fix: restore owned animals lost from the world save

src/main/java/net/tfminecraft/cooking/husbandry/HusbandryConfig.java

@@ -49,6 +49,7 @@ public final class HusbandryConfig {
     private static double geneticSlowdownDivisor = 1;
     private static double careInfluence = 0.02;
     private static String statsRevision = "1";
+    private static boolean restoreLostAnimals = true;
     private static List<HusbandryAmountBand> amountBands = List.of();
     private static double mountSpeedMinPct = 0.40;
     private static double mountSpeedGeneticsPct = 0.30;
@@ -157,6 +158,14 @@ public static void setStatsRevision(String revision) {
         statsRevision = revision == null ? "" : revision.trim();
     }
 
+    public static void setRestoreLostAnimals(boolean enabled) {
+        restoreLostAnimals = enabled;
+    }
+
+    public static boolean restoreLostAnimals() {
+        return restoreLostAnimals;
+    }
+
     public static void setProfessionExp(String profession, HusbandryExpBracket bracket) {
         professionId = profession == null ? "" : profession.trim();
         defaultExp = bracket == null ? HusbandryExpBracket.of(6, 8) : bracket;

src/main/java/net/tfminecraft/cooking/husbandry/HusbandryEntityScan.java

@@ -7,6 +7,7 @@
 import java.io.InputStream;
 import java.nio.file.Files;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -17,7 +18,8 @@
 import java.util.zip.InflaterInputStream;
 
 /**
- * Reads saved entity chunks ({@code entities/r.X.Z.mca}) to find where unloaded animals are.
+ * Reads saved entity chunks ({@code entities/r.X.Z.mca}) to find where unloaded animals are,
+ * and player files for animals saved with a rider who logged out ({@code RootVehicle}).
  * Runs off the main thread; it only reads files.
  */
 final class HusbandryEntityScan {
@@ -26,8 +28,11 @@ record WorldDir(String world, File entities) {}
 
     record Found(String world, int x, int y, int z) {}
 
-    /** {@code complete} is false when some chunk could not be read, so a missing animal may still exist. */
-    record Result(Map<UUID, Found> found, boolean complete) {}
+    /**
+     * {@code ridden} holds animals saved under a logged-out rider.
+     * {@code complete} is false when some chunk or player file could not be read, so a missing animal may still exist.
+     */
+    record Result(Map<UUID, Found> found, Set<UUID> ridden, boolean complete) {}
 
     private static final Pattern REGION = Pattern.compile("r\\.(-?\\d{1,7})\\.(-?\\d{1,7})\\.mca");
     private static final int SECTOR = 4096;
@@ -37,10 +42,15 @@ record Result(Map<UUID, Found> found, boolean complete) {}
     private HusbandryEntityScan() {}
 
     static Result scan(List<WorldDir> worlds, Set<UUID> targets) {
+        return scan(worlds, null, targets);
+    }
+
+    static Result scan(List<WorldDir> worlds, File playerdata, Set<UUID> targets) {
         Map<UUID, Found> found = new HashMap<>();
+        Set<UUID> ridden = new HashSet<>();
         boolean complete = true;
         if (targets.isEmpty()) {
-            return new Result(found, true);
+            return new Result(found, ridden, true);
         }
         for (WorldDir world : worlds) {
             if (!world.entities().exists()) {
@@ -61,7 +71,31 @@ static Result scan(List<WorldDir> worlds, Set<UUID> targets) {
                 complete &= scanRegion(world, file, regionX, regionZ, targets, found);
             }
         }
-        return new Result(found, complete);
+        complete &= scanPlayers(playerdata, targets, ridden);
+        return new Result(found, ridden, complete);
+    }
+
+    private static boolean scanPlayers(File playerdata, Set<UUID> targets, Set<UUID> ridden) {
+        if (playerdata == null || !playerdata.exists()) {
+            return true;
+        }
+        File[] files = playerdata.listFiles((dir, name) -> name.endsWith(".dat"));
+        if (files == null) {
+            return false;
+        }
+        boolean complete = true;
+        for (File file : files) {
+            try (DataInputStream in = new DataInputStream(new ByteArrayInputStream(
+                    new GZIPInputStream(new ByteArrayInputStream(readBounded(file, MAX_CHUNK_BYTES)))
+                            .readNBytes(MAX_CHUNK_BYTES)))) {
+                Map<UUID, Found> vehicle = new HashMap<>();
+                readPlayer(in, targets, vehicle);
+                ridden.addAll(vehicle.keySet());
+            } catch (IOException | RuntimeException ex) {
+                complete = false;
+            }
+        }
+        return complete;
     }
 
