.

core-bukkit-api/build.gradle.kts

@@ -20,6 +20,7 @@ dependencies {
 
     api("me.lucko:commodore:2.2")
     api("org.spigotmc:spigot-api:1.21.11-R0.1-SNAPSHOT")
+    api("net.kyori:adventure-platform-bukkit:4.4.1")
 }
 
 tasks.findByName("shadowJar")?.let {

core-bukkit-api/src/main/java/de/kentoj/scrow/bukkit/ScrowAPI.java

@@ -2,6 +2,7 @@ package de.kentoj.scrow.bukkit;
 
 import com.mongodb.reactivestreams.client.MongoDatabase;
 import de.kentoj.scrow.bukkit.services.EconomyService;
+import de.kentoj.scrow.bukkit.services.command.CommandManager;
 import lombok.AccessLevel;
 import lombok.Getter;
 import lombok.NoArgsConstructor;
@@ -15,6 +16,8 @@ public class ScrowAPI {
     private static @Nullable MongoDatabase database;
     @Getter
     private static EconomyService economyService;
+    @Getter
+    private static CommandManager commandManager;
 
     @ApiStatus.Internal
     public static void setDatabase(@Nullable MongoDatabase database) {
@@ -25,5 +28,10 @@ public class ScrowAPI {
     public static void setEconomyService(EconomyService economyService) {
         ScrowAPI.economyService = economyService;
     }
+
+    @ApiStatus.Internal
+    public static void setCommandManager(CommandManager commandManager) {
+        ScrowAPI.commandManager = commandManager;
+    }
 }
 

core-bukkit-api/src/main/java/de/kentoj/scrow/bukkit/services/command/CommandArgument.java

@@ -0,0 +1,14 @@
+package de.kentoj.scrow.bukkit.services.command;
+
+import de.kentoj.scrow.bukkit.services.command.arg.ArgumentType;
+import lombok.Value;
+
+import java.util.function.Function;
+
+@Value
+public class CommandArgument<T> {
+    int index;
+    String name;
+    ArgumentType<T> type;
+    Function<CommandContext, T> defaultValue;
+}

core-bukkit-api/src/main/java/de/kentoj/scrow/bukkit/services/command/CommandContext.java

@@ -1,16 +1,14 @@
-package de.kentoj.scrow.bukkit.services.old;
+package de.kentoj.scrow.bukkit.services.command;
 
 import org.bukkit.command.CommandSender;
 import org.bukkit.entity.Entity;
 import org.bukkit.entity.Player;
 
-public interface CmdContext {
+public interface CommandContext {
 
     CommandSender getSender();
 
     Player getSenderPlayer();
 
     Entity getSenderEntity();
-
-    <T> T getArg(String key);
 }

core-bukkit-api/src/main/java/de/kentoj/scrow/bukkit/services/command/CommandExecutionContext.java

@@ -0,0 +1,6 @@
+package de.kentoj.scrow.bukkit.services.command;
+
+public interface CommandExecutionContext extends CommandContext {
+
+    <T> T getArg(String key);
+}

core-bukkit-api/src/main/java/de/kentoj/scrow/bukkit/services/command/CommandExecutor.java

@@ -1,9 +1,9 @@
-package de.kentoj.scrow.bukkit.services.old;
+package de.kentoj.scrow.bukkit.services.command;
 
 public interface CommandExecutor {
 
     /**
      * @return true on success, 1 on failure
      */
-    boolean execute(CmdContext ctx);
+    void execute(CommandExecutionContext ctx);
 }

core-bukkit-api/src/main/java/de/kentoj/scrow/bukkit/services/command/CommandManager.java

@@ -0,0 +1,8 @@
+package de.kentoj.scrow.bukkit.services.command;
+
+import org.bukkit.plugin.Plugin;
+
+public interface CommandManager {
+
+    void register(CommandNode rootCommandNode, Plugin plugin);
+}

core-bukkit-api/src/main/java/de/kentoj/scrow/bukkit/services/command/CommandNode.java

