/*
 * This file is part of Applied Energistics 2.
 * Copyright (c) 2013 - 2015, AlgorithmX2, All rights reserved.
 *
 * Applied Energistics 2 is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Applied Energistics 2 is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with Applied Energistics 2.  If not, see <http://www.gnu.org/licenses/lgpl>.
 */

package appeng.spatial;


import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map.Entry;

import net.minecraft.block.Block;
import net.minecraft.block.state.IBlockState;
import net.minecraft.tileentity.TileEntity;
import net.minecraft.util.math.BlockPos;
import net.minecraft.world.NextTickListEntry;
import net.minecraft.world.World;
import net.minecraft.world.chunk.Chunk;
import net.minecraft.world.chunk.storage.ExtendedBlockStorage;

import appeng.api.AEApi;
import appeng.api.definitions.IBlockDefinition;
import appeng.api.movable.IMovableHandler;
import appeng.api.movable.IMovableRegistry;
import appeng.api.util.AEPartLocation;
import appeng.api.util.WorldCoord;
import appeng.core.AELog;
import appeng.core.worlddata.WorldData;
import appeng.util.Platform;


public class CachedPlane
{
	private final int x_size;
	private final int z_size;
	private final int cx_size;
	private final int cz_size;
	private final int x_offset;
	private final int y_offset;
	private final int z_offset;
	private final int y_size;
	private final Chunk[][] myChunks;
	private final Column[][] myColumns;
	private final LinkedList<TileEntity> tiles = new LinkedList<TileEntity>();
	private final LinkedList<NextTickListEntry> ticks = new LinkedList<NextTickListEntry>();
	private final World world;
	private final IMovableRegistry reg = AEApi.instance().registries().movable();
	private final LinkedList<WorldCoord> updates = new LinkedList<WorldCoord>();
	private final IBlockDefinition matrixFrame = AEApi.instance().definitions().blocks().matrixFrame();
	private int verticalBits;
	private final IBlockState matrixBlockState;

	public CachedPlane( final World w, final int minX, final int minY, final int minZ, final int maxX, final int maxY, final int maxZ )
	{

		Block matrixFrameBlock = AEApi.instance().definitions().blocks().matrixFrame().maybeBlock().orElse( null );
		if( matrixFrameBlock != null )
		{
			this.matrixBlockState = matrixFrameBlock.getDefaultState();
		}
		else
		{
			this.matrixBlockState = null;
		}

		this.world = w;

		this.x_size = maxX - minX + 1;
		this.y_size = maxY - minY + 1;
		this.z_size = maxZ - minZ + 1;

		this.x_offset = minX;
		this.y_offset = minY;
		this.z_offset = minZ;

		final int minCX = minX >> 4;
		final int minCY = minY >> 4;
		final int minCZ = minZ >> 4;
		final int maxCX = maxX >> 4;
		final int maxCY = maxY >> 4;
		final int maxCZ = maxZ >> 4;

		this.cx_size = maxCX - minCX + 1;
		final int cy_size = maxCY - minCY + 1;
		this.cz_size = maxCZ - minCZ + 1;

		this.myChunks = new Chunk[this.cx_size][this.cz_size];
		this.myColumns = new Column[this.x_size][this.z_size];

		this.verticalBits = 0;
		for( int cy = 0; cy < cy_size; cy++ )
		{
			this.verticalBits |= 1 << ( minCY + cy );
		}

		for( int x = 0; x < this.x_size; x++ )
		{
			for( int z = 0; z < this.z_size; z++ )
			{
				this.myColumns[x][z] = new Column( w.getChunkFromChunkCoords( ( minX + x ) >> 4, ( minZ + z ) >> 4 ), ( minX + x ) & 0xF, ( minZ + z ) & 0xF, minCY, cy_size );
			}
		}

		final IMovableRegistry mr = AEApi.instance().registries().movable();

		for( int cx = 0; cx < this.cx_size; cx++ )
		{
			for( int cz = 0; cz < this.cz_size; cz++ )
			{
				final LinkedList<Entry<BlockPos, TileEntity>> rawTiles = new LinkedList<Entry<BlockPos, TileEntity>>();
				final LinkedList<BlockPos> deadTiles = new LinkedList<BlockPos>();

				final Chunk c = w.getChunkFromChunkCoords( minCX + cx, minCZ + cz );
				this.myChunks[cx][cz] = c;

				rawTiles.addAll( ( (HashMap<BlockPos, TileEntity>) c.getTileEntityMap() ).entrySet() );
				for( final Entry<BlockPos, TileEntity> tx : rawTiles )
				{
					final BlockPos cp = tx.getKey();
					final TileEntity te = tx.getValue();

					final BlockPos tePOS = te.getPos();
					if( tePOS.getX() >= minX && tePOS.getX() <= maxX && tePOS.getY() >= minY && tePOS.getY() <= maxY && tePOS.getZ() >= minZ && tePOS.getZ() <= maxZ )
					{
						if( mr.askToMove( te ) )
						{
							this.tiles.add( te );
							deadTiles.add( cp );
						}
						else
						{
							final Object[] details = this.myColumns[tePOS.getX() - minX][tePOS.getZ() - minZ].getDetails( tePOS.getY() );
							final Block blk = (Block) details[0];

