tictactoe: hard ai uses chance to win in row

src/main/java/de/tims/tictactoe/ai/AIHard.java

@@ -19,18 +19,29 @@ public class AIHard implements TicTacToeAI {
 
 	@Override
 	public void calculateNextMove() {
+		int ownCharsInRow = 0;
 		int charsOfOpponentInRow = 0;
 		int charsOfOpponentInCol = 0;
 		int charsOfOpponentInDiag = 0;
 		char[][] board = gl.getBoard();
 		
 		for (int i = 0; i < BOARD_SIZE; i++) {
+			ownCharsInRow = countCharsInRow(i, AI_CHAR);
 			charsOfOpponentInRow = countCharsInRow(i, PLAYER_CHAR);
 			charsOfOpponentInCol = countCharsInCol(i, PLAYER_CHAR);
 			if (i < 2) {
 				charsOfOpponentInDiag = countCharsInDiag(i, PLAYER_CHAR);
 			}
 			
+			if (ownCharsInRow == BOARD_SIZE - 1) {
+				for (int j = 0; j < BOARD_SIZE; j++) {
+					if (board[i][j] == EMPTY_CHAR) {
+						gl.setField(i, j, AI_CHAR);
+						return;
+					}
+				}
+			}
+			
 			if (charsOfOpponentInRow == BOARD_SIZE - 1 || charsOfOpponentInCol == BOARD_SIZE - 1 || charsOfOpponentInDiag == BOARD_SIZE - 1) {
 				for (int j = 0; j < BOARD_SIZE; j++) {
 					if (charsOfOpponentInRow == BOARD_SIZE - 1) {

src/test/java/de/tims/tictactoe/ai/AIHardTest.java

@@ -99,6 +99,17 @@ class AIHardTest {
 		verify(gl, times(1)).setField(2, 2, realChar);
 	}
 	
+	@Test
+	void when2InRowSetThird() {
+		char realChar = 'o';
+		doReturn(new char[][] { {'o', '-', 'o'}, {'-', 'x', '-'}, {'x', 'x', '-'} }).when(gl).getBoard();
+		
+		TicTacToeAI ai = new AIHard(gl);
+		ai.calculateNextMove();
+		
+		verify(gl, times(1)).setField(0, 1, realChar);
+	}
+	
 	@ParameterizedTest
 	@MethodSource("testCasesForCountCharsInRow")
 	void countCharsInRowTest(String testName, char[][] board, int rowNum, char charToCount, int expectedResult) {