feature: use cloud v2 for commands

Bukkit/build.gradle.kts

@@ -53,6 +53,9 @@ dependencies {
 
     // Adventure
     implementation(libs.adventureBukkit)
+
+    // Cloud
+    implementation(libs.cloudPaper)
 }
 
 tasks.processResources {
@@ -77,6 +80,7 @@ tasks.named<ShadowJar>("shadowJar") {
     relocate("com.google.inject", "com.plotsquared.google")
     relocate("org.aopalliance", "com.plotsquared.core.aopalliance")
     relocate("cloud.commandframework.services", "com.plotsquared.core.services")
+    relocate("cloud.commandframework", "com.plotsquared.commands")
     relocate("io.leangen.geantyref", "com.plotsquared.core.geantyref")
     relocate("com.intellectualsites.arkitektonika", "com.plotsquared.core.arkitektonika")
     relocate("com.intellectualsites.http", "com.plotsquared.core.http")

Bukkit/src/main/java/com/plotsquared/bukkit/BukkitPlatform.java

@@ -28,6 +28,7 @@ import com.google.inject.TypeLiteral;
 import com.plotsquared.bukkit.generator.BukkitPlotGenerator;
 import com.plotsquared.bukkit.inject.BackupModule;
 import com.plotsquared.bukkit.inject.BukkitModule;
+import com.plotsquared.bukkit.inject.CloudModule;
 import com.plotsquared.bukkit.inject.PermissionModule;
 import com.plotsquared.bukkit.inject.WorldManagerModule;
 import com.plotsquared.bukkit.listener.BlockEventListener;
@@ -64,6 +65,7 @@ import com.plotsquared.bukkit.uuid.SquirrelIdUUIDService;
 import com.plotsquared.core.PlotPlatform;
 import com.plotsquared.core.PlotSquared;
 import com.plotsquared.core.backup.BackupManager;
+import com.plotsquared.core.commands.PlotSquaredCommandManager;
 import com.plotsquared.core.components.ComponentPresetManager;
 import com.plotsquared.core.configuration.ConfigurationNode;
 import com.plotsquared.core.configuration.ConfigurationSection;
@@ -83,6 +85,7 @@ import com.plotsquared.core.inject.annotations.DefaultGenerator;
 import com.plotsquared.core.inject.annotations.ImpromptuPipeline;
 import com.plotsquared.core.inject.annotations.WorldConfig;
 import com.plotsquared.core.inject.annotations.WorldFile;
+import com.plotsquared.core.inject.modules.CommandModule;
 import com.plotsquared.core.inject.modules.PlotSquaredModule;
 import com.plotsquared.core.listener.PlotListener;
 import com.plotsquared.core.listener.WESubscriber;
@@ -293,6 +296,8 @@ public final class BukkitPlatform extends JavaPlugin implements Listener, PlotPl
                         new PermissionModule(),
                         new WorldManagerModule(),
                         new PlotSquaredModule(),
+                        new CommandModule(),
+                        new CloudModule(this),
                         new BukkitModule(this),
                         new BackupModule()
                 );
@@ -388,6 +393,8 @@ public final class BukkitPlatform extends JavaPlugin implements Listener, PlotPl
         // Commands
         if (Settings.Enabled_Components.COMMANDS) {
             this.registerCommands();
+            // Register the commands.
+            this.injector().getInstance(PlotSquaredCommandManager.class).registerDefaultCommands();
         }
 