     private static boolean scanRegion(
@@ -179,6 +213,31 @@ private static void readEntityChunk(DataInputStream in, String world, Set<UUID>
         }
     }
 
+    private static void readPlayer(DataInputStream in, Set<UUID> targets, Map<UUID, Found> found)
+            throws IOException {
+        if (in.readByte() != COMPOUND) {
+            return;
+        }
+        in.readUTF();
+        byte type;
+        while ((type = in.readByte()) != END) {
+            String key = in.readUTF();
+            if (type == COMPOUND && key.equals("RootVehicle")) {
+                byte inner;
+                while ((inner = in.readByte()) != END) {
+                    String innerKey = in.readUTF();
+                    if (inner == COMPOUND && innerKey.equals("Entity")) {
+                        readEntity(in, "", targets, found);
+                    } else {
+                        skip(in, inner);
+                    }
+                }
+            } else {
+                skip(in, type);
+            }
+        }
+    }
+
     private static void readEntityList(DataInputStream in, String world, Set<UUID> targets, Map<UUID, Found> found)
             throws IOException {
         byte element = in.readByte();

src/main/java/net/tfminecraft/cooking/husbandry/HusbandryLifecycleListener.java

@@ -13,7 +13,9 @@
 import org.bukkit.entity.Entity;
 import org.bukkit.entity.LivingEntity;
 import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
 import org.bukkit.event.Listener;
+import org.bukkit.event.entity.EntityRemoveEvent;
 import org.bukkit.event.world.EntitiesLoadEvent;
 import org.bukkit.event.world.EntitiesUnloadEvent;
 
@@ -35,6 +37,26 @@ public void onEntitiesUnload(EntitiesUnloadEvent event) {
         }
     }
 
+    @EventHandler(priority = EventPriority.MONITOR)
+    public void onEntityRemove(EntityRemoveEvent event) {
+        handleRemove(event.getEntity().getUniqueId(), event.getCause());
+    }
+
+    static void handleRemove(UUID uuid, EntityRemoveEvent.Cause cause) {
+        if (HusbandrySnapshots.keepsSnapshot(cause) || HusbandryEntities.getLoaded(uuid).isEmpty()) {
+            return;
+        }
+        HusbandryRepository repository = HusbandryEntities.repository();
+        if (repository == null) {
+            return;
+        }
+        try {
+            repository.deleteSnapshot(uuid);
+        } catch (SqliteDatabaseException ex) {
+            Bukkit.getLogger().severe("[Cooking] Failed to drop the snapshot of " + uuid + ": " + ex.getMessage());
+        }
+    }
+
     public static void applyStatsRevision() {
         HusbandryRepository repository = HusbandryEntities.repository();
         if (repository == null) {
@@ -100,10 +122,17 @@ public static void flushLoadedForDisable() {
         }
         long now = System.currentTimeMillis();
         List<HusbandryAnimal> toSave = new ArrayList<>(snapshot.size());
+        Map<UUID, byte[]> copies = new HashMap<>();
         for (HusbandryAnimal animal : snapshot) {
             Entity entity = Bukkit.getEntity(animal.uuid());
             if (entity != null) {
                 HusbandryLocation.remember(animal, entity);
+                if (HusbandrySnapshots.shouldCapture(animal)) {
+                    byte[] copy = HusbandrySnapshots.capture(entity, false);
+                    if (copy != null) {
+                        copies.put(animal.uuid(), copy);
+                    }
+                }
             }
             animal.setUnloadedAt(now);
             toSave.add(animal);
@@ -113,6 +142,7 @@ public static void flushLoadedForDisable() {
         } catch (SqliteDatabaseException ex) {
             Bukkit.getLogger().severe("[Cooking] Failed to flush husbandry animals on disable: " + ex.getMessage());
         }
+        HusbandrySnapshots.save(repository, copies);
     }
 
