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

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

import java.awt.Component;
import java.awt.GraphicsEnvironment;
import java.awt.MenuComponent;
import java.awt.event.ActionEvent;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Comparator;
import java.util.EnumMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Map.Entry;
import java.util.stream.Collectors;

import javax.swing.Action;
import javax.swing.JComponent;
import javax.swing.JMenu;
import javax.swing.JMenuItem;
import javax.swing.JPopupMenu;
import javax.swing.event.MenuEvent;
import javax.swing.event.MenuListener;

import org.openstreetmap.josm.actions.AddImageryLayerAction;
import org.openstreetmap.josm.actions.JosmAction;
import org.openstreetmap.josm.actions.MapRectifierWMSmenuAction;
import org.openstreetmap.josm.data.coor.LatLon;
import org.openstreetmap.josm.data.imagery.ImageryInfo;
import org.openstreetmap.josm.data.imagery.ImageryInfo.ImageryCategory;
import org.openstreetmap.josm.data.imagery.ImageryLayerInfo;
import org.openstreetmap.josm.data.imagery.Shape;
import org.openstreetmap.josm.gui.layer.ImageryLayer;
import org.openstreetmap.josm.gui.layer.LayerManager.LayerAddEvent;
import org.openstreetmap.josm.gui.layer.LayerManager.LayerChangeListener;
import org.openstreetmap.josm.gui.layer.LayerManager.LayerOrderChangeEvent;
import org.openstreetmap.josm.gui.layer.LayerManager.LayerRemoveEvent;
import org.openstreetmap.josm.gui.preferences.imagery.ImageryPreference;
import org.openstreetmap.josm.tools.ImageProvider;
import org.openstreetmap.josm.tools.ImageProvider.ImageSizes;
import org.openstreetmap.josm.tools.Logging;
import org.openstreetmap.josm.tools.Utils;

/**
 * Imagery menu, holding entries for imagery preferences, offset actions and dynamic imagery entries
 * depending on current mapview coordinates.
 * @since 3737
 */
public class ImageryMenu extends JMenu implements LayerChangeListener {

    static final class AdjustImageryOffsetAction extends JosmAction {

        AdjustImageryOffsetAction() {
            super(tr("Imagery offset"), "mapmode/adjustimg", tr("Adjust imagery offset"), null, false, false);
            setToolbarId("imagery-offset");
            MainApplication.getToolbar().register(this);
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            Collection<ImageryLayer> layers = MainApplication.getLayerManager().getLayersOfType(ImageryLayer.class);
            if (layers.isEmpty()) {
                setEnabled(false);
                return;
            }
            Component source = null;
            if (e.getSource() instanceof Component) {
                source = (Component) e.getSource();
            }
            JPopupMenu popup = new JPopupMenu();
            if (layers.size() == 1) {
                JComponent c = layers.iterator().next().getOffsetMenuItem(popup);
                if (c instanceof JMenuItem) {
                    ((JMenuItem) c).getAction().actionPerformed(e);
                } else {
                    if (source == null || !source.isShowing()) return;
                    popup.show(source, source.getWidth()/2, source.getHeight()/2);
                }
                return;
            }
            if (source == null || !source.isShowing()) return;
            for (ImageryLayer layer : layers) {
                JMenuItem layerMenu = layer.getOffsetMenuItem();
                layerMenu.setText(layer.getName());
                layerMenu.setIcon(layer.getIcon());
                popup.add(layerMenu);
            }
            popup.show(source, source.getWidth()/2, source.getHeight()/2);
        }
    }

    /**
     * Compare ImageryInfo objects alphabetically by name.
     *
     * ImageryInfo objects are normally sorted by country code first
     * (for the preferences). We don't want this in the imagery menu.
     */
    public static final Comparator<ImageryInfo> alphabeticImageryComparator =
            Comparator.comparing(ii -> ii.getName().toLowerCase(Locale.ENGLISH));

    private final transient Action offsetAction = new AdjustImageryOffsetAction();

    private final JMenuItem singleOffset = new JMenuItem(offsetAction);
    private JMenuItem offsetMenuItem = singleOffset;
    private final MapRectifierWMSmenuAction rectaction = new MapRectifierWMSmenuAction();

