Handle edge case of parcel too large, returning items to player's inventory

Author: md5sha256

src/main/java/io/github/md5sha256/democracypost/database/DatabaseAdapter.java

@@ -55,6 +55,10 @@ public void transferExpiredPackages(@Nonnull Duration returnPackageExpiryDuratio
         }
     }
 
+    public boolean isParcelTooLarge(@Nonnull PostalPackage postalPackage) {
+        return this.schema.isParcelTooLarge(postalPackage);
+    }
+
     @Nonnull
     public List<PostalPackage> getPackagesForRecipient(@Nonnull UUID recipient) throws SQLException {
         try (Connection connection = this.dataSource.getConnection()) {

src/main/java/io/github/md5sha256/democracypost/database/DatabaseSchema.java

@@ -32,4 +32,6 @@ void removePackage(@Nonnull Connection connection,
     @Nonnull
     PackageExpiryData getPackageExpiryData(@Nonnull Connection connection, @Nonnull UUID receiver, @Nonnull Duration fromExpiry)
             throws SQLException;
+
+    boolean isParcelTooLarge(@Nonnull PostalPackage postalPackage);
 }

src/main/java/io/github/md5sha256/democracypost/database/MariaSchema.java

@@ -5,6 +5,7 @@
 import io.github.md5sha256.democracypost.serializer.Serializers;
 import org.bukkit.inventory.ItemStack;
 import org.jetbrains.annotations.NotNull;
+import org.jspecify.annotations.NonNull;
 import org.spongepowered.configurate.ConfigurateException;
 import org.spongepowered.configurate.ConfigurationNode;
 import org.spongepowered.configurate.gson.GsonConfigurationLoader;
@@ -32,7 +33,6 @@
 
 public class MariaSchema implements DatabaseSchema {
 
-
     private static final String CREATE_POST_PACKAGES_TABLE = """
             CREATE TABLE POST_PACKAGE (
               package_id BINARY(16) NOT NULL,
@@ -107,6 +107,12 @@ public String formatJdbcUrl(@NotNull String url) {
         return "jdbc:mariadb://" + url;
     }
 
+    @Override
+    public boolean isParcelTooLarge(@NonNull PostalPackage postalPackage) {
+        // 65535 is the BLOB max size
+        return getBytes(postalPackage.content().items()).length > 65535;
+    }
+
     @Override
     public void initializeSchema(@Nonnull Connection connection) throws SQLException {
         try (PreparedStatement statementCreateTables = connection.prepareStatement(CREATE_POST_PACKAGES_TABLE);

src/main/java/io/github/md5sha256/democracypost/model/PostalPackageFactory.java

@@ -5,12 +5,20 @@
 import javax.annotation.Nonnull;
 import java.util.List;
 import java.util.UUID;
+import java.util.concurrent.CompletableFuture;
 
 public interface PostalPackageFactory {
 
+    enum PostResult {
+        SUCCESS,
+        TOO_LARGE,
+        UNKNOWN_ERROR,
+    }
+
     @Nonnull
     PostalPackage createPackage(@Nonnull UUID sender, @Nonnull UUID recipient, @Nonnull List<ItemStack> contents, boolean isReturn);
 
-    void createAndPostPackage(@Nonnull UUID sender, @Nonnull UUID recipient, @Nonnull List<ItemStack> contents, boolean isReturn);
+    @Nonnull
+    CompletableFuture<PostResult> createAndPostPackage(@Nonnull UUID sender, @Nonnull UUID recipient, @Nonnull List<ItemStack> contents, boolean isReturn);
 
 }

src/main/java/io/github/md5sha256/democracypost/model/SimplePostalPackageFactory.java

@@ -17,6 +17,7 @@
 import java.util.Date;
 import java.util.List;
 import java.util.UUID;
+import java.util.concurrent.CompletableFuture;
 import java.util.logging.Logger;
 
 public class SimplePostalPackageFactory implements PostalPackageFactory {
@@ -54,25 +55,35 @@ public PostalPackage createPackage(@NotNull UUID sender,
     }
 