         // Permissions

Bukkit/src/main/java/com/plotsquared/bukkit/inject/CloudModule.java

@@ -0,0 +1,86 @@
+package com.plotsquared.bukkit.inject;
+
+import cloud.commandframework.CloudCapability;
+import cloud.commandframework.CommandManager;
+import cloud.commandframework.bukkit.CloudBukkitCapabilities;
+import cloud.commandframework.execution.AsynchronousCommandExecutionCoordinator;
+import cloud.commandframework.minecraft.extras.AudienceProvider;
+import cloud.commandframework.minecraft.extras.MinecraftExceptionHandler;
+import cloud.commandframework.paper.PaperCommandManager;
+import com.google.inject.AbstractModule;
+import com.google.inject.Key;
+import com.google.inject.TypeLiteral;
+import com.plotsquared.bukkit.BukkitPlatform;
+import com.plotsquared.bukkit.util.BukkitUtil;
+import com.plotsquared.core.commands.CommonCommandRequirement;
+import com.plotsquared.core.commands.PlotSquaredCaptionProvider;
+import com.plotsquared.core.commands.processing.CommandRequirementPostprocessor;
+import com.plotsquared.core.configuration.caption.TranslatableCaption;
+import com.plotsquared.core.player.ConsolePlayer;
+import com.plotsquared.core.player.PlotPlayer;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.bukkit.Bukkit;
+import org.bukkit.command.CommandSender;
+import org.bukkit.entity.Player;
+import org.checkerframework.checker.nullness.qual.NonNull;
+
+public class CloudModule extends AbstractModule {
+
+    private static final Logger LOGGER = LogManager.getLogger("PlotSquared/" + CloudModule.class.getSimpleName());
+
+    private static @NonNull CommandSender convert(final @NonNull PlotPlayer<?> player) {
+        if (player instanceof ConsolePlayer) {
+            return Bukkit.getConsoleSender();
+        }
+        return (Player) player.getPlatformPlayer();
+    }
+
+    private static @NonNull PlotPlayer<?> convert (final @NonNull CommandSender sender) {
+        if (sender instanceof Player player) {
+            return BukkitUtil.adapt(player);
+        }
+        return ConsolePlayer.getConsole();
+    }
+
+    private final BukkitPlatform bukkitPlatform;
+
+    public CloudModule(final @NonNull BukkitPlatform bukkitPlatform) {
+        this.bukkitPlatform = bukkitPlatform;
+    }
+
+    @Override
+    protected void configure() {
+        try {
+            final PaperCommandManager<PlotPlayer<?>> commandManager = new PaperCommandManager<PlotPlayer<?>>(
+                    this.bukkitPlatform,
+                    AsynchronousCommandExecutionCoordinator.<PlotPlayer<?>>builder().withAsynchronousParsing().build(),
+                    CloudModule::convert,
+                    CloudModule::convert
+            );
+            commandManager.captionRegistry().registerProvider(new PlotSquaredCaptionProvider());
+            if (commandManager.hasCapability(CloudBukkitCapabilities.ASYNCHRONOUS_COMPLETION)) {
+                commandManager.registerAsynchronousCompletions();
+            }
+            if (commandManager.hasCapability(CloudBukkitCapabilities.NATIVE_BRIGADIER)) {
+                commandManager.registerBrigadier();
+            }
+
+            final CommandRequirementPostprocessor requirementPostprocessor = new CommandRequirementPostprocessor();
+            requirementPostprocessor.registerRequirements(CommonCommandRequirement.values());
+            commandManager.registerCommandPostProcessor(requirementPostprocessor);
+
+            // TODO(City): Override parsing errors using MM parsing.
+            MinecraftExceptionHandler.<PlotPlayer<?>>create(PlotPlayer::getAudience)
+                    .defaultHandlers()
+                    .decorator((ctx, component) -> TranslatableCaption.of("core.prefix").
+                            toComponent(ctx.context().sender())
+                            .append(component))
+                    .registerTo(commandManager);
+
+            bind(Key.get(new TypeLiteral<CommandManager<PlotPlayer<?>>>() {})).toInstance(commandManager);
+        } catch (final Exception e) {
+            LOGGER.error("Failed to configure command manager", e);
+        }
+    }
+}

Core/build.gradle.kts

@@ -15,6 +15,10 @@ dependencies {
     api(libs.adventureApi)
     api(libs.adventureMiniMessage)
 
+    // Cloud
+    api(libs.cloud)
+    api(libs.cloudMinecraftExtras)
+
     // Guice
     api(libs.guice) {
         exclude(group = "com.google.guava")

Core/src/main/java/com/plotsquared/core/commands/CommandRequirement.java

@@ -0,0 +1,28 @@
+package com.plotsquared.core.commands;
+
+import cloud.commandframework.context.CommandContext;
+import cloud.commandframework.keys.CloudKeyHolder;
+import com.plotsquared.core.configuration.caption.TranslatableCaption;
+import com.plotsquared.core.player.PlotPlayer;
+import org.checkerframework.checker.nullness.qual.NonNull;
+
+/**
+ * Something that is required for a command to be executed.
+ */
+public interface CommandRequirement extends CloudKeyHolder<Boolean> {
+
+    /**
+     * Returns the caption sent when the requirement is not met.
+     *
+     * @return the caption
+     */
+    @NonNull TranslatableCaption failureCaption();
+
+    /**
+     * Evaluates whether the requirement is met.
+     *
+     * @param context command context to evaluate
+     * @return {@code true} if the requirement is met, else {@code false}
+     */
+    boolean evaluate(final @NonNull CommandContext<PlotPlayer<?>> context);
+}

