package org.bukkit.craftbukkit;

import net.minecraft.world.WorldServer;
import org.bukkit.Chunk;
import org.bukkit.ChunkSnapshot;
import org.bukkit.World;
import org.bukkit.block.Block;
import org.bukkit.block.BlockState;
import org.bukkit.craftbukkit.block.CraftBlock;
import org.bukkit.entity.Entity;
import org.ultramine.mods.bukkit.interfaces.entity.IMixinEntity;
import org.ultramine.mods.bukkit.interfaces.world.IMixinWorld;

import java.lang.ref.WeakReference;
import java.util.Arrays;

public class CraftChunk implements Chunk
{
	private WeakReference<net.minecraft.world.chunk.Chunk> weakChunk;
	private final WorldServer worldServer;
	private final IMixinWorld worldMixin;
	private final int x;
	private final int z;
	private static final byte[] emptyData = new byte[2048];
	private static final short[] emptyBlockIDs = new short[4096];
	private static final byte[] emptySkyLight = new byte[2048];

	public CraftChunk(net.minecraft.world.chunk.Chunk chunk)
	{
		if(!(chunk instanceof net.minecraft.world.chunk.EmptyChunk))
		{
			this.weakChunk = new WeakReference<net.minecraft.world.chunk.Chunk>(chunk);
		}

		net.minecraft.world.chunk.Chunk handle = getHandle();
		worldServer = handle.worldObj instanceof WorldServer ? (WorldServer) handle.worldObj : null;
		this.worldMixin = (IMixinWorld) worldServer;
		x = handle.xPosition;
		z = handle.zPosition;
	}

	public World getWorld()
	{
		return worldMixin.getWorld();
	}

	public CraftWorld getCraftWorld()
	{
		return (CraftWorld) getWorld();
	}

	public net.minecraft.world.chunk.Chunk getHandle()
	{
		net.minecraft.world.chunk.Chunk c = null;
		if(weakChunk != null)
		{
			c = weakChunk.get();
		}

		if(c == null)
		{
			c = worldServer.getChunkFromChunkCoords(x, z);

			if(!(c instanceof net.minecraft.world.chunk.EmptyChunk))
			{
				weakChunk = new WeakReference<net.minecraft.world.chunk.Chunk>(c);
			}
		}

		return c;
	}

	void breakLink()
	{
		weakChunk.clear();
	}

	public int getX()
	{
		return x;
	}

	public int getZ()
	{
		return z;
	}

	@Override
	public String toString()
	{
		return "CraftChunk{" + "x=" + getX() + "z=" + getZ() + '}';
	}

	public Block getBlock(int x, int y, int z)
	{
		return new CraftBlock(this, (getX() << 4) | (x & 0xF), y & 0xFF, (getZ() << 4) | (z & 0xF));
	}

	public Entity[] getEntities()
	{
		int count = 0, index = 0;
		net.minecraft.world.chunk.Chunk chunk = getHandle();

		for(int i = 0; i < 16; i++)
		{
			count += chunk.entityLists[i].size();
		}

		Entity[] entities = new Entity[count];

		for(int i = 0; i < 16; i++)
		{
			for(Object obj : chunk.entityLists[i].toArray())
			{
				if(!(obj instanceof net.minecraft.entity.Entity))
				{
					continue;
				}

				entities[index++] = ((IMixinEntity) ((net.minecraft.entity.Entity) obj)).getBukkitEntity();
			}
		}

		return entities;
	}

	public BlockState[] getTileEntities()
	{
		int index = 0;
		net.minecraft.world.chunk.Chunk chunk = getHandle();
		BlockState[] entities = new BlockState[chunk.chunkTileEntityMap.size()];

		for(Object obj : chunk.chunkTileEntityMap.keySet().toArray())
		{
			if(!(obj instanceof net.minecraft.world.ChunkPosition))
			{
				continue;
			}

