From 7040a6ce1ef80afa69ec97167ff803ab32a56121 Mon Sep 17 00:00:00 2001
From: kento2 <kento@placeq.com>
Date: Sun, 5 Jul 2026 03:06:15 +0200
Subject: [PATCH] .

---
 .idea/workspace.xml                           | 29 ++++--------
 README.md                                     |  7 +--
 core-bukkit-api/build.gradle.kts              |  4 +-
 .../scrow/bukkit/friends/OrderedUUIDPair.java |  2 -
 .../scrow/bukkit/scheduler/TaskImpl.java      | 17 +++----
 core-bukkit-impl/build.gradle.kts             |  6 ++-
 .../kentoj/scrow/bukkit/CoreImplPlugin.java   | 15 +++----
 .../kentoj/scrow/bukkit/ScrowAPISurface.java  | 13 +++++-
 .../friends/command/FriendAddLiteral.java     | 12 ++---
 .../friendship/PostgresFriendshipService.java |  6 +--
 .../request/PostgresFriendRequestService.java | 23 +++++-----
 .../instancemanager/cache/InstanceCache.java  | 44 +++++++++++++++++++
 .../command/InstanceCommand.java              |  5 ++-
 .../command/InstanceDestroyLiteral.java       | 12 +++--
 .../command}/LobbyCommand.java                |  2 +-
 .../command}/PlayCommand.java                 |  2 +-
 core-lib/build.gradle.kts                     |  2 +-
 core-velocity-api/build.gradle.kts            |  4 +-
 core-velocity-impl/build.gradle.kts           |  3 ++
 .../scrow/corevelocity/ScrowAPISurface.java   | 10 ++++-
 20 files changed, 135 insertions(+), 83 deletions(-)
 create mode 100644 core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/instancemanager/cache/InstanceCache.java
 rename core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/{server => instancemanager/command}/LobbyCommand.java (94%)
 rename core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/{server => instancemanager/command}/PlayCommand.java (97%)

