package net.minecraft.server.level;

import com.google.common.annotations.VisibleForTesting;
import com.mojang.datafixers.DataFixer;
import com.mojang.logging.LogUtils;
import it.unimi.dsi.fastutil.longs.LongSet;
import it.unimi.dsi.fastutil.objects.ObjectArrayList;
import it.unimi.dsi.fastutil.objects.ReferenceOpenHashSet;
import java.io.IOException;
import java.nio.file.Path;
import java.util.Arrays;
import java.util.List;
import java.util.Set;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.Executor;
import java.util.function.BooleanSupplier;
import java.util.function.Consumer;
import java.util.function.Supplier;
import net.minecraft.FileUtil;
import net.minecraft.Util;
import net.minecraft.core.BlockPos;
import net.minecraft.core.SectionPos;
import net.minecraft.network.protocol.Packet;
import net.minecraft.server.MinecraftServer;
import net.minecraft.server.level.progress.ChunkProgressListener;
import net.minecraft.util.VisibleForDebug;
import net.minecraft.util.profiling.Profiler;
import net.minecraft.util.profiling.ProfilerFiller;
import net.minecraft.util.thread.BlockableEventLoop;
import net.minecraft.world.entity.Entity;
import net.minecraft.world.entity.MobCategory;
import net.minecraft.world.entity.ai.village.poi.PoiManager;
import net.minecraft.world.level.ChunkPos;
import net.minecraft.world.level.GameRules;
import net.minecraft.world.level.Level;
import net.minecraft.world.level.LightLayer;
import net.minecraft.world.level.LocalMobCapCalculator;
import net.minecraft.world.level.NaturalSpawner;
import net.minecraft.world.level.TicketStorage;
import net.minecraft.world.level.chunk.ChunkAccess;
import net.minecraft.world.level.chunk.ChunkGenerator;
import net.minecraft.world.level.chunk.ChunkGeneratorStructureState;
import net.minecraft.world.level.chunk.ChunkSource;
import net.minecraft.world.level.chunk.LevelChunk;
import net.minecraft.world.level.chunk.LightChunk;
import net.minecraft.world.level.chunk.status.ChunkStatus;
import net.minecraft.world.level.chunk.storage.ChunkScanAccess;
import net.minecraft.world.level.entity.ChunkStatusUpdateListener;
import net.minecraft.world.level.levelgen.RandomState;
import net.minecraft.world.level.levelgen.structure.templatesystem.StructureTemplateManager;
import net.minecraft.world.level.saveddata.SavedData;
import net.minecraft.world.level.storage.DimensionDataStorage;
import net.minecraft.world.level.storage.LevelStorageSource;
import org.jetbrains.annotations.Nullable;
import org.slf4j.Logger;

public class ServerChunkCache extends ChunkSource {
	private static final Logger LOGGER = LogUtils.getLogger();
	private final DistanceManager distanceManager;
	private final ServerLevel level;
	final Thread mainThread;
	final ThreadedLevelLightEngine lightEngine;
	private final ServerChunkCache.MainThreadExecutor mainThreadProcessor;
	public final ChunkMap chunkMap;
	private final DimensionDataStorage dataStorage;
	private final TicketStorage ticketStorage;
	private long lastInhabitedUpdate;
	private boolean spawnEnemies = true;
	private boolean spawnFriendlies = true;
	private static final int CACHE_SIZE = 4;
	private final long[] lastChunkPos = new long[4];
	private final ChunkStatus[] lastChunkStatus = new ChunkStatus[4];
	private final ChunkAccess[] lastChunk = new ChunkAccess[4];
	private final List<LevelChunk> spawningChunks = new ObjectArrayList<>();
	private final Set<ChunkHolder> chunkHoldersToBroadcast = new ReferenceOpenHashSet<>();
	@Nullable
	@VisibleForDebug
	private NaturalSpawner.SpawnState lastSpawnState;