@@ -0,0 +1,40 @@
+package de.kentoj.scrow.bukkit.services.command;
+
+import de.kentoj.scrow.bukkit.services.command.arg.ArgumentType;
+import org.bukkit.permissions.Permission;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.List;
+import java.util.function.Function;
+
+// TODO javadoc
+public interface CommandNode {
+
+    <T> void addArg(String name, ArgumentType<T> type, @Nullable Function<CommandContext, T> defaultValue);
+
+    default <T> void addArg(String name, ArgumentType<T> type) {
+        addArg(name, type, null);
+    }
+
+    void addSubCommand(CommandNode subCommand);
+
+    void setPermission(@Nullable Permission permission);
+
+    default void setPermission(String permission) {
+        setPermission(new Permission(permission));
+    }
+
+    @Nullable Permission getPermission();
+
+    @Nullable CommandArgument<?> getArg(int index);
+
+    List<CommandNode> getSubCommands();
+
+    String getName();
+
+    String[] getAliases();
+
+    String getDescription();
+
+    @Nullable CommandExecutor getExecutor();
+}

core-bukkit-api/src/main/java/de/kentoj/scrow/bukkit/services/command/arg/ArgumentType.java

@@ -0,0 +1,6 @@
+package de.kentoj.scrow.bukkit.services.command.arg;
+
+public interface ArgumentType<S> {
+
+    S parseInput(String str);
+}

core-bukkit-api/src/main/java/de/kentoj/scrow/bukkit/services/command/arg/PlayerArgumentType.java

@@ -1,4 +1,4 @@
-package de.kentoj.scrow.bukkit.services.old.arg;
+package de.kentoj.scrow.bukkit.services.command.arg;
 
 import lombok.AccessLevel;
 import lombok.NoArgsConstructor;
@@ -10,9 +10,9 @@ import java.util.UUID;
 
 // FIXME module stuff
 @NoArgsConstructor(access = AccessLevel.PRIVATE)
-public class PlayerArgType {
+public class PlayerArgumentType {
 
-    public static final CmdArg<Player> player = str -> {
+    public static final ArgumentType<Player> player = str -> {
         if (str.length() == 36) {
             var uuid = UUID.fromString(str);
             return Bukkit.getPlayer(uuid);
@@ -21,7 +21,7 @@ public class PlayerArgType {
         }
     };
 
-    public static final CmdArg<OfflinePlayer> offlinePlayer = str -> {
+    public static final ArgumentType<OfflinePlayer> offlinePlayer = str -> {
         var uuid = UUID.fromString(str);
         return Bukkit.getOfflinePlayer(uuid);
     };

core-bukkit-api/src/main/java/de/kentoj/scrow/bukkit/services/old/CommandsService.java

@@ -1,9 +0,0 @@
-package de.kentoj.scrow.bukkit.services.old;
-
-import org.bukkit.command.Command;
-import org.bukkit.plugin.Plugin;
-
-public interface CommandsService {
-
-    void register(Plugin plugin, Command command);
-}

core-bukkit-api/src/main/java/de/kentoj/scrow/bukkit/services/old/RegisteredCmdArg.java

@@ -1,11 +0,0 @@
-package de.kentoj.scrow.bukkit.services.old;
-
-import de.kentoj.scrow.bukkit.services.old.arg.CmdArg;
-import lombok.Value;
-
-@Value
-public class RegisteredCmdArg<T> {
-    int index;
-    String key;
-    CmdArg<T> arg;
-}

core-bukkit-api/src/main/java/de/kentoj/scrow/bukkit/services/old/SCommand.java

@@ -1,21 +0,0 @@
-package de.kentoj.scrow.bukkit.services.old;
-
-import org.bukkit.permissions.Permission;
-import org.jetbrains.annotations.Nullable;
-
-import java.util.List;
-
-public interface SCommand {
-
-    @Nullable Permission getPermission();
-
-    RegisteredCmdArg<?> getArg(int index);
-
-    List<SCommand> getSubCommands();
-
-    String[] getLabels();
-
-    String getDescription();
-
-    @Nullable CommandExecutor getExecutor();
-}

core-bukkit-api/src/main/java/de/kentoj/scrow/bukkit/services/old/arg/CmdArg.java