Core/src/main/java/com/plotsquared/core/commands/CommonCommandRequirement.java

@@ -0,0 +1,50 @@
+package com.plotsquared.core.commands;
+
+import cloud.commandframework.context.CommandContext;
+import cloud.commandframework.keys.CloudKey;
+import com.plotsquared.core.configuration.caption.TranslatableCaption;
+import com.plotsquared.core.player.PlotPlayer;
+import org.checkerframework.checker.nullness.qual.NonNull;
+
+import java.util.function.Predicate;
+
+/**
+ * Common {@link CommandRequirement command requirements}.
+ */
+public enum CommonCommandRequirement implements CommandRequirement {
+    /**
+     * Requires that the command sender is currently in a plot.
+     */
+    REQUIRES_PLOT(TranslatableCaption.of("errors.not_in_plot"), ctx -> ctx.sender().getCurrentPlot() != null),
+    /**
+     * Requires that the command sender is in a claimed plot.
+     */
+    REQUIRES_OWNER(TranslatableCaption.of("working.plot_not_claimed"),
+            ctx -> ctx.sender().getCurrentPlot() != null && ctx.sender().getCurrentPlot().hasOwner()
+    );
+
+    private final TranslatableCaption failureCaption;
+    private final Predicate<CommandContext<PlotPlayer<?>>> predicate;
+
+    CommonCommandRequirement(
+            final @NonNull TranslatableCaption failureCaption,
+            final @NonNull Predicate<CommandContext<PlotPlayer<?>>> predicate
+    ) {
+        this.failureCaption = failureCaption;
+        this.predicate = predicate;
+    }
+
+    public @NonNull TranslatableCaption failureCaption() {
+        return this.failureCaption;
+    }
+
+    @Override
+    public boolean evaluate(final @NonNull CommandContext<PlotPlayer<?>> context) {
+        return this.predicate.test(context);
+    }
+
+    @Override
+    public @NonNull CloudKey<Boolean> key() {
+        return CloudKey.of(String.format("requirement_%s", this.name()), Boolean.class);
+    }
+}

Core/src/main/java/com/plotsquared/core/commands/PlotSquaredCaptionProvider.java

@@ -0,0 +1,32 @@
+package com.plotsquared.core.commands;
+
+import cloud.commandframework.captions.Caption;
+import cloud.commandframework.captions.CaptionProvider;
+import com.plotsquared.core.PlotSquared;
+import com.plotsquared.core.configuration.caption.CaptionMap;
+import com.plotsquared.core.configuration.caption.TranslatableCaption;
+import com.plotsquared.core.player.PlotPlayer;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+/**
+ * {@link CaptionProvider} that retrieves caption values from the {@link CaptionMap caption map}.
+ */
+public final class PlotSquaredCaptionProvider implements CaptionProvider<PlotPlayer<?>> {
+
+    private static final Logger LOGGER = LogManager.getLogger("PlotSquared/" + PlotSquaredCaptionProvider.class.getSimpleName());
+
+    @Override
+    public @Nullable String provide(final @NonNull Caption caption, final @NonNull PlotPlayer<?> recipient) {
+        try {
+            return PlotSquared.get()
+                    .getCaptionMap(TranslatableCaption.DEFAULT_NAMESPACE)
+                    .getMessage(TranslatableCaption.of(caption.key()), recipient);
+        } catch (final CaptionMap.NoSuchCaptionException ignored) {
+            LOGGER.warn("Missing caption '{}', will attempt to fall back on Cloud defaults", caption.key());
+            return null;
+        }
+    }
+}

Core/src/main/java/com/plotsquared/core/commands/PlotSquaredCommandBean.java

@@ -0,0 +1,47 @@
+package com.plotsquared.core.commands;
+
+import cloud.commandframework.Command;
+import cloud.commandframework.CommandBean;
+import cloud.commandframework.CommandProperties;
+import com.plotsquared.core.command.CommandCategory;
+import com.plotsquared.core.player.PlotPlayer;
+import org.checkerframework.checker.nullness.qual.NonNull;
+
+import java.util.Set;
+
+public abstract class PlotSquaredCommandBean extends CommandBean<PlotPlayer<?>> {
+
+    /**
+     * Returns the category of the command.
+     *
+     * @return the category
+     */
+    public abstract @NonNull CommandCategory category();
+
+    /**
+     * Returns the requirements for the command to be executable.
+     *
+     * @return the requirements
+     */
+    public abstract @NonNull Set<@NonNull CommandRequirement> requirements();
+
+    @Override
+    protected final @NonNull CommandProperties properties() {
+        return CommandProperties.of("platsquared", "plat");
+    }
+
+    @Override
+    protected final Command.@NonNull Builder<PlotPlayer<?>> configure(final Command.@NonNull Builder<PlotPlayer<?>> builder) {
+        Command.@NonNull Builder<PlotPlayer<?>> intermediaryBuilder =
+                this.configurePlotCommand(builder.meta(PlotSquaredCommandMeta.META_CATEGORY,
+                this.category()));
+        for (final CommandRequirement requirement : this.requirements()) {
+            intermediaryBuilder = intermediaryBuilder.meta(requirement.key(), true);
+        }
+        return intermediaryBuilder;
+    }
+
+    protected abstract Command.@NonNull Builder<PlotPlayer<?>> configurePlotCommand(
+            Command.@NonNull Builder<PlotPlayer<?>> builder
+    );
+}