diff --git a/.idea/workspace.xml b/.idea/workspace.xml
index 59049e3..044afa9 100644
--- a/.idea/workspace.xml
+++ b/.idea/workspace.xml
@@ -5,38 +5,25 @@
   </component>
   <component name="ChangeListManager">
     <list default="true" id="56c685a1-f609-4ffd-a951-849beb2a7f8d" name="Changes" comment="currently refactoring a lot">
-      <change beforePath="$PROJECT_DIR$/../build-logic/convention/src/main/kotlin/de/kentoj/scrow/BaseDependenciesConvention.kt" beforeDir="false" afterPath="$PROJECT_DIR$/../build-logic/convention/src/main/kotlin/de/kentoj/scrow/BaseDependenciesConvention.kt" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/../build-logic/convention/src/main/kotlin/de/kentoj/scrow/DatabaseConvention.kt" beforeDir="false" afterPath="$PROJECT_DIR$/../build-logic/convention/src/main/kotlin/de/kentoj/scrow/DatabaseConvention.kt" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/instancemanager/cache/InstanceCache.java" afterDir="false" />
       <change beforePath="$PROJECT_DIR$/.idea/workspace.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/workspace.xml" afterDir="false" />
       <change beforePath="$PROJECT_DIR$/core-bukkit-api/build.gradle.kts" beforeDir="false" afterPath="$PROJECT_DIR$/core-bukkit-api/build.gradle.kts" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/core-bukkit-api/src/main/java/de/kentoj/scrow/bukkit/ScrowAPI.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-bukkit-api/src/main/java/de/kentoj/scrow/bukkit/ScrowAPI.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/core-bukkit-api/src/main/java/de/kentoj/scrow/bukkit/friends/OrderedUUIDPair.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-bukkit-api/src/main/java/de/kentoj/scrow/bukkit/friends/OrderedUUIDPair.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/core-bukkit-api/src/main/java/de/kentoj/scrow/bukkit/scheduler/TaskImpl.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-bukkit-api/src/main/java/de/kentoj/scrow/bukkit/scheduler/TaskImpl.java" afterDir="false" />
       <change beforePath="$PROJECT_DIR$/core-bukkit-impl/build.gradle.kts" beforeDir="false" afterPath="$PROJECT_DIR$/core-bukkit-impl/build.gradle.kts" afterDir="false" />
       <change beforePath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/CoreImplPlugin.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/CoreImplPlugin.java" afterDir="false" />
       <change beforePath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/ScrowAPISurface.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/ScrowAPISurface.java" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/economy/command/CoinsCommand.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/economy/command/CoinsCommand.java" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/economy/command/CoinsGetLiteral.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/economy/command/CoinsGetLiteral.java" afterDir="false" />
       <change beforePath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/friends/command/FriendAddLiteral.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/friends/command/FriendAddLiteral.java" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/friends/command/FriendRemoveLiteral.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/friends/command/FriendRemoveLiteral.java" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/friends/command/FriendRequestsLiteral.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/friends/command/FriendRequestsLiteral.java" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/instancemanager/command/InstanceDeployLiteral.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/instancemanager/command/InstanceDeployLiteral.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/friends/friendship/PostgresFriendshipService.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/friends/friendship/PostgresFriendshipService.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/friends/request/PostgresFriendRequestService.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/friends/request/PostgresFriendRequestService.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/instancemanager/command/InstanceCommand.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/instancemanager/command/InstanceCommand.java" afterDir="false" />
       <change beforePath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/instancemanager/command/InstanceDestroyLiteral.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/instancemanager/command/InstanceDestroyLiteral.java" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/playermanager/PlayerManagerImpl.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/playermanager/PlayerManagerImpl.java" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/server/PlayCommand.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/server/PlayCommand.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/server/LobbyCommand.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/instancemanager/command/LobbyCommand.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/server/PlayCommand.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/instancemanager/command/PlayCommand.java" afterDir="false" />
       <change beforePath="$PROJECT_DIR$/core-lib/build.gradle.kts" beforeDir="false" afterPath="$PROJECT_DIR$/core-lib/build.gradle.kts" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/core-lib/src/main/java/de/kentoj/scrowlib/convention/ScrowMessageStyle.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-lib/src/main/java/de/kentoj/scrowlib/convention/ScrowMessageStyle.java" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/core-lib/src/main/java/de/kentoj/scrowlib/instancemanager/InstanceManagerImpl.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-lib/src/main/java/de/kentoj/scrowlib/instancemanager/InstanceManagerImpl.java" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/core-lib/src/main/java/de/kentoj/scrowlib/messaging/MessageBroker.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-lib/src/main/java/de/kentoj/scrowlib/messaging/MessageBroker.java" afterDir="false" />
       <change beforePath="$PROJECT_DIR$/core-velocity-api/build.gradle.kts" beforeDir="false" afterPath="$PROJECT_DIR$/core-velocity-api/build.gradle.kts" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/core-velocity-api/src/main/java/de/kentoj/scrow/velocity/ScrowAPI.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-velocity-api/src/main/java/de/kentoj/scrow/velocity/ScrowAPI.java" afterDir="false" />
       <change beforePath="$PROJECT_DIR$/core-velocity-impl/build.gradle.kts" beforeDir="false" afterPath="$PROJECT_DIR$/core-velocity-impl/build.gradle.kts" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/core-velocity-impl/src/main/java/de/kentoj/scrow/corevelocity/CoreVelocityPlugin.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-velocity-impl/src/main/java/de/kentoj/scrow/corevelocity/CoreVelocityPlugin.java" afterDir="false" />
       <change beforePath="$PROJECT_DIR$/core-velocity-impl/src/main/java/de/kentoj/scrow/corevelocity/ScrowAPISurface.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-velocity-impl/src/main/java/de/kentoj/scrow/corevelocity/ScrowAPISurface.java" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/core-velocity-impl/src/main/java/de/kentoj/scrow/corevelocity/command/OnlineCommand.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-velocity-impl/src/main/java/de/kentoj/scrow/corevelocity/command/OnlineCommand.java" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/core-velocity-impl/src/main/java/de/kentoj/scrow/corevelocity/privmsg/MsgCommand.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-velocity-impl/src/main/java/de/kentoj/scrow/corevelocity/privmsg/MsgCommand.java" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/core-velocity-impl/src/main/java/de/kentoj/scrow/corevelocity/privmsg/PrivMsgHandler.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-velocity-impl/src/main/java/de/kentoj/scrow/corevelocity/privmsg/PrivMsgHandler.java" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/core-velocity-impl/src/main/java/de/kentoj/scrow/corevelocity/privmsg/ReplyCommand.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-velocity-impl/src/main/java/de/kentoj/scrow/corevelocity/privmsg/ReplyCommand.java" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/core-velocity-impl/src/main/java/de/kentoj/scrow/corevelocity/server/SendPlayerWatchdog.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-velocity-impl/src/main/java/de/kentoj/scrow/corevelocity/server/SendPlayerWatchdog.java" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/core-velocity-impl/src/main/java/de/kentoj/scrow/corevelocity/server/ServerRegisterWatchdog.java" beforeDir="false" afterPath="$PROJECT_DIR$/core-velocity-impl/src/main/java/de/kentoj/scrow/corevelocity/server/ServerRegisterWatchdog.java" afterDir="false" />
     </list>
     <option name="SHOW_DIALOG" value="false" />
     <option name="HIGHLIGHT_CONFLICTS" value="true" />
diff --git a/README.md b/README.md
index c0ca189..88b73ad 100644
--- a/README.md
+++ b/README.md
@@ -1,8 +1,9 @@
 TODO
-- cleanup nats
-- timeout/error handling with reactive
+- /friend add command is behaving weird: silent return no error
+  - improve error handling in Task ig
+  - try with InMemory db and debug postgres implementation
 - logging in general, log some exceptions to game chat
-- djb's multilogd for logging(?)
+- sleep
 
