// License: GPL. Copyright 2007 by Immanuel Scholz and others
package org.openstreetmap.josm.tools;

import static org.openstreetmap.josm.tools.I18n.tr;

import java.awt.GridBagLayout;
import java.awt.Toolkit;
import java.awt.datatransfer.Clipboard;
import java.awt.datatransfer.ClipboardOwner;
import java.awt.datatransfer.StringSelection;
import java.awt.datatransfer.Transferable;
import java.io.BufferedReader;
import java.io.File;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.net.URL;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Arrays;
import java.util.Date;
import java.util.LinkedList;

import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;

import org.openstreetmap.josm.Main;
import org.openstreetmap.josm.plugins.PluginException;
import org.openstreetmap.josm.plugins.PluginProxy;

/**
 * An exception handler, that ask the user to send a bug report.
 *
 * @author imi
 */
public final class BugReportExceptionHandler implements Thread.UncaughtExceptionHandler {

	public void uncaughtException(Thread t, Throwable e) {
		e.printStackTrace();
		if (Main.parent != null) {
			if (e instanceof OutOfMemoryError) {
				// do not translate the string, as translation may raise an exception
				JOptionPane.showMessageDialog(Main.parent, "You are out of memory. Strange things may happen.\nPlease restart JOSM and load smaller data sets.");
				return;
			}

			PluginProxy plugin = null;

			// Check for an explicit problem when calling a plugin function
			if (e instanceof PluginException)
				plugin = ((PluginException)e).plugin;
			
			if (plugin == null)
				plugin = guessPlugin(e);

			if (plugin != null) {
				int answer = JOptionPane.showConfirmDialog(
						Main.parent, 
						tr("An unexpected exception occurred, that may come from in the ''{0}'' plugin.", plugin.info.name)+"\n"+
						(plugin.info.author != null ? tr("According to the information within the plugin, the author is {0}.", plugin.info.author) : "")+"\n"+
						tr("Should the plugin be disabled?"),
						tr("Disable plugin"),
						JOptionPane.YES_NO_OPTION);
				if (answer == JOptionPane.OK_OPTION) {
					LinkedList<String> plugins = new LinkedList<String>(Arrays.asList(Main.pref.get("plugins").split(",")));
					if (plugins.contains(plugin.info.name)) {
						while (plugins.remove(plugin.info.name)) {}
						String p = "";
						for (String s : plugins)
							p += ","+s;
						if (p.length() > 0)
							p = p.substring(1);
						Main.pref.put("plugins", p);
						JOptionPane.showMessageDialog(Main.parent, tr("The plugin has been removed from the configuration. Please restart JOSM to unload the plugin."));
					} else {
						JOptionPane.showMessageDialog(Main.parent, tr("The plugin could not be removed. Please tell the people you got JOSM from about the problem."));
					}
					return;
				}
			}

			Object[] options = new String[]{tr("Do nothing"), tr("Report Bug")};
			int answer = JOptionPane.showOptionDialog(Main.parent, tr("An unexpected exception occurred.\n\n" +
					"This is always a coding error. If you are running the latest\n" +
			"version of JOSM, please consider being kind and file a bug report."),
			tr("Unexpected Exception"), JOptionPane.YES_NO_OPTION, JOptionPane.ERROR_MESSAGE,
			null, options, options[0]);
			if (answer == 1) {
				try {
					StringWriter stack = new StringWriter();
					e.printStackTrace(new PrintWriter(stack));

					URL revUrl = Main.class.getResource("/REVISION");
					StringBuilder sb = new StringBuilder();
					if (revUrl == null) {
						sb.append("Development version. Unknown revision.");
						File f = new File("org/openstreetmap/josm/Main.class");
						if (!f.exists())
							f = new File("bin/org/openstreetmap/josm/Main.class");
						if (!f.exists())
							f = new File("build/org/openstreetmap/josm/Main.class");
						if (f.exists()) {
							DateFormat sdf = SimpleDateFormat.getDateTimeInstance();
							sb.append("\nMain.class build on "+sdf.format(new Date(f.lastModified())));
							sb.append("\n");
						}
					} else {
						BufferedReader in = new BufferedReader(new InputStreamReader(revUrl.openStream()));
						for (String line = in.readLine(); line != null; line = in.readLine()) {
							sb.append(line);
							sb.append('\n');
						}
					}
					sb.append("\n"+stack.getBuffer().toString());

					JPanel p = new JPanel(new GridBagLayout());
					p.add(new JLabel(tr("Please report a ticket at http://josm.openstreetmap.de/newticket, including your steps to get to\n" +
							            "the error and be sure to include the following information")), GBC.eol());
					try {
	                    Toolkit.getDefaultToolkit().getSystemClipboard().setContents(new StringSelection(sb.toString()), new ClipboardOwner(){
	                    	public void lostOwnership(Clipboard clipboard, Transferable contents) {}
	                    });
	                    p.add(new JLabel(tr("The text has already been copied to your clipboard.")), GBC.eop());
                    } catch (RuntimeException x) {
                    }

					JTextArea info = new JTextArea(sb.toString(), 20, 60);
					info.setCaretPosition(0);
					info.setEditable(false);
					p.add(new JScrollPane(info), GBC.eop());

					JOptionPane.showMessageDialog(Main.parent, p);
				} catch (Exception e1) {
					e1.printStackTrace();
				}
			}
		}
	}

	private PluginProxy guessPlugin(Throwable e) {
		String name = guessPluginName(e);
		for (PluginProxy p : Main.plugins)
			if (p.info.name.equals(name))
				return p;
		return null;
	}

	/**
	 * Analyze the stack of the argument and return a name of a plugin, if
	 * some known problem pattern has been found or <code>null</code>, if
	 * the stack does not contain plugin-code.
	 * 
	 * Note: This heuristic is not meant as discrimination against specific
	 * plugins, but only to stop the flood of similar bug reports about plugins.
	 * Of course, plugin writers are free to install their own version of 
	 * an exception handler with their email address listed to receive 
	 * bug reports ;-). 
	 */
	private String guessPluginName(Throwable e) {
		for (StackTraceElement element : e.getStackTrace()) {
			String c = element.getClassName();
			
			if (c.contains("wmsplugin.") || c.contains(".WMSLayer"))
				return "wmsplugin";
			if (c.contains("landsat.") || c.contains(".LandsatLayer"))
				return "landsat";
			if (c.contains("livegps."))
				return "livegps";
			if (c.contains("mappaint."))
				return "mappaint";
			if (c.contains("annotationtester."))
				return "annotation-tester";
			if (c.startsWith("UtilsPlugin."))
				return "UtilsPlugin";

			if (c.startsWith("org.openstreetmap.josm.plugins.")) {
				String p = c.substring("org.openstreetmap.josm.plugins.".length());
				if (p.indexOf('.') != -1 && p.matches("[a-z].*")) {
					return p.substring(0,p.indexOf('.'));
				}
			}
		}
		return null;
	}
}