@@ -1,6 +0,0 @@
-package de.kentoj.scrow.bukkit.services.old.arg;
-
-public interface CmdArg<S> {
-
-    S parseInput(String str);
-}

core-bukkit-api/src/main/java/de/kentoj/scrow/bukkit/util/chat/ErrorMessage.java

@@ -0,0 +1,15 @@
+package de.kentoj.scrow.bukkit.util.chat;
+
+import lombok.AccessLevel;
+import lombok.NoArgsConstructor;
+import net.kyori.adventure.audience.Audience;
+import net.kyori.adventure.audience.Audiences;
+import net.kyori.adventure.platform.bukkit.BukkitAudiences;
+import net.kyori.adventure.text.Component;
+import org.bukkit.Bukkit;
+import org.bukkit.entity.Player;
+
+@NoArgsConstructor(access = AccessLevel.PRIVATE)
+public class ErrorMessage {
+
+}

core-bukkit-api/src/main/java/de/kentoj/scrow/bukkit/util/command/PlayerArgument.java

@@ -0,0 +1,30 @@
+package de.kentoj.scrow.bukkit.util.command;
+
+import com.mojang.brigadier.LiteralMessage;
+import com.mojang.brigadier.context.CommandContext;
+import com.mojang.brigadier.exceptions.CommandSyntaxException;
+import com.mojang.brigadier.exceptions.SimpleCommandExceptionType;
+import lombok.AccessLevel;
+import lombok.NoArgsConstructor;
+import org.bukkit.Bukkit;
+import org.bukkit.entity.Player;
+
+import java.util.UUID;
+
+@NoArgsConstructor(access = AccessLevel.PRIVATE)
+public class PlayerArgument {
+
+    public static Player resolve(CommandContext<Object> ctx, String argumentName) throws CommandSyntaxException {
+        var str = ctx.getArgument(argumentName, String.class);
+        boolean isUUID = str.length() == 36;
+        return isUUID ? Bukkit.getPlayer(parseUUID(str)) : Bukkit.getPlayerExact(str);
+    }
+
+    private static UUID parseUUID(String string) throws CommandSyntaxException {
+        try {
+            return UUID.fromString(string);
+        } catch (IllegalArgumentException ex) {
+            throw new SimpleCommandExceptionType(new LiteralMessage("Invalid UUID")).create();
+        }
+    }
+}

core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/CoreImplPlugin.java

@@ -1,5 +1,9 @@
 package de.kentoj.scrow.bukkit;
 
+import de.kentoj.scrow.bukkit.friends.casd.FriendCommand;
+import de.kentoj.scrow.bukkit.friends.command.LaunchCommand;
+import me.lucko.commodore.CommodoreProvider;
+import org.bukkit.command.PluginCommand;
 import org.bukkit.plugin.java.JavaPlugin;
 import reactor.core.publisher.Mono;
 
@@ -10,6 +14,11 @@ public class CoreImplPlugin extends JavaPlugin {
     @Override
     public void onEnable() {
         ScrowAPISurface.initScrowAPI(false);
+
+        {
+            ScrowAPI.getCommandManager().register(new LaunchCommand(), this);
+        }
+
         {
             var playerId = UUID.randomUUID();
             var economyService = ScrowAPI.getEconomyService();

core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/ScrowAPISurface.java

@@ -4,6 +4,7 @@ import com.mongodb.ConnectionString;
 import com.mongodb.MongoClientSettings;
 import com.mongodb.reactivestreams.client.MongoClient;
 import com.mongodb.reactivestreams.client.MongoClients;
+import de.kentoj.scrow.bukkit.command.bukkit.CommandManagerImpl;
 import de.kentoj.scrow.bukkit.economy.InMemoryEconomyService;
 import de.kentoj.scrow.bukkit.economy.MongoEconomyService;
 import lombok.AccessLevel;
@@ -37,6 +38,8 @@ public class ScrowAPISurface {
                 ScrowAPI.getDatabase() != null ?
                         new MongoEconomyService(ScrowAPI.getDatabase()) : new InMemoryEconomyService()
         );
+
+        ScrowAPI.setCommandManager(new CommandManagerImpl());
     }
 
     public static void destroyScrowAPI() {

core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/command/AbstractCommandNode.java

