/*      QuestionEditor.java
 *      August 3, 2003
 */
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.net.*;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.event.*;
import java.util.*;
 
import javax.xml.transform.*;
import javax.xml.transform.dom.*;
import javax.xml.transform.stream.*;
import org.w3c.dom.*;
 
/**     QuestionEditor
 */
public class QuestionEditor extends JFrame implements ActionListener, CaretListener{
 
    private int index = 0;
    private File[] files;
    private JTextPane viewer;
    private JTextArea display;
    private String stylesheetFileName = "WebQuestionViewer.xsl";
    public QuestionEditor(){
        super("QuestionEditor");
        init();
    }
    
    public static void main(String[] args){
        new QuestionEditor();
    }
    
    public void init(){
        
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);     
 
 
        viewer = new JTextPane();
        viewer.setContentType("text/html");
        viewer.setEditable(false);
        JScrollPane viewerPane = new JScrollPane(viewer);
        Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
        Dimension viewerSize = new Dimension(screenSize.width, screenSize.height*8/10);
        viewerPane.setPreferredSize(viewerSize);
        
        display = new JTextArea();
        display.setEditable(true);
        display.addCaretListener(this);
        JScrollPane editorPane = new JScrollPane(display);
        editorPane.setPreferredSize(viewerSize);
        
        JPanel controlPanel = new JPanel();
        
        JButton selectFilesButton = new JButton("Select Files");
        selectFilesButton.addActionListener(this);
        controlPanel.add(selectFilesButton);
        
        JButton previousButton = new JButton("Previous");
        previousButton.addActionListener(this);
        controlPanel.add(previousButton);
        
        JButton nextButton = new JButton("Next");
        nextButton.addActionListener(this);
        controlPanel.add(nextButton);
 
        JButton refreshButton = new JButton("Refresh");
        refreshButton.addActionListener(this);
        controlPanel.add(refreshButton);
        
        JButton saveButton = new JButton("Save");
        saveButton.addActionListener(this);
        controlPanel.add(saveButton);
        
        JButton exitButton = new JButton("Exit");
        exitButton.addActionListener(this);
        controlPanel.add(exitButton);
 
        JTabbedPane tabbedPane = new JTabbedPane(JTabbedPane.TOP);
        tabbedPane.addTab("View", viewerPane);
        tabbedPane.addTab("Edit", editorPane);
        
        getContentPane().add(tabbedPane, BorderLayout.CENTER);
        getContentPane().add(controlPanel, BorderLayout.SOUTH);
        pack();
        setLocationRelativeTo(null);
        show();
        
    }
    
    public void actionPerformed(ActionEvent actionEvent){
        String actionCommand = actionEvent.getActionCommand();
 
        if (actionCommand.equals("Refresh")) {
            edit();
        }else if (actionCommand.equals("Exit")) {
            System.exit(0);
        }else if (actionCommand.equals("Previous")) {
            index= index -1;
            if (index < 0) index = files.length - 1;
            edit();
        }else if (actionCommand.equals("Next")) {
            index++;
            if (index >= files.length) index = 0;
            edit();
        }else if (actionCommand.equals("Save")) {
            if (files != null){
                try{
                    FileWriter fw = new FileWriter(files[index]);
                    fw.write(display.getText());
                    fw.close();
                }catch (FileNotFoundException fnfe){
                    System.err.println("FileNotFoundException: " + fnfe.getMessage());
                }catch (IOException ioe){
                    System.err.println("IOException: " + ioe.getMessage());
                }
            }
        }else if (actionCommand.equals("Select Files")) {
            files = getFiles();
            if (files != null){
                index= 0;
                edit();
            }
        }
    }  
    
    public void caretUpdate(CaretEvent e){
        viewer.setText(transform(display.getText()));
        viewer.setCaretPosition(0);
    }
    
    private void edit(){
        if (files != null){
            display.setText("");
            display.setBorder(new TitledBorder(files[index].getName()));
            viewer.setBorder(new TitledBorder(files[index].getName()));
 
            try{
                FileReader fr = new FileReader(files[index]);
                BufferedReader br = new BufferedReader(fr);
                String nextLine = "";
                String xml = "";
                while ((nextLine = br.readLine()) != null){
                    xml = xml + nextLine + "\n";
                }
                fr.close();
                br.close();
                display.setText(xml);
                display.setCaretPosition(0);
            }catch (FileNotFoundException fnfe){
                System.err.println("FileNotFoundException: " + fnfe.getMessage());
            }catch (IOException ioe){
                System.err.println("IOException: " + ioe.getMessage());
            }
 
        }else{
            if (files == null)display.append("No files selected.\n");
        }    
    }
    
    private File[] getFiles(){
        display.setText("");
        files = null;
        JFileChooser fileChooser = new JFileChooser();
        fileChooser.setCurrentDirectory(new File("k:\\OPS_TRAINING\\Exambank"));
        fileChooser.setMultiSelectionEnabled(true);
        fileChooser.setFileFilter(new XMLFileFilter());
        if (fileChooser.showDialog(this, "Select xml files") == JFileChooser.APPROVE_OPTION ){
            files = fileChooser.getSelectedFiles();
        }        
        return files;
    }
    
    /**	Transform all document into html using an xsl stylesheet.
    *	Output is a string.
    */
    public String transform(String xmlText){
        String htmlstring = "";
        try{
            if (xmlText.length() > 0){
                StreamSource source = new StreamSource(new StringReader(xmlText));
                StringWriter stringwriter = new StringWriter();
                TransformerFactory transformerfactory = TransformerFactory.newInstance();
                StreamSource stylesheet = new StreamSource(new File(stylesheetFileName));
                Transformer transformer = transformerfactory.newTransformer(stylesheet);
                transformer.transform(source, new StreamResult(stringwriter));
                htmlstring = stringwriter.toString();
            }
        }catch (TransformerConfigurationException tce){
                System.err.println("TransformerConfigurationException: " + tce.getMessage());
        }catch (TransformerException te){
                System.err.println("TransformerException: " + te.getMessageAndLocation());
        }catch (Exception exception) {
                System.err.println("Exception: " + exception.getMessage());
        }
        return htmlstring;
    }
 
    
    class XMLFileFilter extends javax.swing.filechooser.FileFilter{
        public boolean accept(File file){
            return (file.isDirectory() || (file.getName().toLowerCase().indexOf(".xml") > 0));
        }
        public String getDescription(){
            return "xml files";
        }
    }
}