     @Override
-    public void createAndPostPackage(@NotNull UUID sender,
-                                     @NotNull UUID recipient,
-                                     @NotNull List<ItemStack> contents,
-                                     boolean isReturnPackage) {
+    @Nonnull
+    public CompletableFuture<PostResult> createAndPostPackage(@NotNull UUID sender,
+                                                  @NotNull UUID recipient,
+                                                  @NotNull List<ItemStack> contents,
+                                                  boolean isReturnPackage) {
+        CompletableFuture<PostResult> future = new CompletableFuture<>();
         Logger logger = this.plugin.getLogger();
         BukkitScheduler scheduler = this.plugin.getServer().getScheduler();
+        PostalPackage postalPackage = createPackage(sender, recipient, contents, isReturnPackage);
+        if (this.adapter.isParcelTooLarge(postalPackage)) {
+            future.complete(PostResult.TOO_LARGE);
+            return future;
+        }
         scheduler.runTaskAsynchronously(this.plugin, () -> {
             try {
-                PostalPackage postalPackage = createPackage(sender, recipient, contents, isReturnPackage);
+
                 logger.fine("Posting package: " + postalPackage.id() + " sender: " + sender + " receiver: " + recipient);
                 this.adapter.addPackage(postalPackage);
+                future.complete(PostResult.SUCCESS);
                 scheduler.runTask(this.plugin, () -> {
                     OfflinePlayer senderPlayer = this.plugin.getServer().getOfflinePlayer(sender);
                     this.mailService.notifyNewParcel(recipient, senderPlayer.getName());
                 });
             } catch (SQLException ex) {
                 logger.warning("Failed to post package!");
+                future.complete(PostResult.UNKNOWN_ERROR);
                 ex.printStackTrace();
             }
         });
+        return future;
     }
 }

src/main/java/io/github/md5sha256/democracypost/ui/PostPrompt.java

@@ -57,7 +57,7 @@ public PostPrompt(
             return this;
         }
         Conversable sender = context.getForWhom();
-        if (!(context.getForWhom() instanceof Player player)) {
+        if (!(sender instanceof Player player)) {
             return END_OF_CONVERSATION;
         }
         OfflinePlayer offlinePlayer = this.server.getOfflinePlayerIfCached(input);
@@ -77,7 +77,20 @@ public PostPrompt(
             sender.sendRawMessage(this.messageContainer.plaintextMessageFor("prompt.post-parcel.insufficient-balance"));
             return END_OF_CONVERSATION;
         }
-        this.postalPackageFactory.createAndPostPackage(player.getUniqueId(), recipient, this.contents, false);
+        this.postalPackageFactory.createAndPostPackage(player.getUniqueId(), recipient, this.contents, false)
+                .thenAccept(result -> {
+                    var messageKey = switch (result) {
+                        case SUCCESS -> null;
+                        case TOO_LARGE -> "prompt.post-parcel.parcel-too-large";
+                        case UNKNOWN_ERROR -> "prompt.post-parcel.send-parcel-failed";
+                    };
+                    if (messageKey == null) {
+                        return;
+                    }
+                    player.getInventory().addItem(this.contents.toArray(ItemStack[]::new));
+                    var message = this.messageContainer.plaintextMessageFor(messageKey);
+                    sender.sendRawMessage(message);
+                });
         sender.sendRawMessage(this.messageContainer.plaintextMessageFor("prompt.post-parcel.send-parcel-success"));
         return END_OF_CONVERSATION;
     }

src/main/resources/en.yml

@@ -22,6 +22,8 @@ prompt:
         unknown-player: 'Unknown player: %player%'
         send-parcel-self: "You can't mail a parcel to yourself!"
         send-parcel-success: "Parcel mailed!"
+        send-parcel-failed: "Parcel mailing failed, the parcel has been returned to your inventory."
+        parcel-too-large: "Parcel too large to send, please split up your items into smaller parcels!"
 
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