 environment
 -----------
diff --git a/core-bukkit-api/build.gradle.kts b/core-bukkit-api/build.gradle.kts
index 033c45a..1f54bb7 100644
--- a/core-bukkit-api/build.gradle.kts
+++ b/core-bukkit-api/build.gradle.kts
@@ -23,9 +23,9 @@ dependencies {
     // https://mvnrepository.com/artifact/io.nats/jnats
     api("io.nats:jnats:2.25.2")
     // http://forge.kentoj.de/scrow/-/packages/maven/de.kentoj.scrow:kencommandapi-core
-    api("de.kentoj.scrow:kencommandapi-core:0.28")
+    api("de.kentoj.scrow:kencommandapi-core:0.30")
     // http://forge.kentoj.de/scrow/-/packages/maven/de.kentoj.scrow:kencommandapi-bukkit
-    api("de.kentoj.scrow:kencommandapi-bukkit:0.28")
+    api("de.kentoj.scrow:kencommandapi-bukkit:0.30")
 }
 
 publishing {
diff --git a/core-bukkit-api/src/main/java/de/kentoj/scrow/bukkit/friends/OrderedUUIDPair.java b/core-bukkit-api/src/main/java/de/kentoj/scrow/bukkit/friends/OrderedUUIDPair.java
index a0a210a..cf892b0 100644
--- a/core-bukkit-api/src/main/java/de/kentoj/scrow/bukkit/friends/OrderedUUIDPair.java
+++ b/core-bukkit-api/src/main/java/de/kentoj/scrow/bukkit/friends/OrderedUUIDPair.java
@@ -1,6 +1,5 @@
 package de.kentoj.scrow.bukkit.friends;
 
-import com.google.common.base.Preconditions;
 import lombok.Getter;
 
 import java.util.UUID;
@@ -11,7 +10,6 @@ public class OrderedUUIDPair {
     private final UUID second;
 
     public OrderedUUIDPair(UUID uuid1, UUID uuid2) {
-        Preconditions.checkArgument(uuid1 != uuid2, "UUIDPair may consist of identical UUIDs");
         if (uuid1.compareTo(uuid2) < 0) {
             this.first = uuid1;
             this.second = uuid2;
diff --git a/core-bukkit-api/src/main/java/de/kentoj/scrow/bukkit/scheduler/TaskImpl.java b/core-bukkit-api/src/main/java/de/kentoj/scrow/bukkit/scheduler/TaskImpl.java
index ebcbb65..7157252 100644
--- a/core-bukkit-api/src/main/java/de/kentoj/scrow/bukkit/scheduler/TaskImpl.java
+++ b/core-bukkit-api/src/main/java/de/kentoj/scrow/bukkit/scheduler/TaskImpl.java
@@ -1,22 +1,16 @@
 package de.kentoj.scrow.bukkit.scheduler;
 
-import com.google.common.base.Preconditions;
 import de.kentoj.scrow.bukkit.ScrowAPI;
 import lombok.AccessLevel;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.bukkit.Bukkit;
 
-import java.util.concurrent.CompletableFuture;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
+import java.util.concurrent.*;
 import java.util.function.Function;
 import java.util.function.Predicate;
 import java.util.function.Supplier;
 
