feat: hot reload map

Author: Restioson

src/main/java/io/github/restioson/siege/game/active/SiegeActive.java

@@ -2,6 +2,7 @@
 
 import com.google.common.collect.Multimap;
 import eu.pb4.sgui.api.gui.SimpleGui;
+import io.github.restioson.siege.Siege;
 import io.github.restioson.siege.game.SiegeConfig;
 import io.github.restioson.siege.game.SiegeKit;
 import io.github.restioson.siege.game.SiegeSpawnLogic;
@@ -21,6 +22,7 @@
 import net.minecraft.entity.projectile.ProjectileEntity;
 import net.minecraft.item.*;
 import net.minecraft.registry.tag.DamageTypeTags;
+import net.minecraft.resource.LifecycledResourceManager;
 import net.minecraft.server.network.ServerPlayerEntity;
 import net.minecraft.server.world.ServerWorld;
 import net.minecraft.sound.SoundCategory;
@@ -129,6 +131,7 @@ public static void open(ServerWorld world, GameSpace gameSpace, SiegeMap map, Si
             activity.allow(GameRuleType.PLACE_BLOCKS);
             activity.allow(GameRuleType.UNSTABLE_TNT);
 
+            activity.listen(GameActivityEvents.RELOAD, active::onReload);
             activity.listen(GameActivityEvents.ENABLE, active::onOpen);
             activity.listen(GameActivityEvents.DISABLE, active::onClose);
             activity.listen(ItemThrowEvent.EVENT, active::onDropItem);
@@ -154,6 +157,14 @@ public static void open(ServerWorld world, GameSpace gameSpace, SiegeMap map, Si
         });
     }
 
+    private void onReload(LifecycledResourceManager resourceManager, boolean success) {
+        if (success) {
+            this.map.reload(this);
+        } else {
+            Siege.LOGGER.warn("Failed to reload datapacks and resources; not reloading map...");
+        }
+    }
+
     private void onExplosion(Explosion explosion, boolean particles) {
         gate:
         for (SiegeGate gate : this.map.gates) {

src/main/java/io/github/restioson/siege/game/map/SiegeMap.java

@@ -39,6 +39,86 @@ public SiegeMap(SiegeMapConfig config, MapTemplate template) {
         this.time = 1000;
     }
 
+    private static SiegeMap merge(SiegeActive active, SiegeMap oldMap, SiegeMap newMap) {
+        var world = active.world;
+        var gameSpace = active.gameSpace;
+
+        for (var newFlag : newMap.flags) {
+            oldMap.flags.stream().filter(f -> f.id.equals(newFlag.id)).findFirst()
+                    .ifPresent(oldFlag -> {
+                        newFlag.captureProgressTicks = oldFlag.captureProgressTicks;
+                        newFlag.team = oldFlag.team;
+                        newFlag.setTeamBlocks(world, newFlag.team);
+                    });
+        }
+
+        for (var oldFlag : oldMap.flags) {
+            oldFlag.captureBar.clearPlayers();
+        }
+
+        for (var newGate : newMap.gates) {
+            oldMap.gates.stream().filter(g -> g.id.equals(newGate.id)).findFirst()
+                    .ifPresent(oldGate -> {
+                        newGate.bashedOpen = oldGate.bashedOpen;
+                        newGate.health = oldGate.health;
+                        newGate.openSlide = oldGate.openSlide;
+
+                        if (newGate.bashedOpen) {
+                            newGate.slider.setOpen(world);
+                        } else {
+                            newGate.slider.set(world, newGate.openSlide);
+                        }
+                    });
+        }
+
+        newMap.spawnKitStands(active);
+
+        for (var player : gameSpace.getPlayers()) {
+            if (!newMap.template.getBounds().contains(player.getBlockPos()) || player.isInsideWall()) {
+                SiegeSpawnLogic.spawnPlayer(player, newMap.waitingSpawn, world);
+            }
+        }
+
+        gameSpace.getPlayers().sendMessage(Text.literal("[Siege] Map reloaded!"));
+        return newMap;
+    }
+
+    public void reload(SiegeActive active) {
+        var world = active.world;
+        var gameSpace = active.gameSpace;
+
+        var server = world.getServer();
+
+        long time = System.currentTimeMillis();
+        var newMap = SiegeMapLoader.load(server, this.config);
+        System.out.printf("Loading took %sms%n", System.currentTimeMillis() - time);
+
+        time = System.currentTimeMillis();
+        var diff = newMap.template.diff(this.template);
+        System.out.printf("Diffing took %sms%n", System.currentTimeMillis() - time);
+
+        Siege.LOGGER.info("Loaded new template with diff {}", diff);
+
+        if (diff.needsRegeneration()) {
+            Siege.LOGGER.info("Regenerating world");
+            gameSpace.getWorlds().regenerate(world, newMap.asGenerator(server), newMap.template.getBounds().union(this.template.getBounds()));
+        } else {
+            Siege.LOGGER.debug("Diff does not warrant regeneration");
+        }
+
+        if (newMap.time != this.time) {
+            Siege.LOGGER.info("Changing time from {} to {}", this.time, newMap.time);
+            world.setTimeOfDay(newMap.time);
+        } else {
+            Siege.LOGGER.debug("Skipping changing time, as they are the same");
+        }
+
+        var merged = merge(active, this, newMap);
+        Siege.LOGGER.info("Done reloading map!");
+
+        active.map = merged;
+    }
+
     public SiegeSpawn getFirstSpawn(GameTeam team) {
         if (team == SiegeTeams.ATTACKERS) {
             return this.attackerFirstSpawn;