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

import static org.openstreetmap.josm.gui.help.HelpUtil.ht;
import static org.openstreetmap.josm.tools.I18n.tr;

import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.swing.ButtonGroup;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JRadioButton;

import org.openstreetmap.josm.data.imagery.ImageryInfo;
import org.openstreetmap.josm.data.imagery.ImageryInfo.ImageryType;
import org.openstreetmap.josm.gui.ExtendedDialog;
import org.openstreetmap.josm.gui.MainApplication;
import org.openstreetmap.josm.gui.datatransfer.ClipboardUtils;
import org.openstreetmap.josm.gui.layer.ImageryLayer;
import org.openstreetmap.josm.gui.widgets.JosmTextField;
import org.openstreetmap.josm.gui.widgets.UrlLabel;
import org.openstreetmap.josm.io.imagery.WMSImagery.WMSGetCapabilitiesException;
import org.openstreetmap.josm.tools.GBC;
import org.openstreetmap.josm.tools.Logging;
import org.openstreetmap.josm.tools.Shortcut;

/**
 * Download rectified images from various services.
 * @since 3715
 */
public class MapRectifierWMSmenuAction extends JosmAction {

    /**
     * Class that bundles all required information of a rectifier service
     */
    public static class RectifierService {
        private final String name;
        private final String url;
        private final String wmsUrl;
        private final Pattern urlRegEx;
        private final Pattern idValidator;
        private JRadioButton btn;

        /**
         * Constructs a new {@code RectifierService}.
         * @param name Name of the rectifing service
         * @param url URL to the service where users can register, upload, etc.
         * @param wmsUrl URL to the WMS server where JOSM will grab the images. Insert __s__ where the ID should be placed
         * @param urlRegEx a regular expression that determines if a given URL is one of the service and returns the WMS id if so
         * @param idValidator regular expression that checks if a given ID is syntactically valid
         */
        public RectifierService(String name, String url, String wmsUrl, String urlRegEx, String idValidator) {
            this.name = name;
            this.url = url;
            this.wmsUrl = wmsUrl;
            this.urlRegEx = Pattern.compile(urlRegEx);
            this.idValidator = Pattern.compile(idValidator);
        }

        private boolean isSelected() {
            return btn.isSelected();
        }
    }

    /**
     * List of available rectifier services.
     */
    private final transient List<RectifierService> services = new ArrayList<>();

    /**
     * Constructs a new {@code MapRectifierWMSmenuAction}.
     */
    public MapRectifierWMSmenuAction() {
        super(tr("Rectified Image..."),
                "OLmarker",
                tr("Download Rectified Images From Various Services"),
                Shortcut.registerShortcut("imagery:rectimg",
                        tr("Imagery: {0}", tr("Rectified Image...")),
                        KeyEvent.CHAR_UNDEFINED, Shortcut.NONE),
                true
        );
        setHelpId(ht("/Menu/Imagery"));

        // Add default services
        services.add(
                new RectifierService("Metacarta Map Rectifier",
                        "http://labs.metacarta.com/rectifier/",
                        "http://labs.metacarta.com/rectifier/wms.cgi?id=__s__&srs=EPSG:4326"
                        + "&Service=WMS&Version=1.1.0&Request=GetMap&format=image/png&",
                        // This matches more than the "classic" WMS link, so users can pretty much
                        // copy any link as long as it includes the ID
                        "labs\\.metacarta\\.com/(?:.*?)(?:/|=)([0-9]+)(?:\\?|/|\\.|$)",
                "^[0-9]+$")
        );
        services.add(
                new RectifierService("Map Warper",
                        "http://mapwarper.net/",
                        "http://mapwarper.net/maps/wms/__s__?request=GetMap&version=1.1.1"
                        + "&styles=&format=image/png&srs=epsg:4326&exceptions=application/vnd.ogc.se_inimage&",
                        // This matches more than the "classic" WMS link, so users can pretty much
                        // copy any link as long as it includes the ID
                        "(?:mapwarper\\.net|warper\\.geothings\\.net)/(?:.*?)/([0-9]+)(?:\\?|/|\\.|$)",
                "^[0-9]+$")
        );

        // This service serves the purpose of "just this once" without forcing the user
        // to commit the link to the preferences

        // Clipboard content gets trimmed, so matching whitespace only ensures that this
        // service will never be selected automatically.
        services.add(new RectifierService(tr("Custom WMS Link"), "", "", "^\\s+$", ""));
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        if (!isEnabled()) return;
        JPanel panel = new JPanel(new GridBagLayout());
        panel.add(new JLabel(tr("Supported Rectifier Services:")), GBC.eol());

        JosmTextField tfWmsUrl = new JosmTextField(30);

        String clip = ClipboardUtils.getClipboardStringContent();
        clip = clip == null ? "" : clip.trim();
        ButtonGroup group = new ButtonGroup();