	public ServerChunkCache(
		ServerLevel level,
		LevelStorageSource.LevelStorageAccess levelStorageAccess,
		DataFixer fixerUpper,
		StructureTemplateManager structureManager,
		Executor dispatcher,
		ChunkGenerator generator,
		int viewDistance,
		int simulationDistance,
		boolean sync,
		ChunkProgressListener progressListener,
		ChunkStatusUpdateListener chunkStatusListener,
		Supplier<DimensionDataStorage> overworldDataStorage
	) {
		this.level = level;
		this.mainThreadProcessor = new ServerChunkCache.MainThreadExecutor(level);
		this.mainThread = Thread.currentThread();
		Path path = levelStorageAccess.getDimensionPath(level.dimension()).resolve("data");

		try {
			FileUtil.createDirectoriesSafe(path);
		} catch (IOException var15) {
			LOGGER.error("Failed to create dimension data storage directory", (Throwable)var15);
		}

		this.dataStorage = new DimensionDataStorage(new SavedData.Context(level), path, fixerUpper, level.registryAccess());
		this.ticketStorage = this.dataStorage.computeIfAbsent(TicketStorage.TYPE);
		this.chunkMap = new ChunkMap(
			level,
			levelStorageAccess,
			fixerUpper,
			structureManager,
			dispatcher,
			this.mainThreadProcessor,
			this,
			generator,
			progressListener,
			chunkStatusListener,
			overworldDataStorage,
			this.ticketStorage,
			viewDistance,
			sync
		);
		this.lightEngine = this.chunkMap.getLightEngine();
		this.distanceManager = this.chunkMap.getDistanceManager();
		this.distanceManager.updateSimulationDistance(simulationDistance);
		this.clearCache();
	}

	public ThreadedLevelLightEngine getLightEngine() {
		return this.lightEngine;
	}

	@Nullable
	private ChunkHolder getVisibleChunkIfPresent(long chunkPos) {
		return this.chunkMap.getVisibleChunkIfPresent(chunkPos);
	}

	public int getTickingGenerated() {
		return this.chunkMap.getTickingGenerated();
	}

	private void storeInCache(long chunkPos, @Nullable ChunkAccess chunk, ChunkStatus chunkStatus) {
		for (int i = 3; i > 0; i--) {
			this.lastChunkPos[i] = this.lastChunkPos[i - 1];
			this.lastChunkStatus[i] = this.lastChunkStatus[i - 1];
			this.lastChunk[i] = this.lastChunk[i - 1];
		}

		this.lastChunkPos[0] = chunkPos;
		this.lastChunkStatus[0] = chunkStatus;
		this.lastChunk[0] = chunk;
	}

	@Nullable
	@Override
	public ChunkAccess getChunk(int x, int z, ChunkStatus chunkStatus, boolean requireChunk) {
		if (Thread.currentThread() != this.mainThread) {
			return (ChunkAccess)CompletableFuture.supplyAsync(() -> this.getChunk(x, z, chunkStatus, requireChunk), this.mainThreadProcessor).join();
		} else {
			ProfilerFiller profilerFiller = Profiler.get();
			profilerFiller.incrementCounter("getChunk");
			long l = ChunkPos.asLong(x, z);

			for (int i = 0; i < 4; i++) {
				if (l == this.lastChunkPos[i] && chunkStatus == this.lastChunkStatus[i]) {
					ChunkAccess chunkAccess = this.lastChunk[i];
					if (chunkAccess != null || !requireChunk) {
						return chunkAccess;
					}
				}
			}

			profilerFiller.incrementCounter("getChunkCacheMiss");
			CompletableFuture<ChunkResult<ChunkAccess>> completableFuture = this.getChunkFutureMainThread(x, z, chunkStatus, requireChunk);
			this.mainThreadProcessor.managedBlock(completableFuture::isDone);
			ChunkResult<ChunkAccess> chunkResult = (ChunkResult<ChunkAccess>)completableFuture.join();
			ChunkAccess chunkAccess2 = chunkResult.orElse(null);
			if (chunkAccess2 == null && requireChunk) {
				throw (IllegalStateException)Util.pauseInIde(new IllegalStateException("Chunk not there when requested: " + chunkResult.getError()));
			} else {
				this.storeInCache(l, chunkAccess2, chunkStatus);
				return chunkAccess2;
			}
		}
	}

