package dev.kske.chess.ui;

import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.Insets;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;

import javax.swing.DefaultListModel;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.ListSelectionModel;

import dev.kske.chess.board.MoveNode;
import dev.kske.chess.board.Piece.Color;
import dev.kske.chess.event.Event;
import dev.kske.chess.event.EventBus;
import dev.kske.chess.event.MoveEvent;
import dev.kske.chess.event.Subscribable;
import dev.kske.chess.game.Game;
import dev.kske.chess.game.NaturalPlayer;

/**
 * Project: <strong>Chess</strong><br>
 * File: <strong>GamePane.java</strong><br>
 * Created: <strong>23.08.2019</strong><br>
 * Author: <strong>Kai S. K. Engelbart</strong>
 */
public class GamePane extends JComponent {

	private static final long serialVersionUID = 4349772338239617477L;

	private JButton		btnRestart, btnSwapColors;
	private BoardPane	boardPane;
	private Game		game;
	private Color		activeColor;
	private JPanel		moveSelectionPanel;
	private JButton		btnNext;
	private JButton		btnFirst;
	private JButton		btnLast;

	public GamePane() {
		activeColor = Color.WHITE;

		GridBagLayout gridBagLayout = new GridBagLayout();
		gridBagLayout.columnWidths	= new int[] { 450, 1, 0 };
		gridBagLayout.rowHeights	= new int[] { 33, 267, 1, 0 };
		gridBagLayout.columnWeights	= new double[] { 0.0, 1.0, 1.0 };
		gridBagLayout.rowWeights	= new double[] { 1.0, 1.0, 1.0, Double.MIN_VALUE };
		setLayout(gridBagLayout);

		JPanel toolPanel = new JPanel();
		btnRestart = new JButton("Restart");
		btnRestart.addActionListener((evt) -> { if (game != null) game.reset(); game.start(); });

		btnSwapColors = new JButton("Play as black");
		btnSwapColors.addActionListener((evt) -> {
			game.swapColors();
			btnSwapColors.setText("Play as " + activeColor.toString().toLowerCase());
			activeColor = activeColor.opposite();
		});

		toolPanel.add(btnRestart);
		toolPanel.add(btnSwapColors);

		GridBagConstraints gbc_toolPanel = new GridBagConstraints();
		gbc_toolPanel.insets	= new Insets(0, 0, 5, 5);
		gbc_toolPanel.anchor	= GridBagConstraints.NORTH;
		gbc_toolPanel.fill		= GridBagConstraints.HORIZONTAL;
		gbc_toolPanel.gridx		= 0;
		gbc_toolPanel.gridy		= 0;
		gbc_toolPanel.gridwidth	= 2;
		add(toolPanel, gbc_toolPanel);

		moveSelectionPanel = new JPanel();
		GridBagConstraints gbc_moveSelectionPanel = new GridBagConstraints();
		gbc_moveSelectionPanel.insets	= new Insets(0, 0, 5, 0);
		gbc_moveSelectionPanel.fill		= GridBagConstraints.BOTH;
		gbc_moveSelectionPanel.gridx	= 2;
		gbc_moveSelectionPanel.gridy	= 0;
		add(moveSelectionPanel, gbc_moveSelectionPanel);

		btnFirst = new JButton("First");
		btnFirst.setEnabled(false);
		moveSelectionPanel.add(btnFirst);

		JButton btnPreviousMove = new JButton("Previous");
		btnPreviousMove.setEnabled(false);
		moveSelectionPanel.add(btnPreviousMove);

		btnNext = new JButton("Next");
		btnNext.setEnabled(false);
		moveSelectionPanel.add(btnNext);

		btnLast = new JButton("Last");
		btnLast.setEnabled(false);
		moveSelectionPanel.add(btnLast);
		boardPane = new BoardPane();
		GridBagConstraints gbc_boardPane = new GridBagConstraints();
		gbc_boardPane.insets	= new Insets(0, 0, 5, 5);
		gbc_boardPane.fill	= GridBagConstraints.BOTH;
		gbc_boardPane.gridx	= 0;
		gbc_boardPane.gridy	= 1;
		add(boardPane, gbc_boardPane);

