// License: GPL. For details, see LICENSE file.
package org.openstreetmap.josm.gui.preferences.plugin;

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

import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.List;

import javax.swing.JLabel;
import javax.swing.SwingConstants;
import javax.swing.SwingUtilities;
import javax.swing.event.HyperlinkEvent.EventType;

import org.openstreetmap.josm.gui.widgets.HtmlPanel;
import org.openstreetmap.josm.gui.widgets.VerticallyScrollablePanel;
import org.openstreetmap.josm.plugins.PluginInformation;
import org.openstreetmap.josm.tools.OpenBrowser;

/**
 * A panel displaying the list of known plugins.
 */
public class PluginListPanel extends VerticallyScrollablePanel {
    static final class PluginCheckBoxMouseAdapter extends MouseAdapter {
        private final PluginCheckBox cbPlugin;

        PluginCheckBoxMouseAdapter(PluginCheckBox cbPlugin) {
            this.cbPlugin = cbPlugin;
        }

        @Override
        public void mouseClicked(MouseEvent e) {
            cbPlugin.doClick();
        }
    }

    private transient PluginPreferencesModel model;

    /**
     * Constructs a new {@code PluginListPanel} with a default model.
     */
    public PluginListPanel() {
        this(new PluginPreferencesModel());
    }

    /**
     * Constructs a new {@code PluginListPanel} with a given model.
     * @param model The plugin model
     */
    public PluginListPanel(PluginPreferencesModel model) {
        this.model = model;
        setLayout(new GridBagLayout());
    }

    protected static String formatPluginRemoteVersion(PluginInformation pi) {
        StringBuilder sb = new StringBuilder();
        if (pi.version == null || pi.version.trim().isEmpty()) {
            sb.append(tr("unknown"));
        } else {
            sb.append(pi.version);
            if (pi.oldmode) {
                sb.append('*');
            }
        }
        return sb.toString();
    }

    protected static String formatPluginLocalVersion(PluginInformation pi) {
        if (pi == null)
            return tr("unknown");
        if (pi.localversion == null || pi.localversion.trim().isEmpty())
            return tr("unknown");
        return pi.localversion;
    }

    protected static String formatCheckboxTooltipText(PluginInformation pi) {
        if (pi == null)
            return "";
        if (pi.downloadlink == null)
            return tr("Plugin bundled with JOSM");
        else
            return pi.downloadlink;
    }

    /**
     * Displays a message when the plugin list is empty.
     */
    public void displayEmptyPluginListInformation() {
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.anchor = GridBagConstraints.CENTER;
        gbc.fill = GridBagConstraints.BOTH;
        gbc.insets = new Insets(40, 0, 40, 0);
        gbc.weightx = 1.0;
        gbc.weighty = 1.0;

        HtmlPanel hint = new HtmlPanel();
        hint.setText(
                "<html>"
                + tr("Please click on <strong>Download list</strong> to download and display a list of available plugins.")
                + "</html>"
        );
        add(hint, gbc);
    }

    /**
     * Refreshes the list.
     */
    public void refreshView() {
        final Rectangle visibleRect = getVisibleRect();
        List<PluginInformation> displayedPlugins = model.getDisplayedPlugins();
        removeAll();

        GridBagConstraints gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.fill = GridBagConstraints.HORIZONTAL;
        gbc.weightx = 1.0;

        if (displayedPlugins.isEmpty()) {
            displayEmptyPluginListInformation();
            return;
        }

        int row = -1;
        for (final PluginInformation pi : displayedPlugins) {
            boolean selected = model.isSelectedPlugin(pi.getName());
            String remoteversion = formatPluginRemoteVersion(pi);
            String localversion = formatPluginLocalVersion(model.getPluginInformation(pi.getName()));

            final PluginCheckBox cbPlugin = new PluginCheckBox(pi, selected, this, model);
            String pluginText = tr("{0}: Version {1} (local: {2})", pi.getName(), remoteversion, localversion);
            if (pi.requires != null && !pi.requires.isEmpty()) {
                pluginText += tr(" (requires: {0})", pi.requires);
            }
            JLabel lblPlugin = new JLabel(
                    pluginText,
                    pi.getScaledIcon(),
                    SwingConstants.LEFT);
            lblPlugin.addMouseListener(new PluginCheckBoxMouseAdapter(cbPlugin));

            gbc.gridx = 0;
            gbc.gridy = ++row;
            gbc.insets = new Insets(5, 5, 0, 5);
            gbc.weighty = 0.0;
            gbc.weightx = 0.0;
            add(cbPlugin, gbc);

            gbc.gridx = 1;
            gbc.weightx = 1.0;
            add(lblPlugin, gbc);

            HtmlPanel description = new HtmlPanel();
            description.setText(pi.getDescriptionAsHtml());
            description.getEditorPane().addHyperlinkListener(e -> {
                if (e.getEventType() == EventType.ACTIVATED) {
                    OpenBrowser.displayUrl(e.getURL().toString());
                }
            });
            lblPlugin.setLabelFor(description);

            gbc.gridx = 1;
            gbc.gridy = ++row;
            gbc.insets = new Insets(3, 25, 5, 5);
            gbc.weighty = 1.0;
            add(description, gbc);
        }
        revalidate();
        repaint();
        SwingUtilities.invokeLater(() -> scrollRectToVisible(visibleRect));
    }
}