Added AI

Server/src/game/TicTacToe_GameRules.java

@@ -0,0 +1,157 @@
+package game;
+
+import ai.MinMax;
+
+import java.awt.*;
+import java.nio.charset.StandardCharsets;
+import java.util.LinkedList;
+
+public class TicTacToe_GameRules {
+
+    private String gameState;
+    private Integer[][] board;
+    private MinMax ai;
+    Point startWin, endWin;
+
+    public TicTacToe_GameRules(){
+        gameState = "---------";
+        ai = new MinMax();
+    }
+
+    public void resetGameState() {
+        this.gameState = "---------";
+    }
+
+    public String getGameState() {
+        return gameState;
+    }
+
+    private void makeMoveOnBoard(int index, int player){
+        byte[] gameStateBytes = gameState.getBytes();
+        if (player == 0){
+            gameStateBytes[index] = (byte) 'x';
+        } else if (player == 1) {
+            gameStateBytes[index] = (byte) 'o';
+        }
+        gameState = new String(gameStateBytes, StandardCharsets.UTF_8);
+        board = this.convertToNumbers(gameState);
+    }
+
+    public boolean makeClientMove(String input, int id) {
+        int column = 0;
+        int row = 0;
+        if (input.contains(",")){
+            column = Integer.valueOf(input.split("\\|")[0].split(",")[0]) / 300;
+            row = Integer.valueOf(input.split("\\|")[1].split(",")[0]) / 300;
+        } else {
+            column = (int) Double.valueOf(input.split("\\|")[0]).doubleValue() / 300;
+            row = (int) Double.valueOf(input.split("\\|")[1]).doubleValue() / 300;
+        }
+        int index = column * 3 + row;
+
+        if (isLegalMove(column, row)) {
+            makeMoveOnBoard(index, id);
+            return true;
+        } else {
+            return false;
+        }
+    }
+
+    public void makeComputerMove(){
+        int index = ai.findBestMove(ai.convertBoard(this.getGameState()));
+        makeMoveOnBoard(index, 1);
+    }
+
+    private LinkedList<Integer> getEmptySpaces(){
+        LinkedList<Integer> emptySpaces = new LinkedList<>();
+        for (int column = 0; column < 3; column++){
+            for (int row = 0; row < 3; row++){
+                if (isLegalMove(column, row)){
+                    emptySpaces.add(column * 3 + row);
+                }
+            }
+        }
+        return emptySpaces;
+    }
+
+    private boolean isLegalMove(int column, int row){
+        int index = column * 3 + row;
+        return gameState.charAt(index) == '-';
+    }
+
+    private Integer[][] convertToNumbers(String gameState){
+        Integer[][] board = new Integer[3][3];
+        for (int i = 0; i < 3; i++){
+            for (int k = 0; k < 3; k++){
+                char currentChar = gameState.charAt(i*3+k);
+                if (currentChar == 'x'){
+                    board[i][k] = 1;
+                } else if (currentChar == 'o'){
+                    board[i][k] = -1;
+                } else if (currentChar == '-'){
+                    board[i][k] = 0;
+                }
+            }
+        }
+        return board;
+    }
+
+    private boolean diagonalWin(){
+        int sumLeftUp = 0;
+        int sumLeftDown = 0;
+        for (int i = 0; i < 3; i++){
+            sumLeftUp += board[i][i];
+            sumLeftDown += board[i][2-i];
+        }
+        if (sumLeftDown == 3 || sumLeftDown == -3){
+            startWin = new Point(2,0);
+            endWin = new Point(0,2);
+            return true;
+        } else if (sumLeftUp == 3 || sumLeftUp == -3){
+            startWin = new Point(0,0);
+            endWin = new Point(2,2);
+            return true;
+        } else {
+            return false;
+        }
+    }
+
+    private boolean horizontalWin(){
+        for (int row = 0; row < 3; row++){
+            int sum = 0;
+            for (int column = 0; column < 3; column++){
+                sum += board[row][column];
+            }
+            if (sum == 3 || sum == -3){
+                startWin = new Point(row, 0);
+                endWin = new Point(row, 0);
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private boolean verticalWin(){
+        for (int column = 0; column < 3; column++){
+            int sum = 0;
+            for (int row = 0; row < 3; row++){
+                sum += board[row][column];
+            }
+            if (sum == 3 || sum == -3){
+                startWin = new Point(0, column);
+                endWin = new Point(2, column);
+                return true;
+            }
+        }
+        return false;
+    }
+
+    public boolean gameEnded(){
+        return horizontalWin() || verticalWin() || diagonalWin() || this.gameState.matches("([xo]){9}");
+    }
+
+    public Point[] getWinCoordinates(){
+        return new Point[]{startWin, endWin};
+    }
+
+}