Core/src/main/java/com/plotsquared/core/commands/PlotSquaredCommandManager.java

@@ -0,0 +1,56 @@
+package com.plotsquared.core.commands;
+
+import cloud.commandframework.CommandManager;
+import cloud.commandframework.annotations.injection.GuiceInjectionService;
+import com.google.inject.Inject;
+import com.google.inject.Injector;
+import com.google.inject.Key;
+import com.google.inject.Singleton;
+import com.google.inject.TypeLiteral;
+import com.plotsquared.core.commands.injection.PlotInjector;
+import com.plotsquared.core.player.PlotPlayer;
+import com.plotsquared.core.plot.Plot;
+import org.checkerframework.checker.nullness.qual.NonNull;
+
+import java.util.Set;
+
+@Singleton
+public final class PlotSquaredCommandManager {
+
+    private final CommandManager<PlotPlayer<?>> commandManager;
+    private final Injector injector;
+
+    @Inject
+    public PlotSquaredCommandManager(
+            final @NonNull CommandManager<PlotPlayer<?>> commandManager,
+            final @NonNull Injector injector
+    ) {
+        this.commandManager = commandManager;
+        this.injector = injector;
+        this.registerInjectors();
+    }
+
+    /**
+     * Registers the commands that are shipped with PlotSquared.
+     */
+    public void registerDefaultCommands() {
+        final Set<PlotSquaredCommandBean> commands =
+                this.injector.getInstance(Key.get(new TypeLiteral<Set<PlotSquaredCommandBean>>() {}));
+        commands.forEach(command -> this.commandManager().command(command));
+    }
+
+    /**
+     * Returns the command manager.
+     *
+     * @return the command manager
+     */
+    public @NonNull CommandManager<PlotPlayer<?>> commandManager() {
+        return this.commandManager;
+    }
+
+    private void registerInjectors() {
+        this.commandManager.parameterInjectorRegistry().registerInjector(Plot.class,
+                this.injector.getInstance(PlotInjector.class));
+        this.commandManager.parameterInjectorRegistry().registerInjectionService(GuiceInjectionService.create(this.injector));
+    }
+}

Core/src/main/java/com/plotsquared/core/commands/PlotSquaredCommandMeta.java

@@ -0,0 +1,18 @@
+package com.plotsquared.core.commands;
+
+import cloud.commandframework.keys.CloudKey;
+import com.plotsquared.core.command.CommandCategory;
+
+/**
+ * Shared {@link cloud.commandframework.meta.CommandMeta command meta} keys.
+ */
+public final class PlotSquaredCommandMeta {
+
+    /**
+     * Key that determines what {@link CommandCategory category} a command belongs to.
+     */
+    public static final CloudKey<CommandCategory> META_CATEGORY = CloudKey.of("category", CommandCategory.class);
+
+    private PlotSquaredCommandMeta() {
+    }
+}

Core/src/main/java/com/plotsquared/core/commands/command/setting/flag/FlagSetCommand.java