@@ -0,0 +1,79 @@
+package de.kentoj.scrow.bukkit.command;
+
+import com.google.common.collect.ImmutableList;
+import de.kentoj.scrow.bukkit.services.command.CommandContext;
+import de.kentoj.scrow.bukkit.services.command.CommandExecutor;
+import de.kentoj.scrow.bukkit.services.command.CommandArgument;
+import de.kentoj.scrow.bukkit.services.command.CommandNode;
+import de.kentoj.scrow.bukkit.services.command.arg.ArgumentType;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.Setter;
+import org.bukkit.permissions.Permission;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.function.Function;
+
+public abstract class AbstractCommandNode implements CommandNode {
+
+    private final List<CommandNode> subCommands = new ArrayList<>();
+    private final List<CommandArgument<?>> args = new ArrayList<>();
+
+    @Getter
+    private final String name;
+    @Getter
+    private final String[] aliases;
+    @Getter
+    private @Nullable Permission permission = null;
+    @Getter
+    @Setter(value = AccessLevel.PROTECTED)
+    private @Nullable String description;
+    @Getter
+    @Setter(value = AccessLevel.PROTECTED)
+    private @Nullable CommandExecutor executor = null;
+
+    public AbstractCommandNode(String name, String... aliases) {
+        this.name = name;
+        this.aliases = aliases;
+    }
+
+    @Override
+    public <T> void addArg(String name, ArgumentType<T> type, Function<CommandContext, T> defaultValue) {
+        var index = args.size();
+        if (index > 0) {
+            boolean isPreviousArgumentOptional = args.get(index - 1).getDefaultValue() != null;
+            boolean isNewArgumentOptional = defaultValue != null;
+            if (isPreviousArgumentOptional && !isNewArgumentOptional) {
+                // TODO document in javadoc
+                throw new IllegalStateException("an optional argument(an argument with a defaultValue set) may not be followed by a required argument");
+            }
+        }
+        args.add(new CommandArgument<>(index, name, type, defaultValue));
+        // TODO
+    }
+
+    @Override
+    public void addSubCommand(CommandNode subCommand) {
+        subCommands.add(subCommand);
+    }
+
+    @Override
+    public void setPermission(@Nullable Permission permission) {
+        this.permission = permission;
+    }
+
+    @Override
+    public @Nullable CommandArgument<?> getArg(int index) {
+        return args.stream()
+                .filter(ra -> ra.getIndex() == index)
+                .findFirst()
+                .orElse(null);
+    }
+
+    @Override
+    public List<CommandNode> getSubCommands() {
+        return ImmutableList.copyOf(subCommands);
+    }
+}

core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/command/AbstractSCommand.java

@@ -1,69 +0,0 @@
-package de.kentoj.scrow.bukkit.command;
-
-import com.google.common.collect.ImmutableList;
-import de.kentoj.scrow.bukkit.services.old.CommandExecutor;
-import de.kentoj.scrow.bukkit.services.old.RegisteredCmdArg;
-import de.kentoj.scrow.bukkit.services.old.SCommand;
-import de.kentoj.scrow.bukkit.services.old.arg.CmdArg;
-import lombok.AccessLevel;
-import lombok.Getter;
-import lombok.Setter;
-import org.bukkit.permissions.Permission;
-import org.jetbrains.annotations.Nullable;
-
-import java.util.ArrayList;
-import java.util.List;
-
-public abstract class AbstractSCommand implements SCommand {
-
-    private final List<SCommand> subCommands = new ArrayList<>();
-    private final List<RegisteredCmdArg<?>> args = new ArrayList<>();
-
-    @Getter
-    private final String[] labels;
-    @Getter
-    private @Nullable Permission permission = null;
-    @Getter
-    @Setter(value = AccessLevel.PROTECTED)
-    private @Nullable String description;
-    @Getter
-    @Setter(value = AccessLevel.PROTECTED)
-    private @Nullable CommandExecutor executor = null;
-
-    public AbstractSCommand(String... labels) {
-        this.labels = labels;
-    }
-
-    protected <T> void addArg(String key, CmdArg<T> arg) {
-
-    }
-    protected <T> void addArg(String key, CmdArg<T> arg, T defaultValue) {
-        var index = args.size();
-        args.add(new RegisteredCmdArg<>(index, key, arg));
-    }
-
-    @Override
-    public RegisteredCmdArg<?> getArg(int index) {
-        //noinspection OptionalGetWithoutIsPresent
-        return args.stream()
-                .filter(ra -> ra.getIndex() == index)
-                .findFirst()
-                .get();
-    }
-
-    public void addSubCommand(SCommand subCommand) {
-        subCommands.add(subCommand);
-    }
-
-    protected void setPermission(@Nullable Permission permission) {
-        this.permission = permission;
-    }
-
-    protected void setPermission(String permission) {
-        setPermission(new Permission(permission));
-    }
-
-    public List<SCommand> getSubCommands() {
-        return ImmutableList.copyOf(subCommands);
-    }
-}

