package com.ts3client.ui;

import com.ts3client.config.Settings;
import com.ts3client.gfx.IconPack;

import javax.swing.BorderFactory;
import javax.swing.DefaultListCellRenderer;
import javax.swing.DefaultListModel;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JComponent;
import javax.swing.JFileChooser;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextField;
import javax.swing.SwingConstants;
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.io.File;

/**
 * Options page for icon packs: which pack the user interface is drawn with, where
 * to look for more of them, and a viewer showing everything the pack contains.
 *
 * <p>Picking a pack applies it right away so the change can be seen in the window
 * behind the dialog; cancelling puts the previous one back.
 */
final class IconPackPanel extends JPanel {

    /** Size of the tiles in the icon viewer. */
    private static final int PREVIEW_SIZE = 32;
    private static final int TILE = 44;

    /** Stands for "no pack": the icons the client draws itself. */
    private static final String BUILT_IN = "Built-in icons";

    private final Settings settings;
    private final String originalPackId;
    private final String originalPackDir;

    private final JComboBox<Object> packCombo = new JComboBox<>();
    private final JLabel packInfo = new JLabel();
    private final JTextField packDirField;
    private final DefaultListModel<String> previewModel = new DefaultListModel<>();
    private final JList<String> preview = new JList<>(previewModel);

    IconPackPanel(Settings settings) {
        super(new BorderLayout(0, 8));
        this.settings = settings;
        this.originalPackId = settings.iconPack;
        this.originalPackDir = settings.iconPackDir;
        this.packDirField = new JTextField(settings.iconPackDir, 18);

        setBorder(BorderFactory.createEmptyBorder(12, 12, 12, 12));
        add(buildHeader(), BorderLayout.NORTH);
        add(buildPreview(), BorderLayout.CENTER);

        reloadPacks();
    }

    /** Copies the chosen pack into the settings; the caller saves them. */
    void apply() {
        settings.iconPackDir = packDirField.getText().trim();
        Object selected = packCombo.getSelectedItem();
        settings.iconPack = selected instanceof IconPack pack ? pack.id() : "";
    }

    /** Puts back the pack the dialog started with, for a cancelled edit. */
    void revert() {
        settings.iconPack = originalPackId;
        settings.iconPackDir = originalPackDir;
        IconTheme.get().reload(settings);
    }

    // ---- layout ----

    private JComponent buildHeader() {
        JPanel p = new JPanel(new GridBagLayout());
        GridBagConstraints c = new GridBagConstraints();
        c.insets = new Insets(2, 2, 2, 2);
        c.anchor = GridBagConstraints.WEST;
        c.fill = GridBagConstraints.HORIZONTAL;

        packCombo.setToolTipText("Icon packs installed here or in a TeamSpeak 3 client");
        packCombo.addActionListener(e -> onPackSelected());
        packCombo.setRenderer(new DefaultListCellRenderer() {
            @Override
            public Component getListCellRendererComponent(JList<?> list, Object value, int index,
                                                          boolean selected, boolean focus) {
                super.getListCellRendererComponent(list, value, index, selected, focus);
                setText(value instanceof IconPack pack ? pack.name() : String.valueOf(value));
                return this;
            }
        });

        int row = 0;
        addRow(p, c, row++, new JLabel("Icon pack:"), packCombo);
        c.gridx = 1;
        c.gridy = row++;
        packInfo.setEnabled(false);
        p.add(packInfo, c);

        JPanel dirRow = new JPanel(new BorderLayout(6, 0));
        JButton browse = new JButton("Browse…");
        browse.addActionListener(e -> browseForPackFolder());
        dirRow.add(packDirField, BorderLayout.CENTER);
        dirRow.add(browse, BorderLayout.EAST);
        packDirField.setToolTipText("Extra folder to look for icon packs in");
        addRow(p, c, row, new JLabel("Extra pack folder:"), dirRow);
        return p;
    }

    private JComponent buildPreview() {
        preview.setLayoutOrientation(JList.HORIZONTAL_WRAP);
        preview.setVisibleRowCount(-1);
        preview.setFixedCellWidth(TILE);
        preview.setFixedCellHeight(TILE);
        preview.setCellRenderer(new DefaultListCellRenderer() {
            @Override
            public Component getListCellRendererComponent(JList<?> list, Object value, int index,
                                                          boolean selected, boolean focus) {
                super.getListCellRendererComponent(list, value, index, selected, focus);
                String key = String.valueOf(value);
                ImageIcon icon = Icons.of(key, PREVIEW_SIZE);
                setText("");
                setIcon(icon);
                setToolTipText(key);
                setHorizontalAlignment(SwingConstants.CENTER);
                return this;
            }
        });

        JScrollPane scroll = new JScrollPane(preview);
        scroll.setPreferredSize(new Dimension(360, 200));
        scroll.setBorder(BorderFactory.createTitledBorder("Icons in this pack"));
        return scroll;
    }

    // ---- behaviour ----

    private void reloadPacks() {
        IconTheme theme = IconTheme.get();
        theme.reload(settings);
        // Filling the combo box changes its selection, and with it the active pack,
        // so remember the one the settings asked for before touching it.
        IconPack selected = theme.activePack();

        packCombo.removeAllItems();
        packCombo.addItem(BUILT_IN);
        for (IconPack pack : theme.packs()) packCombo.addItem(pack);
        packCombo.setSelectedItem(selected == null ? BUILT_IN : selected);
        onPackSelected();
    }

    private void onPackSelected() {
        Object selected = packCombo.getSelectedItem();
        IconPack pack = selected instanceof IconPack p ? p : null;
        IconTheme.get().setPack(pack);

        previewModel.clear();
        if (pack == null) {
            packInfo.setText("Drawn by the client itself");
        } else {
            for (String key : pack.keys()) previewModel.addElement(key);
            packInfo.setText(pack.keys().size() + " icons"
                    + (pack.fallsBack() ? ", missing ones from the default pack" : ""));
        }
    }

    private void browseForPackFolder() {
        JFileChooser chooser = new JFileChooser();
        chooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
        chooser.setDialogTitle("Folder containing icon packs");
        String current = packDirField.getText().trim();
        if (!current.isEmpty()) chooser.setCurrentDirectory(new File(current));
        if (chooser.showOpenDialog(this) != JFileChooser.APPROVE_OPTION) return;
        packDirField.setText(chooser.getSelectedFile().getAbsolutePath());
        settings.iconPackDir = packDirField.getText();
        reloadPacks();
    }

    private static void addRow(JPanel p, GridBagConstraints c, int row, JLabel label, Component field) {
        c.gridx = 0;
        c.gridy = row;
        c.weightx = 0;
        p.add(label, c);
        c.gridx = 1;
        c.weightx = 1;
        p.add(field, c);
    }
}