/*
 * ViewerPlugin.java
 * Created on 26 April 2005
 * Author: Mashooq Badar
 */

package com.valtech.wiki.excel;

import java.util.Map;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.Transformer;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.stream.StreamSource;
import javax.xml.transform.dom.DOMSource;
import org.apache.xml.serialize.OutputFormat;
import org.apache.xml.serialize.XMLSerializer;
import javax.xml.parsers.*;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import com.ecyrd.jspwiki.WikiContext;
import com.ecyrd.jspwiki.plugin.WikiPlugin;
import com.ecyrd.jspwiki.plugin.PluginException;
import java.io.*;
import org.apache.log4j.Logger;

import jxl.*; 
import org.w3c.dom.*;

/**
 * Given an excel file 
 * @author Mashooq Badar
 * excel=<excel file>    absolute path to the excel file to view
 */
public class ViewerPlugin implements WikiPlugin {
    private static final Logger log = Logger.getLogger(ViewerPlugin.class);
    private final String XSL = "ToHTML.xsl";
   
    public String execute(WikiContext context, Map params) throws PluginException {
        // Get the names of the XML and XSL files to use
        String excel = (String)params.get("excel");
        String root = context.getEngine().getRootPath() == null? "" : context.getEngine().getRootPath();
        File excelFile = new File(excel);
        if (!excelFile.exists()) {
         return "Excel file (" + excelFile.getPath() + ") does not exist!";
        }
        File excelXMLFile = new File(excel + ".xml");
        
        File xslFile = new File(root, XSL);
        if (!xslFile.exists()) {
         return "XSL file (" + xslFile.getPath() + ") does not exist!";
        }
             
        String result = "";       
        try {           
            // Create a Transformer
            TransformerFactory transformerFactory = TransformerFactory.newInstance();
            Transformer transformer = transformerFactory.newTransformer(new StreamSource(xslFile));
            
            String sheet = context.getHttpParameter("sheet") == null ? "" : context.getHttpParameter("sheet");
            String page = context.getPage().getName() == null ? "" : context.getPage().getName();
            
            transformer.setParameter("sheet", sheet);
            transformer.setParameter("page", page);
            transformer.setParameter("excel", excelFile.getName());
            transformer.setParameter("uri", context.getHttpRequest().getRequestURI());
            
            // Transform the given XML file using the given XSL file, placing it in a String.
            if (!excelXMLFile.exists() || excelXMLFile.lastModified() < excelFile.lastModified()) {
               Document dom = exportToXML(excelFile);
               OutputFormat format = new OutputFormat(dom);
               FileWriter writer = new FileWriter(excelXMLFile);
               XMLSerializer toFile = new XMLSerializer(writer, format);
               toFile.serialize(dom);
               writer.close();
            }
            
            StringWriter resultWriter = new StringWriter();
            transformer.transform(new StreamSource(excelXMLFile), new StreamResult(resultWriter));
            
            result = resultWriter.toString();
        } catch( Exception e ) {
            System.out.println( e.toString() );
            throw new PluginException("Exception performing export spreadsheet.", e);
        }
        
        return result;
    }
    
    public Document exportToXML(File excelFile) throws Exception {
       DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
       DocumentBuilder builder = factory.newDocumentBuilder();
       factory.setNamespaceAware(true);
       Document dom = builder.newDocument();
       
       
       Workbook workbook = Workbook.getWorkbook(excelFile); 
       
       Element workbookElm = dom.createElement("workbook");
       dom.appendChild(workbookElm);
       
       for (int i=0; i<workbook.getNumberOfSheets(); i++) {
          Sheet sheet = workbook.getSheet(i);
          
          Element table = dom.createElement("sheet");
          workbookElm.appendChild(table);
          table.setAttribute("name", sheet.getName());
          
          int rowCount = sheet.getRows();
          for (int j=0; j<rowCount; j++) {
             Element row = dom.createElement("row");
             table.appendChild(row);
             
             Cell[] cells = sheet.getRow(j);
             for (int x=0; x<cells.length; x++) {
               Element column = dom.createElement("column");
               row.appendChild(column);
               
               Text value = dom.createTextNode(cells[x].getContents());
               column.appendChild(value);
             }
          }
       }
       return dom;
    }
}