-import static com.google.common.base.Preconditions.*;
-
 /**
  * A Task runs entirely async, when sync is used, a subtask is run on the main thread and the async thread
  * blocks until the subtask returns.
@@ -34,7 +28,14 @@ public class TaskImpl<T> implements Task<T> {
 
     @Override
     public CompletableFuture<T> toFuture() {
-        return CompletableFuture.supplyAsync(() -> state().getValue(), EXECUTOR);
+        return CompletableFuture.supplyAsync(() -> {
+            try {
+                return state().getValue();
+            } catch (Exception ex) {
+                log.error("failed completing future", ex);
+                throw new CompletionException(ex);
+            }
+        }, EXECUTOR);
     }
 
     /**
diff --git a/core-bukkit-impl/build.gradle.kts b/core-bukkit-impl/build.gradle.kts
index 070114d..546d20f 100644
--- a/core-bukkit-impl/build.gradle.kts
+++ b/core-bukkit-impl/build.gradle.kts
@@ -26,9 +26,11 @@ dependencies {
     // https://mvnrepository.com/artifact/io.nats/jnats
     implementation("io.nats:jnats:2.25.2")
     // http://forge.kentoj.de/scrow/-/packages/maven/de.kentoj.scrow:kencommandapi-core
-    implementation("de.kentoj.scrow:kencommandapi-core:0.28")
+    implementation("de.kentoj.scrow:kencommandapi-core:0.30")
     // http://forge.kentoj.de/scrow/-/packages/maven/de.kentoj.scrow:kencommandapi-bukkit
-    implementation("de.kentoj.scrow:kencommandapi-bukkit:0.28")
+    implementation("de.kentoj.scrow:kencommandapi-bukkit:0.30")
+    // https://mvnrepository.com/artifact/org.postgresql/postgresql
+    implementation("org.postgresql:postgresql:42.7.12")
 }
 
 tasks {
diff --git a/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/CoreImplPlugin.java b/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/CoreImplPlugin.java
index 260a5f0..997af36 100644
--- a/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/CoreImplPlugin.java
+++ b/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/CoreImplPlugin.java
@@ -2,33 +2,30 @@ package de.kentoj.scrow.bukkit;
 
 import de.kentoj.scrow.bukkit.economy.command.CoinsCommand;
 import de.kentoj.scrow.bukkit.friends.command.FriendCommand;
+import de.kentoj.scrow.bukkit.instancemanager.cache.InstanceCache;
 import de.kentoj.scrow.bukkit.instancemanager.command.InstanceCommand;
 import de.kentoj.scrow.bukkit.region.RegionPlayerTracker;
 import de.kentoj.scrow.bukkit.region.RegionTask;
-import de.kentoj.scrow.bukkit.server.LobbyCommand;
-import de.kentoj.scrow.bukkit.server.PlayCommand;
+import de.kentoj.scrow.bukkit.instancemanager.command.LobbyCommand;
+import de.kentoj.scrow.bukkit.instancemanager.command.PlayCommand;
 import org.bukkit.plugin.java.JavaPlugin;
 
-import java.io.FileDescriptor;
 import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.nio.channels.FileChannel;
-import java.nio.file.OpenOption;
 import java.nio.file.Path;
 import java.nio.file.StandardOpenOption;
 
 public class CoreImplPlugin extends JavaPlugin {
 
-    public static boolean ENABLE_DATABASE = false;
-
     @Override
     public void onEnable() {
-        ScrowAPISurface.initScrowAPI(this, ENABLE_DATABASE);
-
+        ScrowAPISurface.initScrowAPI(this, true);
         {
             ScrowAPI.getCommandApi().register(new CoinsCommand().getRootNode());
             ScrowAPI.getCommandApi().register(FriendCommand.create());
-            ScrowAPI.getCommandApi().register(InstanceCommand.create());
+            var instanceCache = new InstanceCache();
+            ScrowAPI.getCommandApi().register(InstanceCommand.create(instanceCache));
             ScrowAPI.getCommandApi().register(new PlayCommand().getRootNode());
             ScrowAPI.getCommandApi().register(new LobbyCommand().getRootNode());
         }
diff --git a/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/ScrowAPISurface.java b/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/ScrowAPISurface.java
index 9ad8344..f4d6408 100644
--- a/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/ScrowAPISurface.java
+++ b/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/ScrowAPISurface.java
@@ -17,9 +17,13 @@ import io.nats.client.Options;
 import lombok.AccessLevel;
 import lombok.NoArgsConstructor;
 import org.bukkit.plugin.Plugin;
+import org.jdbi.v3.core.ConnectionFactory;
 import org.jdbi.v3.core.Jdbi;
 
 import java.io.IOException;
+import java.sql.Connection;
+import java.sql.SQLException;
+import java.util.Properties;
 