			net.minecraft.world.ChunkPosition position = (net.minecraft.world.ChunkPosition) obj;
			entities[index++] = worldMixin.getWorld().getBlockAt(position.chunkPosX + (chunk.xPosition << 4), position.chunkPosY, position.chunkPosZ + (chunk.zPosition << 4)).getState();
		}
		return entities;
	}

	public boolean isLoaded()
	{
		return getWorld().isChunkLoaded(this);
	}

	public boolean load()
	{
		return getWorld().loadChunk(getX(), getZ(), true);
	}

	public boolean load(boolean generate)
	{
		return getWorld().loadChunk(getX(), getZ(), generate);
	}

	public boolean unload()
	{
		return getWorld().unloadChunk(getX(), getZ());
	}

	public boolean unload(boolean save)
	{
		return getWorld().unloadChunk(getX(), getZ(), save);
	}

	public boolean unload(boolean save, boolean safe)
	{
		return getWorld().unloadChunk(getX(), getZ(), save, safe);
	}

	public ChunkSnapshot getChunkSnapshot()
	{
		return getChunkSnapshot(true, false, false);
	}

	public ChunkSnapshot getChunkSnapshot(boolean includeMaxBlockY, boolean includeBiome, boolean includeBiomeTempRain)
	{
		net.minecraft.world.chunk.Chunk chunk = getHandle();

		net.minecraft.world.chunk.storage.ExtendedBlockStorage[] cs = chunk.getBlockStorageArray(); /* Get sections */
		short[][] sectionBlockIDs = new short[cs.length][];
		byte[][] sectionBlockData = new byte[cs.length][];
		byte[][] sectionSkyLights = new byte[cs.length][];
		byte[][] sectionEmitLights = new byte[cs.length][];
		boolean[] sectionEmpty = new boolean[cs.length];

		for(int i = 0; i < cs.length; i++)
		{
			if(cs[i] == null)
			{ /* Section is empty? */
				sectionBlockIDs[i] = emptyBlockIDs;
				sectionBlockData[i] = emptyData;
				sectionSkyLights[i] = emptySkyLight;
				sectionEmitLights[i] = emptyData;
				sectionEmpty[i] = true;
			}
			else
			{ /* Not empty */
				short[] blockids = new short[4096];
				byte[] baseids = cs[i].getSlot().copyLSB();

                /* Copy base IDs */
				for(int j = 0; j < 4096; j++)
				{
					blockids[j] = (short) (baseids[j] & 0xFF);
				}

				if(true /*cs[i].getBlockMSBArray() != null*/)
				{ /* If we've got extended IDs */
					byte[] extids = cs[i].getSlot().copyMSB();
					// Spigot end

					for(int j = 0; j < 2048; j++)
					{
						short b = (short) (extids[j] & 0xFF);

						if(b == 0)
						{
							continue;
						}

						blockids[j << 1] |= (b & 0x0F) << 8;
						blockids[(j << 1) + 1] |= (b & 0xF0) << 4;
					}
				}

				sectionBlockIDs[i] = blockids;

				sectionBlockData[i] = cs[i].getSlot().copyBlockMetadata();
				sectionSkyLights[i] = cs[i].getSlot().copySkylight();
				sectionEmitLights[i] = cs[i].getSlot().copyBlocklight();
			}
		}

		int[] hmap = null;

		if(includeMaxBlockY)
		{
			hmap = new int[256]; // Get copy of height map
			System.arraycopy(chunk.heightMap, 0, hmap, 0, 256);
		}

		net.minecraft.world.biome.BiomeGenBase[] biome = null;
		double[] biomeTemp = null;
		double[] biomeRain = null;

		if(includeBiome || includeBiomeTempRain)
		{
			net.minecraft.world.biome.WorldChunkManager wcm = chunk.worldObj.getWorldChunkManager();

