From 88d559c6c9a46f36f7c5d3f4a05ef91ab6c1bb7a Mon Sep 17 00:00:00 2001
From: Tobias Krause <tobias.krause@informatik.hs-fulda.de>
Date: Mon, 31 Jan 2022 12:21:54 +0100
Subject: [PATCH] tictactoe: added hard AI

---
 .../java/de/tims/tictactoe/ai/AIHard.java     | 22 ++++++++++++++
 .../java/de/tims/tictactoe/ai/AIHardTest.java | 30 +++++++++++++++++++
 2 files changed, 52 insertions(+)
 create mode 100644 src/main/java/de/tims/tictactoe/ai/AIHard.java
 create mode 100644 src/test/java/de/tims/tictactoe/ai/AIHardTest.java

diff --git a/src/main/java/de/tims/tictactoe/ai/AIHard.java b/src/main/java/de/tims/tictactoe/ai/AIHard.java
new file mode 100644
index 0000000..2165b1d
--- /dev/null
+++ b/src/main/java/de/tims/tictactoe/ai/AIHard.java
@@ -0,0 +1,22 @@
+package de.tims.tictactoe.ai;
+
+import de.tims.tictactoe.GameLogic;
+
+public class AIHard implements TicTacToeAI {
+	private static final char AI_CHAR = 'o';
+	private static final char EMPTY_CHAR = '-';
+	
+	private GameLogic gl;
+	
+	public AIHard(GameLogic gl) throws IllegalArgumentException {
+		if (gl.getBoard().length != 3) {
+			throw new IllegalArgumentException("Hard AI only supports 3x3 boards!");
+		}
+		this.gl = gl;
+	}
+
+	@Override
+	public void calculateNextMove() {
+		gl.setField(1, 1, AI_CHAR);
+	}
+}
diff --git a/src/test/java/de/tims/tictactoe/ai/AIHardTest.java b/src/test/java/de/tims/tictactoe/ai/AIHardTest.java
new file mode 100644
index 0000000..c52ac3f
--- /dev/null
+++ b/src/test/java/de/tims/tictactoe/ai/AIHardTest.java
@@ -0,0 +1,30 @@
+package de.tims.tictactoe.ai;
+
+import static org.mockito.Mockito.*;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import de.tims.tictactoe.GameLogic;
+
+@ExtendWith(MockitoExtension.class)
+class AIHardTest {
+	static int size = 3;
+	
+	@Mock
+	private GameLogic gl;
+	
+	@Test
+	void emptyBoardChooseMiddleField() {
+		char realChar = 'o';
+		doReturn(new char[][] { {'-', '-', '-'}, {'-', '-', '-'}, {'-', '-', '-'} }).when(gl).getBoard();
+		
+		TicTacToeAI ai = new AIHard(gl);
+		ai.calculateNextMove();
+		
+		verify(gl, times(1)).setField(1, 1, realChar);
+	}
+
+}