()))
      {
	this.sourceFileTime = source.lastModified ();
	this.doc = Presenter.fileToTree (sourceFilePath, errorOutput);

	if (this.doc != null)
	  {
	    Presenter.addMetaTag (doc, "generator", "XID 0.0");
	  }
      }

    // Build the web page.
    result = Presenter.doXid (doc, datas, this.webappPath, errorOutput);

    //
    return (result);
  }


  /*
   *
   */
  static public StringBuffer doXid (String fileName,  String webappPath, StringBuffer errorOutput)
  {
    StringBuffer result;

    Document doc = Presenter.fileToTree (fileName, errorOutput);

    if (doc == null)
      {
	result = null;
      }
    else
      {
	Presenter.addMetaTag (doc, "generator", "XID 0.0");
	
	result = Presenter.doXid (doc, null, webappPath, errorOutput);
      }

    //
    return (result);
  }


  /*
   *
   */
  static public StringBuffer doXid (Document doc, TagsData datas, String webappPath, StringBuffer errorOutput)
  {
    StringBuffer result;

    result = Presenter.process (doc, datas, webappPath, errorOutput);

    //
    return (result);
  }

  /*
   *
   */
  static public StringBuffer doXid (String html, TagsData datas, String webappPath, StringBuffer errorOutput)
  {
    StringBuffer result;

    Document doc = null;


    result = Presenter.process (doc, datas, webappPath, errorOutput);

    //
    return (result);
  }


  /*
   *
   */
  static public String getClassAttributeValue (Node node)
  {
    String result;
    
    NamedNodeMap attributes = node.getAttributes ();
    if (attributes == null)
      {
	result = null;
      }
    else
      {
	Node nameAttribute = attributes.getNamedItem ("class");
	
	if (nameAttribute == null)
	  {
	    result = null;
	  }
	else
	  {
	    result = nameAttribute.getNodeValue ();
	  }
      }

    //
    return (result);
  }


  /*
   *
   */
  static protected StringBuffer processChildren (Node node, TagsData datas,  String webappPath, StringBuffer errorOutput)
  {
    StringBuffer result;

    result = new StringBuffer ();
    
    NodeList children = node.getChildNodes();
    
    if (children == null)
      {
	result.append (" ");
      }
    else
      {
	int childrenCount = children.getLength ();
	
	for (int i = 0; i < childrenCount; i++)
	  {
	    result.append (process (children.item(i), datas, webappPath, errorOutput));
	  }
      }

    //
    return (result);
  }



  /**
   * Includes another HSP file into the current page.
   * 
   * @param node
   * @param attrMap
   * @param idAttr
   */
  static protected StringBuffer processObjectTag (Node node, NamedNodeMap attrMap, Node idAttr, TagsData datas,  String webappPath, StringBuffer errorOutput)
  {
    StringBuffer result;

    result = new StringBuffer ();

    // Find codetype.
    String codetype;
    if (attrMap == null)
      {
	codetype = null;
      }
    else if (attrMap.getNamedItem ("codetype") == null)
      {
	codetype = null;
      }
    else
      {
	codetype = attrMap.getNamedItem ("codetype").getNodeValue ();
      }


    // Check tag requirements.
    if ((attrMap == null) ||
	(codetype == null) ||
	(!codetype.equals ("application/xid")) ||
	(attrMap.getNamedItem ("data") == null))
      {
	// STU: do default action.
	Presenter.processElementBasically (node, datas, webappPath, errorOutput);
      }
    else
      {
	log.info ("object action");
	result.append ("<!-- STARTING INCLUDE XID FILE " + attrMap.getNamedItem ("data") + " -->");

	// Build the file name.
	String htmlFileName = webappPath + attrMap.getNamedItem ("data").getNodeValue ();
	

	// Load file in tree.
	Document childDoc = null;
	try
	  {
	    childDoc = fileToTree (htmlFileName, errorOutput);
	  }
	catch (Exception ex)
	  {
	    result.append ("unable to build the file tree");
	    log.info ("unable to build the file tree");
	  }
	