	@Nullable
	@Override
	public LevelChunk getChunkNow(int chunkX, int chunkZ) {
		if (Thread.currentThread() != this.mainThread) {
			return null;
		} else {
			Profiler.get().incrementCounter("getChunkNow");
			long l = ChunkPos.asLong(chunkX, chunkZ);

			for (int i = 0; i < 4; i++) {
				if (l == this.lastChunkPos[i] && this.lastChunkStatus[i] == ChunkStatus.FULL) {
					ChunkAccess chunkAccess = this.lastChunk[i];
					return chunkAccess instanceof LevelChunk ? (LevelChunk)chunkAccess : null;
				}
			}

			ChunkHolder chunkHolder = this.getVisibleChunkIfPresent(l);
			if (chunkHolder == null) {
				return null;
			} else {
				ChunkAccess chunkAccess = chunkHolder.getChunkIfPresent(ChunkStatus.FULL);
				if (chunkAccess != null) {
					this.storeInCache(l, chunkAccess, ChunkStatus.FULL);
					if (chunkAccess instanceof LevelChunk) {
						return (LevelChunk)chunkAccess;
					}
				}

				return null;
			}
		}
	}

	private void clearCache() {
		Arrays.fill(this.lastChunkPos, ChunkPos.INVALID_CHUNK_POS);
		Arrays.fill(this.lastChunkStatus, null);
		Arrays.fill(this.lastChunk, null);
	}

	public CompletableFuture<ChunkResult<ChunkAccess>> getChunkFuture(int x, int z, ChunkStatus chunkStatus, boolean requireChunk) {
		boolean bl = Thread.currentThread() == this.mainThread;
		CompletableFuture<ChunkResult<ChunkAccess>> completableFuture;
		if (bl) {
			completableFuture = this.getChunkFutureMainThread(x, z, chunkStatus, requireChunk);
			this.mainThreadProcessor.managedBlock(completableFuture::isDone);
		} else {
			completableFuture = CompletableFuture.supplyAsync(() -> this.getChunkFutureMainThread(x, z, chunkStatus, requireChunk), this.mainThreadProcessor)
				.thenCompose(completableFuturex -> completableFuturex);
		}

		return completableFuture;
	}

	private CompletableFuture<ChunkResult<ChunkAccess>> getChunkFutureMainThread(int x, int z, ChunkStatus chunkStatus, boolean requireChunk) {
		ChunkPos chunkPos = new ChunkPos(x, z);
		long l = chunkPos.toLong();
		int i = ChunkLevel.byStatus(chunkStatus);
		ChunkHolder chunkHolder = this.getVisibleChunkIfPresent(l);
		if (requireChunk) {
			this.addTicket(new Ticket(TicketType.UNKNOWN, i), chunkPos);
			if (this.chunkAbsent(chunkHolder, i)) {
				ProfilerFiller profilerFiller = Profiler.get();
				profilerFiller.push("chunkLoad");
				this.runDistanceManagerUpdates();
				chunkHolder = this.getVisibleChunkIfPresent(l);
				profilerFiller.pop();
				if (this.chunkAbsent(chunkHolder, i)) {
					throw (IllegalStateException)Util.pauseInIde(new IllegalStateException("No chunk holder after ticket has been added"));
				}
			}
		}

		return this.chunkAbsent(chunkHolder, i) ? GenerationChunkHolder.UNLOADED_CHUNK_FUTURE : chunkHolder.scheduleChunkGenerationTask(chunkStatus, this.chunkMap);
	}

	private boolean chunkAbsent(@Nullable ChunkHolder chunkHolder, int status) {
		return chunkHolder == null || chunkHolder.getTicketLevel() > status;
	}

	@Override
	public boolean hasChunk(int chunkX, int chunkZ) {
		ChunkHolder chunkHolder = this.getVisibleChunkIfPresent(new ChunkPos(chunkX, chunkZ).toLong());
		int i = ChunkLevel.byStatus(ChunkStatus.FULL);
		return !this.chunkAbsent(chunkHolder, i);
	}