 @NoArgsConstructor(access = AccessLevel.NONE)
 public class ScrowAPISurface {
@@ -39,7 +43,14 @@ public class ScrowAPISurface {
         }
 
         if (enableDatabase) {
-            ScrowAPI.setJdbi(Jdbi.create(EnvUtils.envOrThrow("HOST_POSTGRES")));
+            try {
+                Class.forName("org.postgresql.Driver", true, ScrowAPISurface.class.getClassLoader());
+            } catch (ClassNotFoundException e) {
+                throw new RuntimeException(e);
+            }
+            var props = new Properties();
+            props.setProperty("user", "postgres");
+            ScrowAPI.setJdbi(Jdbi.create(EnvUtils.envOrThrow("HOST_POSTGRES"), props));
         }
 
         ScrowAPI.setPlayerManager(new PlayerManagerImpl());
diff --git a/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/friends/command/FriendAddLiteral.java b/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/friends/command/FriendAddLiteral.java
index 601147d..0dd2ffe 100644
--- a/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/friends/command/FriendAddLiteral.java
+++ b/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/friends/command/FriendAddLiteral.java
@@ -45,12 +45,12 @@ public class FriendAddLiteral implements CommandExecutor<CommandSender> {
         var self = (Player) ctx.getSender();
         var other = ctx.getArg(playerArg);
         return Tasks.supplyAsync(() -> findAction(self, other)
-                .mapSuccess(action -> {
-                    if (action == AddAction.SEND_REQUEST) sendRequest(self, other);
-                    else if (action == AddAction.ACCEPT_REQUEST) acceptRequest(self, other);
-                    return new Object();
-                })
-        ).toFuture();
+                        .mapSuccess(action -> {
+                            if (action == AddAction.SEND_REQUEST) sendRequest(self, other);
+                            else if (action == AddAction.ACCEPT_REQUEST) acceptRequest(self, other);
+                            return new Object();
+                        }))
+                .toFuture();
     }
 
     private void sendRequest(Player self, OfflinePlayer other) {
diff --git a/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/friends/friendship/PostgresFriendshipService.java b/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/friends/friendship/PostgresFriendshipService.java
index 9d512b9..ee6fb93 100644
--- a/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/friends/friendship/PostgresFriendshipService.java
+++ b/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/friends/friendship/PostgresFriendshipService.java
@@ -27,9 +27,9 @@ public class PostgresFriendshipService implements FriendshipService {
         jdbi = ScrowAPI.getJdbi();
         jdbi.useHandle(h -> h.execute("""
                 CREATE TABLE IF NOT EXISTS friendships (
-                    first_uuid  UUID        NOT NULL,
-                    second_uuid UUID        NOT NULL,
-                    created_at   TIMESTAMPTZ NOT NULL,
+                    first_uuid UUID NOT NULL,
+                    second_uuid UUID NOT NULL,
+                    created_at TIMESTAMPTZ NOT NULL,
                     PRIMARY KEY (first_uuid, second_uuid),
                     CONSTRAINT friendship_no_self_friendship
                         CHECK (first_uuid <> second_uuid)
diff --git a/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/friends/request/PostgresFriendRequestService.java b/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/friends/request/PostgresFriendRequestService.java
index aab0732..c9c569b 100644
--- a/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/friends/request/PostgresFriendRequestService.java
+++ b/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/friends/request/PostgresFriendRequestService.java
@@ -25,13 +25,13 @@ public class PostgresFriendRequestService implements FriendRequestService {
         jdbi = ScrowAPI.getJdbi();
 
