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

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

import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.Collections;
import java.util.List;
import java.util.stream.Collectors;

import javax.swing.AbstractAction;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.ListSelectionModel;
import javax.swing.event.ListDataEvent;
import javax.swing.event.ListDataListener;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;

import org.openstreetmap.josm.actions.downloadtasks.DownloadReferrersTask;
import org.openstreetmap.josm.data.osm.OsmPrimitive;
import org.openstreetmap.josm.data.osm.PrimitiveId;
import org.openstreetmap.josm.data.osm.Relation;
import org.openstreetmap.josm.gui.MainApplication;
import org.openstreetmap.josm.gui.PrimitiveRenderer;
import org.openstreetmap.josm.gui.io.DownloadPrimitivesTask;
import org.openstreetmap.josm.gui.layer.OsmDataLayer;
import org.openstreetmap.josm.gui.util.GuiHelper;
import org.openstreetmap.josm.tools.ImageProvider;

/**
 * This is browser for a list of relations which refer to another relations.
 * @since 1806
 */
public class ReferringRelationsBrowser extends JPanel {

    /** the list of relations */
    private JList<Relation> referrers;
    private final ReferringRelationsBrowserModel model;
    private final transient OsmDataLayer layer;
    private final JCheckBox cbReadFull = new JCheckBox(tr("including immediate children of parent relations"));
    private EditAction editAction;

    /**
     * Constructs a new {@code ReferringRelationsBrowser}.
     * @param layer OSM data layer
     * @param model referring relations browser model
     */
    public ReferringRelationsBrowser(OsmDataLayer layer, ReferringRelationsBrowserModel model) {
        this.model = model;
        this.layer = layer;
        build();
    }

    /**
     * build the GUI
     */
    protected void build() {
        setLayout(new BorderLayout());
        referrers = new JList<>(model);
        referrers.setCellRenderer(new PrimitiveRenderer());
        add(new JScrollPane(referrers), BorderLayout.CENTER);
        referrers.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        referrers.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                if (e.getClickCount() == 2
                    && !e.isAltDown() && !e.isAltGraphDown() && !e.isControlDown() && !e.isMetaDown() && !e.isShiftDown()) {
                    Rectangle cellBounds = referrers.getCellBounds(referrers.getSelectedIndex(), referrers.getSelectedIndex());
                    if (cellBounds != null && cellBounds.contains(e.getPoint())) {
                        editAction.actionPerformed(new ActionEvent(e.getSource(), ActionEvent.ACTION_PERFORMED, null));
                    }
                }
            }
        });

        JPanel pnl = new JPanel(new FlowLayout(FlowLayout.LEFT));

        ReloadAction reloadAction = new ReloadAction();
        referrers.getModel().addListDataListener(reloadAction);
        pnl.add(new JButton(reloadAction));
        pnl.add(cbReadFull);

        editAction = new EditAction();
        referrers.getSelectionModel().addListSelectionListener(editAction);
        pnl.add(new JButton(editAction));
        add(pnl, BorderLayout.SOUTH);
    }

    /**
     * Initializes the model with layer data.
     */
    public void init() {
        model.populate(getLayer().data);
    }

    protected OsmDataLayer getLayer() {
        return layer;
    }

    /**
     * Action for loading the parent relations of a relation
     *
     */
    class ReloadAction extends AbstractAction implements ListDataListener {
        ReloadAction() {
            putValue(SHORT_DESCRIPTION, tr("Load parent relations"));
            new ImageProvider("dialogs", "refresh").getResource().attachImageIcon(this);
            putValue(NAME, tr("Reload"));
            refreshEnabled();
        }

        protected void refreshEnabled() {
            setEnabled(model.canReload());
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            DownloadReferrersTask task = new DownloadReferrersTask(getLayer(), Collections.singleton(model.getRelation()));
            MainApplication.worker.submit(task);
            MainApplication.worker.submit(() -> {
                if (cbReadFull.isSelected() && !task.getProgressMonitor().isCanceled()) {
                    // download all members of parents
                    List<PrimitiveId> parentsChildren = model.getRelation().referrers(Relation.class)
                            .collect(Collectors.toSet()).stream().flatMap(r -> r.getMemberPrimitives().stream())
                            .distinct().map(OsmPrimitive::getPrimitiveId).distinct().collect(Collectors.toList());
                    new DownloadPrimitivesTask(getLayer(), parentsChildren, false).run();
                }
            });
            GuiHelper.executeByMainWorkerInEDT(() ->
                model.populate(model.getRelation().getReferrers().stream()
                        .filter(Relation.class::isInstance)
                        .map(Relation.class::cast)
                        .collect(Collectors.toList()))
                );
        }

        @Override
        public void contentsChanged(ListDataEvent e) {
            refreshEnabled();
        }

        @Override
        public void intervalAdded(ListDataEvent e) {
            refreshEnabled();
        }

        @Override
        public void intervalRemoved(ListDataEvent e) {
            refreshEnabled();
        }
    }

    /**
     * Action for editing the currently selected relation
     *
     */
    class EditAction extends AbstractAction implements ListSelectionListener {
        EditAction() {
            putValue(SHORT_DESCRIPTION, tr("Edit the currently selected relation"));
            new ImageProvider("dialogs", "edit").getResource().attachImageIcon(this);
            putValue(NAME, tr("Edit"));
            refreshEnabled();
        }

        protected void refreshEnabled() {
            setEnabled(referrers.getSelectionModel().getMinSelectionIndex() >= 0);
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            run();
        }

        public void run() {
            int idx = referrers.getSelectedIndex();
            if (idx < 0)
                return;
            Relation r = model.getElementAt(idx);
            if (r == null)
                return;
            RelationEditor editor = RelationEditor.getEditor(getLayer(), r, null);
            editor.setVisible(true);
        }

        @Override
        public void valueChanged(ListSelectionEvent e) {
            refreshEnabled();
        }
    }
}