	@Nullable
	@Override
	public LightChunk getChunkForLighting(int chunkX, int chunkZ) {
		long l = ChunkPos.asLong(chunkX, chunkZ);
		ChunkHolder chunkHolder = this.getVisibleChunkIfPresent(l);
		return chunkHolder == null ? null : chunkHolder.getChunkIfPresentUnchecked(ChunkStatus.INITIALIZE_LIGHT.getParent());
	}

	public Level getLevel() {
		return this.level;
	}

	public boolean pollTask() {
		return this.mainThreadProcessor.pollTask();
	}

	boolean runDistanceManagerUpdates() {
		boolean bl = this.distanceManager.runAllUpdates(this.chunkMap);
		boolean bl2 = this.chunkMap.promoteChunkMap();
		this.chunkMap.runGenerationTasks();
		if (!bl && !bl2) {
			return false;
		} else {
			this.clearCache();
			return true;
		}
	}

	public boolean isPositionTicking(long chunkPos) {
		if (!this.level.shouldTickBlocksAt(chunkPos)) {
			return false;
		} else {
			ChunkHolder chunkHolder = this.getVisibleChunkIfPresent(chunkPos);
			return chunkHolder == null ? false : ((ChunkResult)chunkHolder.getTickingChunkFuture().getNow(ChunkHolder.UNLOADED_LEVEL_CHUNK)).isSuccess();
		}
	}

	public void save(boolean flush) {
		this.runDistanceManagerUpdates();
		this.chunkMap.saveAllChunks(flush);
	}

	@Override
	public void close() throws IOException {
		this.save(true);
		this.dataStorage.close();
		this.lightEngine.close();
		this.chunkMap.close();
	}

	@Override
	public void tick(BooleanSupplier hasTimeLeft, boolean tickChunks) {
		ProfilerFiller profilerFiller = Profiler.get();
		profilerFiller.push("purge");
		if (this.level.tickRateManager().runsNormally() || !tickChunks) {
			this.ticketStorage.purgeStaleTickets();
		}

		this.runDistanceManagerUpdates();
		profilerFiller.popPush("chunks");
		if (tickChunks) {
			this.tickChunks();
			this.chunkMap.tick();
		}

		profilerFiller.popPush("unload");
		this.chunkMap.tick(hasTimeLeft);
		profilerFiller.pop();
		this.clearCache();
	}

	private void tickChunks() {
		long l = this.level.getGameTime();
		long m = l - this.lastInhabitedUpdate;
		this.lastInhabitedUpdate = l;
		if (!this.level.isDebug()) {
			ProfilerFiller profilerFiller = Profiler.get();
			profilerFiller.push("pollingChunks");
			if (this.level.tickRateManager().runsNormally()) {
				profilerFiller.push("tickingChunks");
				this.tickChunks(profilerFiller, m);
				profilerFiller.pop();
			}

			this.broadcastChangedChunks(profilerFiller);
			profilerFiller.pop();
		}
	}

	private void broadcastChangedChunks(ProfilerFiller profiler) {
		profiler.push("broadcast");

		for (ChunkHolder chunkHolder : this.chunkHoldersToBroadcast) {
			LevelChunk levelChunk = chunkHolder.getTickingChunk();
			if (levelChunk != null) {
				chunkHolder.broadcastChanges(levelChunk);
			}
		}