@@ -0,0 +1,196 @@
+package com.plotsquared.core.commands.command.setting.flag;
+
+import cloud.commandframework.Command;
+import cloud.commandframework.context.CommandContext;
+import cloud.commandframework.keys.CloudKey;
+import com.google.inject.Inject;
+import com.plotsquared.core.PlotSquared;
+import com.plotsquared.core.command.CommandCategory;
+import com.plotsquared.core.commands.CommandRequirement;
+import com.plotsquared.core.commands.CommonCommandRequirement;
+import com.plotsquared.core.commands.PlotSquaredCommandBean;
+import com.plotsquared.core.commands.suggestions.FlagValueSuggestionProvider;
+import com.plotsquared.core.configuration.Settings;
+import com.plotsquared.core.configuration.caption.CaptionUtility;
+import com.plotsquared.core.configuration.caption.TranslatableCaption;
+import com.plotsquared.core.events.PlotFlagAddEvent;
+import com.plotsquared.core.events.Result;
+import com.plotsquared.core.permissions.Permission;
+import com.plotsquared.core.player.PlotPlayer;
+import com.plotsquared.core.plot.Plot;
+import com.plotsquared.core.plot.flag.FlagParseException;
+import com.plotsquared.core.plot.flag.PlotFlag;
+import com.plotsquared.core.plot.flag.types.IntegerFlag;
+import com.plotsquared.core.plot.flag.types.ListFlag;
+import com.plotsquared.core.util.EventDispatcher;
+import com.plotsquared.core.util.MathMan;
+import io.leangen.geantyref.TypeToken;
+import net.kyori.adventure.text.Component;
+import net.kyori.adventure.text.minimessage.tag.Tag;
+import net.kyori.adventure.text.minimessage.tag.resolver.TagResolver;
+import org.checkerframework.checker.nullness.qual.NonNull;
+
+import java.util.List;
+import java.util.Set;
+
+import static cloud.commandframework.arguments.standard.StringParser.greedyStringParser;
+import static com.plotsquared.core.commands.parser.PlotFlagParser.plotFlagParser;
+
+public final class FlagSetCommand extends PlotSquaredCommandBean {
+
+    private static final CloudKey<PlotFlag<?, ?>> COMPONENT_FLAG = CloudKey.of("flag", new TypeToken<PlotFlag<?, ?>>() {});
+    private static final CloudKey<String> COMPONENT_VALUE = CloudKey.of("value", String.class);
+
+    private static boolean checkPermValue(
+            final @NonNull PlotPlayer<?> player,
+            final @NonNull PlotFlag<?, ?> flag, @NonNull String key, @NonNull String value
+    ) {
+        key = key.toLowerCase();
+        value = value.toLowerCase();
+        String perm = Permission.PERMISSION_SET_FLAG_KEY_VALUE.format(key.toLowerCase(), value.toLowerCase());
+        if (flag instanceof IntegerFlag && MathMan.isInteger(value)) {
+            try {
+                int numeric = Integer.parseInt(value);
+                // Getting full permission without ".<amount>" at the end
+                perm = perm.substring(0, perm.length() - value.length() - 1);
+                boolean result = false;
+                if (numeric >= 0) {
+                    int checkRange = PlotSquared.get().getPlatform().equalsIgnoreCase("bukkit") ?
+                            numeric :
+                            Settings.Limit.MAX_PLOTS;
+                    result = player.hasPermissionRange(perm, checkRange) >= numeric;
+                }
+                if (!result) {
+                    player.sendMessage(
+                            TranslatableCaption.of("permission.no_permission"),
+                            TagResolver.resolver(
+                                    "node",
+                                    Tag.inserting(Component.text(perm + "." + numeric))
+                            )
+                    );
+                }
+                return result;
+            } catch (NumberFormatException ignore) {
+            }
+        } else if (flag instanceof final ListFlag<?, ?> listFlag) {
+            try {
+                PlotFlag<? extends List<?>, ?> parsedFlag = listFlag.parse(value);
+                for (final Object entry : parsedFlag.getValue()) {
+                    final String permission = Permission.PERMISSION_SET_FLAG_KEY_VALUE.format(
+                            key.toLowerCase(),
+                            entry.toString().toLowerCase()
+                    );
+                    final boolean result = player.hasPermission(permission);
+                    if (!result) {
+                        player.sendMessage(
+                                TranslatableCaption.of("permission.no_permission"),
+                                TagResolver.resolver("node", Tag.inserting(Component.text(permission)))
+                        );
+                        return false;
+                    }
+                }
+            } catch (final FlagParseException e) {
+                player.sendMessage(
+                        TranslatableCaption.of("flag.flag_parse_error"),
+                        TagResolver.builder()
+                                .tag("flag_name", Tag.inserting(Component.text(flag.getName())))
+                                .tag("flag_value", Tag.inserting(Component.text(e.getValue())))
+                                .tag("error", Tag.inserting(e.getErrorMessage().toComponent(player)))
+                                .build()
+                );
+                return false;
+            } catch (final Exception e) {
+                return false;
+            }
+            return true;
+        }
+        boolean result;
+        String basePerm = Permission.PERMISSION_SET_FLAG_KEY.format(key.toLowerCase());
+        if (flag.isValuedPermission()) {
+            result = player.hasKeyedPermission(basePerm, value);
+        } else {
+            result = player.hasPermission(basePerm);
+            perm = basePerm;
+        }
+        if (!result) {
+            player.sendMessage(
+                    TranslatableCaption.of("permission.no_permission"),
+                    TagResolver.resolver("node", Tag.inserting(Component.text(perm)))
+            );
+        }
+        return result;
+    }
+
+    private final EventDispatcher eventDispatcher;
+
+    @Inject
+    public FlagSetCommand(final @NonNull EventDispatcher eventDispatcher) {
+        this.eventDispatcher = eventDispatcher;
+    }
+
+    @Override
+    public @NonNull CommandCategory category() {
+        return CommandCategory.SETTINGS;
+    }
+
+    @Override
+    public @NonNull Set<@NonNull CommandRequirement> requirements() {
+        // TODO: Figure out how to handle the override permission check :)
+        return Set.of(CommonCommandRequirement.REQUIRES_PLOT, CommonCommandRequirement.REQUIRES_OWNER);
+    }
+
+    @Override
+    protected Command.@NonNull Builder<PlotPlayer<?>> configurePlotCommand(
+            final Command.@NonNull Builder<PlotPlayer<?>> builder
+    ) {
+        return builder.literal("flag")
+                .literal("set")
+                .required(COMPONENT_FLAG, plotFlagParser())
+                .required(COMPONENT_VALUE, greedyStringParser(), new FlagValueSuggestionProvider(COMPONENT_FLAG));
+    }
+
+    @Override
+    public void execute(final @NonNull CommandContext<PlotPlayer<?>> commandContext) {
+        final PlotPlayer<?> player = commandContext.sender();
+        final Plot plot = commandContext.inject(Plot.class).orElseThrow();
+        final PlotFlag<?, ?> flag = commandContext.get(COMPONENT_FLAG);
+        final String flagValue = commandContext.get(COMPONENT_VALUE);
+
+        final PlotFlagAddEvent event = this.eventDispatcher.callFlagAdd(flag, plot);
+        if (event.getEventResult() == Result.DENY) {
+            player.sendMessage(
+                    TranslatableCaption.of("events.event_denied"),
+                    TagResolver.resolver("value", Tag.inserting(Component.text("Flag set")))
+            );
+            return;
+        }
+        if (event.getEventResult() != Result.FORCE && !checkPermValue(player, flag, flag.getName(), flagValue)) {
+            return;
+        }
+
+        final String sanitizedValue = CaptionUtility.stripClickEvents(flag, flagValue);
+        final PlotFlag<?, ?> parsedFlag;
+        try {
+            parsedFlag = flag.parse(flagValue);
+        } catch (final FlagParseException e) {
+            player.sendMessage(
+                    TranslatableCaption.of("flag.flag_parse_error"),
+                    TagResolver.builder()
+                            .tag("flag_name", Tag.inserting(Component.text(flag.getName())))
+                            .tag("flag_value", Tag.inserting(Component.text(e.getValue())))
+                            .tag("error", Tag.inserting(e.getErrorMessage().toComponent(player)))
+                            .build()
+            );
+            return;
+        }
+
+        plot.setFlag(parsedFlag);
+        player.sendMessage(
+                TranslatableCaption.of("flag.flag_added"),
+                TagResolver.builder()
+                        .tag("flag", Tag.inserting(Component.text(flag.getName())))
+                        .tag("value", Tag.inserting(Component.text(parsedFlag.toString())))
+                        .build()
+        );
+    }
+}