core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/command/CommandContextImpl.java

@@ -1,18 +1,15 @@
 package de.kentoj.scrow.bukkit.command;
 
-import de.kentoj.scrow.bukkit.services.old.CmdContext;
+import de.kentoj.scrow.bukkit.services.command.CommandContext;
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import org.bukkit.command.CommandSender;
 import org.bukkit.entity.Entity;
 import org.bukkit.entity.Player;
 
-import java.util.Map;
-
 @RequiredArgsConstructor
-public class CmdContextImpl implements CmdContext {
+public class CommandContextImpl implements CommandContext {
 
-    private final Map<String, Object> args;
     @Getter
     private final CommandSender sender;
 
@@ -25,9 +22,4 @@ public class CmdContextImpl implements CmdContext {
     public Entity getSenderEntity() {
         return (Entity) sender;
     }
-
-    @SuppressWarnings("unchecked")
-    public <T> T getArg(String key) {
-        return (T) args.get(key);
-    }
 }

core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/command/CommandExecutionContextImpl.java

@@ -0,0 +1,21 @@
+package de.kentoj.scrow.bukkit.command;
+
+import de.kentoj.scrow.bukkit.services.command.CommandExecutionContext;
+import org.bukkit.command.CommandSender;
+
+import java.util.Map;
+
+public class CommandExecutionContextImpl extends CommandContextImpl implements CommandExecutionContext {
+
+    private final Map<String, Object> args;
+
+    public CommandExecutionContextImpl(CommandSender sender, Map<String, Object> args) {
+        super(sender);
+        this.args = args;
+    }
+
+    @SuppressWarnings("unchecked")
+    public <T> T getArg(String key) {
+        return (T) args.get(key);
+    }
+}

core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/command/CommandProcessor.java

@@ -1,29 +0,0 @@
-package de.kentoj.scrow.bukkit.command;
-
-import de.kentoj.scrow.bukkit.services.old.CmdContext;
-import de.kentoj.scrow.bukkit.services.old.SCommand;
-import org.bukkit.command.Command;
-import org.bukkit.command.CommandExecutor;
-import org.bukkit.command.CommandSender;
-import org.jetbrains.annotations.NotNull;
-
-import java.util.HashMap;
-import java.util.Map;
-
-public class CommandProcessor implements CommandExecutor {
-
-    public CmdContext process(SCommand scommand, String[] strArgs, CommandSender sender) {
-        Map<String, Object> args = new HashMap<>();
-        for (int i = 0; i < strArgs.length; i++) {
-            var arg = scommand.getArg(i);
-            var value = arg.getArg().parseInput(strArgs[i]);
-            args.put(arg.getKey(), value);
-        }
-        return new CmdContextImpl(args, sender);
-    }
-
-    @Override
-    public boolean onCommand(@NotNull CommandSender sender, @NotNull Command command, @NotNull String label, @NotNull String[] args) {
-        return false;
-    }
-}

core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/command/LaunchCommand.java

