/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * 
 */

package org.apache.jmeter.assertions.gui;

import java.awt.LayoutManager;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.Box;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.TransformerException;

import org.apache.jmeter.util.JMeterUtils;
import org.apache.jmeter.util.XPathUtil;
import org.apache.jorphan.logging.LoggingManager;
import org.apache.log.Logger;
import org.apache.xpath.XPathAPI;
import org.w3c.dom.Document;
import org.w3c.dom.Element;

public class XPathPanel extends JPanel {
    private static final Logger log = LoggingManager.getLoggerForClass();

	private static Document testDoc;

	private JCheckBox negated;

	private JTextField xpath;

	private JButton checkXPath;

	/**
	 * 
	 */
	public XPathPanel() {
		super();
		init();
	}

	/**
	 * @param isDoubleBuffered
	 */
	public XPathPanel(boolean isDoubleBuffered) {
		super(isDoubleBuffered);
		init();
	}

	/**
	 * @param layout
	 */
	public XPathPanel(LayoutManager layout) {
		super(layout);
		init();
	}

	/**
	 * @param layout
	 * @param isDoubleBuffered
	 */
	public XPathPanel(LayoutManager layout, boolean isDoubleBuffered) {
		super(layout, isDoubleBuffered);
		init();
	}

	private void init() {
		Box hbox = Box.createHorizontalBox();
		hbox.add(Box.createHorizontalGlue());
		hbox.add(getXPathTextField());
		hbox.add(Box.createHorizontalGlue());
		hbox.add(getCheckXPathButton());

		Box vbox = Box.createVerticalBox();
		vbox.add(hbox);
		vbox.add(Box.createVerticalGlue());
		vbox.add(getNegatedCheckBox());

		add(vbox);

		setDefaultValues();
	}

    public void setDefaultValues() {
        setXPath("/"); //$NON-NLS-1$
        setNegated(false);
    }

	/**
	 * Get the XPath String
	 * 
	 * @return String
	 */
	public String getXPath() {
		return this.xpath.getText();
	}

	/**
	 * Set the string that will be used in the xpath evaluation
	 * 
	 * @param xpath
	 */
	public void setXPath(String xpath) {
		this.xpath.setText(xpath);
	}

	/**
	 * Does this negate the xpath results
	 * 
	 * @return boolean
	 */
	public boolean isNegated() {
		return this.negated.isSelected();
	}

	/**
	 * Set this to true, if you want success when the xpath does not match.
	 * 
	 * @param negated
	 */
	public void setNegated(boolean negated) {
		this.negated.setSelected(negated);
	}

	/**
	 * Negated chechbox
	 * 
	 * @return JCheckBox
	 */
	public JCheckBox getNegatedCheckBox() {
		if (negated == null) {
			negated = new JCheckBox(JMeterUtils.getResString("xpath_assertion_negate"), false); //$NON-NLS-1$
		}

		return negated;
	}

	/**
	 * Check XPath button
	 * 
	 * @return JButton
	 */
	public JButton getCheckXPathButton() {
		if (checkXPath == null) {
			checkXPath = new JButton(JMeterUtils.getResString("xpath_assertion_button")); //$NON-NLS-1$
			checkXPath.addActionListener(new ActionListener() {
				public void actionPerformed(ActionEvent e) {
					validXPath(xpath.getText(), true);
				}
			});
		}
		return checkXPath;
	}

	public JTextField getXPathTextField() {
		if (xpath == null) {
			xpath = new JTextField(50);
		}
		return xpath;
	}

	/**
	 * @return Returns the showNegate.
	 */
	public boolean isShowNegated() {
		return this.getNegatedCheckBox().isVisible();
	}

	/**
	 * @param showNegate
	 *            The showNegate to set.
	 */
	public void setShowNegated(boolean showNegate) {
		getNegatedCheckBox().setVisible(showNegate);
	}

	/**
	 * Test weather an XPath is valid. It seems the Xalan has no easy way to
	 * check, so this creates a test document, then tries to evaluate the xpath.
	 * 
	 * @param xpathString
	 *            XPath String to validate
	 * @param showDialog
	 *            weather to show a dialog
	 * @return returns true if valid, valse otherwise.
	 */
	public static boolean validXPath(String xpathString, boolean showDialog) {
		String ret = null;
		boolean success = true;
		try {
			if (testDoc == null) {
				testDoc = XPathUtil.makeDocumentBuilder(false, false, false).newDocument();
				Element el = testDoc.createElement("root"); //$NON-NLS-1$
				testDoc.appendChild(el);

			}
			if (XPathAPI.eval(testDoc, xpathString) == null) {
				// We really should never get here
				// because eval will throw an exception
				// if xpath is invalid, but whatever, better
				// safe
				log.warn("xpath eval was null ");
				ret = "xpath eval was null";
				success = false;
			}

		} catch (ParserConfigurationException e) {
			success = false;
			ret = e.getLocalizedMessage();
		} catch (TransformerException e) {
			success = false;
			ret = e.getLocalizedMessage();
		}

		if (showDialog) {
			JOptionPane.showMessageDialog(null, (success) ? JMeterUtils.getResString("xpath_assertion_valid") : ret, //$NON-NLS-1$
					(success) ? JMeterUtils.getResString("xpath_assertion_valid") : JMeterUtils //$NON-NLS-1$
							.getResString("xpath_assertion_failed"), (success) ? JOptionPane.INFORMATION_MESSAGE //$NON-NLS-1$
							: JOptionPane.ERROR_MESSAGE);
		}
		return success;

	}
}