/*
 * Copyright 2004 - 2013 Wayne Grant
 *           2013 - 2025 Kai Kramer
 *
 * This file is part of KeyStore Explorer.
 *
 * KeyStore Explorer is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * KeyStore Explorer is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with KeyStore Explorer.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.kse.gui.dialogs;

import java.awt.BorderLayout;
import java.awt.Dialog;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.util.ResourceBundle;

import javax.swing.AbstractAction;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JProgressBar;
import javax.swing.KeyStroke;
import javax.swing.SwingConstants;
import javax.swing.SwingUtilities;
import javax.swing.border.EmptyBorder;

import org.apache.commons.io.IOUtils;
import org.kse.gui.components.JEscDialog;
import org.kse.gui.PlatformUtil;
import org.kse.gui.error.DProblem;
import org.kse.gui.error.Problem;
import org.kse.utilities.net.URLs;
import org.kse.version.Version;

/**
 * Check for an updated version of KeyStore Explorer. This check works over the
 * net so the user may cancel at any time by pressing the cancel button.
 */
public class DCheckUpdate extends JEscDialog {
    private static final long serialVersionUID = 1L;

    private static ResourceBundle res = ResourceBundle.getBundle("org/kse/gui/dialogs/resources");

    private static final String CANCEL_KEY = "CANCEL_KEY";

    private JPanel jpCheckUpdate;
    private JLabel jlCheckUpdate;
    private JPanel jpProgress;
    private JProgressBar jpbCheckUpdate;
    private JPanel jpCancel;
    private JButton jbCancel;

    private Thread checker;
    private Version latestVersion;

    /**
     * Creates a new DCheckUpdate dialog.
     *
     * @param parent The parent frame
     */
    public DCheckUpdate(JFrame parent) {
        super(parent, Dialog.ModalityType.DOCUMENT_MODAL);
        initComponents();
    }

    private void initComponents() {
        jlCheckUpdate = new JLabel(res.getString("DCheckUpdate.jlCheckUpdate.text"));
        ImageIcon icon = new ImageIcon(getClass().getResource("images/chkup.png"));
        jlCheckUpdate.setIcon(icon);
        jlCheckUpdate.setHorizontalTextPosition(SwingConstants.LEADING);
        jlCheckUpdate.setIconTextGap(15);

        jpCheckUpdate = new JPanel(new FlowLayout(FlowLayout.CENTER));
        jpCheckUpdate.add(jlCheckUpdate);
        jpCheckUpdate.setBorder(new EmptyBorder(5, 5, 5, 5));

        jpbCheckUpdate = new JProgressBar();
        jpbCheckUpdate.setIndeterminate(true);
        jpbCheckUpdate.setString("DCheckUpdate.jlCheckUpdate.text");

        jpProgress = new JPanel(new FlowLayout(FlowLayout.CENTER));
        jpProgress.add(jpbCheckUpdate);
        jpProgress.setBorder(new EmptyBorder(5, 5, 5, 5));

        jbCancel = new JButton(res.getString("DCheckUpdate.jbCancel.text"));
        jbCancel.addActionListener(evt -> cancelPressed());
        jbCancel.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW)
                .put(KeyStroke.getKeyStroke(KeyEvent.VK_ESCAPE, 0), CANCEL_KEY);
        jbCancel.getActionMap().put(CANCEL_KEY, new AbstractAction() {
            private static final long serialVersionUID = 1L;

            @Override
            public void actionPerformed(ActionEvent evt) {
                cancelPressed();
            }
        });

        jpCancel = PlatformUtil.createDialogButtonPanel(jbCancel);

        getContentPane().add(jpCheckUpdate, BorderLayout.NORTH);
        getContentPane().add(jpProgress, BorderLayout.CENTER);
        getContentPane().add(jpCancel, BorderLayout.SOUTH);

        addWindowListener(new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent evt) {
                if ((checker != null) && (checker.isAlive())) {
                    checker.interrupt();
                }
                closeDialog();
            }
        });

        setTitle(res.getString("DCheckUpdate.Title"));
        setResizable(false);

        pack();
    }

    /**
     * Start key pair generation in a separate thread.
     */
    public void startCheck() {
        checker = new Thread(new CheckForUpdate());
        checker.setPriority(Thread.MIN_PRIORITY);
        checker.start();
    }

    private void cancelPressed() {
        if ((checker != null) && (checker.isAlive())) {
            checker.interrupt();
        }
        closeDialog();
    }

    private void closeDialog() {
        setVisible(false);
        dispose();
    }

    /**
     * Get latest version found by check.
     *
     * @return latest version or null if none found.
     */
    public Version getLatestVersion() {
        return latestVersion;
    }

    private class CheckForUpdate implements Runnable {
        @Override
        public void run() {
            try {
                // Get the version number of the latest KeyStore Explorer from its website
                URL latestVersionUrl = new URL(URLs.LATEST_VERSION_ADDRESS);

                String versionString = IOUtils.toString(latestVersionUrl, StandardCharsets.US_ASCII);
                latestVersion = new Version(versionString);

                SwingUtilities.invokeLater(() -> closeDialog());
            } catch (final Exception ex) {
                SwingUtilities.invokeLater(() -> {
                    if (DCheckUpdate.this.isShowing()) {
                        String problemStr = res.getString("DCheckUpdate.NoCheckUpdate.Problem");

                        String[] causes = new String[] { res.getString("DCheckUpdate.UpdateHostUnavailable.Cause"),
                                                         res.getString("DCheckUpdate.ProxySettingsIncorrect.Cause") };

                        Problem problem = new Problem(problemStr, causes, ex);

                        DProblem dProblem = new DProblem(DCheckUpdate.this,
                                                         res.getString("DCheckUpdate.ProblemCheckingUpdate.Title"),
                                                         problem);
                        dProblem.setLocationRelativeTo(DCheckUpdate.this);
                        dProblem.setVisible(true);

                        closeDialog();
                    }
                });
            }
        }
    }
}
