import org.xml.sax.Attributes;
import org.xml.sax.XMLReader;
import org.xml.sax.SAXException;
import org.xml.sax.InputSource;
import org.xml.sax.helpers.DefaultHandler;
import org.xml.sax.helpers.XMLReaderFactory;
import java.io.FileReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Properties;
import javax.swing.JFrame;
import javax.swing.JFileChooser;
import javax.swing.JOptionPane;

public class pmReadXML extends DefaultHandler
{
	
	private final String[] strReadTags = {"name", "email", "age", "des", "pic"};
	private final String strFileType = "Demonisch user profile";
	
	private boolean getFileType = false;
	private boolean readData = false;
	private boolean notProfileFile = false;
	
	private String strCurrentTag = "";
		
	private File file = null;
	private Properties props = null;
	private JFrame mainApp = null;
	
	public File getFile ()
	{
		return file;
	}
	
	public Properties getProperties ()
	{
		return props;
	}
	
	public pmReadXML (JFrame mainApp)
	{
		this.mainApp = mainApp;
	}
	
	public boolean open () throws dialogueException
	{
		
		String strFile = "";
		JFileChooser fileOpen = new JFileChooser();
		boolean validFile = false;
		
		do
		{
		
			fileOpen.addChoosableFileFilter(new fileTypeXML());
			fileOpen.setAcceptAllFileFilterUsed(false);
			fileOpen.setCurrentDirectory(new File(System.getProperty("user.dir")));
			fileOpen.setApproveButtonToolTipText("Open this profile");
			fileOpen.setDialogType(JFileChooser.OPEN_DIALOG);
			fileOpen.setDialogTitle("Open Profile");
			
			int returnValue = fileOpen.showDialog(mainApp, "Open");
			
			if (returnValue == JFileChooser.APPROVE_OPTION)
			{
				
				strFile = fileOpen.getSelectedFile().getAbsolutePath();
				String strExt = pmValidData.getFileExt(strFile);
				
				if (strExt.equals(""))
				{
					
					strExt = "xml";
					strFile += ".xml";
					
				}
				
				if (!strExt.equalsIgnoreCase("xml"))
				{
					throw new dialogueException("The selected file is not an xml document\n" + strFile, "Invalid file format", JOptionPane.WARNING_MESSAGE);
				}
				
				file = new File(strFile);
				
				if (file.exists())
				{
					validFile = true;
				}					
				else
				{
					throw new dialogueException("The specified file does not exist\n" + file.getAbsolutePath(), "Could not find file", JOptionPane.WARNING_MESSAGE);
				}
				
			}
			else
			{
				return false;
			}
			
		}
		while (!validFile);
		
		props = new Properties();
		XMLReader xr = null;
		
		try
		{
			xr = XMLReaderFactory.createXMLReader();
		}
		catch (SAXException ex)
		{
			throw new dialogueException("An internal error occured when an xml parser could not be created", "Critical Error", JOptionPane.ERROR_MESSAGE);
		}
		
		xr.setContentHandler(this);
		
		try
		{			
			xr.parse(new InputSource(new FileReader(file)));		
		}
		catch (FileNotFoundException ex) //Should never hapen
		{
				throw new dialogueException("The specified file does not exist\n" + file.getAbsolutePath(), "Could not find file", JOptionPane.WARNING_MESSAGE);
		}
		catch (IOException ex)
		{
			throw new dialogueException("ACould not read from the file\n" + file.getAbsolutePath(), "Error reading from file", JOptionPane.ERROR_MESSAGE);
		}
		catch (SAXException ex)
		{
			//Because extending the methods, can not throw the dialogueException from the defaultHandler methods
			//Instead set the boolean flag, throw a SAXException and check it here
			if (notProfileFile)
			{
				throw new dialogueException("This is not a valid user profile for the Demonisch profileMaker", "Invalid File Format", JOptionPane.ERROR_MESSAGE);
			}
			
			throw new dialogueException("The profile document contains syntax errors. If you understand xml then try to fix the document\nOtherwise overwrite it with a new profile\n" + ex.getMessage(), "Corrupt File", JOptionPane.ERROR_MESSAGE);
			
		}
		
		return true;
			
	}
	
	public void startElement (String nameSpaceURI, String strTag, String qName, Attributes attr) throws SAXException
	{

		if (strTag.equalsIgnoreCase("fileType"))
		{
			getFileType = true;
		}
		else
		{
			
			for (int i = 0; i < strReadTags.length; i++)
			{
				
				if (strReadTags[i].equalsIgnoreCase(strTag))
				{

					readData = true;
					strCurrentTag = strTag;
					
					break;
					
				}
				
			}
			
		}
		
	}
	
	public void characters (char[] value, int start, int length) throws SAXException
	{
		
		if (getFileType)
		{
			
			if (!strFileType.equalsIgnoreCase(valueToString(value, start, length)))
			{
				
				notProfileFile = true;
				throw new SAXException("");
				
			}
			
			getFileType = false;
			
		}
		else if (readData)
		{

			String strData = valueToString(value, start, length);
			
			props.setProperty(strCurrentTag, strData);
			readData = false;
			
		}
		
	}
	
	public void endElement (String nameSpaceURI, String strTag, String qName) throws SAXException
	{
		
		if (readData) //If readData has been left on (no chars between two profile tags)
		{
			
			props.setProperty(strCurrentTag, "");
			readData = false;
			
		}
		
	}
	//Converts the char array for the data into a string
	private String valueToString (char[] value, int start, int length)
	{

		if (length <= 0)
		{
			return "";
		}
		
		char[] c = new char[length];
		
		for (int i = 0; i < c.length; i++)
		{
			c[i] = value[start + i];
		}
		
		return new String(c);
		
	}
	
}