package ui.gui.widgets;

import model.asn1.exceptions.ParseException;
import ui.Utils;

import javax.swing.*;
import javax.swing.filechooser.FileNameExtensionFilter;
import java.awt.*;
import java.awt.event.ActionListener;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardOpenOption;
import java.util.stream.IntStream;

import static java.awt.GridBagConstraints.BOTH;
import static java.awt.GridBagConstraints.HORIZONTAL;
import static javax.swing.JOptionPane.*;

/**
 * Useful utilities for building GUI.
 */
public class UIUtils {
    /**
     * EFFECTS: Create a horizontal actions pane:
     * -----------------------------------------------------------
     * |                 | Button1 | Button2 | Button3 | ButtonN |
     * -----------------------------------------------------------
     * REQUIRES: buttons != null
     */
    public static JPanel createActionsPane(JButton... buttons) {
        final JPanel panelAct = new JPanel();
        panelAct.setLayout(new GridBagLayout());
        IntStream.range(0, buttons.length)
                .forEach(i -> panelAct.add(buttons[i],
                        new GCBuilder().gridXY(i + 1, 1).fill(HORIZONTAL).build()));
        panelAct.add(new JPanel(), new GCBuilder().expandXY().fill(BOTH).build());
        return panelAct;
    }

    /**
     * EFFECTS: Show / hide default text for a card layout container.
     * MODIFIES: cardLayoutPanel
     * REQUIRES: cardLayoutPanel must have a card layout; it must have CardContent and CardDefault cards.
     */
    public static void setContentVisible(Container cardLayoutPanel, boolean showContent) {
        switchTo(cardLayoutPanel, showContent ? "CardContent" : "CardDefault");
    }

    /**
     * EFFECTS: Switch to the card for a card layout panel.
     * MODIFIES: cardLayoutPanel
     * REQUIRES: cardLayoutPanel must have a card layout; it must have "card" card.
     */
    public static void switchTo(Container cardLayoutPanel, String card) {
        ((CardLayout) cardLayoutPanel.getLayout()).show(cardLayoutPanel, card);
    }

    /**
     * EFFECTS: Show an error message based on {@link Throwable#getMessage()}
     * REQUIRES: component must have a frame.
     */
    public static void alert(Component component, String title, Throwable e) {
        alert(component, title, e.getMessage());
    }

    /**
     * EFFECTS: Show an error message.
     * REQUIRES: component must have a frame.
     */
    public static void alert(Component component, String title, String message) {
        showMessageDialog(getFrameForComponent(component),
                message,
                title,
                ERROR_MESSAGE);
    }

    /**
     * EFFECTS: Show a file chooser with the given filter title and list of extensions. Starting from cwd.
     * Return null if cancelled.
     */
    public static Path chooseFile(Component component, String filterTitle, String... extensions) {
        final JFileChooser fc = new JFileChooser();
        fc.setFileFilter(new FileNameExtensionFilter(filterTitle, extensions));
        fc.setCurrentDirectory(Paths.get("").toAbsolutePath().toFile());
        if (fc.showOpenDialog(getFrameForComponent(component)) == JFileChooser.APPROVE_OPTION) {
            return fc.getSelectedFile().toPath();
        }
        return null;
    }

    /**
     * EFFECTS: Create a JPanel with CardLayout that has CardDefault set to component and CardContent set to a JLabel
     * with the default text.
     */
    public static JPanel defView(Component component, String defaultText) {
        final JPanel panel = new JPanel();
        panel.setLayout(new CardLayout(0, 0));

        JLabel labelDefault = new JLabel(defaultText);
        labelDefault.setHorizontalAlignment(0);
        panel.add(labelDefault, "CardDefault");
        panel.add(component, "CardContent");

        return panel;
    }

    /**
     * EFFECTS: Create a JScrollPane-wrapped JTable.
     * MODIFIES: table
     */
    public static JScrollPane scrTbl(JTable table) {
        final JScrollPane scrollPane = new JScrollPane();
        table.setFillsViewportHeight(true);
        scrollPane.setViewportView(table);
        return scrollPane;
    }

    /**
     * EFFECTS: Parse the given path and automatically determine if it is a DER binary or a PEM. Automatically decode
     * PEM.
     *      Throws {@link IOException} if it cannot be read.
     *      Throws {@link ParseException} if the PEM is invalid.
     */
    public static Byte[] openDERorPEM(Path path, String tag) throws IOException, ParseException {
        final InputStream fd = Files.newInputStream(path, StandardOpenOption.READ);
        Byte[] bs = Utils.byteToByte(fd.readAllBytes());
        fd.close();
        if (bs.length < 1) {
            throw new ParseException("Invalid file: too short");
        }
        if (bs[0] == '-') {
            bs = Utils.parsePEM(bs, tag);
        }
        return bs;
    }

    /**
     * EFFECTS: Create a button with the given label and click listener.
     */
    public static JButton btn(String string, ActionListener onClick) {
        final JButton btn = new JButton(string);
        btn.addActionListener(onClick);
        return btn;
    }

    /**
     * EFFECTS: Create a button with the given label, mnemonic, and click listener.
     */
    public static JButton btn(String string, char m, ActionListener onClick) {
        final JButton btn = new JButton(string);
        btn.setMnemonic(m);
        btn.setDisplayedMnemonicIndex(0);
        btn.addActionListener(onClick);
        return btn;
    }

    /**
     * EFFECTS: Create a button with the given label, mnemonic, icon, and click listener.
     */
    public static JButton btn(String string, String icon, ActionListener onClick) {
        final JButton btn = new JButton(string, new ImageIcon(UIUtils.class.getResource("/" + icon)));
        btn.addActionListener(onClick);
        return btn;
    }
}