Core/src/main/java/com/plotsquared/core/commands/injection/PlotInjector.java

@@ -0,0 +1,24 @@
+package com.plotsquared.core.commands.injection;
+
+import cloud.commandframework.annotations.AnnotationAccessor;
+import cloud.commandframework.annotations.injection.ParameterInjector;
+import cloud.commandframework.context.CommandContext;
+import com.plotsquared.core.player.PlotPlayer;
+import com.plotsquared.core.plot.Plot;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+/**
+ * {@link ParameterInjector} that returns the current plot of the player.
+ */
+public final class PlotInjector implements ParameterInjector<PlotPlayer<?>, Plot> {
+
+    @Override
+    public @Nullable Plot create(
+            final @NonNull CommandContext<PlotPlayer<?>> context,
+            final @NonNull AnnotationAccessor annotationAccessor
+    ) {
+        // TODO: Allow for overriding for console.
+        return context.sender().getCurrentPlot();
+    }
+}

Core/src/main/java/com/plotsquared/core/commands/parser/PlotFlagParser.java

@@ -0,0 +1,81 @@
+package com.plotsquared.core.commands.parser;
+
+import cloud.commandframework.arguments.parser.ArgumentParseResult;
+import cloud.commandframework.arguments.parser.ArgumentParser;
+import cloud.commandframework.arguments.parser.ParserDescriptor;
+import cloud.commandframework.arguments.suggestion.BlockingSuggestionProvider;
+import cloud.commandframework.arguments.suggestion.Suggestion;
+import cloud.commandframework.context.CommandContext;
+import cloud.commandframework.context.CommandInput;
+import cloud.commandframework.exceptions.parsing.ParserException;
+import com.plotsquared.core.configuration.caption.LocaleHolder;
+import com.plotsquared.core.configuration.caption.TranslatableCaption;
+import com.plotsquared.core.player.PlotPlayer;
+import com.plotsquared.core.plot.flag.GlobalFlagContainer;
+import com.plotsquared.core.plot.flag.InternalFlag;
+import com.plotsquared.core.plot.flag.PlotFlag;
+import io.leangen.geantyref.TypeToken;
+import net.kyori.adventure.text.Component;
+import net.kyori.adventure.util.ComponentMessageThrowable;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * Parser that parses and suggests {@link PlotFlag plot flags}.
+ */
+public final class PlotFlagParser implements ArgumentParser<PlotPlayer<?>, PlotFlag<?, ?>>,
+        BlockingSuggestionProvider<PlotPlayer<?>> {
+
+    /**
+     * Returns a new parser that parses {@link PlotFlag plot flags}.
+     *
+     * @return the parser
+     */
+    public static @NonNull ParserDescriptor<PlotPlayer<?>, PlotFlag<?, ?>> plotFlagParser() {
+        return ParserDescriptor.of(new PlotFlagParser(), new TypeToken<PlotFlag<?, ?>>() {
+        });
+    }
+
+    @Override
+    public @NonNull ArgumentParseResult<@NonNull PlotFlag<?, ?>> parse(
+            final @NonNull CommandContext<@NonNull PlotPlayer<?>> commandContext,
+            final @NonNull CommandInput commandInput
+    ) {
+        final String flagName = commandInput.readString();
+        final PlotFlag<?, ?> flag = GlobalFlagContainer.getInstance().getFlagFromString(flagName);
+        if (flag == null) {
+            return ArgumentParseResult.failure(new PlotFlagParseException(commandContext));
+        }
+        return ArgumentParseResult.success(flag);
+    }
+
+    @Override
+    public @NonNull Iterable<@NonNull Suggestion> suggestions(
+            final @NonNull CommandContext<PlotPlayer<?>> context,
+            final @NonNull CommandInput input
+    ) {
+        return GlobalFlagContainer.getInstance()
+                .getRecognizedPlotFlags()
+                .stream()
+                .filter(flag -> (!(flag instanceof InternalFlag)))
+                .map(PlotFlag::getName)
+                .map(Suggestion::simple)
+                .toList();
+    }
+
+    /**
+     * Exception thrown when an invalid flag name is supplied.
+     */
+    public static final class PlotFlagParseException extends ParserException implements ComponentMessageThrowable {
+
+        private PlotFlagParseException(final @NonNull CommandContext<?> context) {
+            super(PlotFlagParser.class, context, TranslatableCaption.of("flag.not_valid_flag"));
+        }
+
+        @Override
+        public @NonNull Component componentMessage() {
+            // TODO(City): This sucks...
+            return ((TranslatableCaption) this.errorCaption()).toComponent(LocaleHolder.console());
+        }
+    }
+}

