// 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.Component;
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.PrintWriter;
import java.io.StringWriter;
import java.net.URL;
import java.nio.ByteBuffer;

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.actions.ShowStatusReportAction;
import org.openstreetmap.josm.gui.JMultilineLabel;
import org.openstreetmap.josm.plugins.PluginHandler;

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

    private static boolean handlingInProgress = false;

    public void uncaughtException(Thread t, Throwable e) {
        handleException(e);
    }

    //http://stuffthathappens.com/blog/2007/10/15/one-more-note-on-uncaught-exception-handlers/
    public void handle(Throwable t) {
        handleException(t);
    }

    public static void handleException(Throwable e) {
        if (handlingInProgress)
            return;                  // we do not handle secondary exceptions, this gets too messy
        handlingInProgress = true;
        try {
            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, "JOSM is out of memory. " +
                            "Strange things may happen.\nPlease restart JOSM with the -Xmx###M option,\n" +
                            "where ### is the number of MB assigned to JOSM (e.g. 256).\n" +
                            "Currently, " + Runtime.getRuntime().maxMemory()/1024/1024 + " MB are available to JOSM.",
                            "Error",
                            JOptionPane.ERROR_MESSAGE
                    );
                    return;
                }

                // Give the user a chance to deactivate the plugin which threw the exception (if it
                // was thrown from a plugin)
                //
                PluginHandler.disablePluginAfterException(e);

                // Then ask for submitting a bug report, for exceptions thrown from a plugin too
                //
                Object[] options = new String[]{tr("Do nothing"), tr("Report Bug")};
                int answer = JOptionPane.showOptionDialog(
                        Main.parent,
                        "<html>"
                        + tr("An unexpected exception occurred.<br>" +
                                "This is always a coding error. If you are running the latest<br>" +
                                "version of JOSM, please consider being kind and file a bug report."
                        )
                        + "</html>",
                        tr("Unexpected Exception"),
                        JOptionPane.YES_NO_OPTION,
                        JOptionPane.ERROR_MESSAGE,
                        null,
                        options, options[0]
                );
                if (answer != 1)  return;

                try {
                    final int maxlen = 6000;
                    StringWriter stack = new StringWriter();
                    e.printStackTrace(new PrintWriter(stack));

                    String text = ShowStatusReportAction.getReportHeader()
                    + stack.getBuffer().toString();
                    String urltext = text.replaceAll("\r",""); /* strip useless return chars */
                    if(urltext.length() > maxlen)
                    {
                        urltext = urltext.substring(0,maxlen);
                        int idx = urltext.lastIndexOf("\n");
                        /* cut whole line when not loosing too much */
                        if(maxlen-idx < 200) {
                            urltext = urltext.substring(0,idx+1);
                        }
                        urltext += "...<snip>...\n";
                    }

                    URL url = new URL("http://josm.openstreetmap.de/josmticket?" +
                            "tdata="+Base64.encode(ByteBuffer.wrap(urltext.getBytes("UTF8")), true));

                    JPanel p = new JPanel(new GridBagLayout());
                    p.add(new JMultilineLabel(
                            tr("You have encountered an error in JOSM. Before you file a bug report " +
                            "make sure you have updated to the latest version of JOSM here:")), GBC.eol());
                    p.add(new UrlLabel("http://josm.openstreetmap.de/#Download"), GBC.eop().insets(8,0,0,0));
                    p.add(new JMultilineLabel(
                            tr("You should also update your plugins. If neither of those help please " +
                            "file a bug report in our bugtracker using this link:")), GBC.eol());
                    p.add(new UrlLabel(url.toString(), "http://josm.openstreetmap.de/josmticket?..."), GBC.eop().insets(8,0,0,0));
                    p.add(new JMultilineLabel(
                            tr("There the error information provided below should already be " +
                                    "filled in for you. Please include information on how to reproduce " +
                            "the error and try to supply as much detail as possible.")), GBC.eop());
                    p.add(new JMultilineLabel(
                            tr("Alternatively, if that does not work you can manually fill in the information " +
                            "below at this URL:")), GBC.eol());
                    p.add(new UrlLabel("http://josm.openstreetmap.de/newticket"), GBC.eop().insets(8,0,0,0));
                    try {
                        Toolkit.getDefaultToolkit().getSystemClipboard().setContents(new StringSelection(text), 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(text, 20, 60);
                    info.setCaretPosition(0);
                    info.setEditable(false);
                    p.add(new JScrollPane(info), GBC.eop());

                    for (Component c: p.getComponents()) {
                        if (c instanceof JMultilineLabel) {
                            ((JMultilineLabel)c).setMaxWidth(400);
                        }
                    }

                    JOptionPane.showMessageDialog(Main.parent, p, tr("You have encountered a bug in JOSM"), JOptionPane.ERROR_MESSAGE);
                } catch (Exception e1) {
                    e1.printStackTrace();
                }
            }
        } finally {
            handlingInProgress = false;
        }
    }
    public static boolean exceptionHandlingInProgress() {
        return handlingInProgress;
    }
}