@@ -1,26 +0,0 @@
-package de.kentoj.scrow.bukkit.command;
-
-import de.kentoj.scrow.bukkit.services.old.CommandExecutor;
-import de.kentoj.scrow.bukkit.services.old.arg.PlayerArgType;
-import de.kentoj.scrow.bukkit.services.old.CmdContext;
-import org.bukkit.entity.Player;
-import org.bukkit.permissions.Permission;
-import org.bukkit.util.Vector;
-
-public class LaunchCommand extends AbstractSCommand implements CommandExecutor {
-
-    public LaunchCommand() {
-        super("launch");
-        setPermission(new Permission("corebukkit.cmd.launch"));
-        setExecutor(this);
-        addArg("player", PlayerArgType.player);
-        addArg("factor", IntRangeType.range(1, 5), 1);
-    }
-
-    @Override
-    public boolean execute(CmdContext ctx) {
-        final Player player = ctx.getArg("player");
-        player.setVelocity(new Vector(0, 1, 0));
-        return true;
-    }
-}

core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/command/bukkit/BukkitCommand.java

@@ -0,0 +1,36 @@
+package de.kentoj.scrow.bukkit.command.bukkit;
+
+import de.kentoj.scrow.bukkit.services.command.CommandNode;
+import org.bukkit.command.Command;
+import org.bukkit.command.CommandSender;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.List;
+
+public class BukkitCommand extends Command {
+
+    private static final CommandProcessor commandProcessor = new CommandProcessor();
+
+    private final CommandNode rootCommandNode;
+
+    protected BukkitCommand(CommandNode rootCommandNode, @NotNull String name, @NotNull String description, @NotNull String usageMessage, @NotNull List<String> aliases) {
+        super(name, description, usageMessage, aliases);
+        this.rootCommandNode = rootCommandNode;
+    }
+
+    @Override
+    public boolean execute(@NotNull CommandSender sender, @NotNull String commandLabel, @NotNull String[] args) {
+        final Runnable runnable;
+        try {
+            runnable = commandProcessor.toRunnable(rootCommandNode, sender, args);
+        } catch (CommandProcessException e) {
+            sender.sendMessage(e.getMessage());
+            return true;
+        } catch (IllegalStateException e) {
+            throw new RuntimeException("failed processing command " + rootCommandNode.getName(), e);
+        }
+
+        runnable.run();
+        return true;
+    }
+}

core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/command/bukkit/CommandManagerImpl.java

@@ -0,0 +1,41 @@
+package de.kentoj.scrow.bukkit.command.bukkit;
+
+import de.kentoj.scrow.bukkit.services.command.CommandManager;
+import de.kentoj.scrow.bukkit.services.command.CommandNode;
+import org.bukkit.Bukkit;
+import org.bukkit.command.Command;
+import org.bukkit.command.CommandMap;
+import org.bukkit.plugin.Plugin;
+
+import java.util.Arrays;
+
+public class CommandManagerImpl implements CommandManager {
+
+    private final CommandMap commandMap;
+
+    public CommandManagerImpl() {
+        try {
+            var field = Bukkit.getPluginManager().getClass().getDeclaredField("commandMap");
+            field.setAccessible(true);
+            commandMap = (CommandMap) field.get(Bukkit.getPluginManager());
+        } catch (NoSuchFieldException | IllegalAccessException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    @Override
+    public void register(CommandNode rootCommandNode, Plugin plugin) {
+        var bukkitCmd = toBukkitCommand(rootCommandNode);
+        commandMap.register(plugin.getName(), bukkitCmd);
+    }
+
+    private Command toBukkitCommand(CommandNode commandNode) {
+        return new BukkitCommand(
+                commandNode,
+                commandNode.getName(),
+                commandNode.getDescription(),
+                "",
+                Arrays.stream(commandNode.getAliases()).toList()
+        );
+    }
+}

core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/command/bukkit/CommandProcessException.java

@@ -0,0 +1,10 @@
+package de.kentoj.scrow.bukkit.command.bukkit;
+
+public class CommandProcessException extends RuntimeException {
+    public CommandProcessException(String message) {
+        super(message);
+    }
+    public CommandProcessException(String message, Throwable throwable) {
+        super(message + ": " + throwable.getMessage());
+    }
+}

core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/command/bukkit/CommandProcessor.java