Core/src/main/java/com/plotsquared/core/commands/processing/CommandRequirementPostprocessor.java

@@ -0,0 +1,63 @@
+package com.plotsquared.core.commands.processing;
+
+import cloud.commandframework.execution.postprocessor.CommandPostprocessingContext;
+import cloud.commandframework.execution.postprocessor.CommandPostprocessor;
+import cloud.commandframework.services.types.ConsumerService;
+import com.plotsquared.core.commands.CommandRequirement;
+import com.plotsquared.core.player.PlotPlayer;
+import org.checkerframework.checker.nullness.qual.NonNull;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Objects;
+
+/**
+ * Processor that evaluates registered {@link CommandRequirement command requirements} before a command is executed.
+ */
+public final class CommandRequirementPostprocessor implements CommandPostprocessor<PlotPlayer<?>> {
+
+    private final Collection<@NonNull CommandRequirement> requirements = new ArrayList<>();
+
+    /**
+     * Requires a single requirement.
+     *
+     * @param requirement the requirement
+     */
+    public void registerRequirement(final @NonNull CommandRequirement requirement) {
+        this.requirements.add(Objects.requireNonNull(requirement, "requirement"));
+    }
+
+    /**
+     * Registers the given {@code requirements}.
+     *
+     * @param requirements the requirements
+     */
+    public void registerRequirements(final @NonNull Collection<@NonNull CommandRequirement> requirements) {
+        requirements.forEach(this::registerRequirement);
+    }
+
+    /**
+     * Registers the given {@code requirements}.
+     *
+     * @param requirements the requirements
+     */
+    public void registerRequirements(final @NonNull CommandRequirement @NonNull... requirements) {
+        this.registerRequirements(Arrays.asList(requirements));
+    }
+
+    @Override
+    public void accept(final @NonNull CommandPostprocessingContext<PlotPlayer<?>> processingContext) {
+        for (final CommandRequirement requirement : this.requirements) {
+            if (!processingContext.command().commandMeta().getOrDefault(requirement.key(), false)) {
+                continue;
+            }
+            if (requirement.evaluate(processingContext.commandContext())) {
+                continue;
+            }
+            processingContext.commandContext().sender().sendMessage(requirement.failureCaption());
+            // Not allowed :(
+            ConsumerService.interrupt();
+        }
+    }
+}

Core/src/main/java/com/plotsquared/core/commands/suggestions/FlagValueSuggestionProvider.java