         jdbi.useHandle(h -> h.execute("""
-                CREATE TABLE IF NOT EXISTS friend-requests (
+                CREATE TABLE IF NOT EXISTS friendrequests (
                     from_uuid UUID NOT NULL,
                     to_uuid UUID NOT NULL,
-                    created_at   TIMESTAMPTZ NOT NULL,
-                    PRIMARY KEY (first_uuid, second_uuid),
-                    CONSTRAINT friendship_no_self_friendship
-                        CHECK (first_uuid <> second_uuid)
+                    created_at TIMESTAMPTZ NOT NULL,
+                    PRIMARY KEY (from_uuid, to_uuid),
+                    CONSTRAINT friendship_no_self_request
+                        CHECK (from_uuid <> to_uuid)
                 )
                 """));
     }
@@ -40,7 +40,7 @@ public class PostgresFriendRequestService implements FriendRequestService {
     public @Nullable FriendRequest getFriendRequest(UUID from, UUID to) {
         return jdbi.withHandle(h -> h.createQuery("""
                         SELECT *
-                        FROM friend-requests
+                        FROM friendrequests
                         WHERE from_uuid = :from AND to_uuid = :to
                         """)
                 .bind("from", from)
@@ -53,11 +53,12 @@ public class PostgresFriendRequestService implements FriendRequestService {
     @Override
     public boolean saveFriendRequest(FriendRequest friendRequest) {
         return jdbi.withHandle(h -> h.createUpdate("""
-                        INSERT INTO friend-requests (from_uuid, to_uuid, created_at)
-                        VALUES (:from, :to, :created_at)
+                        INSERT INTO friendrequests (from_uuid, to_uuid, created_at)
+                        VALUES (:from, :to, :createdAt)
                         """)
                 .bind("from", friendRequest.getFrom())
                 .bind("to", friendRequest.getTo())
+                .bind("createdAt", friendRequest.getCreatedAt())
                 .execute() > 0);
     }
 
@@ -65,7 +66,7 @@ public class PostgresFriendRequestService implements FriendRequestService {
     public List<FriendRequest> getFriendRequestsTo(UUID playerId) {
         return jdbi.withHandle(h -> h.createQuery("""
                         SELECT *
-                        FROM friend-requests
+                        FROM friendrequests
                         WHERE to_uuid = :to
                         """)
                 .bind("to", playerId)
@@ -77,7 +78,7 @@ public class PostgresFriendRequestService implements FriendRequestService {
     public List<FriendRequest> getFriendRequestsFrom(UUID playerId) {
         return jdbi.withHandle(h -> h.createQuery("""
                         SELECT *
-                        FROM friend-requests
+                        FROM friendrequests
                         WHERE from_uuid = :from
                         """)
                 .bind("from", playerId)
@@ -89,7 +90,7 @@ public class PostgresFriendRequestService implements FriendRequestService {
     public boolean deleteFriendRequest(UUID from, UUID to) {
         return jdbi.withHandle(h -> h.createUpdate("""
                         DELETE
-                        FROM friend-requests
+                        FROM friendrequests
                         WHERE from_uuid = :from AND to_uuid = :to
                         """)
                 .bind("from", from)
diff --git a/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/instancemanager/cache/InstanceCache.java b/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/instancemanager/cache/InstanceCache.java
new file mode 100644
index 0000000..228903a
--- /dev/null
+++ b/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/instancemanager/cache/InstanceCache.java
@@ -0,0 +1,44 @@
+package de.kentoj.scrow.bukkit.instancemanager.cache;
+
+import de.kentoj.scrow.bukkit.ScrowAPI;
+import de.kentoj.scrowlib.instancemanager.ServerInstance;
+import de.kentoj.scrowlib.messaging.MessageBroker;
+import org.bson.Document;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.Collection;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+
+public class InstanceCache {
+
+    private final MessageBroker messageBroker = ScrowAPI.getMessageBroker();
+
+    private final ConcurrentMap<String, ServerInstance> cache = new ConcurrentHashMap<>();
+
+    public InstanceCache() {
+        messageBroker.subscribe("event.instance.up", doc -> {
+            var inst = toInstance(doc);
+            cache.put(inst.getHandle(), inst);
+        });
+        messageBroker.subscribe("event.instance.down", doc -> {
+            cache.remove(doc.getString("handle"));
+        });
+    }
+
+    public Collection<ServerInstance> getInstances() {
+        return cache.values();
+    }
+
+    public @Nullable ServerInstance getInstance(String handle) {
+        return cache.get(handle);
+    }
+
+    private ServerInstance toInstance(Document doc) {
+        return new ServerInstance(
+                doc.getString("handle"),
+                doc.getString("template"),
+                doc.getInteger("port")
+        );
+    }
+}
diff --git a/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/instancemanager/command/InstanceCommand.java b/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/instancemanager/command/InstanceCommand.java
index 31d83f1..32502ca 100644
--- a/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/instancemanager/command/InstanceCommand.java
+++ b/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/instancemanager/command/InstanceCommand.java
@@ -2,6 +2,7 @@ package de.kentoj.scrow.bukkit.instancemanager.command;
 