		this.chunkHoldersToBroadcast.clear();
		profiler.pop();
	}

	private void tickChunks(ProfilerFiller profiler, long timeInhabited) {
		profiler.popPush("naturalSpawnCount");
		int i = this.distanceManager.getNaturalSpawnChunkCount();
		NaturalSpawner.SpawnState spawnState = NaturalSpawner.createState(
			i, this.level.getAllEntities(), this::getFullChunk, new LocalMobCapCalculator(this.chunkMap)
		);
		this.lastSpawnState = spawnState;
		profiler.popPush("spawnAndTick");
		boolean bl = this.level.getGameRules().getBoolean(GameRules.RULE_DOMOBSPAWNING);
		int j = this.level.getGameRules().getInt(GameRules.RULE_RANDOMTICKING);
		List<MobCategory> list;
		if (bl && (this.spawnEnemies || this.spawnFriendlies)) {
			boolean bl2 = this.level.getLevelData().getGameTime() % 400L == 0L;
			list = NaturalSpawner.getFilteredSpawningCategories(spawnState, this.spawnFriendlies, this.spawnEnemies, bl2);
		} else {
			list = List.of();
		}

		List<LevelChunk> list2 = this.spawningChunks;

		try {
			profiler.push("filteringSpawningChunks");
			this.chunkMap.collectSpawningChunks(list2);
			profiler.popPush("shuffleSpawningChunks");
			Util.shuffle(list2, this.level.random);
			profiler.popPush("tickSpawningChunks");

			for (LevelChunk levelChunk : list2) {
				this.tickSpawningChunk(levelChunk, timeInhabited, list, spawnState);
			}
		} finally {
			list2.clear();
		}

		profiler.popPush("tickTickingChunks");
		this.chunkMap.forEachBlockTickingChunk(levelChunkx -> this.level.tickChunk(levelChunkx, j));
		profiler.pop();
		profiler.popPush("customSpawners");
		if (bl) {
			this.level.tickCustomSpawners(this.spawnEnemies, this.spawnFriendlies);
		}
	}

	private void tickSpawningChunk(LevelChunk chunk, long timeInhabited, List<MobCategory> spawnCategories, NaturalSpawner.SpawnState spawnState) {
		ChunkPos chunkPos = chunk.getPos();
		chunk.incrementInhabitedTime(timeInhabited);
		if (this.distanceManager.inEntityTickingRange(chunkPos.toLong())) {
			this.level.tickThunder(chunk);
		}

		if (!spawnCategories.isEmpty()) {
			if (this.level.canSpawnEntitiesInChunk(chunkPos)) {
				NaturalSpawner.spawnForChunk(this.level, chunk, spawnState, spawnCategories);
			}
		}
	}

	private void getFullChunk(long chunkPos, Consumer<LevelChunk> fullChunkGetter) {
		ChunkHolder chunkHolder = this.getVisibleChunkIfPresent(chunkPos);
		if (chunkHolder != null) {
			((ChunkResult)chunkHolder.getFullChunkFuture().getNow(ChunkHolder.UNLOADED_LEVEL_CHUNK)).ifSuccess(fullChunkGetter);
		}
	}

	@Override
	public String gatherStats() {
		return Integer.toString(this.getLoadedChunksCount());
	}

	@VisibleForTesting
	public int getPendingTasksCount() {
		return this.mainThreadProcessor.getPendingTasksCount();
	}

	public ChunkGenerator getGenerator() {
		return this.chunkMap.generator();
	}

	public ChunkGeneratorStructureState getGeneratorState() {
		return this.chunkMap.generatorState();
	}

	public RandomState randomState() {
		return this.chunkMap.randomState();
	}

	@Override
	public int getLoadedChunksCount() {
		return this.chunkMap.size();
	}

	public void blockChanged(BlockPos pos) {
		int i = SectionPos.blockToSectionCoord(pos.getX());
		int j = SectionPos.blockToSectionCoord(pos.getZ());
		ChunkHolder chunkHolder = this.getVisibleChunkIfPresent(ChunkPos.asLong(i, j));
		if (chunkHolder != null && chunkHolder.blockChanged(pos)) {
			this.chunkHoldersToBroadcast.add(chunkHolder);
		}
	}