@@ -0,0 +1,78 @@
+package de.kentoj.scrow.bukkit.command.bukkit;
+
+import com.google.common.base.Strings;
+import de.kentoj.scrow.bukkit.command.CommandContextImpl;
+import de.kentoj.scrow.bukkit.command.CommandExecutionContextImpl;
+import de.kentoj.scrow.bukkit.services.command.CommandArgument;
+import de.kentoj.scrow.bukkit.services.command.CommandContext;
+import de.kentoj.scrow.bukkit.services.command.CommandNode;
+import lombok.RequiredArgsConstructor;
+import org.bukkit.command.CommandSender;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+
+@RequiredArgsConstructor
+public class CommandProcessor {
+
+    public Runnable toRunnable(final CommandNode rootCommandNode, final CommandSender sender, final String[] args) throws CommandProcessException {
+        final var argToValueFunMap = new HashMap<String, Function<CommandContext, ?>>();
+        CommandNode lastNode = rootCommandNode;
+
+        for (int cursor = 0; true; cursor++) {
+            final var arg = lastNode.getArg(cursor);
+            if (arg != null) {
+                final var valueFun = getArgValueFun(cursor, arg);
+                argToValueFunMap.put(arg.getName(), valueFun);
+            } else {
+                if (lastNode.getSubCommands().isEmpty()) break;
+                final var subcommand = getSubCommand(lastNode, args[cursor]);
+                if (subcommand == null) {
+                    final var subcommands = lastNode.getSubCommands().stream().map(CommandNode::getName).toList();
+                    throw new CommandProcessException("Illegal argument -- " + args[cursor] + "\nExpected arguments: " + String.join(", ", subcommands));
+                }
+
+                lastNode = subcommand;
+            }
+        }
+        if (lastNode.getExecutor() == null) throw new IllegalStateException("Last CommandNode must have an executor");
+
+        final CommandNode finalLastNode = lastNode;
+        return () -> {
+            var ctx = new CommandExecutionContextImpl(sender, remap(argToValueFunMap, sender));
+            finalLastNode.getExecutor().execute(ctx);
+        };
+    }
+
+    private Map<String, Object> remap(Map<String, Function<CommandContext, ?>> argToValueFunMap, CommandSender sender) {
+        var ctx = new CommandContextImpl(sender);
+        return argToValueFunMap.entrySet()
+                .stream()
+                .collect(Collectors.toMap(
+                        Map.Entry::getKey,
+                        ent -> ent.getValue().apply(ctx)
+                ));
+    }
+
+    private Function<CommandContext, ?> getArgValueFun(int argIndex, CommandArgument<?> arg) throws CommandProcessException {
+        if (args.length - 1 < argIndex) {
+            if (arg.getDefaultValue() == null)
+                throw new CommandProcessException("usage: missing arg value for " + arg.getName());
+            return arg.getDefaultValue();
+        } else {
+            return __ -> arg.getType().parseInput(args[argIndex]);
+        }
+    }
+
+    private @Nullable CommandNode getSubCommand(CommandNode commandNode, String label) {
+        return commandNode.getSubCommands()
+                .stream()
+                .filter(c -> Arrays.stream(c.getAliases()).toList().contains(label))
+                .findFirst()
+                .orElse(null);
+    }
+}

core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/friends/casd/FriendAddCommand.java

@@ -0,0 +1,28 @@
+package de.kentoj.scrow.bukkit.friends.casd;
+
+import com.mojang.brigadier.Command;
+import com.mojang.brigadier.LiteralMessage;
+import com.mojang.brigadier.context.CommandContext;
+import com.mojang.brigadier.exceptions.CommandSyntaxException;
+import com.mojang.brigadier.exceptions.SimpleCommandExceptionType;
+import com.mojang.brigadier.tree.ArgumentCommandNode;
+import de.kentoj.scrow.bukkit.util.command.PlayerArgument;
+import lombok.AccessLevel;
+import lombok.NoArgsConstructor;
+import org.bukkit.entity.Player;
+import org.bukkit.util.Vector;
+
+@NoArgsConstructor(access = AccessLevel.PRIVATE)
+public class FriendAddCommand implements Command<Object> {
+
+    @Override
+    public int run(CommandContext<Object> ctx) throws CommandSyntaxException {
+        final Player player = PlayerArgument.resolve(ctx, "player");
+        if (player == null) {
+            throw new SimpleCommandExceptionType(new LiteralMessage("Player is not online")).create();
+        }
+
+        player.setVelocity(new Vector(0, 2, 0));
+        return 0;
+    }
+}

core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/friends/casd/FriendCommand.java