			if(includeBiome)
			{
				biome = new net.minecraft.world.biome.BiomeGenBase[256];
				for(int i = 0; i < 256; i++)
				{
					biome[i] = chunk.getBiomeGenForWorldCoords(i & 0xF, i >> 4, wcm);
				}
			}

			if(includeBiomeTempRain)
			{
				biomeTemp = new double[256];
				biomeRain = new double[256];
				float[] dat = getTemperatures(wcm, getX() << 4, getZ() << 4);

				for(int i = 0; i < 256; i++)
				{
					biomeTemp[i] = dat[i];
				}

				dat = wcm.getRainfall(null, getX() << 4, getZ() << 4, 16, 16);

				for(int i = 0; i < 256; i++)
				{
					biomeRain[i] = dat[i];
				}
			}
		}

		World world = getWorld();
		return new CraftChunkSnapshot(getX(), getZ(), world.getName(), world.getFullTime(), sectionBlockIDs, sectionBlockData, sectionSkyLights, sectionEmitLights, sectionEmpty, hmap, biome, biomeTemp, biomeRain);
	}

	public static ChunkSnapshot getEmptyChunkSnapshot(int x, int z, CraftWorld world, boolean includeBiome, boolean includeBiomeTempRain)
	{
		net.minecraft.world.biome.BiomeGenBase[] biome = null;
		double[] biomeTemp = null;
		double[] biomeRain = null;

		if(includeBiome || includeBiomeTempRain)
		{
			net.minecraft.world.biome.WorldChunkManager wcm = world.getHandle().getWorldChunkManager();

			if(includeBiome)
			{
				biome = new net.minecraft.world.biome.BiomeGenBase[256];
				for(int i = 0; i < 256; i++)
				{
					biome[i] = world.getHandle().getBiomeGenForCoords((x << 4) + (i & 0xF), (z << 4) + (i >> 4));
				}
			}

			if(includeBiomeTempRain)
			{
				biomeTemp = new double[256];
				biomeRain = new double[256];
				float[] dat = getTemperatures(wcm, x << 4, z << 4);

				for(int i = 0; i < 256; i++)
				{
					biomeTemp[i] = dat[i];
				}

				dat = wcm.getRainfall(null, x << 4, z << 4, 16, 16);

				for(int i = 0; i < 256; i++)
				{
					biomeRain[i] = dat[i];
				}
			}
		}

        /* Fill with empty data */
		int hSection = world.getMaxHeight() >> 4;
		short[][] blockIDs = new short[hSection][];
		byte[][] skyLight = new byte[hSection][];
		byte[][] emitLight = new byte[hSection][];
		byte[][] blockData = new byte[hSection][];
		boolean[] empty = new boolean[hSection];

		for(int i = 0; i < hSection; i++)
		{
			blockIDs[i] = emptyBlockIDs;
			skyLight[i] = emptySkyLight;
			emitLight[i] = emptyData;
			blockData[i] = emptyData;
			empty[i] = true;
		}

		return new CraftChunkSnapshot(x, z, world.getName(), world.getFullTime(), blockIDs, blockData, skyLight, emitLight, empty, new int[256], biome, biomeTemp, biomeRain);
	}

	private static float[] getTemperatures(net.minecraft.world.biome.WorldChunkManager chunkmanager, int chunkX, int chunkZ)
	{
		net.minecraft.world.biome.BiomeGenBase[] biomes = chunkmanager.getBiomesForGeneration(null, chunkX, chunkZ, 16, 16);
		float[] temps = new float[biomes.length];

		for(int i = 0; i < biomes.length; i++)
		{
			float temp = biomes[i].temperature; // Vanilla of olde: ((int) biomes[i].temperature * 65536.0F) / 65536.0F

			if(temp > 1F)
			{
				temp = 1F;
			}

			temps[i] = temp;
		}

		return temps;
	}

	static
	{
		Arrays.fill(emptySkyLight, (byte) 0xFF);
	}
}