Fix nation deleted message showing when a predeletenationevent is

cancelled.

Not really happy with the implementation of this, as it changes our
DataSource pattern to one where only a single removeObject method
returns a boolean. The TownUtil change is also not ideal now or before
this PR as the Nation can be prevented from being deleted, while still
processing a refund.

Potential alternative solutions:
- Run the message in the DatabaseHandler method, and lose the custom
deleted by admin message sent to the admin who deleted the nation.
- Run the PreDeleteNation event before the removeNation(Nation) in order
to prevent the TownUtil method being made redundant, and causing issues.

Closes #7380.

Towny/src/main/java/com/palmergames/bukkit/towny/command/NationCommand.java

@@ -1062,10 +1062,11 @@ public void nationDelete(Player player, String[] split) throws TownyException {
 			}
 
 			Confirmation.runOnAccept(() -> {
-				TownyMessaging.sendGlobalMessage(Translatable.of("msg_del_nation", nation.getName()));
-				TownyUniverse.getInstance().getDataSource().removeNation(nation);
-				if (tooManyResidents)
-					ResidentUtil.reduceResidentCountToFitTownMaxPop(town);
+				if (TownyUniverse.getInstance().getDataSource().removeNation(nation)) {
+					TownyMessaging.sendGlobalMessage(Translatable.of("msg_del_nation", nation.getName()));
+					if (tooManyResidents)
+						ResidentUtil.reduceResidentCountToFitTownMaxPop(town);
+				}
 			})
 			.sendTo(player);
 			return;

Towny/src/main/java/com/palmergames/bukkit/towny/command/TownyAdminCommand.java

@@ -1663,11 +1663,11 @@ public void parseAdminNationCommand(CommandSender sender, String[] split) throws
 		case "delete":
 			checkPermOrThrow(sender, PermissionNodes.TOWNY_COMMAND_TOWNYADMIN_NATION_DELETE.getNode());
 			Confirmation.runOnAccept(() -> {
-				if (sender instanceof Player)
-					TownyMessaging.sendMsg(sender, Translatable.of("nation_deleted_by_admin", nation.getName()));
-
-				TownyUniverse.getInstance().getDataSource().removeNation(nation);
-				TownyMessaging.sendGlobalMessage(Translatable.of("MSG_DEL_NATION", nation.getName()));
+				if (TownyUniverse.getInstance().getDataSource().removeNation(nation)) {
+					if (sender instanceof Player)
+						TownyMessaging.sendMsg(sender, Translatable.of("nation_deleted_by_admin", nation.getName()));
+					TownyMessaging.sendGlobalMessage(Translatable.of("msg_del_nation", nation.getName()));
+				}
 			}).sendTo(sender);
 			break;
 		case "meta":

Towny/src/main/java/com/palmergames/bukkit/towny/db/TownyDataSource.java

@@ -298,7 +298,7 @@ public boolean saveTownBlocks() {
 
 	abstract public void removeTownBlocks(Town town);
 
-	abstract public void removeNation(Nation nation);
+	abstract public boolean removeNation(Nation nation);
 
 	abstract public @NotNull Resident newResident(String name) throws AlreadyRegisteredException, NotRegisteredException;
 

Towny/src/main/java/com/palmergames/bukkit/towny/db/TownyDatabaseHandler.java

@@ -463,11 +463,11 @@ public void removeTown(Town town, boolean delayFullRemoval) {
 	}
 
 	@Override
-	public void removeNation(Nation nation) {
+	public boolean removeNation(Nation nation) {
 
 		PreDeleteNationEvent preEvent = new PreDeleteNationEvent(nation);
 		if (BukkitTools.isEventCancelled(preEvent))
-			return;
+			return false;
 
 		Resident king = null;
 		if (nation.hasKing())
@@ -543,6 +543,8 @@ public void removeNation(Nation nation) {
 		plugin.resetCache();
 
 		BukkitTools.fireEvent(new DeleteNationEvent(nation, king));
+
+		return true;
 	}
 
 	@Override

Towny/src/main/java/com/palmergames/bukkit/towny/utils/TownUtil.java

@@ -52,11 +52,13 @@ public static void checkNationResidentsRequirementsOfTown(Town town) {
 			if (findNewCapital(town, nation))
 				return;
 
+			if (!TownyUniverse.getInstance().getDataSource().removeNation(nation))
+				return;
+
 			// No new capital found, delete the nation and potentially refund the capital town.
 			TownyMessaging.sendPrefixedNationMessage(nation, Translatable.of("msg_nation_disbanded_town_not_enough_residents", town.getName()));
-			TownyMessaging.sendGlobalMessage(Translatable.of("msg_del_nation", nation));
-			TownyUniverse.getInstance().getDataSource().removeNation(nation);
 
+			TownyMessaging.sendGlobalMessage(Translatable.of("msg_del_nation", nation));
 			if (TownyEconomyHandler.isActive() && TownySettings.isRefundNationDisbandLowResidents()) {
 				town.getAccount().deposit(TownySettings.getNewNationPrice(), "nation refund");
 				TownyMessaging.sendPrefixedTownMessage(town, Translatable.of("msg_not_enough_residents_refunded", TownySettings.getNewNationPrice()));