Implemented the purgebannedplayers command

src/main/java/fr/xephi/authme/command/CommandManager.java

@@ -232,6 +232,20 @@ public class CommandManager {
         purgeCommand.setCommandPermissions("authme.admin.purge", CommandPermissions.DefaultPermission.OP_ONLY);
         purgeCommand.addArgument(new CommandArgumentDescription("days", "Number of days", false));
 
+        // Register the purgebannedplayers command
+        CommandDescription purgeBannedPlayersCommand = new CommandDescription(
+                new PurgeBannedPlayersCommand(),
+                new ArrayList<String>() {{
+                    add("purgebannedplayers");
+                    add("purgebannedplayer");
+                    add("deletebannedplayers");
+                    add("deletebannedplayer");
+                }},
+                "Purge banned palyers data",
+                "Purge all AuthMeReloaded data for banned players.",
+                authMeCommand);
+        purgeBannedPlayersCommand.setCommandPermissions("authme.admin.purgebannedplayers", CommandPermissions.DefaultPermission.OP_ONLY);
+
         // Register the reload command
         CommandDescription reloadCommand = new CommandDescription(
                 new ReloadCommand(),

src/main/java/fr/xephi/authme/command/executable/authme/PurgeBannedPlayersCommand.java

@@ -0,0 +1,50 @@
+package fr.xephi.authme.command.executable.authme;
+
+import fr.xephi.authme.AuthMe;
+import fr.xephi.authme.command.CommandParts;
+import fr.xephi.authme.command.ExecutableCommand;
+import fr.xephi.authme.settings.Settings;
+import org.bukkit.OfflinePlayer;
+import org.bukkit.command.CommandSender;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class PurgeBannedPlayersCommand extends ExecutableCommand {
+
+    /**
+     * Execute the command.
+     *
+     * @param sender           The command sender.
+     * @param commandReference The command reference.
+     * @param commandArguments The command arguments.
+     *
+     * @return True if the command was executed successfully, false otherwise.
+     */
+    @Override
+    public boolean executeCommand(CommandSender sender, CommandParts commandReference, CommandParts commandArguments) {
+        // AuthMe plugin instance
+        final AuthMe plugin = AuthMe.getInstance();
+
+        // Get the list of banned players
+        List<String> bannedPlayers = new ArrayList<>();
+        for (OfflinePlayer offlinePlayer : plugin.getServer().getBannedPlayers()) {
+            bannedPlayers.add(offlinePlayer.getName().toLowerCase());
+        }
+
+        // Purge the banned players
+        plugin.database.purgeBanned(bannedPlayers);
+        if (Settings.purgeEssentialsFile && plugin.ess != null)
+            plugin.dataManager.purgeEssentials(bannedPlayers);
+        if (Settings.purgePlayerDat)
+            plugin.dataManager.purgeDat(bannedPlayers);
+        if (Settings.purgeLimitedCreative)
+            plugin.dataManager.purgeLimitedCreative(bannedPlayers);
+        if (Settings.purgeAntiXray)
+            plugin.dataManager.purgeAntiXray(bannedPlayers);
+
+        // Show a status message
+        sender.sendMessage("[AuthMe] Database has been purged correctly");
+        return true;
+    }
+}