	@Override
	public void onLightUpdate(LightLayer layer, SectionPos pos) {
		this.mainThreadProcessor.execute(() -> {
			ChunkHolder chunkHolder = this.getVisibleChunkIfPresent(pos.chunk().toLong());
			if (chunkHolder != null && chunkHolder.sectionLightChanged(layer, pos.y())) {
				this.chunkHoldersToBroadcast.add(chunkHolder);
			}
		});
	}

	public void addTicket(Ticket ticket, ChunkPos chunkPos) {
		this.ticketStorage.addTicket(ticket, chunkPos);
	}

	public void addTicketWithRadius(TicketType ticket, ChunkPos chunkPos, int radius) {
		this.ticketStorage.addTicketWithRadius(ticket, chunkPos, radius);
	}

	public void removeTicketWithRadius(TicketType ticket, ChunkPos chunkPos, int radius) {
		this.ticketStorage.removeTicketWithRadius(ticket, chunkPos, radius);
	}

	@Override
	public boolean updateChunkForced(ChunkPos chunkPos, boolean add) {
		return this.ticketStorage.updateChunkForced(chunkPos, add);
	}

	@Override
	public LongSet getForceLoadedChunks() {
		return this.ticketStorage.getForceLoadedChunks();
	}

	public void move(ServerPlayer player) {
		if (!player.isRemoved()) {
			this.chunkMap.move(player);
		}
	}

	public void removeEntity(Entity entity) {
		this.chunkMap.removeEntity(entity);
	}

	public void addEntity(Entity entity) {
		this.chunkMap.addEntity(entity);
	}

	public void broadcastAndSend(Entity entity, Packet<?> packet) {
		this.chunkMap.broadcastAndSend(entity, packet);
	}

	public void broadcast(Entity entity, Packet<?> packet) {
		this.chunkMap.broadcast(entity, packet);
	}

	public void setViewDistance(int viewDistance) {
		this.chunkMap.setServerViewDistance(viewDistance);
	}

	public void setSimulationDistance(int simulationDistance) {
		this.distanceManager.updateSimulationDistance(simulationDistance);
	}

	@Override
	public void setSpawnSettings(boolean spawnSettings) {
		this.spawnEnemies = spawnSettings;
		this.spawnFriendlies = this.spawnFriendlies;
	}

	public String getChunkDebugData(ChunkPos chunkPos) {
		return this.chunkMap.getChunkDebugData(chunkPos);
	}

	public DimensionDataStorage getDataStorage() {
		return this.dataStorage;
	}

	public PoiManager getPoiManager() {
		return this.chunkMap.getPoiManager();
	}

	public ChunkScanAccess chunkScanner() {
		return this.chunkMap.chunkScanner();
	}

	@Nullable
	@VisibleForDebug
	public NaturalSpawner.SpawnState getLastSpawnState() {
		return this.lastSpawnState;
	}

	public void deactivateTicketsOnClosing() {
		this.ticketStorage.deactivateTicketsOnClosing();
	}

	public void onChunkReadyToSend(ChunkHolder chunkHolder) {
		if (chunkHolder.hasChangesToBroadcast()) {
			this.chunkHoldersToBroadcast.add(chunkHolder);
		}
	}

	final class MainThreadExecutor extends BlockableEventLoop<Runnable> {
		MainThreadExecutor(final Level level) {
			super("Chunk source main thread executor for " + level.dimension().location());
		}

		@Override
		public void managedBlock(BooleanSupplier isDone) {
			super.managedBlock(() -> MinecraftServer.throwIfFatalException() && isDone.getAsBoolean());
		}

		@Override
		public Runnable wrapRunnable(Runnable runnable) {
			return runnable;
		}

		@Override
		protected boolean shouldRun(Runnable runnable) {
			return true;
		}

		@Override
		protected boolean scheduleExecutables() {
			return true;
		}

		@Override
		protected Thread getRunningThread() {
			return ServerChunkCache.this.mainThread;
		}

		@Override
		protected void doRunTask(Runnable task) {
			Profiler.get().incrementCounter("runTask");
			super.doRunTask(task);
		}

		@Override
		protected boolean pollTask() {
			if (ServerChunkCache.this.runDistanceManagerUpdates()) {
				return true;
			} else {
				ServerChunkCache.this.lightEngine.tryScheduleUpdate();
				return super.pollTask();
			}
		}
	}
}