plugin.yml

name: TNTStep
version: 1.0-SNAPSHOT
main: com.bringholm.tntstep.TNTStep
author: AlvinB
commands:
  tntstep:
    description: |
      /tntstep on [world] - Turns on TNTStep in the world the player is in, or the world optionally specified world in the third argument
      /tntstep off [world] - Turns off TNTStep in the world the player is in, or the world optionally specified world in the third argument
      /tntstep reload - Reloads the config for TNTStep
      /tntstep list - Lists all worlds TNTStep is enabled in.
    usage: /tntstep <on|off|reload|list> [world]
permissions:
  tntstep.*:
    description: Gives access to all permissions of this plugin.
    children:
      tntstep.toggle: true
      tntstep.reload: true
  tntstep.toggle:
    description: Allows you to toggle TNTStep on and off in a certain world
    default: op
  tntstep.reload:
    description: Allows you to reload the TNTStep config
    default: op
  tntstep.list:
    description: Allows you to list all the worlds TNTStep is enabled in
    default: op

TNTStep.java

package com.bringholm.tntstep;

import com.google.common.collect.Lists;
import org.bukkit.Bukkit;
import org.bukkit.ChatColor;
import org.bukkit.Material;
import org.bukkit.block.Block;
import org.bukkit.block.BlockFace;
import org.bukkit.command.Command;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.EntityType;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.player.PlayerMoveEvent;
import org.bukkit.plugin.java.JavaPlugin;

import java.util.List;

public class TNTStep extends JavaPlugin implements Listener {
    private List<String> activeWorlds = Lists.newArrayList();

    @Override
    public void onEnable() {
        this.getServer().getPluginManager().registerEvents(this, this);
        reloadConfigValues();
    }

    @Override
    public void onDisable() {
        saveConfigValues();
    }

    private void saveConfigValues() {
        this.getConfig().set("active-worlds", activeWorlds);
        this.saveConfig();
    }

    private boolean reloadConfigValues() {
        try {
            saveDefaultConfig();
            if (getConfig().contains("active-worlds")) {
                activeWorlds = getConfig().getStringList("active-worlds");
            } else {
                this.getLogger().warning("config.yml does not contain the list of active worlds!");
                return false;
            }
            return true;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    @EventHandler
    public void onMove(PlayerMoveEvent e) {
        if (activeWorlds.contains(e.getTo().getWorld().getName())) {
            Block block = e.getTo().getBlock().getRelative(BlockFace.DOWN);
            if (block.getType() == Material.TNT && e.getPlayer().isOnGround()) {
                block.setType(Material.AIR);
                block.getWorld().spawnEntity(block.getLocation().add(0.5, 0, 0.5), EntityType.PRIMED_TNT);
            }
        }
    }

    @Override
    public boolean onCommand(CommandSender sender, Command command, String label, String[] args) {
        if (args.length == 0 || args.length > 2) {
            sender.sendMessage(ChatColor.RED + "Incorrect arguments!");
            return true;
        }
        switch (args[0]) {
            case "on":
                if (!sender.hasPermission("tntstep.toggle")) {
                    sender.sendMessage(ChatColor.RED + "You don't have permission to do this!");
                    return true;
                }
                if (args.length == 2) {
                    if (Bukkit.getWorld(args[1]) != null) {
                        if (activeWorlds.contains(args[1])) {
                            sender.sendMessage(ChatColor.RED + "TNTStep is already active in this world!");
                        } else {
                            activeWorlds.add(args[1]);
                            saveConfigValues();
                            sender.sendMessage(ChatColor.GOLD + "TNTStep is now active in world " + args[1] + "!");
                        }
                    } else {
                        sender.sendMessage(ChatColor.RED + "World " + args[1] + "could not be found!");
                    }
                } else if (sender instanceof Player) {
                    String worldName = ((Player) sender).getWorld().getName();
                    if (activeWorlds.contains(worldName)) {
                        sender.sendMessage(ChatColor.RED + "TNTStep is already active in this world!");
                    } else {
                        activeWorlds.add(worldName);
                        saveConfigValues();
                        sender.sendMessage(ChatColor.GOLD + "TNTStep is now active in world " + worldName + "!");
                    }
                } else {
                    sender.sendMessage(ChatColor.RED + "You must specify a world to activate TNTStep in!");
                }
                break;
            case "off":
                if (!sender.hasPermission("tntstep.toggle")) {
                    sender.sendMessage(ChatColor.RED + "You don't have permission to do this!");
                    return true;
                }
                if (args.length == 2) {
                    if (activeWorlds.contains(args[1])) {
                        activeWorlds.remove(args[1]);
                        saveConfigValues();
                        sender.sendMessage(ChatColor.GOLD + "TNTStep is no longer active in world " + args[1] + "!");
                    } else {
                        sender.sendMessage(ChatColor.RED + "TNTStep is not active in this world!");
                    }
                } else if (sender instanceof Player) {
                    String worldName = ((Player) sender).getWorld().getName();
                    if (activeWorlds.contains(worldName)) {
                        activeWorlds.remove(worldName);
                        saveConfigValues();
                        sender.sendMessage(ChatColor.GOLD + "TNTStep is no longer active in world " + worldName + "!");
                    } else {
                        sender.sendMessage(ChatColor.RED + "TNTStep is not active in this world!");
                    }
                } else {
                    sender.sendMessage(ChatColor.RED + "You must specify a world to deactivate TNTStep in!");
                }
                break;
            case "reload":
                if (!sender.hasPermission("tntstep.reload")) {
                    sender.sendMessage(ChatColor.RED + "You don't have permission to do this!");
                }
                if (reloadConfigValues()) {
                    sender.sendMessage(ChatColor.GOLD + "Successfully reloaded config!");
                } else {
                    sender.sendMessage(ChatColor.RED + "Something went wrong while reloading the config! Check the console for details!");
                }
                break;
            case "list":
                if (!sender.hasPermission("tntstep.list")) {
                    sender.sendMessage(ChatColor.RED + "You don't have permission to do this!");
                    return true;
                }
                if (activeWorlds.size() == 0) {
                    sender.sendMessage(ChatColor.GOLD + "There are no worlds to display!");
                } else {
                    sender.sendMessage(ChatColor.GOLD + "Listing all worlds TNTStep is enabled in:");
                    for (String string : activeWorlds) {
                        sender.sendMessage(ChatColor.GOLD + string);
                    }
                }
                break;
            default:
                sender.sendMessage(ChatColor.RED + "Incorrect arguments!");
        }
        return true;
    }
}