// License: GPL. For details, see LICENSE file.
package org.openstreetmap.josm.plugins.graphview.plugin.dialogs;

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

import java.awt.Color;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Observable;
import java.util.Observer;
import java.util.Set;

import javax.swing.AbstractAction;
import javax.swing.JComboBox;
import javax.swing.JLabel;
import javax.swing.JPanel;

import org.openstreetmap.josm.gui.SideButton;
import org.openstreetmap.josm.gui.dialogs.ToggleDialog;
import org.openstreetmap.josm.plugins.graphview.core.access.AccessRulesetReader;
import org.openstreetmap.josm.plugins.graphview.core.visualisation.ColorScheme;
import org.openstreetmap.josm.plugins.graphview.core.visualisation.EndNodeColorScheme;
import org.openstreetmap.josm.plugins.graphview.core.visualisation.InclineColorScheme;
import org.openstreetmap.josm.plugins.graphview.core.visualisation.MaxheightColorScheme;
import org.openstreetmap.josm.plugins.graphview.core.visualisation.MaxspeedColorScheme;
import org.openstreetmap.josm.plugins.graphview.core.visualisation.MaxweightColorScheme;
import org.openstreetmap.josm.plugins.graphview.plugin.GraphViewPlugin;
import org.openstreetmap.josm.plugins.graphview.plugin.layer.PreferencesColorScheme;
import org.openstreetmap.josm.plugins.graphview.plugin.preferences.GraphViewPreferences;
import org.openstreetmap.josm.plugins.graphview.plugin.preferences.InternalRuleset;
import org.openstreetmap.josm.tools.ImageProvider;
import org.openstreetmap.josm.tools.Logging;
import org.openstreetmap.josm.tools.Shortcut;

/**
 * Dialog for graph view configuration.
 */
public class GraphViewDialog extends ToggleDialog implements Observer {

    private static final int HEIGHT = 150;

    /** map from labels to available color schemes */
    private final LinkedHashMap<String, ColorScheme> availableColorSchemes;

    private final GraphViewPreferences preferences;
    private final GraphViewPlugin plugin;

    private final JComboBox<String> rulesetComboBox;
    private final JComboBox<String> bookmarkComboBox;
    private final JComboBox<String> colorSchemeComboBox;

    /**
     * list of ruleset files in the order currently used by rulesetComboBox;
     * null if internal rulesets are used
     */
    private List<File> rulesetFiles;

    public GraphViewDialog(final GraphViewPlugin plugin) {

        super(tr("Graph View Dialog"), "graphview",
                tr("Open the dialog for graph view configuration."), (Shortcut) null, HEIGHT);

        this.preferences = GraphViewPreferences.getInstance();
        this.plugin = plugin;

        availableColorSchemes = new LinkedHashMap<>();

        availableColorSchemes.put(tr("default"),
                new PreferencesColorScheme(preferences));
        availableColorSchemes.put(tr("end nodes"),
                new EndNodeColorScheme(Color.GRAY, Color.RED, Color.GRAY));
        availableColorSchemes.put(tr("maxspeed"),
                new MaxspeedColorScheme());
        availableColorSchemes.put(tr("maxweight"),
                new MaxweightColorScheme());
        availableColorSchemes.put(tr("maxheight"),
                new MaxheightColorScheme());
        availableColorSchemes.put(tr("incline"),
                new InclineColorScheme());

        JPanel selectionPanel = new JPanel();
        GridBagLayout selectionLayout = new GridBagLayout();
        selectionPanel.setLayout(selectionLayout);

        GridBagConstraints gbcLabel = new GridBagConstraints();
        gbcLabel.gridx = 0;
        gbcLabel.anchor = GridBagConstraints.WEST;
        gbcLabel.insets = new Insets(0, 5, 0, 5);

        GridBagConstraints gbcComboBox = new GridBagConstraints();
        gbcComboBox.gridx = 1;
        gbcComboBox.fill = GridBagConstraints.HORIZONTAL;
        gbcComboBox.weightx = 1;


        /* create ruleset label and combo box */
        {
            JLabel rulesetLabel = new JLabel(tr("Ruleset:"));
            gbcLabel.gridy = 0;
            selectionLayout.setConstraints(rulesetLabel, gbcLabel);
            selectionPanel.add(rulesetLabel);

            rulesetComboBox = new JComboBox<>();
            rulesetComboBox.addActionListener(rulesetActionListener);
            gbcComboBox.gridy = 0;
            selectionLayout.setConstraints(rulesetComboBox, gbcComboBox);
            selectionPanel.add(rulesetComboBox);
        }

        /* create bookmark label and combo box */
        {
            JLabel bookmarkLabel = new JLabel(tr("Parameters:"));
            gbcLabel.gridy = 1;
            selectionLayout.setConstraints(bookmarkLabel, gbcLabel);
            selectionPanel.add(bookmarkLabel);

            bookmarkComboBox = new JComboBox<>();
            bookmarkComboBox.addActionListener(bookmarkActionListener);
            gbcComboBox.gridy = 1;
            selectionLayout.setConstraints(bookmarkComboBox, gbcComboBox);
            selectionPanel.add(bookmarkComboBox);
        }

