Add game state handlers

src/main/java/gent/zeus/mc13dtl/MC13DTL.java

@@ -1,6 +1,25 @@
 package gent.zeus.mc13dtl;
 
+import org.bukkit.plugin.Plugin;
 import org.bukkit.plugin.java.JavaPlugin;
 
+import gent.zeus.mc13dtl.gamestate.GameStateCommand;
+import gent.zeus.mc13dtl.gamestate.GameStateHandler;
+import io.papermc.paper.command.brigadier.Commands;
+import io.papermc.paper.plugin.lifecycle.event.LifecycleEventManager;
+import io.papermc.paper.plugin.lifecycle.event.types.LifecycleEvents;
+
 public class MC13DTL extends JavaPlugin {
+  public static MC13DTL instance;
+
+  @Override
+  public void onEnable() {
+    instance = this;
+    getServer().getPluginManager().registerEvents(new GameStateHandler(), this);
+    LifecycleEventManager<Plugin> manager = this.getLifecycleManager();
+    manager.registerEventHandler(LifecycleEvents.COMMANDS, event -> {
+      Commands commands = event.registrar();
+      commands.register("start-game", "Start a game of 13 days to live", new GameStateCommand());
+    });
+  }
 }

src/main/java/gent/zeus/mc13dtl/gamestate/GameStateCommand.java

@@ -0,0 +1,38 @@
+package gent.zeus.mc13dtl.gamestate;
+
+import org.bukkit.Bukkit;
+import org.bukkit.NamespacedKey;
+import org.bukkit.OfflinePlayer;
+import org.bukkit.World;
+import org.bukkit.entity.Player;
+import org.bukkit.persistence.PersistentDataType;
+import org.bukkit.potion.PotionEffect;
+
+import gent.zeus.mc13dtl.MC13DTL;
+import io.papermc.paper.command.brigadier.BasicCommand;
+import io.papermc.paper.command.brigadier.CommandSourceStack;
+
+public class GameStateCommand implements BasicCommand {
+  @Override
+  public void execute(CommandSourceStack stack, String[] args) {
+    World world = Bukkit.getWorld("world");
+    NamespacedKey key = new NamespacedKey(MC13DTL.instance, "game-state");
+    world.getPersistentDataContainer().set(key, PersistentDataType.STRING, "active");
+    GameStateUtil.loadWorld(world);
+    for (OfflinePlayer i : Bukkit.getOfflinePlayers()) {
+      Player player = i.getPlayer();
+      player.getInventory().clear();
+      player.heal(100);
+      player.getActivePotionEffects().clear();
+      for (PotionEffect effect : player.getActivePotionEffects()) {
+        player.removePotionEffect(effect.getType());
+      }
+      GameStateUtil.loadPlayer(player);
+    }
+  }
+
+  @Override
+  public String permission() {
+    return "13dtl.manage-game";
+  }
+}

src/main/java/gent/zeus/mc13dtl/gamestate/GameStateHandler.java

@@ -0,0 +1,23 @@
+package gent.zeus.mc13dtl.gamestate;
+
+import org.bukkit.World;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.Listener;
+import org.bukkit.event.player.PlayerJoinEvent;
+import org.bukkit.event.world.WorldLoadEvent;
+
+public class GameStateHandler implements Listener {
+  @EventHandler
+  void onPlayerJoin(PlayerJoinEvent event) {
+    GameStateUtil.loadPlayer(event.getPlayer());
+  }
+
+  @EventHandler
+  void onWorldLoad(WorldLoadEvent event) {
+    World world = event.getWorld();
+    if (!world.getName().equals("world")) {
+      return;
+    }
+    GameStateUtil.loadWorld(world);
+  }
+}

src/main/java/gent/zeus/mc13dtl/gamestate/GameStateUtil.java

@@ -0,0 +1,49 @@
+package gent.zeus.mc13dtl.gamestate;
+
+import org.bukkit.Bukkit;
+import org.bukkit.Difficulty;
+import org.bukkit.GameMode;
+import org.bukkit.GameRule;
+import org.bukkit.NamespacedKey;
+import org.bukkit.World;
+import org.bukkit.entity.Player;
+import org.bukkit.persistence.PersistentDataType;
+
+import gent.zeus.mc13dtl.MC13DTL;
+import net.md_5.bungee.api.ChatColor;
+
+public class GameStateUtil {
+  static void loadWorld(World world) {
+    NamespacedKey key = new NamespacedKey(MC13DTL.instance, "game-state");
+    if (!world.getPersistentDataContainer().has(key)) {
+      world.getPersistentDataContainer().set(key, PersistentDataType.STRING, "lobby");
+    }
+    String gameState = world.getPersistentDataContainer().get(key, PersistentDataType.STRING);
+    if (gameState.equals("lobby")) {
+      world.setDifficulty(Difficulty.PEACEFUL);
+      world.setGameRule(GameRule.DO_DAYLIGHT_CYCLE, false);
+      world.setFullTime(0);
+      world.getWorldBorder().setSize(200);
+    }
+    if (gameState.equals("active")) {
+      world.setDifficulty(Difficulty.NORMAL);
+      world.setGameRule(GameRule.DO_DAYLIGHT_CYCLE, true);
+      world.getWorldBorder().setSize(10000);
+    }
+  }
+
+  static void loadPlayer(Player player) {
+    NamespacedKey key = new NamespacedKey(MC13DTL.instance, "game-state");
+    String gameState = Bukkit.getWorld("world").getPersistentDataContainer().get(key, PersistentDataType.STRING);
+    if (gameState.equals("lobby")) {
+      player.setGameMode(GameMode.ADVENTURE);
+      player.setInvulnerable(true);
+      player.sendMessage(ChatColor.DARK_PURPLE + "Game hasn't started yet, please wait...");
+    }
+    if (gameState.equals("active")) {
+      player.setGameMode(GameMode.SURVIVAL);
+      player.setInvulnerable(false);
+      player.sendMessage(ChatColor.DARK_PURPLE + "Game is active, have fun!");
+    }
+  }
+}

src/main/resources/plugin.yml

@@ -2,3 +2,4 @@ name: 13DTL
 version: 0.0.1
 main: gent.zeus.mc13dtl.MC13DTL
 api-version: '1.21.1'
+load: STARTUP