Make the generator AcidIsland-aware

src/main/java/world/bentobox/magiccobblestonegenerator/config/Settings.java

@@ -372,6 +372,30 @@ public void setUseBankAccount(boolean useBankAccount)
     }
 
 
+    /**
+     * Is acid island aware boolean.
+     *
+     * @return {@code true} if the addon must not replace blocks that AcidIsland reverts to water.
+     * @since 2.10.0
+     */
+    public boolean isAcidIslandAware()
+    {
+        return acidIslandAware;
+    }
+
+
+    /**
+     * Sets acid island aware.
+     *
+     * @param acidIslandAware new value for this object.
+     * @since 2.10.0
+     */
+    public void setAcidIslandAware(boolean acidIslandAware)
+    {
+        this.acidIslandAware = acidIslandAware;
+    }
+
+
     /**
      * Gets the default number of blocks a generator is allowed to generate during a single exhaustion period.
      *
@@ -558,6 +582,17 @@ public enum GuiAction
     @ConfigEntry(path = "use-bank-account")
     private boolean useBankAccount = false;
 
+    @ConfigComment("")
+    @ConfigComment("This indicates if the addon should respect AcidIsland acid water.")
+    @ConfigComment("AcidIsland turns stone, that is created when lava pours into its acid water, back")
+    @ConfigComment("into water. If this option is enabled, the addon will not process such blocks, so")
+    @ConfigComment("a single lava bucket cannot be used to convert an entire ocean into generator")
+    @ConfigComment("blocks. Normal cobblestone generators are not affected by this option.")
+    @ConfigComment("This option does nothing in worlds that are not managed by AcidIsland, or if acid")
+    @ConfigComment("damage is disabled in the AcidIsland config.")
+    @ConfigEntry(path = "acid-island-aware")
+    private boolean acidIslandAware = true;
+
     @ConfigComment("")
     @ConfigComment("This list stores GameModes in which the addon should not work.")
     @ConfigComment("To disable addon it is necessary to write its name in new line that starts with -. Example:")

src/main/java/world/bentobox/magiccobblestonegenerator/listeners/VanillaGeneratorListener.java

@@ -17,6 +17,7 @@
 
 import world.bentobox.bentobox.database.objects.Island;
 import world.bentobox.magiccobblestonegenerator.StoneGeneratorAddon;
+import world.bentobox.magiccobblestonegenerator.utils.AcidIslandHelper;
 import world.bentobox.magiccobblestonegenerator.utils.CustomBlocks;
 import world.bentobox.magiccobblestonegenerator.utils.Why;
 
@@ -70,6 +71,19 @@ public void onBlockFormEvent(BlockFormEvent event)
 
         Island island = islandOptional.get();
 
+        if (this.addon.getSettings().isAcidIslandAware() &&
+            event.getNewState().getType() == Material.STONE &&
+            eventSourceBlock.getType() == Material.WATER &&
+            AcidIslandHelper.revertsStoneFormedInWater(this.addon, eventSourceBlock.getWorld()))
+        {
+            // Lava poured into acid water. AcidIsland turns this stone back into water on the next
+            // tick, but only if it is still stone. Replacing it would defeat that protection and
+            // allow whole oceans to be converted into generator blocks.
+            Why.report(island, eventSourceBlock.getLocation(),
+                "AcidIsland reverts stone that is formed in acid water!");
+            return;
+        }
+
         if (!island.isAllowed(StoneGeneratorAddon.MAGIC_COBBLESTONE_GENERATOR))
         {
             // Currently addon is not working outside island protection ranges.

src/main/java/world/bentobox/magiccobblestonegenerator/utils/AcidIslandHelper.java