	// Extract the 'body' section.
	Node body = null;
	try
	  {
	    NodeList nodes = childDoc.getElementsByTagName ("body");
	    
	    if (nodes.getLength () == 0)
	      {
		result.append ("no body tag in include html");
		log.info ("no body tag in include html");
	      }
	    else
	      {		
		  body = nodes.item(0);
	      }
	  }
	catch (Exception e)
	  {
	    result.append ("error getting child");
	    log.info ("error getting child");
	  }
	
	// Process the body child as part of the primary tree.
	NodeList bodyChildren = body.getChildNodes ();

	if (bodyChildren != null)
	  {
	    int childCount = bodyChildren.getLength ();
	    for (int childCounter = 0; childCounter < childCount; childCounter++)
	      {
		result.append (process (bodyChildren.item (childCounter), datas, webappPath, errorOutput));
	      }
	  }

	//
	result.append ("<!-- ENDING INCLUDE XID FILE " + attrMap.getNamedItem ("data") + " -->");
      }
    log.info ("end of object action");
    //
    return (result);
  }

  

  /**
   * Processes a node that has dynamic content. Calls the appropriate code
   * generator method, depending on the tag.
   * 
   * @param node
   *            Current node.
   * @param attrs
   *            The tag attributes.
   * @param idAttr
   *            The ID.
   */
  static protected StringBuffer processElementWithId (Node node,
						      NamedNodeMap attrs,
						      Node idAttr,
						      TagsData datas,
						      String webappPath,
						      StringBuffer errorOutput)
  {
    StringBuffer result;
    result = new StringBuffer ();

    String tag = node.getNodeName();
    String idValue = idAttr.getNodeValue();

    log.info ("tag=" + tag);
    
    // Get data of this id.
    TagData data = datas.get (idAttr.getNodeValue ());
    String theClass;
    if (data == null)
      {
	theClass = null;
      }
    else
      {
	theClass = data.getAttributes ().getAttribute ("class");
      }

    if ((theClass == null) ||
	(!theClass.equals ("xid:nodisplay")))
      {
	if ((tag.equals ("a")) ||
	    (tag.equals ("b")) ||
	    (tag.equals ("div")) ||
	    (tag.equals ("em")) ||
	    (tag.equals ("p")) ||
	    (tag.equals ("span")))
	  {
	    // Open the tag.
	    result.append ('<');
	    result.append (node.getNodeName());
	    
	    // Build the tag attributes.
	    result.append (processAttributes (attrs, data));
	    //result.append (attributesFromNode (attrs));
	    //result.append (attributesFromTagData (data));
	    
	    result.append ('>');
	    
	    // Insert data.
	    if ((data == null) ||
		(data.display ().equals ("")))
	      {
		result.append (processChildren (node, datas, webappPath, errorOutput));
	      }
	    else
	      {
		result.append (data.display ());
	      }

	    // Close the tag.
	    result.append ("</");
	    result.append (node.getNodeName());
	    result.append ('>');
	  }
	else if (tag.equals("img"))
	  {
	    // Possibility to merge with previous case if <div /> is a correct tag.

	    // Open the tag.
	    result.append ("<");
	    result.append (node.getNodeName());
	    
	    // Build the tag attributes.
	    result.append (processAttributes (attrs, data));
	    //result.append (attributesFromNode (attrs));
	    //result.append (attributesFromTagData (data));
	    
	    result.append ("/>");
	  }
	else if (tag.equals("textarea"))
	  {
	    result.append ("[textarea]");
	  }
	else if (tag.equals("select"))
	  {
	    result.append ("[select]");
	  }
	else if (tag.equals("input"))
	  {
	    result.append ("[input]");
	  }
	else if (tag.equals("table"))
	  {
	    result.append ("[table]");
	  }
	else if (tag.equals("tbody"))
	  {
	    result.append ("[tbody]");
	  }
	else if (tag.equals("object"))
	  {
	    result.append (processObjectTag (node, attrs, idAttr, datas, webappPath, errorOutput));
	  }
	else
	  {
	    log.info ("Id on <" + tag + "> not supported.");
	  }
      }

    //
    log.info ("Exit");
    return (result);
  }



  /**
   * Recursive method that processes a node and any child nodes.
   * 
   */
  static protected StringBuffer process (Node node, TagsData datas,  String webappPath, StringBuffer errorOutput)
  {
    log.info ("Enter");
    String TRANSITIONAL_DTD = "xhtml1-transitional.dtd";
    String TRANSITIONAL_DOCTYPE = "<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 "
      + "Transitional//EN\" \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\">\n";

    StringBuffer result;
    result = new StringBuffer ();

    // Is there anything to do?
    if (node != null)
      {
	log.info ("nodeName=" + node.getNodeName ());

	// Find the name attribute value.
	String name;
	name = getClassAttributeValue (node);

	if ((name == null) ||
	    ((name != null) &&
	     (!name.equals ("xid:nodisplay"))))
	  {
	    int type = node.getNodeType();
	    switch (type)
	      {
	      case Node.DOCUMENT_NODE:
		{
		  log.info ("case Node.DOCUMENT_NODE");
		  DocumentType dt = ((Document) node).getDoctype();
		  String publicId = dt.getPublicId();
		  String systemId = dt.getSystemId();
		  
		  if (systemId.equals(TRANSITIONAL_DTD))
		    {
		      result.append(TRANSITIONAL_DOCTYPE);
		    }
		  
		  // Log.write(Log.TRACE,"publicId = " + publicId);
		  // Log.write(Log.TRACE,"systemId = " + systemId);
		  
		  result.append (Presenter.process (((Document) node).getDocumentElement(), datas, webappPath, errorOutput));
		  
		  break;
		}
		
	      case Node.ELEMENT_NODE:
		{
		  log.info ("case Node.ELEMENT_NODE");
		  
		  NamedNodeMap attrs = node.getAttributes ();
		  Node idAttr = attrs.getNamedItem ("id");
		  
		  if (idAttr != null)
		    {
		      result.append (Presenter.processElementWithId (node, attrs, idAttr, datas, webappPath, errorOutput));
		    }
		  else
		    {
		      result.append (Presenter.processElementBasically (node, datas, webappPath, errorOutput));
		    }
		  
		  break;
		}
		
		// handle entity reference nodes
	      case Node.ENTITY_REFERENCE_NODE:
		{
		  log.info ("case Node.ENTITY_REFERENCE_NODE");
		  
		  result.append ('&');
		  result.append (node.getNodeName());
		  result.append (';');
		  break;
		}
		
		// print cdata sections
	      case Node.CDATA_SECTION_NODE:
		{
		  log.info ("case Node.CDATA_SECTION_NODE");
		  
		  result.append ("<![CDATA[");
		  result.append (node.getNodeValue());
		  result.append ("]]>");
	      
		  break;
		}
	    
		// print text
	      case Node.TEXT_NODE:
		{
		  log.info ("case Node.TEXTE_NODE");
		  result.append (restoreEntities (new StringBuffer(node.getNodeValue())));
		  break;
		}

		// print processing instruction
	      case Node.PROCESSING_INSTRUCTION_NODE:
		{
		  log.info ("Node.PROCESSING_INSTRUCTION_NODE");

		  result.append ("<?");
		  result.append (node.getNodeName());
		  String data = node.getNodeValue();
		  if ((data != null) && (data.length () > 0))
		    {
		      result.append (' ');
		      result.append (data);
		    }
		  result.append ("?>");
		  break;
		}
	      }
	  }
      }

    //
    //log.info ("result=" + result);
    log.info ("Exit");
    return (result);
  }
  

  /*
   */
  static StringBuffer processElementBasically (Node node, TagsData datas,  String webappPath, StringBuffer errorOutput)
  {
    StringBuffer result;
    result = new StringBuffer ();

    // Open the tag.
    result.append ('<');
    result.append (node.getNodeName());
    
    // Build the tag attributes.
    NamedNodeMap attrs = node.getAttributes ();
    if (attrs != null)
      {
	for (int i = 0; i < attrs.getLength(); i++)
	  {
	    Attr attr = (Attr) attrs.item(i);
	    result.append (' ');
	    result.append (attr.getNodeName());
	    result.append ("=\"");
	    result.append (restoreEntities(new StringBuffer(attr.getNodeValue())));
	    result.append ("\"");
	  }
	

	//
	NodeList children = node.getChildNodes();
	if (children == null)
	  {
	    result.append(" />");
	  }
	else
	  {
	    int childrenCount = children.getLength ();
	    
	    if (childrenCount == 0)
	      {
		result.append(" />");
	      }
	    else
	      {
		result.append('>');
		
		for (int i = 0; i < childrenCount; i++)
		  {
		    result.append (process (children.item(i), datas, webappPath, errorOutput));
		  }
		
		result.append("</");
		result.append(node.getNodeName());
		result.append('>');
	      }
	  }
      }
   
