/*
 * 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.log4j.chainsaw;

import java.awt.BorderLayout;
import java.text.MessageFormat;
import java.util.Date;
import javax.swing.BorderFactory;
import javax.swing.JEditorPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.ListSelectionModel;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;
import org.apache.log4j.Logger;

/**
 * A panel for showing a stack trace.
 *
 * @author <a href="mailto:oliver@puppycrawl.com">Oliver Burn</a>
 */
class DetailPanel extends JPanel implements ListSelectionListener {
    /** used to log events **/
    private static final Logger LOG = Logger.getLogger(DetailPanel.class);

    /** used to format the logging event **/
    private static final MessageFormat FORMATTER = new MessageFormat(
	    "<b>Time:</b> <code>{0,time,medium}</code>" + "&nbsp;&nbsp;<b>Priority:</b> <code>{1}</code>"
		    + "&nbsp;&nbsp;<b>Thread:</b> <code>{2}</code>" + "&nbsp;&nbsp;<b>NDC:</b> <code>{3}</code>"
		    + "<br><b>Logger:</b> <code>{4}</code>" + "<br><b>Location:</b> <code>{5}</code>"
		    + "<br><b>Message:</b>" + "<pre>{6}</pre>" + "<b>Throwable:</b>" + "<pre>{7}</pre>");

    /** the model for the data to render **/
    private final MyTableModel mModel;
    /** pane for rendering detail **/
    private final JEditorPane mDetails;

    /**
     * Creates a new <code>DetailPanel</code> instance.
     *
     * @param aTable the table to listen for selections on
     * @param aModel the model backing the table
     */
    DetailPanel(JTable aTable, final MyTableModel aModel) {
	mModel = aModel;
	setLayout(new BorderLayout());
	setBorder(BorderFactory.createTitledBorder("Details: "));

	mDetails = new JEditorPane();
	mDetails.setEditable(false);
	mDetails.setContentType("text/html");
	add(new JScrollPane(mDetails), BorderLayout.CENTER);

	final ListSelectionModel rowSM = aTable.getSelectionModel();
	rowSM.addListSelectionListener(this);
    }

    /** @see ListSelectionListener **/
    public void valueChanged(ListSelectionEvent aEvent) {
	// Ignore extra messages.
	if (aEvent.getValueIsAdjusting()) {
	    return;
	}

	final ListSelectionModel lsm = (ListSelectionModel) aEvent.getSource();
	if (lsm.isSelectionEmpty()) {
	    mDetails.setText("Nothing selected");
	} else {
	    final int selectedRow = lsm.getMinSelectionIndex();
	    final EventDetails e = mModel.getEventDetails(selectedRow);
	    final Object[] args = { new Date(e.getTimeStamp()), e.getPriority(), escape(e.getThreadName()),
		    escape(e.getNDC()), escape(e.getCategoryName()), escape(e.getLocationDetails()),
		    escape(e.getMessage()), escape(getThrowableStrRep(e)) };
	    mDetails.setText(FORMATTER.format(args));
	    mDetails.setCaretPosition(0);
	}
    }

    ////////////////////////////////////////////////////////////////////////////
    // Private methods
    ////////////////////////////////////////////////////////////////////////////

    /**
     * Returns a string representation of a throwable.
     *
     * @param aEvent contains the throwable information
     * @return a <code>String</code> value
     */
    private static String getThrowableStrRep(EventDetails aEvent) {
	final String[] strs = aEvent.getThrowableStrRep();
	if (strs == null) {
	    return null;
	}

	final StringBuilder sb = new StringBuilder();
	for (int i = 0; i < strs.length; i++) {
	    sb.append(strs[i]).append("\n");
	}

	return sb.toString();
    }

    /**
     * Escape &lt;, &gt; &amp; and &quot; as their entities. It is very dumb about
     * &amp; handling.
     * 
     * @param aStr the String to escape.
     * @return the escaped String
     */
    private String escape(String aStr) {
	if (aStr == null) {
	    return null;
	}

	final StringBuilder buf = new StringBuilder();
	for (int i = 0; i < aStr.length(); i++) {
	    char c = aStr.charAt(i);
	    switch (c) {
	    case '<':
		buf.append("&lt;");
		break;
	    case '>':
		buf.append("&gt;");
		break;
	    case '\"':
		buf.append("&quot;");
		break;
	    case '&':
		buf.append("&amp;");
		break;
	    default:
		buf.append(c);
		break;
	    }
	}
	return buf.toString();
    }
}
