Move loot spawning from GUI timer to SpawnerRangeChecker for independent operation

Co-authored-by: ptthanh02 <73684260+ptthanh02@users.noreply.github.com>

Author: Copilot

core/src/main/java/github/nighter/smartspawner/spawner/gui/synchronization/services/TimerUpdateService.java

@@ -389,7 +389,8 @@ private void updateMainMenuViewers(SpawnerData spawner) {
     }
 
     /**
-     * Calculates time until next spawn with loot pre-generation logic.
+     * Calculates time until next spawn for GUI display purposes only.
+     * Actual loot spawning is handled by SpawnerRangeChecker independently.
      */
     private long calculateTimeUntilNextSpawn(SpawnerData spawner) {
         long cachedDelay = spawner.getCachedSpawnDelay();
@@ -413,21 +414,11 @@ private long calculateTimeUntilNextSpawn(SpawnerData spawner) {
         long timeUntilNextSpawn = cachedDelay - timeElapsed;
         timeUntilNextSpawn = Math.max(0, Math.min(timeUntilNextSpawn, cachedDelay));
 
-        // Pre-generate loot when timer is low
+        // Pre-generate loot when timer is low for smooth GUI display
         if (lootHelper.shouldPreGenerateLoot(timeUntilNextSpawn)) {
             lootHelper.preGenerateLoot(spawner);
         }
 
-        // Add loot early for smooth UX
-        if (lootHelper.shouldAddLootEarly(timeUntilNextSpawn)) {
-            lootHelper.addPreGeneratedLootEarly(spawner, cachedDelay);
-        }
-
-        // Handle timer reaching zero
-        if (timeUntilNextSpawn <= 0) {
-            return lootHelper.handleLootSpawnAtZero(spawner, cachedDelay, timeElapsed);
-        }
-
         return timeUntilNextSpawn;
     }
 

core/src/main/java/github/nighter/smartspawner/spawner/lootgen/SpawnerRangeChecker.java

@@ -59,6 +59,12 @@ private void scheduleRegionSpecificCheck() {
                             handleSpawnerStateChange(sd, expectedStop);
                         }
                     });
+                } else {
+                    // Spawner state hasn't changed, but check if it's time to spawn loot
+                    // Only process active spawners that are not stopped
+                    if (sd.getSpawnerActive() && !sd.getSpawnerStop().get()) {
+                        checkAndSpawnLoot(sd);
+                    }
                 }
             }
         });
@@ -145,6 +151,75 @@ public void deactivateSpawner(SpawnerData spawner) {
         spawner.clearPreGeneratedLoot();
     }
 
+    /**
+     * Checks if a spawner should spawn loot based on its timer and spawns if needed.
+     * This runs independently of GUI updates to ensure loot spawns even when no one is viewing.
+     *
+     * @param spawner The spawner to check
+     */
+    private void checkAndSpawnLoot(SpawnerData spawner) {
+        // Calculate spawn delay
+        long cachedDelay = spawner.getCachedSpawnDelay();
+        if (cachedDelay == 0) {
+            cachedDelay = spawner.getSpawnDelay() * 50L; // Convert ticks to milliseconds
+            spawner.setCachedSpawnDelay(cachedDelay);
+        }
+
+        long currentTime = System.currentTimeMillis();
+        long lastSpawnTime = spawner.getLastSpawnTime();
+        long timeElapsed = currentTime - lastSpawnTime;
+
+        // Check if it's time to spawn loot
+        if (timeElapsed >= cachedDelay) {
+            // Try to acquire lock with short timeout to avoid blocking
+            try {
+                if (spawner.getDataLock().tryLock(50, java.util.concurrent.TimeUnit.MILLISECONDS)) {
+                    try {
+                        // Double-check time and state after acquiring lock
+                        currentTime = System.currentTimeMillis();
+                        lastSpawnTime = spawner.getLastSpawnTime();
+                        timeElapsed = currentTime - lastSpawnTime;
+
+                        if (timeElapsed >= cachedDelay && spawner.getSpawnerActive() && !spawner.getSpawnerStop().get()) {
+                            Location spawnerLocation = spawner.getSpawnerLocation();
+                            if (spawnerLocation != null) {
+                                // Schedule loot spawning on the correct region thread
+                                Scheduler.runLocationTask(spawnerLocation, () -> {
+                                    // Final check before spawning
+                                    if (!spawner.getSpawnerActive() || spawner.getSpawnerStop().get()) {
+                                        spawner.clearPreGeneratedLoot();
+                                        return;
+                                    }
+
+                                    // Spawn loot (pre-generated if available, otherwise generate new)
+                                    if (spawner.hasPreGeneratedLoot()) {
+                                        java.util.List<org.bukkit.inventory.ItemStack> items = spawner.getAndClearPreGeneratedItems();
+                                        int exp = spawner.getAndClearPreGeneratedExperience();
+                                        plugin.getSpawnerLootGenerator().addPreGeneratedLoot(spawner, items, exp);
+                                    } else {
+                                        plugin.getSpawnerLootGenerator().spawnLootToSpawner(spawner);
+                                    }
+
+                                    // Update last spawn time to reset the timer
+                                    spawner.setLastSpawnTime(System.currentTimeMillis());
+
+                                    // Update any open GUIs to show the new loot
+                                    if (plugin.getSpawnerGuiViewManager().hasViewers(spawner)) {
+                                        plugin.getSpawnerGuiViewManager().updateSpawnerMenuViewers(spawner);
+                                    }
+                                });
+                            }
+                        }
+                    } finally {
+                        spawner.getDataLock().unlock();
+                    }
+                }
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+            }
+        }
+    }
+
     public void cleanup() {
         executor.shutdown();
         try {