    /**
     * Constructs a new {@code ImageryMenu}.
     * @param subMenu submenu in that contains plugin-managed additional imagery layers
     */
    public ImageryMenu(JMenu subMenu) {
        /* I18N: mnemonic: I */
        super(trc("menu", "Imagery"));
        setupMenuScroller();
        MainApplication.getLayerManager().addLayerChangeListener(this);
        // build dynamically
        addMenuListener(new MenuListener() {
            @Override
            public void menuSelected(MenuEvent e) {
                refreshImageryMenu();
            }

            @Override
            public void menuDeselected(MenuEvent e) {
                // Do nothing
            }

            @Override
            public void menuCanceled(MenuEvent e) {
                // Do nothing
            }
        });
        MainMenu.add(subMenu, rectaction);
    }

    private void setupMenuScroller() {
        if (!GraphicsEnvironment.isHeadless()) {
            MenuScroller.setScrollerFor(this, 150, 2);
        }
    }

    /**
     * For layers containing complex shapes, check that center is in one of its shapes (fix #7910)
     * @param info layer info
     * @param pos center
     * @return {@code true} if center is in one of info shapes
     */
    private static boolean isPosInOneShapeIfAny(ImageryInfo info, LatLon pos) {
        List<Shape> shapes = info.getBounds().getShapes();
        return Utils.isEmpty(shapes) || shapes.stream().anyMatch(s -> s.contains(pos));
    }

    /**
     * Refresh imagery menu.
     *
     * Outside this class only called in {@link ImageryPreference#initialize()}.
     * (In order to have actions ready for the toolbar, see #8446.)
     */
    public void refreshImageryMenu() {
        removeDynamicItems();

        addDynamic(offsetMenuItem);
        addDynamicSeparator();

        // for each configured ImageryInfo, add a menu entry.
        final List<ImageryInfo> savedLayers = new ArrayList<>(ImageryLayerInfo.instance.getLayers());
        savedLayers.sort(alphabeticImageryComparator);
        for (final ImageryInfo u : savedLayers) {
            addDynamic(trackJosmAction(new AddImageryLayerAction(u)), null);
        }

        // list all imagery entries where the current map location is within the imagery bounds
        if (MainApplication.isDisplayingMapView()) {
            MapView mv = MainApplication.getMap().mapView;
            LatLon pos = mv.getProjection().eastNorth2latlon(mv.getCenter());
            final List<ImageryInfo> alreadyInUse = ImageryLayerInfo.instance.getLayers();
            final List<ImageryInfo> inViewLayers = ImageryLayerInfo.instance.getDefaultLayers()
                    .stream().filter(i -> i.getBounds() != null && i.getBounds().contains(pos)
                        && !alreadyInUse.contains(i) && isPosInOneShapeIfAny(i, pos))
                    .sorted(alphabeticImageryComparator)
                    .collect(Collectors.toList());
            if (!inViewLayers.isEmpty()) {
                if (inViewLayers.stream().anyMatch(i -> i.getImageryCategory() == ImageryCategory.PHOTO)) {
                    addDynamicSeparator();
                }
                for (ImageryInfo i : inViewLayers) {
                    addDynamic(trackJosmAction(new AddImageryLayerAction(i)), i.getImageryCategory());
                }
            }
            if (!dynamicNonPhotoItems.isEmpty()) {
                addDynamicSeparator();
                for (Entry<ImageryCategory, List<JMenuItem>> e : dynamicNonPhotoItems.entrySet()) {
                    ImageryCategory cat = e.getKey();
                    List<JMenuItem> list = e.getValue();
                    if (list.size() > 1) {
                        JMenuItem categoryMenu = new JMenu(cat.getDescription());
                        categoryMenu.setIcon(cat.getIcon(ImageSizes.MENU));
                        for (JMenuItem it : list) {
                            categoryMenu.add(it);
                        }
                        dynamicNonPhotoMenus.add(add(categoryMenu));
                    } else if (!list.isEmpty()) {
                        dynamicNonPhotoMenus.add(add(list.get(0)));
                    }
                }
            }
        }

        addDynamicSeparator();
        JMenu subMenu = MainApplication.getMenu().imagerySubMenu;
        int heightUnrolled = 30*(getItemCount()+subMenu.getItemCount());
        if (heightUnrolled < MainApplication.getMainPanel().getHeight()) {
            // add all items of submenu if they will fit on screen
            int n = subMenu.getItemCount();
            for (int i = 0; i < n; i++) {
                addDynamic(subMenu.getItem(i).getAction(), null);
            }
        } else {
            // or add the submenu itself
            addDynamic(subMenu);
        }
    }

