package dev.kske.chess.ui;

import java.awt.Desktop;
import java.awt.Toolkit;
import java.awt.dnd.DropTarget;
import java.io.File;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.util.List;

import javax.swing.*;

import dev.kske.chess.board.Board;
import dev.kske.chess.board.FENString;
import dev.kske.chess.exception.ChessException;
import dev.kske.chess.game.Game;
import dev.kske.chess.pgn.PGNDatabase;
import dev.kske.chess.pgn.PGNGame;

/**
 * Project: <strong>Chess</strong><br>
 * File: <strong>MainWindow.java</strong><br>
 * Created: <strong>01.07.2019</strong><br>
 *
 * @since Chess v0.1-alpha
 * @author Kai S. K. Engelbart
 */
public class MainWindow extends JFrame {

	private JTabbedPane tabbedPane = new JTabbedPane();

	private static final long serialVersionUID = -3100939302567978977L;

	/**
	 * Launch the application.
	 *
	 * @param args command line arguments are ignored
	 */
	public static void main(String[] args) {
		SwingUtilities.invokeLater(MainWindow::new);
	}

	/**
	 * Create the application.
	 */
	private MainWindow() {
		super("Chess by Kai S. K. Engelbart");

		// Configure frame
		setResizable(false);
		setBounds(100, 100, 494, 565);
		setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
		setIconImage(
			Toolkit.getDefaultToolkit()
				.getImage(getClass().getResource("/pieces/queen_white.png"))
		);

		// Add tabbed pane, menu bar and drop target
		getContentPane().add(tabbedPane);
		setJMenuBar(new MenuBar(this));
		new DropTarget(this, new GameDropTarget(this));

		// Update position and dimensions
		pack();
		setLocationRelativeTo(null);
		setVisible(true);
	}

	/**
	 * @return the currently selected {@link GamePane} component
	 */
	public GamePane getSelectedGamePane() {
		return (GamePane) tabbedPane.getSelectedComponent();
	}

	/**
	 * Creates a new {@link GamePane}, adds it to the tabbed pane and opens it.
	 * The new tab has the title {@code Game n} where {@code n} is its number.
	 *
	 * @return the new {@link GamePane}
	 */
	public GamePane addGamePane() {
		return addGamePane("Game " + (tabbedPane.getTabCount() + 1));
	}

	/**
	 * Creates a new {@link GamePane}, adds it to the tabbed pane and opens it.
	 *
	 * @param title The title of the {@link GamePane}
	 * @return the new {@link GamePane}
	 */
	public GamePane addGamePane(String title) {
		GamePane gamePane = new GamePane();
		tabbedPane.add(title, gamePane);
		tabbedPane.setTabComponentAt(
			tabbedPane.getTabCount() - 1,
			new GameTabComponent(tabbedPane)
		);
		tabbedPane.setSelectedIndex(tabbedPane.getTabCount() - 1);
		return gamePane;
	}

	/**
	 * Creates a new {@link GamePane}, adds it to the tabbed pane and
	 * immediately
	 * displays a game configuration dialog for a new game on an existing
	 * {@link Board}.
	 *
	 * @param title the title of the {@link GamePane}
	 * @param board the {@link Board} with which the new {@link Game} is started
	 * @return the new {@link GamePane}
	 */
	public GamePane addGamePane(String title, Board board) {
		GamePane gamePane = addGamePane(title);
		DialogUtil.showGameConfigurationDialog(
			this,
			(whiteName, blackName) -> {
				Game game = new Game(
					gamePane.getBoardPane(),
					whiteName,
					blackName,
					board
				);
				gamePane.setGame(game);
				game.start();
			}
		);
		return gamePane;
	}

	/**
	 * Removes a {@link GamePane} form the tabbed pane.
	 *
	 * @param index The index of the {@link GamePane} to remove
	 */
	public void removeGamePane(int index) {
		tabbedPane.remove(index);
	}

	/**
	 * Loads a game file (FEN or PGN) and adds it to a new {@link GamePane}.
	 *
	 * @param files the files to load the game from
	 */
	public void loadFiles(List<File> files) {
		files.forEach(file -> {
			final String name
				= file.getName().substring(0, file.getName().lastIndexOf('.'));
			final String extension = file.getName()
				.substring(file.getName().lastIndexOf('.'))
				.toLowerCase();
			try {
				Board board;
				switch (extension) {
					case ".fen":
						board = new FENString(
							new String(Files.readAllBytes(file.toPath()), StandardCharsets.UTF_8)
						).getBoard();
						break;
					case ".pgn":
						PGNDatabase pgnDB = new PGNDatabase();
						pgnDB.load(file);
						if (pgnDB.getGames().size() > 0) {
							String[] gameNames
								= new String[pgnDB.getGames().size()];
							for (int i = 0; i < gameNames.length; i++) {
								final PGNGame game = pgnDB.getGames().get(i);
								gameNames[i] = String.format(
									"%s vs %s: %s",
									game.getTag("White"),
									game.getTag("Black"),
									game.getTag("Result")
								);
							}
							JComboBox<String> comboBox
								= new JComboBox<>(gameNames);
							JOptionPane.showMessageDialog(
								this,
								comboBox,
								"Select a game",
								JOptionPane.QUESTION_MESSAGE
							);
							board = pgnDB.getGames()
								.get(comboBox.getSelectedIndex())
								.getBoard();
						} else
							throw new ChessException(
								"The PGN database '" + name + "' is empty!"
							);
						break;
					default:
						throw new ChessException(
							"The file extension '" + extension
								+ "' is not supported!"
						);
				}
				addGamePane(name, board);
			} catch (Exception e) {
				e.printStackTrace();
				JOptionPane.showMessageDialog(
					this,
					"Failed to load the file " + file.getName() + ": "
						+ e.toString(),
					"File loading error",
					JOptionPane.ERROR_MESSAGE
				);
			}
		});
	}

	/**
	 * Saves the current {@link Game} as a file in {@code PGN} or {@code FEN}
	 * format.
	 *
	 * @param file the file in which to save the current {@link Game}
	 */
	public void saveFile(File file) {
		final int dotIndex = file.getName().lastIndexOf('.');
		final String extension
			= file.getName().substring(dotIndex).toLowerCase();

		if (extension.equals(".pgn"))
			try {
				PGNGame pgnGame
					= new PGNGame(getSelectedGamePane().getGame().getBoard());
				pgnGame.setTag(
					"Event",
					tabbedPane.getTitleAt(tabbedPane.getSelectedIndex())
				);
				pgnGame.setTag("Result", "*");
				PGNDatabase pgnDB = new PGNDatabase();
				pgnDB.getGames().add(pgnGame);
				pgnDB.save(file);

				if (
					JOptionPane.showConfirmDialog(
						this,
						"Game export finished. Do you want to view the created file?",
						"Game export finished",
						JOptionPane.YES_NO_OPTION
					) == JOptionPane.YES_OPTION
				)
					Desktop.getDesktop().open(file);
			} catch (IOException e) {
				e.printStackTrace();
				JOptionPane.showMessageDialog(
					this,
					"Failed to save the file " + file.getName() + ": " + e,
					"File saving error",
					JOptionPane.ERROR_MESSAGE
				);
			}
	}
}