		JPanel				numberPanel		= new JPanel(new GridLayout(8, 1));
		GridBagConstraints	gbc_numberPanel	= new GridBagConstraints();
		gbc_numberPanel.insets	= new Insets(0, 0, 5, 5);
		gbc_numberPanel.anchor	= GridBagConstraints.WEST;
		gbc_numberPanel.fill	= GridBagConstraints.VERTICAL;
		gbc_numberPanel.gridx	= 1;
		gbc_numberPanel.gridy	= 1;
		add(numberPanel, gbc_numberPanel);

		JPanel				letterPanel		= new JPanel(new GridLayout(1, 8));
		GridBagConstraints	gbc_letterPanel	= new GridBagConstraints();
		gbc_letterPanel.insets	= new Insets(0, 0, 0, 5);
		gbc_letterPanel.anchor	= GridBagConstraints.NORTH;
		gbc_letterPanel.fill	= GridBagConstraints.HORIZONTAL;
		gbc_letterPanel.gridx	= 0;
		gbc_letterPanel.gridy	= 2;
		add(letterPanel, gbc_letterPanel);

		// Initialize board coordinates
		for (int i = 0; i < 8; i++) {
			numberPanel.add(new JLabel(String.valueOf(8 - i)));
			JLabel letterLabel = new JLabel(String.valueOf((char) (65 + i)));
			letterLabel.setHorizontalAlignment(JLabel.CENTER);
			letterPanel.add(letterLabel);
		}
		
		JScrollPane			scrollPane		= new JScrollPane();
		GridBagConstraints	gbc_scrollPane	= new GridBagConstraints();
		gbc_scrollPane.insets	= new Insets(0, 0, 5, 0);
		gbc_scrollPane.fill		= GridBagConstraints.BOTH;
		gbc_scrollPane.gridx	= 2;
		gbc_scrollPane.gridy	= 1;
		add(scrollPane, gbc_scrollPane);

		JList<MoveNode> pgnList = new JList<>();
		pgnList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
		pgnList.setLayoutOrientation(JList.HORIZONTAL_WRAP);
		pgnList.setVisibleRowCount(0);
		pgnList.setCellRenderer(new MoveNodeRenderer());
		scrollPane.setViewportView(pgnList);

		EventBus.getInstance().register(new Subscribable() {

			// TODO: Clean on restart
			@Override
			public void handle(Event<?> event) {
				if (game.getBoard().getLog() == null || game.getBoard().getLog().isEmpty()) return;

				DefaultListModel<MoveNode> model = new DefaultListModel<>();
				game.getBoard().getLog().forEach(node -> model.addElement(node));
				pgnList.setModel(model);
			}

			@Override
			public Set<Class<?>> supports() {
				return new HashSet<>(Arrays.asList(MoveEvent.class));
			}
		});
	}

	/**
	 * @return The {@link BoardPane} instance associated with this game pane
	 */
	public BoardPane getBoardPane() { return boardPane; }

	/**
	 * @return The {@link Game} instance associated with this game pane
	 */
	public Game getGame() { return game; }

	/**
	 * Assigns a new {@link Game} instance to this game pane. If exactly one of the
	 * players is natural, color swapping functionality is enabled.
	 * 
	 * @param game The {@link Game} to assign to this game pane.
	 */
	public void setGame(Game game) {
		if (this.game != null) this.game.stop();
		this.game = game;
		btnSwapColors.setEnabled(game.getPlayers().get(Color.WHITE) instanceof NaturalPlayer
				^ game.getPlayers().get(Color.BLACK) instanceof NaturalPlayer);
	}
}