    
    //
    return (result);
  }



  /*
   *
   */
  static protected Document fileToTree (String fileName, StringBuffer errorOutput)
  {
    Document result;

    File source = new File (fileName);

    if (source == null)
      {
	String errorMessage = "source file not defined (null)";
	errorOutput.append (errorMessage);
	log.error (errorMessage);
	result = null;
      }
    else if (!source.exists ())
      {
	String errorMessage = "source file not found (" + fileName + ")";
	errorOutput.append (errorMessage);
	log.error (errorMessage);
	result = null;
      }
    else
      {
	try
	  {
	    // Create a DocumentBuilderFactory and configure it.
	    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance ();
	    
	    // Set various configuration options.
	    dbf.setValidating (true);
	    dbf.setIgnoringComments (true);
	    dbf.setIgnoringElementContentWhitespace (false);
	    dbf.setCoalescing (false);
	    
	    // Keep entity references as they are.
	    dbf.setExpandEntityReferences(false);
	    
	    // Create a DocumentBuilder that satisfies the constraints
	    // specified by the DocumentBuilderFactory.
	    DocumentBuilder db = dbf.newDocumentBuilder ();
	    
	    ParserErrorHandler errorHandler;
	    errorHandler = new ParserErrorHandler();
	    
	    // Set the error handler.
	    db.setErrorHandler (errorHandler);
	    
	    Schema schema = db.getSchema ();
	    log.info ("schema=" + schema);
	    
	    // Parse the input file.
	    result = db.parse (fileName);

	    if (errorHandler.hasError ())
	      {
		errorOutput.append (errorHandler.toString ());
	      }	    
	  }
	catch (ParserConfigurationException exception)
	  {
	    String errorMessage = "Parser configuration exception: " + exception.getMessage ();
	    errorOutput.append (errorMessage);
	    log.error (errorMessage);
	    result = null;
	  }
	catch (SAXException exception)
	  {
	    String errorMessage = "Error during SAX parsing: " + exception.getMessage ();
	    errorOutput.append (errorMessage);
	    log.error (errorMessage);
	    result = null;
	  }
	catch (IOException exception)
	  {
	    String errorMessage = "IOError during parsing." + exception.getMessage ();
	    errorOutput.append (errorMessage);
	    log.error (errorMessage);
	    result = null;
	  }
      }

    //
    return (result);
  }



  /*
   *
   */
  static protected void addMetaTag (Document doc, String name, String content)
  {
    // Find head tag.
    
    Node headNode = Presenter.findHeadNode (doc);
    
    Node metaNode = doc.createElement ("meta");
    
    NamedNodeMap attrMap = metaNode.getAttributes();
    Node attrNode = doc.createAttribute("name");
    attrMap.setNamedItem(attrNode);
    attrNode.setNodeValue(name);
    
    attrNode = doc.createAttribute("content");
    attrMap.setNamedItem(attrNode);
    attrNode.setNodeValue(content);
    headNode.insertBefore(metaNode, headNode.getFirstChild());
  }


  /**
   * Finds the node containing the &lt;head&gt; tag.
   * 
   * @param node
   *            Document node.
   * @return The head tag node
   */
  static protected Node findHeadNode (Node node)
  {
    Node headNode = null;
    
    int type = node.getNodeType();
    switch (type)
      {
	// print document
      case Node.DOCUMENT_NODE:
	{
	  headNode = findHeadNode(((Document) node).getDocumentElement());
	  break;
	}
	
      case Node.ELEMENT_NODE:
	{
	  String tag = node.getNodeName();
	  
	  if ("head".equals(tag))
	    {
	      headNode = node;
	      break;
	    }
	  
	  NodeList children = node.getChildNodes();
	  int numChildren = 0;
	  
	  if (children != null)
	    numChildren = children.getLength();
	  
	  for (int i = 0; i < numChildren; i++)
	    {
	      headNode = findHeadNode(children.item(i));
	      if (headNode != null)
		break;
	    }
	  break;
	}
      }
    return headNode;
  }


