package nooga.server;
//Only the server should invoke this AIFE, so it is in
//the server package

import nooga.client.*;
import nooga.util.*;
import nooga.board.*;

import javax.swing.*;
import java.util.*;
import java.io.*;


/**
      This is the front end for the "computer player" that plays against 
   the client when only 1 client is playing when the DotsGameHandler 
in intizialized.

   When it is the AI's turn, it will try to find a move as follows:
Step 1.  If there is a square that can be taken, take that square.
Step 2.  If step 1 fails, randomly make a move that will not allow
   your opponent to be able to make a square on their next move, if such
   a move exists.  
Step 3. If no move can be found in steps 1 and 2, make
   any random legal move (Since step 2 failed, making such a move in step
   three will enable the AI's opponent to make a aquare on thier next
   turn.)

  Since DotsAIFE is only used by the server, DotsAIFE appears in the 
server package.
   @see DotsGameHandler
**/

public class DotsAIFE extends NOOGAAIFE
{

    public DotsAIFE() 
    {
	myRandom = new Random();
	try {
	    myClient = new NOOGAClientImpl(this,null);
	} catch (Exception e) { e.printStackTrace();}

    }

    public String getGameType() {
	return Constants.DOTS;
    }


/**
  This is the main "brains" function of the AI.  The AI will
  try to find a move as follows:
1.  If there is a square that can be taken, take that square.
2.  Randomly make a move that will not allow your opponent
to be able to make a square on thier next mo, IF such a move exists.
3. If no move can be found in steps 1 and 2, make any random legal move
(Since step 2 failed, making a move in step three will enable the 
AI's opponent to make a aquare on thier next turn.
*/
    public void doTurn(Object dotsBoard) 
    {
	try{	Thread.sleep(250);}
	catch(Exception e) {e.printStackTrace();}
	System.out.println("\nComputer taking turn...");

	myDotsBoard = (DotsBoard) dotsBoard;

	if (makeSquare()) {
	    try{ 
		myClient.reportMove(myMove); 
		return;
	    } catch (Exception e){e.printStackTrace();}
	} else {
	    if ( ! leaveNoOpenSquaresMove() ) {
		randomMove();
	    }
	}
		   
	try {
	    myClient.reportMove(myMove);
	    return;
	} catch (Exception e) {
	    e.printStackTrace();
	}    


	//System.out.println("AI done doing move");
    }

  /**  
  Make any random move ("Step 3").
*/  
  private void randomMove() 
    {

	int maxMoveAttempts = 4000;
	int index=0;
	int rightOrDown=RIGHT;
	for(int i =0; i < maxMoveAttempts; i++) {
	    index = myRandom.nextInt(myDotsBoard.getHeight()*myDotsBoard.getWidth());
	    rightOrDown = myRandom.nextInt(2);

	    if( index >= ((myDotsBoard.getHeight() -1) * myDotsBoard.getWidth()))
                if(rightOrDown == DOWN)
		    continue;

	    if(  (index % (myDotsBoard.getWidth())) == (myDotsBoard.getWidth()-1) ) 
		if( rightOrDown == RIGHT)
		    continue;
	    
	    if( !isConnected(index,rightOrDown) ) {
		int point1 = index;
		int point2;
		if(rightOrDown == 0) {
		    point2 = index + 1;
		} else {
		    point2 = index + myDotsBoard.getWidth();
		}
		myMove = new DotsMove(point1, point2);
		return;
	    }


	}
     
	System.out.println("ERROR: UNABLE TO FIND MOVE");
    }
  
/**
    Try to make a move that will not leave a square available for
  the AI's opponent to take ("Step 2).
*/  
  private boolean leaveNoOpenSquaresMove() 
    {
	int maxMoveAttempts = 1000;
	int index;
	int rightOrDown;
	for(int i= 0; i < maxMoveAttempts; i++) 
	{
	    index = myRandom.nextInt(myDotsBoard.getHeight()*myDotsBoard.getWidth());
	    rightOrDown = myRandom.nextInt(2);

	    if( index >= ((myDotsBoard.getHeight() -1) * myDotsBoard.getWidth()))
		if(rightOrDown == DOWN)
		    continue;

	    if(  (index % (myDotsBoard.getWidth())) == (myDotsBoard.getWidth()-1) ) 
		if( rightOrDown == RIGHT)
		    continue;


	    if( !isConnected(index,rightOrDown)) {
		if(rightOrDown ==DOWN) {
		    if( (numSidesTaken(index) != 2) && (numSidesTaken(index-1)!= 2) ) {
			int point1 = index;
			int point2 = index + myDotsBoard.getWidth();
			myMove = new DotsMove(point1, point2);
			return true;
		    }
		} else if (rightOrDown == RIGHT) {
		    if(  (numSidesTaken(index) != 2) && (numSidesTaken(index - myDotsBoard.getWidth()) != 2 ) ) {
			int point1 = index;
			int point2 = index + 1;
			myMove = new DotsMove(point1, point2);
			return true;
		    }
		}
	    }
	}
	return false;
    }





/**
Try to take a square ("Step 1.")
*/
    private boolean makeSquare()
    {
	for(int i =0; i < myDotsBoard.getHeight()*myDotsBoard.getWidth(); i++) {
	    if(numSidesTaken(i) == 3) {
		takeSquare(i);
		return true;
	    }
	}
	return false;   
    }
    
    
    private void takeSquare(int index) {
	if(!isConnected(index,RIGHT)) {
	    int point1 = index;
	    int point2 = index + 1;
	    myMove = new DotsMove(point1, point2);
	}
	if(  !isConnected(index,DOWN)) {
	    int point1 = index;
	    int point2 = index + myDotsBoard.getWidth();
	    myMove = new DotsMove(point1, point2);
	}

	if( !isConnected(index+1,DOWN) ) {
	    int point1 = index+1;
	    int point2 = index +1 + myDotsBoard.getWidth();
	    myMove = new DotsMove(point1, point2);
	}


   	if( !isConnected(index+myDotsBoard.getWidth(),RIGHT) )  {
	    int point1 = index + myDotsBoard.getWidth();
	    int point2 = index + myDotsBoard.getWidth() + 1;
	    myMove = new DotsMove(point1, point2);
	}    

    }


    
    private boolean isConnected(int index, int rightOrDown) {
//if we are checking to the right of the dot
	if(rightOrDown == RIGHT) {
	    return myDotsBoard.checkConnected(index, index+1);
	} else if(rightOrDown ==DOWN) {
	    return myDotsBoard.checkConnected(index, index+ myDotsBoard.getWidth());
	} else {

	    System.out.println("Error in AI");
	    return false;
	}

    
    }

    
    private int numSidesTaken(int index) 
    {

	int numSidesTaken = 0;
	if(  isConnected(index,RIGHT) ) {
	    numSidesTaken++;
	}
	if( isConnected(index,DOWN) ) {
	    numSidesTaken++;
	}
	if(  isConnected(index+1,DOWN) ) {
	    numSidesTaken++;
	}
	
	if(isConnected(index+ myDotsBoard.getWidth(), RIGHT) ) {
	    numSidesTaken++;
	}
	return numSidesTaken;
    }


    private DotsBoard myDotsBoard;
    private DotsMove myMove;

    private static final int RIGHT = 0;
    private static final int DOWN = 1;
}