        /* create color scheme label and combo box */
        {
            JLabel colorSchemeLabel = new JLabel(tr("Coloring:"));
            gbcLabel.gridy = 2;
            selectionLayout.setConstraints(colorSchemeLabel, gbcLabel);
            selectionPanel.add(colorSchemeLabel);

            colorSchemeComboBox = new JComboBox<>();
            for (String colorSchemeName : availableColorSchemes.keySet()) {
                colorSchemeComboBox.addItem(colorSchemeName);
                ColorScheme colorScheme = availableColorSchemes.get(colorSchemeName);
                if (colorScheme.getClass().equals(preferences.getCurrentColorScheme().getClass())) {
                    colorSchemeComboBox.setSelectedItem(colorSchemeName);
                }
            }
            colorSchemeComboBox.addActionListener(colorSchemeActionListener);
            gbcComboBox.gridy = 2;
            selectionLayout.setConstraints(colorSchemeComboBox, gbcComboBox);
            selectionPanel.add(colorSchemeComboBox);
        }

        createLayout(selectionPanel, true, Arrays.asList(
            new SideButton(new GraphViewAction())
        ));

        updateSelections();
        this.preferences.addObserver(this);
    }

    private class GraphViewAction extends AbstractAction {

        GraphViewAction() {
            super(tr("Create/update graph"));
            new ImageProvider("graphview_no_shadow").getResource().attachImageIcon(this, true);
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            plugin.createGraphViewLayer();
        }
    }

    private final ActionListener rulesetActionListener = new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent e) {
            if (rulesetComboBox.getSelectedItem() != null) {
                int selectedRulesetIndex = rulesetComboBox.getSelectedIndex();
                if (rulesetFiles != null) {
                    File selectedRulesetFile = rulesetFiles.get(selectedRulesetIndex);
                    preferences.setCurrentRulesetFile(selectedRulesetFile);
                    preferences.distributeChanges();
                    plugin.updateGraphViewLayer();
                } else {
                    if (selectedRulesetIndex < InternalRuleset.values().length) {
                        InternalRuleset selectedIRR = InternalRuleset.values()[selectedRulesetIndex];
                        preferences.setCurrentInternalRuleset(selectedIRR);
                        preferences.distributeChanges();
                        plugin.updateGraphViewLayer();
                    }
                }
            }
        }
    };

    private final ActionListener bookmarkActionListener = new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent e) {
            String selectedBookmarkName = (String) bookmarkComboBox.getSelectedItem();
            if (selectedBookmarkName != null) {
                preferences.setCurrentParameterBookmarkName(selectedBookmarkName);
                preferences.distributeChanges();
                plugin.updateGraphViewLayer();
            }
        }
    };

    private final ActionListener colorSchemeActionListener = new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent e) {
            assert availableColorSchemes.containsKey(colorSchemeComboBox.getSelectedItem());
            String colorSchemeLabel = (String) colorSchemeComboBox.getSelectedItem();
            preferences.setCurrentColorScheme(availableColorSchemes.get(colorSchemeLabel));
            preferences.distributeChanges();
            plugin.repaintGraphViewLayer();
        }
    };

    @Override
    public void update(Observable observable, Object param) {
        if (observable == preferences) {
            updateSelections();
        }
    }

    protected void updateSelections() {

        /* update rulesets */

        rulesetComboBox.removeActionListener(rulesetActionListener);

        if (preferences.getUseInternalRulesets()) {

            rulesetFiles = null;

            rulesetComboBox.removeAllItems();
            for (int i = 0; i < InternalRuleset.values().length; i++) {
                InternalRuleset ruleset = InternalRuleset.values()[i];
                rulesetComboBox.addItem(ruleset.toString());
                if (ruleset == preferences.getCurrentInternalRuleset()) {
                    rulesetComboBox.setSelectedIndex(i);
                }
            }

            if (preferences.getCurrentInternalRuleset() == null) {
                rulesetComboBox.addItem("");
                rulesetComboBox.setSelectedIndex(InternalRuleset.values().length);
            }

        } else {

            rulesetFiles = new LinkedList<>();

            File[] filesInRulesetFolder = preferences.getRulesetFolder().listFiles();

            if (filesInRulesetFolder != null) {
                for (File possibleRulesetFile : filesInRulesetFolder) {
                    try {
                        AccessRulesetReader.readAccessRuleset(new FileInputStream(possibleRulesetFile));
                        rulesetFiles.add(possibleRulesetFile);
                    } catch (IOException ioe) {
                        //don't add to rulesetFiles
                        Logging.debug(ioe);
                    }
                }
            }

            Collections.sort(rulesetFiles);

            rulesetComboBox.removeAllItems();
            for (int i = 0; i < rulesetFiles.size(); i++) {
                File rulesetFile = rulesetFiles.get(i);
                rulesetComboBox.addItem(rulesetFile.getName());
                if (rulesetFile.equals(preferences.getCurrentRulesetFile())) {
                    rulesetComboBox.setSelectedIndex(i);
                }
            }

        }

        rulesetComboBox.addActionListener(rulesetActionListener);

        /* update bookmarks */

        bookmarkComboBox.removeActionListener(bookmarkActionListener);

        String activeBookmarkName = preferences.getCurrentParameterBookmarkName();
        Set<String> bookmarkNames = new HashSet<>(preferences.getParameterBookmarks().keySet());

        bookmarkComboBox.removeAllItems();
        for (String bookmarkName : bookmarkNames) {
            bookmarkComboBox.addItem(bookmarkName);
            if (bookmarkName.equals(activeBookmarkName)) {
                bookmarkComboBox.setSelectedItem(bookmarkName);
            }
        }

        bookmarkComboBox.addActionListener(bookmarkActionListener);
    }
}
