Use only southermost ghost wave for cerb plugin

Closes #2252

runelite-client/src/main/java/net/runelite/client/plugins/cerberus/CerberusOverlay.java

@@ -29,7 +29,6 @@ import java.awt.Graphics2D;
 import javax.inject.Inject;
 import javax.inject.Singleton;
 import lombok.extern.slf4j.Slf4j;
-import net.runelite.api.NPC;
 import net.runelite.client.game.SkillIconManager;
 import net.runelite.client.ui.overlay.Overlay;
 import net.runelite.client.ui.overlay.OverlayPosition;
@@ -61,11 +60,16 @@ public class CerberusOverlay extends Overlay
 		final ImagePanelComponent imagePanelComponent = new ImagePanelComponent();
 		imagePanelComponent.setTitle("Ghost order");
 
-		for (final NPC npc : plugin.getGhosts())
+		// Ghosts are already sorted
-		{
+		plugin.getGhosts().stream()
-			CerberusGhost.fromNPC(npc).ifPresent(ghost -> imagePanelComponent
+			// Iterate only through the correct amount of ghosts
-				.getImages().add(iconManager.getSkillImage(ghost.getType())));
+			.limit(CerberusGhost.values().length)
-		}
+			.forEach(npc -> CerberusGhost
+				.fromNPC(npc)
+				.ifPresent(ghost -> imagePanelComponent
+					.getImages()
+					.add(iconManager.getSkillImage(ghost.getType()))));
+
 
 		return imagePanelComponent.render(graphics);
 	}

runelite-client/src/main/java/net/runelite/client/plugins/cerberus/CerberusPlugin.java

@@ -25,13 +25,16 @@
 
 package net.runelite.client.plugins.cerberus;
 
+import com.google.common.collect.ComparisonChain;
 import com.google.common.eventbus.Subscribe;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import javax.inject.Inject;
 import javax.inject.Singleton;
 import lombok.Getter;
 import net.runelite.api.NPC;
+import net.runelite.api.events.GameTick;
 import net.runelite.api.events.NpcDespawned;
 import net.runelite.api.events.NpcSpawned;
 import net.runelite.client.plugins.Plugin;
@@ -64,18 +67,7 @@ public class CerberusPlugin extends Plugin
 	public void onNpcSpawned(final NpcSpawned event)
 	{
 		final NPC npc = event.getNpc();
-
+		CerberusGhost.fromNPC(npc).ifPresent(ghost -> ghosts.add(npc));
-		CerberusGhost.fromNPC(npc).ifPresent(ghost ->
-		{
-			if (ghosts.size() == CerberusGhost.values().length)
-			{
-				// Reset ghosts as this is new ghost wave
-				ghosts.clear();
-			}
-
-			ghosts.add(npc);
-			ghosts.sort((a, b) -> Integer.compare(b.getLocalLocation().getY(), a.getLocalLocation().getY()));
-		});
 	}
 
 	@Subscribe
@@ -83,4 +75,22 @@ public class CerberusPlugin extends Plugin
 	{
 		ghosts.remove(event.getNpc());
 	}
+
+	@Subscribe
+	public void onGameTick(GameTick gameTick)
+	{
+		if (ghosts.isEmpty())
+		{
+			return;
+		}
+
+		Collections.sort(ghosts, (a, b) -> ComparisonChain.start()
+			// First, sort by the southernmost ghost (e.g with lowest y)
+			.compare(a.getLocalLocation().getY(), b.getLocalLocation().getY())
+			// Then, sort by the westernmost ghost (e.g with lowest x)
+			.compare(a.getLocalLocation().getX(), b.getLocalLocation().getX())
+			// This will give use the current wave and order of the ghosts based on
+			// what ghost will attack first
+			.result());
+	}
 }

runelite-client/src/test/java/net/runelite/client/plugins/cerberus/CerberusPluginTest.java

@@ -0,0 +1,85 @@
+/*
+ * Copyright (c) 2018, Adam <Adam@sigterm.info>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package net.runelite.client.plugins.cerberus;
+
+import com.google.inject.Guice;
+import com.google.inject.testing.fieldbinder.BoundFieldModule;
+import java.util.Arrays;
+import java.util.List;
+import javax.inject.Inject;
+import net.runelite.api.NPC;
+import net.runelite.api.coords.LocalPoint;
+import net.runelite.api.events.GameTick;
+import static org.junit.Assert.assertEquals;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+import org.mockito.runners.MockitoJUnitRunner;
+
+@RunWith(MockitoJUnitRunner.class)
+public class CerberusPluginTest
+{
+	@Inject
+	CerberusPlugin cerberusPlugin;
+
+	@Before
+	public void before()
+	{
+		Guice.createInjector(BoundFieldModule.of(this)).injectMembers(this);
+	}
+
+	@Test
+	public void testOnGameTick()
+	{
+		List<NPC> ghosts = cerberusPlugin.getGhosts();
+		ghosts.addAll(Arrays.asList(
+			mockNpc(new LocalPoint(0, 0)),
+			mockNpc(new LocalPoint(1, 0)),
+			mockNpc(new LocalPoint(0, 5)),
+			mockNpc(new LocalPoint(2, 0)),
+			mockNpc(new LocalPoint(2, 5)),
+			mockNpc(new LocalPoint(1, 5))
+		));
+		cerberusPlugin.onGameTick(new GameTick());
+
+		// Expected sort is by lowest y first, then by lowest x
+		assertEquals(ghosts.get(0).getLocalLocation(), new LocalPoint(0, 0));
+		assertEquals(ghosts.get(1).getLocalLocation(), new LocalPoint(1, 0));
+		assertEquals(ghosts.get(2).getLocalLocation(), new LocalPoint(2, 0));
+
+		assertEquals(ghosts.get(3).getLocalLocation(), new LocalPoint(0, 5));
+		assertEquals(ghosts.get(4).getLocalLocation(), new LocalPoint(1, 5));
+		assertEquals(ghosts.get(5).getLocalLocation(), new LocalPoint(2, 5));
+	}
+
+	private static NPC mockNpc(LocalPoint localPoint)
+	{
+		NPC npc = mock(NPC.class);
+		when(npc.getLocalLocation()).thenReturn(localPoint);
+		return npc;
+	}
+}