@@ -0,0 +1,66 @@
+package com.plotsquared.core.commands.suggestions;
+
+import cloud.commandframework.arguments.suggestion.BlockingSuggestionProvider;
+import cloud.commandframework.context.CommandContext;
+import cloud.commandframework.context.CommandInput;
+import cloud.commandframework.keys.CloudKey;
+import com.plotsquared.core.player.PlotPlayer;
+import com.plotsquared.core.plot.flag.PlotFlag;
+import com.plotsquared.core.plot.flag.types.ListFlag;
+import org.checkerframework.checker.nullness.qual.NonNull;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Locale;
+import java.util.Objects;
+
+/**
+ * Suggestion provider that provides context-aware {@link PlotFlag plot flag} value suggestions using
+ * {@link PlotFlag#getTabCompletions()}.
+ */
+public final class FlagValueSuggestionProvider implements BlockingSuggestionProvider.Strings<PlotPlayer<?>> {
+
+    private final CloudKey<PlotFlag<?, ?>> flagKey;
+
+    /**
+     * Creates a new suggestion provider.
+     *
+     * @param flagKey the key of the argument that contains the flag to provide value suggestions for
+     */
+    public FlagValueSuggestionProvider(final @NonNull CloudKey<PlotFlag<?, ?>> flagKey) {
+        this.flagKey = Objects.requireNonNull(flagKey, "flagKey");
+    }
+
+    @Override
+    public @NonNull Iterable<@NonNull String> stringSuggestions(
+            @NonNull final CommandContext<PlotPlayer<?>> context,
+            @NonNull final CommandInput input
+    ) {
+        final PlotFlag<?, ?> plotFlag = context.getOrDefault(this.flagKey, null);
+        if (plotFlag == null) {
+            return List.of();
+        }
+        final Collection<String> completions = plotFlag.getTabCompletions();
+        if (plotFlag instanceof ListFlag<?,?> && input.peekString().contains(",")) {
+            final String[] split = input.peekString().split(",");
+            final StringBuilder prefix = new StringBuilder();
+            for (int i = 0; i < split.length - i; i++) {
+                prefix.append(split[i]).append(",");
+            }
+
+            final String cmp;
+            if (!input.peekString().endsWith(",")) {
+                cmp = split[split.length - 1];
+            } else {
+                prefix.append(split[split.length - 1]).append(",");
+                cmp = "";
+            }
+
+            return completions.stream()
+                    .filter(value -> value.startsWith(cmp.toLowerCase(Locale.ENGLISH)))
+                    .map(value -> prefix + value)
+                    .toList();
+        }
+        return completions;
+    }
+}

Core/src/main/java/com/plotsquared/core/configuration/caption/TranslatableCaption.java

@@ -18,6 +18,7 @@
  */
 package com.plotsquared.core.configuration.caption;
 
+import cloud.commandframework.captions.Caption;
 import com.google.common.base.Objects;
 import com.plotsquared.core.PlotSquared;
 import net.kyori.adventure.text.Component;
@@ -33,7 +34,7 @@ import java.util.regex.Pattern;
 /**
  * Caption that is user modifiable
  */
-public final class TranslatableCaption implements NamespacedCaption {
+public final class TranslatableCaption implements NamespacedCaption, Caption {
 
     /**
      * Default caption namespace
@@ -72,6 +73,11 @@ public final class TranslatableCaption implements NamespacedCaption {
         );
     }
 
+    @Override
+    public @NonNull String key() {
+        return this.getKey();
+    }
+
     /**
      * Get a new {@link TranslatableCaption} instance
      *

Core/src/main/java/com/plotsquared/core/inject/modules/CommandModule.java

@@ -0,0 +1,20 @@
+package com.plotsquared.core.inject.modules;
+
+import com.google.inject.AbstractModule;
+import com.google.inject.Scopes;
+import com.google.inject.multibindings.Multibinder;
+import com.plotsquared.core.commands.PlotSquaredCommandBean;
+import com.plotsquared.core.commands.command.setting.flag.FlagSetCommand;
+
+public final class CommandModule extends AbstractModule {
+
+    @Override
+    protected void configure() {
+        final Multibinder<PlotSquaredCommandBean> commands = Multibinder.newSetBinder(
+                this.binder(),
+                PlotSquaredCommandBean.class
+        );
+
+        commands.addBinding().to(FlagSetCommand.class).in(Scopes.SINGLETON);
+    }
+}

build.gradle.kts

@@ -39,6 +39,7 @@ subprojects {
     version = rootProject.version
 
     repositories {
+        mavenLocal() // TODO(City): Remove once Cloud 2 is on central.
         mavenCentral()
 
         maven {

gradle/libs.versions.toml

@@ -31,6 +31,7 @@ paperlib = "1.0.8"
 informative-annotations = "1.4"
 vault = "1.7.1"
 serverlib = "2.3.4"
+cloud = "2.0.0-SNAPSHOT"
 
 # Gradle plugins
 shadow = "8.1.1"
@@ -77,6 +78,9 @@ informativeAnnotations = { group = "com.intellectualsites.informative-annotation
 paperlib = { group = "io.papermc", name = "paperlib", version.ref = "paperlib" }
 vault = { group = "com.github.MilkBowl", name = "VaultAPI", version.ref = "vault" }
 serverlib = { group = "dev.notmyfault.serverlib", name = "ServerLib", version.ref = "serverlib" }
+cloud = { group = "cloud.commandframework", name = "cloud-core", version.ref = "cloud" }
+cloudPaper = { group = "cloud.commandframework", name = "cloud-paper", version.ref = "cloud" }
+cloudMinecraftExtras = { group = "cloud.commandframework", name = "cloud-minecraft-extras", version.ref = "cloud" }
 
 [plugins]
 shadow = { id = "com.github.johnrengelman.shadow", version.ref = "shadow" }