import javax.swing.*;
import javax.swing.border.*;
import java.awt.*;
import java.awt.event.*;

public class CheckersApplet extends JApplet
{
    private Board b;
    private boolean pieceSelected = false;
    private int selectedRow, selectedColumn;
    private CheckersAI ai;
    private CheckersAI ai2;
    private boolean playerOneIsHuman;
    private boolean playerTwoIsHuman;
    
    public void init()
    {
        repaint();
    }
    
    public CheckersApplet()
    {
        setUpPlayers();
                       
        //listens for player input
        class CheckersListener extends MouseAdapter implements KeyListener
        {
            private int toBoardCoordinates(int i)
            {
                return (i - (i % Board.SPACE_SIZE)) / Board.SPACE_SIZE;
            }
            
            public void mousePressed(MouseEvent e)
            {              
                if(toBoardCoordinates(e.getX()) > Board.BOARD_SIZE - 1 || toBoardCoordinates(e.getY()) > Board.BOARD_SIZE - 1)
                 return;
                 
                if(pieceSelected)
                {                   
                    int boardRow = toBoardCoordinates(e.getY());
                    int boardColumn = toBoardCoordinates(e.getX());
                    b.move(selectedRow, selectedColumn, boardRow, boardColumn);
                    pieceSelected = false;
                }
                else
                {
                    selectedRow = toBoardCoordinates(e.getY());
                    selectedColumn = toBoardCoordinates(e.getX());
                    pieceSelected = true;
                }
                
                repaint();
            }
            
            public void keyTyped(KeyEvent k) {}
            
            public void keyPressed(KeyEvent k)
            {
                if(k.getKeyCode() == KeyEvent.VK_F2)
                {
                    resetGame();
                    repaint();
                }
                
                if(k.getKeyCode() == KeyEvent.VK_SPACE)
                {
                    if(b.getTurn() == Piece.PLAYER_ONE && !playerOneIsHuman)
                    {
                        ai.doMove(b);
                    }
                
                    if(b.getTurn() == Piece.PLAYER_TWO && !playerTwoIsHuman)
                    {
                        ai2.doMove(b);
                    }
                    repaint();
                }
                                            
                if(k.getKeyCode() == KeyEvent.VK_UP && pieceSelected && selectedRow != 0)
                {
                    selectedRow--;
                    repaint();
                }
                
                if(k.getKeyCode() == KeyEvent.VK_DOWN && pieceSelected && selectedRow != Board.BOARD_SIZE - 1)
                {
                    selectedRow++;
                    repaint();
                }
                
                if(k.getKeyCode() == KeyEvent.VK_LEFT && pieceSelected && selectedColumn != 0)
                {
                    selectedColumn--;
                    repaint();
                }
                
                if(k.getKeyCode() == KeyEvent.VK_RIGHT && pieceSelected && selectedColumn != Board.BOARD_SIZE - 1)
                {
                    selectedColumn++;
                    repaint();
                }
                
                if(isArrowKey(k.getKeyCode()))
                {
                    pieceSelected = true;
                    repaint();
                }
            }
            
            private boolean isArrowKey(int k)
            {
                return k == KeyEvent.VK_UP || k == KeyEvent.VK_DOWN || k == KeyEvent.VK_LEFT || k == KeyEvent.VK_RIGHT;
            }
            
            public void keyReleased(KeyEvent k){}
        }
        
        MouseListener listener = new CheckersListener();
        addMouseListener(listener);
        addKeyListener((KeyListener)listener);
    }
    
    //gets names and types of players in the game
    private void setUpPlayers()
    {
        String playerOneName = JOptionPane.showInputDialog("Player one's (white's) name:");
        String playerOneIsHuman_ = JOptionPane.showInputDialog("Is player one a human or computer? (H/C)");
        playerOneIsHuman = playerOneIsHuman_.equals("H") || playerOneIsHuman_.equals("h");
        
        String playerTwoName = JOptionPane.showInputDialog("Player two's (yellow's) name:");
        String playerTwoIsHuman_ = JOptionPane.showInputDialog("Is player two a human or computer? (H/C)");
        playerTwoIsHuman = playerTwoIsHuman_.equals("H") || playerTwoIsHuman_.equals("h");
        
        if(!playerOneIsHuman)
         ai = new BasicCheckersAI(Piece.PLAYER_ONE);
        
        if(!playerTwoIsHuman)
         ai2 = new BasicCheckersAI(Piece.PLAYER_TWO);
         
        b = new Board(playerOneName, playerTwoName);            
    }
    
    public void paint(Graphics g)
    {
        Graphics2D g2 = (Graphics2D)g;
        
        b.draw(g2);
        
        if(pieceSelected)
        {
            g2.setColor(Color.green);
            g2.draw(new Rectangle(Board.SPACE_SIZE * selectedColumn, Board.SPACE_SIZE * selectedRow, Board.SPACE_SIZE, Board.SPACE_SIZE));
        }
        
        //clear the text area
        g2.setColor(Color.white);
        g2.fillRect(5, Board.SPACE_SIZE * Board.BOARD_SIZE + 1, Board.SPACE_SIZE * Board.BOARD_SIZE, 30); 
        
        g2.setColor(Color.black);
        g2.setFont(new Font("SansSerif", Font.BOLD, 24));
        g2.drawString(b.getMessage(), 5, Board.SPACE_SIZE * Board.BOARD_SIZE + 20);
    }
    
    public void resetGame()
    {
        setUpPlayers();
    }
    
    public void destroy()
    {
        b.killGame();
    }
}