     static void handleLoad(Entity entity) {
@@ -185,5 +215,11 @@ static void handleUnload(Entity entity) {
         HusbandryLocation.remember(animal, entity);
         animal.setUnloadedAt(System.currentTimeMillis());
         repository.upsertAnimal(animal);
+        if (HusbandrySnapshots.shouldCapture(animal)) {
+            byte[] copy = HusbandrySnapshots.capture(entity, true);
+            if (copy != null) {
+                HusbandrySnapshots.save(repository, Map.of(uuid, copy));
+            }
+        }
     }
 }

src/main/java/net/tfminecraft/cooking/husbandry/HusbandryLoader.java

@@ -82,6 +82,7 @@ public void load(File file) {
                 config.getDouble("breeding.genetic-slowdown-divisor", 0.4),
                 config.getDouble("breeding.care-influence", 0.02));
         HusbandryConfig.setStatsRevision(config.getString("stats-revision", "1"));
+        HusbandryConfig.setRestoreLostAnimals(config.getBoolean("restore-lost-animals", true));
         HusbandryConfig.setProfessionExp(
                 config.getString("profession", "farming"),
                 parseExpBracket(config.getConfigurationSection("exp"), 6, 8));
@@ -329,6 +330,7 @@ private static void applyDefaults() {
         HusbandryConfig.setMountSpeedShares(0.40, 0.30, 0.20);
         HusbandryConfig.setBreeding(0.4, 0.4, 0.02);
         HusbandryConfig.setStatsRevision("1");
+        HusbandryConfig.setRestoreLostAnimals(true);
         HusbandryConfig.setProfessionExp("farming", HusbandryExpBracket.of(6, 8));
     }
 }

src/main/java/net/tfminecraft/cooking/husbandry/HusbandryLocator.java

@@ -22,7 +22,8 @@
 /**
  * Finds owned animals sitting in unloaded chunks by reading the saved entity chunks,
  * so {@code /animals} can point at them. An owned animal that is not in any saved chunk
- * of a fully scanned world is a ghost: its row is deleted and logged.
+ * of a fully scanned world, nor under a logged-out rider, was lost from the save: it is
+ * respawned from its snapshot, or, without one, its row is deleted as a ghost and logged.
  */
 public final class HusbandryLocator {
 
