/*

 Copyright (C) 2016 Apple Inc. All Rights Reserved.

 See LICENSE.txt for this sample’s licensing information

 Abstract:

 AI engine that calculates a move for the computer opponent from the current board state.

 */

#import "AAPLTicTacToeAIEngine.h"

@implementation AAPLTicTacToeAIEngine

- (instancetype)init

{

    self = [super init];

    if ( self != nil )

    {

        _difficulty = 5;

    }

    return self;

}

- (NSPoint)moveForBoard:(AAPLTicTacToeBoard *)board

{

    // pick a random open location

    NSPoint move = NSZeroPoint;

    if ( !board.isFull )

    {

        int row;

        int column;

        do

        {

            row = arc4random() % board.numRows;

            column = arc4random() % board.numColumns;

        }

        while ( ![board squareAtRow:row column:column].isEmpty );

        move = NSMakePoint(row, column);

    }

    return move;

}

@end