@@ -0,0 +1,157 @@
+//
+// Created by BONNe
+// Copyright - 2020
+//
+
+
+package world.bentobox.magiccobblestonegenerator.utils;
+
+
+import java.lang.reflect.Method;
+import java.util.Optional;
+
+import org.bukkit.World;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import world.bentobox.bentobox.api.addons.GameModeAddon;
+import world.bentobox.bentobox.api.configuration.WorldSettings;
+import world.bentobox.magiccobblestonegenerator.StoneGeneratorAddon;
+
+
+/**
+ * Helper that detects if AcidIsland is going to undo a block that this addon is about to replace.
+ * <p>
+ * AcidIsland water is acid, so its LavaCheck listener turns stone that vanilla creates when lava
+ * pours into water back into water again. It does that by checking, one tick later, if the block is
+ * stone. If this addon replaces the forming stone with a generator block, that check no longer
+ * matches and the block survives, which lets a single lava bucket turn an entire ocean into
+ * generator blocks.
+ * <p>
+ * AcidIsland is only a soft dependency, so the game mode is recognised by its name and the acid
+ * damage value is read reflectively. That also keeps this working if AcidIsland is not installed at
+ * all.
+ *
+ * @since 2.10.0
+ */
+public final class AcidIslandHelper
+{
+    /**
+     * Private constructor. This is a utility class.
+     */
+    private AcidIslandHelper()
+    {
+        // Utility class.
+    }
+
+
+    /**
+     * This method returns if AcidIsland manages the given world and will revert stone that is formed
+     * inside its acid water back to water.
+     *
+     * @param addon Instance of this addon.
+     * @param world World where the block is formed.
+     * @return {@code true} if AcidIsland will revert the formed stone, {@code false} otherwise.
+     */
+    public static boolean revertsStoneFormedInWater(@NotNull StoneGeneratorAddon addon, @NotNull World world)
+    {
+        Optional<GameModeAddon> gameMode = addon.getPlugin().getIWM().getAddon(world);
+
+        if (gameMode.isEmpty() || !ACID_ISLAND.equals(gameMode.get().getDescription().getName()))
+        {
+            // Not an AcidIsland world.
+            return false;
+        }
+
+        // AcidIsland reverts the stone only if acid actually does damage.
+        return getAcidDamage(gameMode.get().getWorldSettings()) > 0;
+    }
+
+
+    /**
+     * This method returns the acid damage value from AcidIsland world settings.
+     *
+     * @param worldSettings World settings of the AcidIsland game mode.
+     * @return Acid damage value or 0 if it could not be read.
+     */
+    private static int getAcidDamage(@Nullable WorldSettings worldSettings)
+    {
+        if (worldSettings == null)
+        {
+            return 0;
+        }
+
+        Method method = getAcidDamageMethod(worldSettings.getClass());
+
+        if (method == null)
+        {
+            return 0;
+        }
+
+        try
+        {
+            return ((Number) method.invoke(worldSettings)).intValue();
+        }
+        catch (ReflectiveOperationException | ClassCastException | NullPointerException e)
+        {
+            return 0;
+        }
+    }
+
+
+    /**
+     * This method returns the cached acid damage getter for the given world settings class.
+     *
+     * @param settingsClass Class of the AcidIsland world settings.
+     * @return The getter method or {@code null} if the class does not have one.
+     */
+    @Nullable
+    private static Method getAcidDamageMethod(@NotNull Class<?> settingsClass)
+    {
+        if (settingsClass.equals(cachedSettingsClass))
+        {
+            return cachedAcidDamageMethod;
+        }
+
+        Method method;
+
+        try
+        {
+            method = settingsClass.getMethod(ACID_DAMAGE_GETTER);
+        }
+        catch (NoSuchMethodException | SecurityException e)
+        {
+            method = null;
+        }
+
+        cachedSettingsClass = settingsClass;
+        cachedAcidDamageMethod = method;
+
+        return method;
+    }
+
+
+// ---------------------------------------------------------------------
+// Section: Variables
+// ---------------------------------------------------------------------
+
+    /**
+     * Name of the AcidIsland game mode addon.
+     */
+    private static final String ACID_ISLAND = "AcidIsland";
+
+    /**
+     * Name of the method that returns player acid damage in AcidIsland settings.
+     */
+    private static final String ACID_DAMAGE_GETTER = "getAcidDamage";
+
+    /**
+     * Class for which the acid damage getter is cached.
+     */
+    private static Class<?> cachedSettingsClass;
+
+    /**
+     * Cached acid damage getter.
+     */
+    private static Method cachedAcidDamageMethod;
+}

src/main/resources/config.yml

@@ -37,6 +37,15 @@ notify-on-unlock: true
 # Requires Bank Addon
 use-bank: false
 #
+# This indicates if the addon should respect AcidIsland acid water.
+# AcidIsland turns stone, that is created when lava pours into its acid water, back
+# into water. If this option is enabled, the addon will not process such blocks, so
+# a single lava bucket cannot be used to convert an entire ocean into generator
+# blocks. Normal cobblestone generators are not affected by this option.
+# This option does nothing in worlds that are not managed by AcidIsland, or if acid
+# damage is disabled in the AcidIsland config.
+acid-island-aware: true
+#
 # This list stores GameModes in which the addon should not work.
 # To disable addon it is necessary to write its name in new line that starts with -. Example:
 # disabled-gamemodes: