fix(flight): show boundary warning only while flying

design/user-stories/us-004-unlock-and-control-base-flight.md

@@ -21,7 +21,7 @@ As a **player with Base I**, I want to unlock controlled flight around my base s
 - [x] Flight II expands the vertical range to 100 blocks below and above base Y by default.
 - [x] Flight III expands the vertical range to the world's minimum and maximum build heights.
 - [x] A configurable five-block horizontal warning buffer extends beyond the current base radius.
-- [x] Plugin-granted flight remains active in the warning buffer and displays prominent on-screen notice that the player is leaving the base.
+- [x] Plugin-granted flight remains active in the warning buffer, and a prominent on-screen notice that the player is leaving the base appears only while the player is actively flying.
 - [x] Passing beyond the warning buffer removes only flight granted by this plugin.
 - [x] Flight is not granted outside the unlocked vertical range.
 - [x] `/basesettings flight enable` enables unlocked flight idempotently, and `/basesettings flight disable` disables it idempotently.

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

@@ -112,7 +112,7 @@ final class BaseFlightController implements Runnable {
             player.setAllowFlight(true);
             grantedFlight.add(player.getUniqueId());
         }
-        if (distanceSquared > (double) radius * radius) {
+        if (distanceSquared > (double) radius * radius && player.isFlying()) {
             if (warned.add(player.getUniqueId())) {
                 player.sendTitle(
                     ChatColor.RED + "Leaving Your Base",

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

@@ -0,0 +1,93 @@
+package games.dmg.spigotbase;
+
+import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.ArgumentMatchers.anyString;
+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.List;
+import java.util.Map;
+import java.util.UUID;
+import org.bukkit.Location;
+import org.bukkit.Server;
+import org.bukkit.World;
+import org.bukkit.entity.Player;
+import org.bukkit.inventory.ItemStack;
+import org.bukkit.inventory.PlayerInventory;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+final class BaseFlightControllerTest {
+    private final UUID playerId = UUID.randomUUID();
+    private final UUID worldId = UUID.randomUUID();
+    private final Server server = mock(Server.class);
+    private final BaseStateManager stateManager = mock(BaseStateManager.class);
+    private final Player player = mock(Player.class);
+    private final PlayerState state = PlayerState.newPlayer(playerId, "Alex")
+        .withGrassAndDirtProgress(250, 1)
+        .withBase(new BaseLocation(worldId, "world", 0, 64, 0, 0, 0), Instant.EPOCH)
+        .withFlightLevel(1, true);
+    private final BaseFlightController controller = new BaseFlightController(
+        server,
+        stateManager,
+        new SecondaryProgressionService(PluginSettings.from(Map.of())),
+        new BaseBoundsService(PluginSettings.from(Map.of())),
+        new PluginSettingsProvider(PluginSettings.from(Map.of()))
+    );
+
+    @BeforeEach
+    void setUp() {
+        World world = mock(World.class);
+        Location location = mock(Location.class);
+        PlayerInventory inventory = mock(PlayerInventory.class);
+
+        doReturn(List.of(player)).when(server).getOnlinePlayers();
+        when(player.getUniqueId()).thenReturn(playerId);
+        when(player.getName()).thenReturn("Alex");
+        when(player.getGameMode()).thenReturn(org.bukkit.GameMode.SURVIVAL);
+        when(player.getInventory()).thenReturn(inventory);
+        when(inventory.getStorageContents()).thenReturn(new ItemStack[0]);
+        when(stateManager.player(playerId, "Alex")).thenReturn(state);
+        when(player.getWorld()).thenReturn(world);
+        when(world.getUID()).thenReturn(worldId);
+        when(player.getLocation()).thenReturn(location);
+        when(location.getX()).thenReturn(12.5);
+        when(location.getZ()).thenReturn(0.5);
+        when(location.getBlockY()).thenReturn(64);
+        when(player.getAllowFlight()).thenReturn(true);
+    }
+
+    @Test
+    void walkingInWarningBufferDoesNotShowLeavingBaseWarning() {
+        when(player.isFlying()).thenReturn(false);
+
+        controller.run();
+
+        verify(player, never()).sendTitle(anyString(), anyString(), anyInt(), anyInt(), anyInt());
+    }
+
+    @Test
+    void flyingInWarningBufferShowsLeavingBaseWarning() {
+        when(player.isFlying()).thenReturn(true);
+
+        controller.run();
+
+        verify(player).sendTitle(anyString(), anyString(), anyInt(), anyInt(), anyInt());
+    }
+
+    @Test
+    void warningCanAppearAgainAfterPlayerStopsAndResumesFlyingInBuffer() {
+        when(player.isFlying()).thenReturn(true, false, true);
+
+        controller.run();
+        controller.run();
+        controller.run();
+
+        verify(player, times(2)).sendTitle(anyString(), anyString(), anyInt(), anyInt(), anyInt());
+    }
+}