import java.util.*;

public class BasicCheckersAI implements CheckersAI  
{
	private boolean isWhite;
	private static RandomCheckersAI randy;
	
	//cannot initialize without parameters
	private BasicCheckersAI(){}
	
	public BasicCheckersAI(boolean isWhite_)
	{
	    isWhite = isWhite_;
	    randy = new RandomCheckersAI();
	}

	public void doMove(Board b)
	{
	    if(b.gameOver())
	     return;
	    
	    int[][] board = b.getAIBoard();
	    int[] curMove = new int[4];
	    	    
	    for(int i = 0; i < Board.BOARD_SIZE; i++)
	    {
	        for(int j = 0; j < Board.BOARD_SIZE; j++)
	        {	            
	            if(isAIPiece(board[i][j]))
	            {
	            	if(canJump(i, j, b).length != 0)
	            	{
	            	 	curMove = canJump(i, j, b);
	            	 	b.move(curMove[0], curMove[1], curMove[2], curMove[3]);
	            	}
	            } 
	        }  
	    }
	    	    
	    if(b.getTurn() == isWhite)
	     randy.doMove(b);
	}
	
	private boolean isAIPiece(int p)
	{
	    if(isWhite && (p == CheckersAI.WHITE_PIECE || p == CheckersAI.WHITE_KING))
	     return true;
	    
	    if(!isWhite && (p == CheckersAI.BLACK_PIECE || p == CheckersAI.BLACK_KING))
	     return true;
	    
	    return false;
	}
	
	//generates a move if there exists a possible legal jump for piece at position row & column
	private int[] canJump(int row, int column, Board b)
	{
		int[] jump = new int[4];
		    
	    for(int i = -2; i <= 2; i ++)
	    {
	        for(int j = -2; j <= 2; j++)
	        {
	            if(b.isLegalMove(row, column, row + i, column + j))
	            {
	                if(b.checkJump(row, column, row + i, column + j))
	                {
	                    jump[0] = row;
	                    jump[1] = column;
	                    jump[2] = row + i;
	                    jump[3] = column + j;
	                }
	            }
	        }
	    }
	    
	    return jump;
	}
	
	//generates a move if there exists a possible legal move for piece at position row & column
	private int[] generateMove(int row, int column, Board b)
	{
		int[] move = new int[0];
		
		for(int i = -1; i <= 1; i++)
		{
			for(int j = -1; j <= 1; j++)
			 {
			 	if(b.isLegalMove(row, column, row + i, column + j))
			 	{
			 		move[0] = row;
			 		move[1] = column;
			 		move[2] = row + i;
			 		move[3] = column + j;
			 	}
			 }
		}
		
		return move;
	}
}