 import de.kentoj.kencommandapi.api.node.CommandNode;
 import de.kentoj.kencommandapi.api.node.RootCommandNode;
+import de.kentoj.scrow.bukkit.instancemanager.cache.InstanceCache;
 import de.kentoj.scrowlib.convention.ScrowMessageStyle;
 import lombok.AccessLevel;
 import lombok.NoArgsConstructor;
@@ -10,12 +11,12 @@ import org.bukkit.command.CommandSender;
 
 @NoArgsConstructor(access = AccessLevel.NONE)
 public class InstanceCommand {
-    public static RootCommandNode<CommandSender> create() {
+    public static RootCommandNode<CommandSender> create(InstanceCache instanceCache) {
         var style = new ScrowMessageStyle("server-manager", NamedTextColor.RED);
         RootCommandNode<CommandSender> rootNode = CommandNode.rootNode(style, "instance", "server-manager");
         rootNode.addLiteral(new InstanceListLiteral(style).getNode());
         rootNode.addLiteral(new InstanceDeployLiteral(style).getLiteral());
-        rootNode.addLiteral(new InstanceDestroyLiteral(style).getLiteral());
+        rootNode.addLiteral(new InstanceDestroyLiteral(instanceCache, style).getLiteral());
         return rootNode;
     }
 }
diff --git a/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/instancemanager/command/InstanceDestroyLiteral.java b/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/instancemanager/command/InstanceDestroyLiteral.java
index 02de206..7349434 100644
--- a/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/instancemanager/command/InstanceDestroyLiteral.java
+++ b/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/instancemanager/command/InstanceDestroyLiteral.java
@@ -8,6 +8,7 @@ import de.kentoj.kencommandapi.api.invocation.CommandContext;
 import de.kentoj.kencommandapi.api.invocation.CommandExecutor;
 import de.kentoj.kencommandapi.api.node.CommandNode;
 import de.kentoj.scrow.bukkit.ScrowAPI;
+import de.kentoj.scrow.bukkit.instancemanager.cache.InstanceCache;
 import de.kentoj.scrow.bukkit.scheduler.Tasks;
 import de.kentoj.scrowlib.convention.ScrowMessageStyle;
 import de.kentoj.scrowlib.instancemanager.ServerInstance;
@@ -23,16 +24,13 @@ public class InstanceDestroyLiteral implements CommandExecutor<CommandSender> {
     private final CommandArgument<CommandSender, String> handleArg;
     private final ScrowMessageStyle style;
 
-    public InstanceDestroyLiteral(ScrowMessageStyle style) {
+    public InstanceDestroyLiteral(InstanceCache cache, ScrowMessageStyle style) {
         this.style = style;
 
         handleArg = CommandArgument.arg("handle", new StringArgumentType<>());
-        handleArg.setSuggestionProvider(ctx ->
-                Tasks.supplyAsync(() -> ScrowAPI.getInstanceManager().getInstances().stream()
-                                .map(ServerInstance::getHandle)
-                                .toList())
-                        .toFuture());
-
+        handleArg.setSuggestionProvider(ctx -> cache.getInstances().stream()
+                .map(ServerInstance::getHandle)
+                .toList());
         literal = CommandNode.node("destroy");
         literal.addArgument(handleArg);
         literal.setExecutor(this);
diff --git a/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/server/LobbyCommand.java b/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/instancemanager/command/LobbyCommand.java
similarity index 94%
rename from core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/server/LobbyCommand.java
rename to core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/instancemanager/command/LobbyCommand.java
index 0b6be99..4266092 100644
--- a/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/server/LobbyCommand.java
+++ b/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/instancemanager/command/LobbyCommand.java
@@ -1,4 +1,4 @@
-package de.kentoj.scrow.bukkit.server;
+package de.kentoj.scrow.bukkit.instancemanager.command;
 