        JRadioButton firstBtn = null;
        for (RectifierService s : services) {
            JRadioButton serviceBtn = new JRadioButton(s.name);
            if (firstBtn == null) {
                firstBtn = serviceBtn;
            }
            // Checks clipboard contents against current service if no match has been found yet.
            // If the contents match, they will be inserted into the text field and the corresponding
            // service will be pre-selected.
            if (!clip.isEmpty() && tfWmsUrl.getText().isEmpty()
                    && (s.urlRegEx.matcher(clip).find() || s.idValidator.matcher(clip).matches())) {
                serviceBtn.setSelected(true);
                tfWmsUrl.setText(clip);
            }
            s.btn = serviceBtn;
            group.add(serviceBtn);
            if (!s.url.isEmpty()) {
                panel.add(serviceBtn, GBC.std());
                panel.add(new UrlLabel(s.url, tr("Visit Homepage")), GBC.eol().anchor(GridBagConstraints.EAST));
            } else {
                panel.add(serviceBtn, GBC.eol().anchor(GridBagConstraints.WEST));
            }
        }

        // Fallback in case no match was found
        if (tfWmsUrl.getText().isEmpty() && firstBtn != null) {
            firstBtn.setSelected(true);
        }

        panel.add(new JLabel(tr("WMS URL or Image ID:")), GBC.eol());
        panel.add(tfWmsUrl, GBC.eol().fill(GridBagConstraints.HORIZONTAL));

        ExtendedDialog diag = new ExtendedDialog(MainApplication.getMainFrame(),
                tr("Add Rectified Image"),
                tr("Add Rectified Image"), tr("Cancel"))
            .setContent(panel)
            .configureContextsensitiveHelp(ht("/Menu/Imagery"), true)
            .setButtonIcons("OLmarker", "cancel");

        // This repeatedly shows the dialog in case there has been an error.
        // The loop is break;-ed if the users cancels
        outer: while (true) {
            diag.showDialog();
            int answer = diag.getValue();
            // Break loop when the user cancels
            if (answer != 1) {
                break;
            }

            String text = tfWmsUrl.getText().trim();
            // Loop all services until we find the selected one
            for (RectifierService s : services) {
                if (!s.isSelected()) {
                    continue;
                }

                // We've reached the custom WMS URL service
                // Just set the URL and hope everything works out
                if (s.wmsUrl.isEmpty()) {
                    try {
                        addWMSLayer(s.name + " (" + text + ')', text);
                        break outer;
                    } catch (IllegalStateException ex) {
                        Logging.log(Logging.LEVEL_ERROR, ex);
                    }
                }

                // First try to match if the entered string as an URL
                Matcher m = s.urlRegEx.matcher(text);
                if (m.find()) {
                    String id = m.group(1);
                    String newURL = s.wmsUrl.replaceAll("__s__", id);
                    String title = s.name + " (" + id + ')';
                    addWMSLayer(title, newURL);
                    break outer;
                }
                // If not, look if it's a valid ID for the selected service
                if (s.idValidator.matcher(text).matches()) {
                    String newURL = s.wmsUrl.replaceAll("__s__", text);
                    String title = s.name + " (" + text + ')';
                    addWMSLayer(title, newURL);
                    break outer;
                }

                // We've found the selected service, but the entered string isn't suitable for
                // it. So quit checking the other radio buttons
                break;
            }

            // and display an error message. The while loop ensures that the dialog pops up again
            JOptionPane.showMessageDialog(MainApplication.getMainFrame(),
                    tr("Couldn''t match the entered link or id to the selected service. Please try again."),
                    tr("No valid WMS URL or id"),
                    JOptionPane.ERROR_MESSAGE);
            diag.setVisible(true);
        }
    }

    /**
     * Adds a WMS Layer with given title and URL
     * @param title Name of the layer as it will show up in the layer manager
     * @param url URL to the WMS server
     * @throws IllegalStateException if imagery time is neither HTML nor WMS
     */
    private static void addWMSLayer(String title, String url) {
        ImageryInfo info = new ImageryInfo(title, url);
        if (info.getImageryType() == ImageryType.WMS_ENDPOINT) {
            try {
                info = AddImageryLayerAction.getWMSLayerInfo(info);
            } catch (IOException | WMSGetCapabilitiesException e) {
                handleException(e);
                return;
            }
        }
        try {
            MainApplication.getLayerManager().addLayer(ImageryLayer.create(info));
        } catch (IllegalArgumentException e) {
            handleException(e);
        }
    }

    private static void handleException(Exception e) {
        Logging.error(e);
        JOptionPane.showMessageDialog(MainApplication.getMainFrame(),
                e.getMessage(), tr("No valid WMS URL or id"), JOptionPane.ERROR_MESSAGE);
    }

    @Override
    protected void updateEnabledState() {
        setEnabled(!getLayerManager().getLayers().isEmpty());
    }
}