From 7c7e134ad9e874f5c625c2867f4233a00dcc7c24 Mon Sep 17 00:00:00 2001
From: Tobias Krause <tobias.krause@informatik.hs-fulda.de>
Date: Mon, 31 Jan 2022 13:06:34 +0100
Subject: [PATCH] tictactoe: hard AI sets middle field if it hasnt been set yet

---
 src/main/java/de/tims/tictactoe/ai/AIHard.java     |  4 ++--
 src/test/java/de/tims/tictactoe/ai/AIHardTest.java | 11 +++++++++++
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/src/main/java/de/tims/tictactoe/ai/AIHard.java b/src/main/java/de/tims/tictactoe/ai/AIHard.java
index ae1e7cb..146101a 100644
--- a/src/main/java/de/tims/tictactoe/ai/AIHard.java
+++ b/src/main/java/de/tims/tictactoe/ai/AIHard.java
@@ -21,10 +21,10 @@ public class AIHard implements TicTacToeAI {
 		char[][] board = gl.getBoard();
 		for (char[] row : board) {
 			for (char field : row) {
-				emptyBoard &= field == '-';
+				emptyBoard &= field == EMPTY_CHAR;
 			}
 		}
-		if (emptyBoard) {			
+		if (emptyBoard || board[1][1] == EMPTY_CHAR) {			
 			gl.setField(1, 1, AI_CHAR);
 		} else {
 			gl.setField(0, 0, AI_CHAR);
diff --git a/src/test/java/de/tims/tictactoe/ai/AIHardTest.java b/src/test/java/de/tims/tictactoe/ai/AIHardTest.java
index dddb7d2..856c1a7 100644
--- a/src/test/java/de/tims/tictactoe/ai/AIHardTest.java
+++ b/src/test/java/de/tims/tictactoe/ai/AIHardTest.java
@@ -37,5 +37,16 @@ class AIHardTest {
 		
 		verify(gl, times(1)).setField(0, 0, realChar);
 	}
+	
+	@Test
+	void opponentDidntChooseMiddleFieldSoAIDoes() {
+		char realChar = 'o';
+		doReturn(new char[][] { {'-', '-', 'x'}, {'-', '-', '-'}, {'-', '-', '-'} }).when(gl).getBoard();
+		
+		TicTacToeAI ai = new AIHard(gl);
+		ai.calculateNextMove();
+		
+		verify(gl, times(1)).setField(1, 1, realChar);
+	}
 
 }