fix(navigation): hide guidance near base

src/main/java/games/dmg/spigotbase/BaseNavigationController.java

@@ -10,6 +10,7 @@ final class BaseNavigationController implements Runnable {
     private final Server server;
     private final BaseStateManager stateManager;
     private final PluginSettingsProvider settings;
+    private final BaseBoundsService boundsService;
 
     BaseNavigationController(
         Server server,
@@ -19,6 +20,7 @@ final class BaseNavigationController implements Runnable {
         this.server = server;
         this.stateManager = stateManager;
         this.settings = settings;
+        this.boundsService = new BaseBoundsService(settings);
     }
 
     @Override
@@ -32,7 +34,16 @@ final class BaseNavigationController implements Runnable {
             if (!player.getWorld().getUID().equals(base.worldId())) {
                 continue;
             }
-            Location origin = player.getLocation().clone().add(0.0, 0.15, 0.0);
+            Location playerLocation = player.getLocation();
+            if (!BaseNavigationVisibility.isBeyondBorderBuffer(
+                    base,
+                    boundsService.radius(state),
+                    playerLocation.getX(),
+                    playerLocation.getZ()
+            )) {
+                continue;
+            }
+            Location origin = playerLocation.clone().add(0.0, 0.15, 0.0);
             Vector direction = new Vector(
                 base.x() + 0.5 - origin.getX(),
                 0.0,

src/main/java/games/dmg/spigotbase/BaseNavigationVisibility.java

@@ -0,0 +1,26 @@
+package games.dmg.spigotbase;
+
+final class BaseNavigationVisibility {
+    static final int BORDER_BUFFER = 25;
+
+    private BaseNavigationVisibility() {
+    }
+
+    static boolean isBeyondBorderBuffer(
+        BaseLocation base,
+        int radius,
+        double playerX,
+        double playerZ
+    ) {
+        if (base == null) {
+            throw new IllegalArgumentException("base is required");
+        }
+        if (radius <= 0) {
+            throw new IllegalArgumentException("base radius must be positive");
+        }
+        double deltaX = playerX - (base.x() + 0.5);
+        double deltaZ = playerZ - (base.z() + 0.5);
+        double minimumDistance = radius + BORDER_BUFFER;
+        return deltaX * deltaX + deltaZ * deltaZ > minimumDistance * minimumDistance;
+    }
+}

src/test/java/games/dmg/spigotbase/BaseNavigationControllerTest.java

@@ -0,0 +1,60 @@
+package games.dmg.spigotbase;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.time.Instant;
+import java.util.Map;
+import java.util.UUID;
+import org.bukkit.Location;
+import org.bukkit.Particle;
+import org.bukkit.Server;
+import org.bukkit.World;
+import org.bukkit.entity.Player;
+import org.junit.jupiter.api.Test;
+
+final class BaseNavigationControllerTest {
+    @Test
+    void showsParticlesOnlyMoreThanTwentyFiveBlocksBeyondBorder() {
+        UUID playerId = UUID.randomUUID();
+        UUID worldId = UUID.randomUUID();
+        PlayerState state = PlayerState.newPlayer(playerId, "Builder")
+            .withAdministrativeLevels(2, 0, 0, 0, 0, true, false, false)
+            .withBase(new BaseLocation(worldId, "world", 0, 64, 0, 0, 0), Instant.EPOCH);
+        World world = mock(World.class);
+        when(world.getUID()).thenReturn(worldId);
+        Player player = mock(Player.class);
+        when(player.getUniqueId()).thenReturn(playerId);
+        when(player.getName()).thenReturn("Builder");
+        when(player.getWorld()).thenReturn(world);
+        when(player.getLocation()).thenReturn(new Location(world, 35.5, 64.0, 0.5));
+        Server server = mock(Server.class);
+        doReturn(java.util.List.of(player)).when(server).getOnlinePlayers();
+        BaseStateManager stateManager = mock(BaseStateManager.class);
+        when(stateManager.player(playerId, "Builder")).thenReturn(state);
+        PluginSettingsProvider settings = new PluginSettingsProvider(
+            PluginSettings.from(Map.of())
+        );
+
+        new BaseNavigationController(server, stateManager, settings).run();
+
+        verify(player, never()).spawnParticle(
+            eq(Particle.END_ROD), any(Location.class), eq(1),
+            eq(0.0), eq(0.0), eq(0.0), eq(0.0)
+        );
+
+        when(player.getLocation()).thenReturn(new Location(world, 35.51, 64.0, 0.5));
+        new BaseNavigationController(server, stateManager, settings).run();
+
+        verify(player, times(settings.current().navigationParticleCount())).spawnParticle(
+            eq(Particle.END_ROD), any(Location.class), eq(1),
+            eq(0.0), eq(0.0), eq(0.0), eq(0.0)
+        );
+    }
+}

src/test/java/games/dmg/spigotbase/BaseNavigationVisibilityTest.java

@@ -0,0 +1,26 @@
+package games.dmg.spigotbase;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.UUID;
+import org.junit.jupiter.api.Test;
+
+final class BaseNavigationVisibilityTest {
+    private static final BaseLocation BASE = new BaseLocation(
+        UUID.randomUUID(), "world", 0, 64, 0, 0, 0
+    );
+
+    @Test
+    void hidesNavigationAtAndWithinTwentyFiveBlocksBeyondBorder() {
+        assertFalse(BaseNavigationVisibility.isBeyondBorderBuffer(BASE, 10, 35.5, 0.5));
+        assertFalse(BaseNavigationVisibility.isBeyondBorderBuffer(BASE, 10, 20.5, 0.5));
+    }
+
+    @Test
+    void showsNavigationMoreThanTwentyFiveBlocksBeyondCurrentBorder() {
+        assertTrue(BaseNavigationVisibility.isBeyondBorderBuffer(BASE, 10, 35.51, 0.5));
+        assertFalse(BaseNavigationVisibility.isBeyondBorderBuffer(BASE, 75, 100.5, 0.5));
+        assertTrue(BaseNavigationVisibility.isBeyondBorderBuffer(BASE, 75, 100.51, 0.5));
+    }
+}