feat: allow for custom plot limit handling (#4261)

* feat: allow for custom plot limit handling

* feat: allow for custom plot limit handling

* chore: use fluent setter

Core/src/main/java/com/plotsquared/core/events/PlayerPlotLimitEvent.java

@@ -0,0 +1,77 @@
+/*
+ * 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.events;
+
+import com.plotsquared.core.player.PlotPlayer;
+import org.checkerframework.checker.index.qual.NonNegative;
+import org.checkerframework.checker.nullness.qual.NonNull;
+
+/**
+ * Called every time after PlotSquared calculated a players plot limit based on their permission.
+ * <p>
+ * May be used to grant a player more plots based on another rank or bought feature.
+ *
+ * @since TODO
+ */
+public class PlayerPlotLimitEvent {
+
+    private final PlotPlayer<?> player;
+
+    private int limit;
+
+    public PlayerPlotLimitEvent(@NonNull final PlotPlayer<?> player, @NonNegative final int limit) {
+        this.player = player;
+        this.limit = limit;
+    }
+
+    /**
+     * Overrides the previously calculated or set plot limit for {@link #player()}.
+     *
+     * @param limit The amount of plots a player may claim. Must be {@code 0} or greater.
+     * @since TODO
+     */
+    public void limit(@NonNegative final int limit) {
+        if (limit < 0) {
+            throw new IllegalArgumentException("Player plot limit must be greater or equal 0");
+        }
+        this.limit = limit;
+    }
+
+    /**
+     * Returns the previous set limit, if none was overridden before this event handler the default limit based on the players
+     * permissions node is returned.
+     *
+     * @return The currently defined plot limit of this player.
+     * @since TODO
+     */
+    public @NonNegative int limit() {
+        return limit;
+    }
+
+    /**
+     * The player for which the limit is queried.
+     *
+     * @return the player.
+     * @since TODO
+     */
+    public @NonNull PlotPlayer<?> player() {
+        return player;
+    }
+
+}

Core/src/main/java/com/plotsquared/core/player/PlotPlayer.java

@@ -306,7 +306,8 @@ public abstract class PlotPlayer<P> implements CommandCaller, OfflinePlotPlayer,
      * @return number of allowed plots within the scope (globally, or in the player's current world as defined in the settings.yml)
      */
     public int getAllowedPlots() {
-        return hasPermissionRange("plots.plot", Settings.Limit.MAX_PLOTS);
+        final int calculatedLimit = hasPermissionRange("plots.plot", Settings.Limit.MAX_PLOTS);
+        return this.eventDispatcher.callPlayerPlotLimit(this, calculatedLimit).limit();
     }
 
     /**

Core/src/main/java/com/plotsquared/core/util/EventDispatcher.java

@@ -30,6 +30,7 @@ import com.plotsquared.core.events.PlayerEnterPlotEvent;
 import com.plotsquared.core.events.PlayerLeavePlotEvent;
 import com.plotsquared.core.events.PlayerPlotDeniedEvent;
 import com.plotsquared.core.events.PlayerPlotHelperEvent;
+import com.plotsquared.core.events.PlayerPlotLimitEvent;
 import com.plotsquared.core.events.PlayerPlotTrustedEvent;
 import com.plotsquared.core.events.PlayerTeleportToPlotEvent;
 import com.plotsquared.core.events.PlotAutoMergeEvent;
@@ -308,6 +309,12 @@ public class EventDispatcher {
         return event;
     }
 
+    public PlayerPlotLimitEvent callPlayerPlotLimit(PlotPlayer<?> player, int calculatedLimit) {
+        PlayerPlotLimitEvent event = new PlayerPlotLimitEvent(player, calculatedLimit);
+        eventBus.post(event);
+        return event;
+    }
+
     public void doJoinTask(final PlotPlayer<?> player) {
         if (player == null) {
             return; //possible future warning message to figure out where we are retrieving null