@@ -40,6 +41,12 @@ static void markFound(UUID uuid) {
         }
     }
 
+    static void markMissing(UUID uuid) {
+        if (uuid != null) {
+            MISSING.add(uuid);
+        }
+    }
+
     /** Scans once in the background. Call on the main thread after loaded worlds have resumed. */
     public static void scanUnloaded() {
         HusbandryRepository repository = HusbandryEntities.repository();
@@ -59,8 +66,9 @@ public static void scanUnloaded() {
         for (World world : Bukkit.getWorlds()) {
             worlds.add(new HusbandryEntityScan.WorldDir(world.getName(), entitiesFolder(world)));
         }
+        File playerdata = new File(Bukkit.getWorlds().get(0).getWorldFolder(), "playerdata");
         Bukkit.getScheduler().runTaskAsynchronously(Cooking.plugin, () -> {
-            HusbandryEntityScan.Result result = HusbandryEntityScan.scan(worlds, targets.keySet());
+            HusbandryEntityScan.Result result = HusbandryEntityScan.scan(worlds, playerdata, targets.keySet());
             if (Cooking.plugin != null && Cooking.plugin.isEnabled()) {
                 Bukkit.getScheduler().runTask(Cooking.plugin, () -> apply(targets, result, worlds));
             }
@@ -85,6 +93,7 @@ private static void apply(
             return;
         }
         int located = 0;
+        int restoring = 0;
         int dropped = 0;
         int missing = 0;
         List<String> scannedWorlds = worlds.stream().map(HusbandryEntityScan.WorldDir::world).toList();
@@ -98,13 +107,31 @@ private static void apply(
                 // Loaded or unloaded again during the scan; the stored location is newer.
                 continue;
             }
+            if (result.ridden().contains(uuid)) {
+                // Saved with a rider who logged out; it comes back when they join.
+                MISSING.remove(uuid);
+                continue;
+            }
             HusbandryEntityScan.Found found = result.found().get(uuid);
             if (found == null) {
                 HusbandryAnimal animal = stored.get();
                 // An animal last seen in a world that was not scanned may still be there.
                 if (!isConfirmedGhost(result.complete(), animal.world(), scannedWorlds)) {
                     continue;
                 }
+                try {
+                    if (HusbandrySnapshots.restore(repository, animal, repository.listOwners(uuid))) {
+                        MISSING.remove(uuid);
+                        restoring++;
+                        continue;
+                    }
+                } catch (SqliteDatabaseException ex) {
+                    Bukkit.getLogger().severe("[Cooking] Failed to read the snapshot of " + uuid
+                            + ": " + ex.getMessage());
+                    MISSING.add(uuid);
+                    missing++;
+                    continue;
+                }
                 try {
                     String line = deleteGhost(repository, animal);
                     Bukkit.getLogger().warning(line);
@@ -130,12 +157,12 @@ private static void apply(
                 Bukkit.getLogger().severe("[Cooking] Failed to save husbandry animal location: " + ex.getMessage());
             }
         }
-        if (located > 0 || dropped > 0 || missing > 0 || !result.complete()) {
+        if (located > 0 || restoring > 0 || dropped > 0 || missing > 0 || !result.complete()) {
             String failed = missing > 0
                     ? ", " + missing + " still marked missing after a failed drop"
                     : "";
-            Bukkit.getLogger().info("[Cooking] Animal scan: updated " + located + " locations, dropped "
-                    + dropped + " ghost animals" + failed
+            Bukkit.getLogger().info("[Cooking] Animal scan: updated " + located + " locations, restoring "
+                    + restoring + " lost animals from snapshots, dropped " + dropped + " ghost animals" + failed
                     + (result.complete() ? "." : " (some chunks could not be read, none dropped)."));
         }
     }
@@ -167,19 +194,23 @@ static String deleteGhost(HusbandryRepository repository, HusbandryAnimal animal
     }
 
     static String ghostLog(HusbandryAnimal animal, List<HusbandryOwner> owners) {
-        String name = animal.name() == null || animal.name().isBlank() ? "(unnamed)" : animal.name();
-        String type = animal.type() == null || animal.type().isBlank() ? "unknown" : animal.type();
         String place = animal.hasLocation()
                 ? animal.world() + " " + animal.x() + ", " + animal.y() + ", " + animal.z()
                 : "unknown";
+        return "[Cooking] Dropped ghost animal " + describe(animal, owners) + " last seen " + place;
+    }
+
+    /** Name, type, uuid and owners, as the ghost and restore log lines print them. */
+    static String describe(HusbandryAnimal animal, List<HusbandryOwner> owners) {
+        String name = animal.name() == null || animal.name().isBlank() ? "(unnamed)" : animal.name();
+        String type = animal.type() == null || animal.type().isBlank() ? "unknown" : animal.type();
         String ownerText = owners == null || owners.isEmpty()
                 ? "none"
                 : owners.stream()
                         .sorted((left, right) -> left.playerUuid().compareTo(right.playerUuid()))
                         .map(owner -> owner.playerUuid() + " (" + owner.role() + ")")
                         .collect(Collectors.joining(", "));
-        return "[Cooking] Dropped ghost animal " + name + " (" + type + ") " + animal.uuid()
-                + " owners=" + ownerText + " last seen " + place;
+        return name + " (" + type + ") " + animal.uuid() + " owners=" + ownerText;
     }
 
     private static boolean sameLocation(HusbandryAnimal animal, HusbandryEntityScan.Found found) {