improve the requirement system

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

@@ -28,7 +28,6 @@
 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;
@@ -83,7 +82,6 @@ protected void configure() {
             }
 
             final CommandRequirementPostprocessor requirementPostprocessor = new CommandRequirementPostprocessor();
-            requirementPostprocessor.registerRequirements(CommonCommandRequirement.values());
             commandManager.registerCommandPostProcessor(requirementPostprocessor);
 
             // TODO(City): Override parsing errors using MM parsing.

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

@@ -19,15 +19,17 @@
 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.permissions.Permission;
 import com.plotsquared.core.player.PlotPlayer;
+import net.kyori.adventure.text.minimessage.tag.Tag;
+import net.kyori.adventure.text.minimessage.tag.resolver.TagResolver;
 import org.checkerframework.checker.nullness.qual.NonNull;
 
 /**
  * Something that is required for a command to be executed.
  */
-public interface CommandRequirement extends CloudKeyHolder<Boolean> {
+public interface CommandRequirement {
 
     /**
      * Returns the caption sent when the requirement is not met.
@@ -43,4 +45,42 @@ public interface CommandRequirement extends CloudKeyHolder<Boolean> {
      * @return {@code true} if the requirement is met, else {@code false}
      */
     boolean evaluate(final @NonNull CommandContext<PlotPlayer<?>> context);
+
+    /**
+     * Returns the placeholder values.
+     *
+     * @return placeholder values
+     */
+    default @NonNull TagResolver @NonNull[] tagResolvers() {
+        return new TagResolver[0];
+    }
+
+    /**
+     * Returns a requirement that evaluates to {@code true} if the sender has the given {@code permission} or if
+     * this requirement evaluates to {@code true}.
+     *
+     * @param permission the override permission
+     * @return the new requirement
+     */
+    default @NonNull CommandRequirement withPermissionOverride(final @NonNull Permission permission) {
+        final CommandRequirement thisRequirement = this;
+        return new CommandRequirement() {
+            @Override
+            public @NonNull TranslatableCaption failureCaption() {
+                return TranslatableCaption.of("permission.no_permission");
+            }
+
+            @Override
+            public @NonNull TagResolver @NonNull [] tagResolvers() {
+                return new TagResolver[] {
+                        TagResolver.resolver("node", Tag.inserting(Permission.PERMISSION_SET_FLAG_OTHER))
+                };
+            }
+
+            @Override
+            public boolean evaluate(final @NonNull CommandContext<PlotPlayer<?>> context) {
+                return context.sender().hasPermission(permission) || thisRequirement.evaluate(context);
+            }
+        };
+    }
 }

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

@@ -0,0 +1,61 @@
+/*
+ * PlotSquared, a land and world management plugin for Minecraft.
+ * Copyright (C) IntellectualSites <https://intellectualsites.com>
+ * Copyright (C) IntellectualSites team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.plotsquared.core.commands;
+
+import cloud.commandframework.keys.CloudKey;
+import org.checkerframework.checker.nullness.qual.NonNull;
+
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.List;
+
+/**
+ * Holder of {@link CommandRequirement} requirements.
+ */
+public final class CommandRequirements implements Iterable<@NonNull CommandRequirement> {
+
+    /**
+     * The key used to store the requirements in the {@link cloud.commandframework.meta.CommandMeta}.
+     */
+    public static final CloudKey<CommandRequirements> REQUIREMENTS_KEY = CloudKey.of(
+            "requirements",
+            CommandRequirements.class
+    );
+
+    /**
+     * Creates a new instance.
+     *
+     * @param requirements the requirements
+     * @return the instance
+     */
+    public static @NonNull CommandRequirements create(final @NonNull Collection<@NonNull CommandRequirement> requirements) {
+        return new CommandRequirements(requirements);
+    }
+
+    private final List<CommandRequirement> requirements;
+
+    private CommandRequirements(final @NonNull Collection<@NonNull CommandRequirement> requirements) {
+        this.requirements = List.copyOf(requirements);
+    }
+
+    @Override
+    public @NonNull Iterator<@NonNull CommandRequirement> iterator() {
+        return this.requirements.iterator();
+    }
+}

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

@@ -19,7 +19,6 @@
 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;
@@ -39,7 +38,14 @@ public enum CommonCommandRequirement implements CommandRequirement {
      */
     REQUIRES_OWNER(TranslatableCaption.of("working.plot_not_claimed"),
             ctx -> ctx.sender().getCurrentPlot() != null && ctx.sender().getCurrentPlot().hasOwner()
-    );
+    ),
+    /**
+     * Requires that the command sender is the plot owner.
+     */
+    IS_OWNER(TranslatableCaption.of("permission.no_plot_perms"),
+            ctx -> ctx.sender().getCurrentPlot() != null && ctx.sender().getCurrentPlot().isOwner(ctx.sender().getUUID())
+    )
+    ;
 
     private final TranslatableCaption failureCaption;
     private final Predicate<CommandContext<PlotPlayer<?>>> predicate;
@@ -60,9 +66,4 @@ public enum CommonCommandRequirement implements CommandRequirement {
     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/PlotSquaredCommandBean.java

@@ -63,12 +63,8 @@ public abstract class PlotSquaredCommandBean extends CommandBean<PlotPlayer<?>>
 
     @Override
     protected final Command.@NonNull Builder<PlotPlayer<?>> configure(final Command.@NonNull Builder<PlotPlayer<?>> builder) {
-        Command.@NonNull Builder<PlotPlayer<?>> intermediaryBuilder =
-                this.configurePlotCommand(this.prepare(builder.meta(PlotSquaredCommandMeta.META_CATEGORY, this.category())));
-        for (final CommandRequirement requirement : this.requirements()) {
-            intermediaryBuilder = intermediaryBuilder.meta(requirement.key(), true);
-        }
-        return intermediaryBuilder;
+        return this.configurePlotCommand(this.prepare(builder.meta(PlotSquaredCommandMeta.META_CATEGORY, this.category())))
+                .meta(CommandRequirements.REQUIREMENTS_KEY, CommandRequirements.create(this.requirements()));
     }
 
     protected abstract Command.@NonNull Builder<PlotPlayer<?>> configurePlotCommand(

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

@@ -130,8 +130,11 @@ protected static boolean checkPermValue(
 
     @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);
+        return Set.of(
+                CommonCommandRequirement.REQUIRES_PLOT,
+                CommonCommandRequirement.REQUIRES_OWNER,
+                CommonCommandRequirement.IS_OWNER.withPermissionOverride(Permission.PERMISSION_SET_FLAG_OTHER)
+        );
     }
 
     @Override

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

@@ -22,58 +22,29 @@
 import cloud.commandframework.execution.postprocessor.CommandPostprocessor;
 import cloud.commandframework.services.types.ConsumerService;
 import com.plotsquared.core.commands.CommandRequirement;
+import com.plotsquared.core.commands.CommandRequirements;
 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;
-            }
+        final CommandRequirements requirements = processingContext.command().commandMeta().getOrDefault(
+                CommandRequirements.REQUIREMENTS_KEY,
+                null
+        );
+        if (requirements == null) {
+            return;
+        }
+        for (final CommandRequirement requirement : requirements) {
             if (requirement.evaluate(processingContext.commandContext())) {
                 continue;
             }
-            processingContext.commandContext().sender().sendMessage(requirement.failureCaption());
+            processingContext.commandContext().sender().sendMessage(requirement.failureCaption(), requirement.tagResolvers());
             // Not allowed :(
             ConsumerService.interrupt();
         }