  /**
   * Any ampersand lt;, ampersand gt; and ampersand amp; sequences in text
   * nodes get read in as symbols. This method converts them back to entities.
   * 
   * @param s String that is to have the entities restored..
   * @return The processed string.
   */
  static public String restoreEntities (StringBuffer s)
  {
    String result;

    if (s == null)
      {
	result = null;
      }
    else
      {
	StringBuffer str = new StringBuffer();
	
	int len = (s != null) ? s.length() : 0;
	for (int i = 0; i < len; i++)
	  {
	    char ch = s.charAt(i);
	    switch (ch)
	      {
	      case '<':
		{
		  str.append("&lt;");
		  break;
		}
		
	      case '>':
		{
		  str.append("&gt;");
		  break;
		}
		
	      case '&':
		{
		  str.append("&amp;");
		  break;
		}
		
	      default:
		{
		  str.append(ch);
		}
	      }
	  }
	result = str.toString ();
      }


    //
    return (result);
  }


  /**
   * Get the text for an element. Converts new lines to spaces.
   *
   * @param node
   */
  static protected String getElementText (Node node)
  {
    String result;
    result = ""; // Grrrr, Java ...

    NodeList children = node.getChildNodes();
    if (children == null)
      {
	result = "";
      }
    else
      {
	boolean ended = false;
	int childCounter = 0;
	int childCount = children.getLength ();
	while (!ended)
	  {
	    if (childCounter >= childCount)
	      {
		ended = true;
		result = "";
	      }
	    else
	      {
		Node child = children.item (childCounter);
		if (child.getNodeType () == Node.TEXT_NODE)
		  {
		    result = newLinesToSpaces (child.getNodeValue ()); // STU (+=, newLines...)
		    ended = true;
		  }
		else
		  {
		    childCounter += 1;
		  }
	      }
	  }
      }

    //
    return (result);
  }


  /**
   * Converts New Line characters to spaces. This is used when for example
   * the text in a div tag goes over serveral lines.
   *
   * @param text String
   * @return String
   */
  static protected String newLinesToSpaces (String text)
  {
    StringBuffer result = new StringBuffer (text);
    
    for (int i = 0; i < result.length(); i++)
      {
	if (result.charAt (i) == '\n')
	  {
	    result.setCharAt (i,' ');
	  }
      }
    
    //
    return (result.toString());
  }


  /*
   *
   */
  static protected StringBuffer processAttributes (NamedNodeMap attrs, TagData model)
  {
    StringBuffer result;

    result = new StringBuffer ();

    // Build the original attributes list.
    HashMap<String, String> mergedAttributes;
    mergedAttributes = new HashMap<String, String> ();
    for (int attributeCounter = 0; attributeCounter < attrs.getLength(); attributeCounter++)
      {
	Attr attr = (Attr) attrs.item (attributeCounter);
	mergedAttributes.put (attr.getNodeName(), attr.getNodeValue ());
      }


    // Put model attributes in the merged attributes list.
    if (model != null)
      {
	Attributes modelAttributes = model.getAttributes();
	
	if (modelAttributes != null)
	  {
            Iterator iterator = modelAttributes.entrySet().iterator();
	    
            while (iterator.hasNext())
	      {
                Map.Entry<String, String> attribute = (Map.Entry<String, String>) iterator.next();
		
                if (mergedAttributes.containsKey (attribute.getKey ()))
		  {
		    if (attribute.getKey ().equalsIgnoreCase ("style"))
		      {
			mergedAttributes.put (attribute.getKey (), mergedAttributes.get (attribute.getKey ()) + attribute.getValue ());
		      }
		    else
		      {
			mergedAttributes.put (attribute.getKey (), attribute.getValue ());
		      }
		  }
		else
		  {
		    mergedAttributes.put (attribute.getKey (), attribute.getValue ());
		  }
	      }
	  }
      }

    
    // Display the attributes
    Iterator iterator = mergedAttributes.entrySet().iterator();
    while (iterator.hasNext ())
      {
	Map.Entry<String, String> attribute = (Map.Entry<String, String>) iterator.next();
	result.append(" " + attribute.getKey () + "=\"" + attribute.getValue ()+ "\"");
      }    
    
    //
    return (result);    
  }
}