 import com.leakyabstractions.result.api.Result;
 import com.leakyabstractions.result.core.Results;
diff --git a/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/server/PlayCommand.java b/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/instancemanager/command/PlayCommand.java
similarity index 97%
rename from core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/server/PlayCommand.java
rename to core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/instancemanager/command/PlayCommand.java
index 28e7833..11b0c2d 100644
--- a/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/server/PlayCommand.java
+++ b/core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/instancemanager/command/PlayCommand.java
@@ -1,4 +1,4 @@
-package de.kentoj.scrow.bukkit.server;
+package de.kentoj.scrow.bukkit.instancemanager.command;
 
 import com.leakyabstractions.result.api.Result;
 import com.leakyabstractions.result.core.Results;
diff --git a/core-lib/build.gradle.kts b/core-lib/build.gradle.kts
index 8eaf8dd..3bc3bf0 100644
--- a/core-lib/build.gradle.kts
+++ b/core-lib/build.gradle.kts
@@ -21,7 +21,7 @@ dependencies {
     api("org.mongodb:bson:5.8.0")
 
     // http://forge.kentoj.de/scrow/-/packages/maven/de.kentoj.scrow:kencommandapi-core
-    api("de.kentoj.scrow:kencommandapi-core:0.28")
+    api("de.kentoj.scrow:kencommandapi-core:0.30")
 
     compileOnly("net.kyori:adventure-api:5.2.0")
 }
diff --git a/core-velocity-api/build.gradle.kts b/core-velocity-api/build.gradle.kts
index 95137c0..2266d0d 100644
--- a/core-velocity-api/build.gradle.kts
+++ b/core-velocity-api/build.gradle.kts
@@ -24,9 +24,9 @@ dependencies {
     api("com.velocitypowered:velocity-api:3.5.0-SNAPSHOT")
 
     // http://forge.kentoj.de/scrow/-/packages/maven/de.kentoj.scrow:kencommandapi-core
-    api("de.kentoj.scrow:kencommandapi-core:0.28")
+    api("de.kentoj.scrow:kencommandapi-core:0.30")
     // http://forge.kentoj.de/scrow/-/packages/maven/de.kentoj.scrow:kencommandapi-velocity
-    api("de.kentoj.scrow:kencommandapi-velocity:0.28")
+    api("de.kentoj.scrow:kencommandapi-velocity:0.30")
 }
 
 publishing {
diff --git a/core-velocity-impl/build.gradle.kts b/core-velocity-impl/build.gradle.kts
index 28e32e6..f20ac0b 100644
--- a/core-velocity-impl/build.gradle.kts
+++ b/core-velocity-impl/build.gradle.kts
@@ -25,6 +25,9 @@ dependencies {
 
     // https://mvnrepository.com/artifact/com.github.ben-manes.caffeine/caffeine
     implementation("com.github.ben-manes.caffeine:caffeine:3.2.4")
+
+    // https://mvnrepository.com/artifact/org.postgresql/postgresql
+    implementation("org.postgresql:postgresql:42.7.12")
 }
 
 tasks.build {
diff --git a/core-velocity-impl/src/main/java/de/kentoj/scrow/corevelocity/ScrowAPISurface.java b/core-velocity-impl/src/main/java/de/kentoj/scrow/corevelocity/ScrowAPISurface.java
index 46a83c2..b550dde 100644
--- a/core-velocity-impl/src/main/java/de/kentoj/scrow/corevelocity/ScrowAPISurface.java
+++ b/core-velocity-impl/src/main/java/de/kentoj/scrow/corevelocity/ScrowAPISurface.java
@@ -13,6 +13,7 @@ import lombok.NoArgsConstructor;
 import org.jdbi.v3.core.Jdbi;
 
 import java.io.IOException;
+import java.util.Properties;
 
 @NoArgsConstructor(access = AccessLevel.NONE)
 public class ScrowAPISurface {
@@ -30,7 +31,14 @@ public class ScrowAPISurface {
         }
 
         if (enableDatabase) {
-            ScrowAPI.setJdbi(Jdbi.create(EnvUtils.envOrThrow("HOST_POSTGRES")));
+            try {
+                Class.forName("org.postgresql.Driver", true, ScrowAPISurface.class.getClassLoader());
+            } catch (ClassNotFoundException e) {
+                throw new RuntimeException(e);
+            }
+            var props = new Properties();
+            props.setProperty("user", "postgres");
+            ScrowAPI.setJdbi(Jdbi.create(EnvUtils.envOrThrow("HOST_POSTGRES"), props));
         }
 
         ScrowAPI.setInstanceManager(new InstanceManagerImpl(ScrowAPI.getMessageBroker()));