    private JMenuItem getNewOffsetMenu() {
        Collection<ImageryLayer> layers = MainApplication.getLayerManager().getLayersOfType(ImageryLayer.class);
        if (layers.isEmpty()) {
            offsetAction.setEnabled(false);
            return singleOffset;
        }
        offsetAction.setEnabled(true);
        JMenu newMenu = new JMenu(trc("layer", "Offset"));
        newMenu.setIcon(ImageProvider.get("mapmode", "adjustimg"));
        newMenu.setAction(offsetAction);
        if (layers.size() == 1)
            return (JMenuItem) layers.iterator().next().getOffsetMenuItem(newMenu);
        for (ImageryLayer layer : layers) {
            JMenuItem layerMenu = layer.getOffsetMenuItem();
            layerMenu.setText(layer.getName());
            layerMenu.setIcon(layer.getIcon());
            newMenu.add(layerMenu);
        }
        return newMenu;
    }

    /**
     * Refresh offset menu item.
     */
    public void refreshOffsetMenu() {
        offsetMenuItem = getNewOffsetMenu();
    }

    @Override
    public void layerAdded(LayerAddEvent e) {
        if (e.getAddedLayer() instanceof ImageryLayer) {
            refreshOffsetMenu();
        }
    }

    @Override
    public void layerRemoving(LayerRemoveEvent e) {
        if (e.getRemovedLayer() instanceof ImageryLayer) {
            refreshOffsetMenu();
        }
    }

    @Override
    public void layerOrderChanged(LayerOrderChangeEvent e) {
        refreshOffsetMenu();
    }

    /**
     * List to store temporary "photo" menu items. They will be deleted
     * (and possibly recreated) when refreshImageryMenu() is called.
     */
    private final List<Object> dynamicItems = new ArrayList<>(20);
    /**
     * Map to store temporary "not photo" menu items. They will be deleted
     * (and possibly recreated) when refreshImageryMenu() is called.
     */
    private final Map<ImageryCategory, List<JMenuItem>> dynamicNonPhotoItems = new EnumMap<>(ImageryCategory.class);
    /**
     * List to store temporary "not photo" submenus. They will be deleted
     * (and possibly recreated) when refreshImageryMenu() is called.
     */
    private final List<JMenuItem> dynamicNonPhotoMenus = new ArrayList<>(20);
    private final List<JosmAction> dynJosmActions = new ArrayList<>(20);

    /**
     * Remove all the items in dynamic items collection
     * @since 5803
     */
    private void removeDynamicItems() {
        dynJosmActions.forEach(JosmAction::destroy);
        dynJosmActions.clear();
        dynamicItems.forEach(this::removeDynamicItem);
        dynamicItems.clear();
        dynamicNonPhotoMenus.forEach(this::removeDynamicItem);
        dynamicItems.clear();
        dynamicNonPhotoItems.clear();
    }

    private void removeDynamicItem(Object item) {
        if (item instanceof JMenuItem) {
            remove((JMenuItem) item);
        } else if (item instanceof MenuComponent) {
            remove((MenuComponent) item);
        } else if (item instanceof Component) {
            remove((Component) item);
        } else {
            Logging.error("Unknown imagery menu item type: {0}", item);
        }
    }

    private void addDynamicSeparator() {
        JPopupMenu.Separator s = new JPopupMenu.Separator();
        dynamicItems.add(s);
        add(s);
    }

    private void addDynamic(Action a, ImageryCategory category) {
        JMenuItem item = createActionComponent(a);
        item.setAction(a);
        doAddDynamic(item, category);
    }

    private void addDynamic(JMenuItem it) {
        doAddDynamic(it, null);
    }

    private void doAddDynamic(JMenuItem item, ImageryCategory category) {
        if (category == null || category == ImageryCategory.PHOTO) {
            dynamicItems.add(this.add(item));
        } else {
            dynamicNonPhotoItems.computeIfAbsent(category, x -> new ArrayList<>()).add(item);
        }
    }

    private Action trackJosmAction(Action action) {
        if (action instanceof JosmAction) {
            dynJosmActions.add((JosmAction) action);
        }
        return action;
    }

}