@@ -1,22 +1,19 @@
-package de.kentoj.scrow.bukkit.friends;
+package de.kentoj.scrow.bukkit.friends.casd;
 
-import com.mojang.brigadier.Command;
 import com.mojang.brigadier.arguments.StringArgumentType;
 import com.mojang.brigadier.builder.LiteralArgumentBuilder;
 import com.mojang.brigadier.builder.RequiredArgumentBuilder;
 
-public class FriendsCommand {
+public class FriendCommand {
 
-    public static Command<?> createCommand() {
+    public static LiteralArgumentBuilder<Object> create() {
         return LiteralArgumentBuilder.literal("friends")
-                .then(LiteralArgumentBuilder.literal("add")
+                .then(LiteralArgumentBuilder.literal("add"))
-                        .then(RequiredArgumentBuilder.argument("player", StringArgumentType.word())))
                 .then(LiteralArgumentBuilder.literal("list"))
                 .then(LiteralArgumentBuilder.literal("requests"))
                 .then(LiteralArgumentBuilder.literal("remove"))
                 .then(LiteralArgumentBuilder.literal("jump"))
                 .then(LiteralArgumentBuilder.literal("accept"))
-                .then(LiteralArgumentBuilder.literal("deny"))
+                .then(LiteralArgumentBuilder.literal("deny"));
-                .build().getCommand();
     }
 }

core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/friends/casd/FriendCommandExecutor.java

@@ -0,0 +1,13 @@
+package de.kentoj.scrow.bukkit.friends.casd;
+
+import org.bukkit.command.Command;
+import org.bukkit.command.CommandExecutor;
+import org.bukkit.command.CommandSender;
+import org.jetbrains.annotations.NotNull;
+
+public class FriendCommandExecutor implements CommandExecutor {
+    @Override
+    public boolean onCommand(@NotNull CommandSender sender, @NotNull Command command, @NotNull String label, @NotNull String[] args) {
+        return false;
+    }
+}

core-bukkit-impl/src/main/java/de/kentoj/scrow/bukkit/friends/command/LaunchCommand.java

@@ -0,0 +1,31 @@
+package de.kentoj.scrow.bukkit.friends.command;
+
+import de.kentoj.scrow.bukkit.command.AbstractCommandNode;
+import de.kentoj.scrow.bukkit.services.command.CommandContext;
+import de.kentoj.scrow.bukkit.services.command.CommandExecutionContext;
+import de.kentoj.scrow.bukkit.services.command.CommandExecutor;
+import de.kentoj.scrow.bukkit.services.command.arg.PlayerArgumentType;
+import net.md_5.bungee.api.chat.TranslatableComponent;
+import org.bukkit.entity.Player;
+import org.bukkit.permissions.Permission;
+import org.bukkit.util.Vector;
+
+public class LaunchCommand extends AbstractCommandNode implements CommandExecutor {
+
+    public LaunchCommand() {
+        super("launch", "lunch");
+        this.setDescription("launches a player in the air");
+        this.setPermission(new Permission("bukkitcore.cmd.launch"));
+
+        this.addArg("player", PlayerArgumentType.player, CommandContext::getSenderPlayer);
+        this.setExecutor(this);
+    }
+
+    @Override
+    public void execute(CommandExecutionContext ctx) {
+        final Player player = ctx.getArg("player");
+        player.spigot().sendMessage(new TranslatableComponent(""));
+        player.setVelocity(new Vector(0, 2, 0));
+        player.sendMessage("Launched " + player.getName() + ".");
+    }
+}