#601 Integrate plugin manager

- Encapsulate captcha functionality into a class instead of two public fields on the AuthMe main class(!)
   - Let CaptchaManager worry about whether it is enabled or not -> no need to check on the outside
- Implement full reloading support to enable/disable captchas + parameters
- Add unit tests

src/test/java/fr/xephi/authme/command/executable/captcha/CaptchaCommandTest.java

@@ -0,0 +1,121 @@
+package fr.xephi.authme.command.executable.captcha;
+
+import fr.xephi.authme.cache.CaptchaManager;
+import fr.xephi.authme.cache.auth.PlayerCache;
+import fr.xephi.authme.command.CommandService;
+import fr.xephi.authme.output.MessageKey;
+import org.bukkit.entity.Player;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.runners.MockitoJUnitRunner;
+
+import java.util.Collections;
+
+import static org.mockito.BDDMockito.given;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyNoMoreInteractions;
+
+/**
+ * Test for {@link CaptchaCommand}.
+ */
+@RunWith(MockitoJUnitRunner.class)
+public class CaptchaCommandTest {
+
+    @InjectMocks
+    private CaptchaCommand command;
+
+    @Mock
+    private CaptchaManager captchaManager;
+
+    @Mock
+    private PlayerCache playerCache;
+
+    @Mock
+    private CommandService commandService;
+
+    @Test
+    public void shouldDetectIfPlayerIsLoggedIn() {
+        // given
+        String name = "creeper011";
+        Player player = mockPlayerWithName(name);
+        given(playerCache.isAuthenticated(name)).willReturn(true);
+
+        // when
+        command.executeCommand(player, Collections.singletonList("123"), commandService);
+
+        // then
+        verify(commandService).send(player, MessageKey.ALREADY_LOGGED_IN_ERROR);
+    }
+
+    @Test
+    public void shouldShowLoginUsageIfCaptchaIsNotRequired() {
+        // given
+        String name = "bobby";
+        Player player = mockPlayerWithName(name);
+        given(playerCache.isAuthenticated(name)).willReturn(false);
+        given(captchaManager.isCaptchaRequired(name)).willReturn(false);
+
+        // when
+        command.executeCommand(player, Collections.singletonList("1234"), commandService);
+
+        // then
+        verify(commandService).send(player, MessageKey.USAGE_LOGIN);
+        verify(captchaManager).isCaptchaRequired(name);
+        verifyNoMoreInteractions(captchaManager);
+    }
+
+    @Test
+    public void shouldHandleCorrectCaptchaInput() {
+        // given
+        String name = "smith";
+        Player player = mockPlayerWithName(name);
+        given(playerCache.isAuthenticated(name)).willReturn(false);
+        given(captchaManager.isCaptchaRequired(name)).willReturn(true);
+        String captchaCode = "3991";
+        given(captchaManager.checkCode(name, captchaCode)).willReturn(true);
+
+        // when
+        command.executeCommand(player, Collections.singletonList(captchaCode), commandService);
+
+        // then
+        verify(captchaManager).isCaptchaRequired(name);
+        verify(captchaManager).checkCode(name, captchaCode);
+        verifyNoMoreInteractions(captchaManager);
+        verify(commandService).send(player, MessageKey.CAPTCHA_SUCCESS);
+        verify(commandService).send(player, MessageKey.LOGIN_MESSAGE);
+        verifyNoMoreInteractions(commandService);
+    }
+
+    @Test
+    public void shouldHandleWrongCaptchaInput() {
+        // given
+        String name = "smith";
+        Player player = mockPlayerWithName(name);
+        given(playerCache.isAuthenticated(name)).willReturn(false);
+        given(captchaManager.isCaptchaRequired(name)).willReturn(true);
+        String captchaCode = "2468";
+        given(captchaManager.checkCode(name, captchaCode)).willReturn(false);
+        String newCode = "1337";
+        given(captchaManager.generateCode(name)).willReturn(newCode);
+
+        // when
+        command.executeCommand(player, Collections.singletonList(captchaCode), commandService);
+
+        // then
+        verify(captchaManager).isCaptchaRequired(name);
+        verify(captchaManager).checkCode(name, captchaCode);
+        verify(captchaManager).generateCode(name);
+        verifyNoMoreInteractions(captchaManager);
+        verify(commandService).send(player, MessageKey.CAPTCHA_WRONG_ERROR, newCode);
+        verifyNoMoreInteractions(commandService);
+    }
+
+    private static Player mockPlayerWithName(String name) {
+        Player player = mock(Player.class);
+        given(player.getName()).willReturn(name);
+        return player;
+    }
+}