							// don't skip air, just let the code replace it...
							if( blk != null && blk.isAir( c.getWorld().getBlockState( tePOS ), c.getWorld(), tePOS ) && blk.isReplaceable( c.getWorld(), tePOS ) )
							{
								c.getWorld().setBlockToAir( tePOS );
							}
							else
							{
								this.myColumns[tePOS.getX() - minX][tePOS.getZ() - minZ].setSkip( tePOS.getY() );
							}
						}
					}
				}

				for( final BlockPos cp : deadTiles )
				{
					c.getTileEntityMap().remove( cp );
				}

				final long k = this.getWorld().getTotalWorldTime();
				final List list = this.getWorld().getPendingBlockUpdates( c, false );
				if( list != null )
				{
					for( final Object o : list )
					{
						final NextTickListEntry entry = (NextTickListEntry) o;
						final BlockPos tePOS = entry.position;
						if( tePOS.getX() >= minX && tePOS.getX() <= maxX && tePOS.getY() >= minY && tePOS.getY() <= maxY && tePOS.getZ() >= minZ && tePOS.getZ() <= maxZ )
						{
							final NextTickListEntry newEntry = new NextTickListEntry( tePOS, entry.getBlock() );
							newEntry.scheduledTime = entry.scheduledTime - k;
							this.ticks.add( newEntry );
						}
					}
				}
			}
		}

		for( final TileEntity te : this.tiles )
		{
			try
			{
				this.getWorld().loadedTileEntityList.remove( te );
			}
			catch( final Exception e )
			{
				AELog.debug( e );
			}
		}
	}

	private IMovableHandler getHandler( final TileEntity te )
	{
		final IMovableRegistry mr = AEApi.instance().registries().movable();
		return mr.getHandler( te );
	}

	void swap( final CachedPlane dst )
	{
		final IMovableRegistry mr = AEApi.instance().registries().movable();

		if( dst.x_size == this.x_size && dst.y_size == this.y_size && dst.z_size == this.z_size )
		{
			AELog.info( "Block Copy Scale: " + this.x_size + ", " + this.y_size + ", " + this.z_size );

			long startTime = System.nanoTime();

			for( int x = 0; x < this.x_size; x++ )
			{
				for( int z = 0; z < this.z_size; z++ )
				{
					final Column a = this.myColumns[x][z];
					final Column b = dst.myColumns[x][z];

					for( int y = 0; y < this.y_size; y++ )
					{
						final int src_y = y + this.y_offset;
						final int dst_y = y + dst.y_offset;

						if( a.doNotSkip( src_y ) && b.doNotSkip( dst_y ) )
						{
							final Object[] aD = a.getDetails( src_y );
							final Object[] bD = b.getDetails( dst_y );

							a.setBlockIDWithMetadata( src_y, bD );
							b.setBlockIDWithMetadata( dst_y, aD );
						}
						else
						{
							this.markForUpdate( x + this.x_offset, src_y, z + this.z_offset );
							dst.markForUpdate( x + dst.x_offset, dst_y, z + dst.z_offset );
						}
					}
				}
			}

			long endTime = System.nanoTime();
			long duration = endTime - startTime;
			AELog.info( "Block Copy Time: " + duration );

			for( final TileEntity te : this.tiles )
			{
				final BlockPos tePOS = te.getPos();
				dst.addTile( tePOS.getX() - this.x_offset, tePOS.getY() - this.y_offset, tePOS.getZ() - this.z_offset, te, this, mr );
			}

			for( final TileEntity te : dst.tiles )
			{
				final BlockPos tePOS = te.getPos();
				this.addTile( tePOS.getX() - dst.x_offset, tePOS.getY() - dst.y_offset, tePOS.getZ() - dst.z_offset, te, dst, mr );
			}

			for( final NextTickListEntry entry : this.ticks )
			{
				final BlockPos tePOS = entry.position;
				dst.addTick( tePOS.getX() - this.x_offset, tePOS.getY() - this.y_offset, tePOS.getZ() - this.z_offset, entry );
			}

			for( final NextTickListEntry entry : dst.ticks )
			{
				final BlockPos tePOS = entry.position;
				this.addTick( tePOS.getX() - dst.x_offset, tePOS.getY() - dst.y_offset, tePOS.getZ() - dst.z_offset, entry );
			}

			startTime = System.nanoTime();
			this.updateChunks();
			dst.updateChunks();
			endTime = System.nanoTime();

			duration = endTime - startTime;
			AELog.info( "Update Time: " + duration );
		}
	}

	private void markForUpdate( final int x, final int y, final int z )
	{
		this.updates.add( new WorldCoord( x, y, z ) );
		for( final AEPartLocation d : AEPartLocation.SIDE_LOCATIONS )
		{
			this.updates.add( new WorldCoord( x + d.xOffset, y + d.yOffset, z + d.zOffset ) );
		}
	}

	private void addTick( final int x, final int y, final int z, final NextTickListEntry entry )
	{
		this.world.scheduleUpdate( new BlockPos( x + this.x_offset, y + this.y_offset, z + this.z_offset ), entry.getBlock(), (int) entry.scheduledTime );
	}

	private void addTile( final int x, final int y, final int z, final TileEntity te, final CachedPlane alternateDestination, final IMovableRegistry mr )
	{
		try
		{
			final Column c = this.myColumns[x][z];

			if( c.doNotSkip( y + this.y_offset ) || alternateDestination == null )
			{
				final IMovableHandler handler = this.getHandler( te );

				try
				{
					handler.moveTile( te, this.world, new BlockPos( x + this.x_offset, y + this.y_offset, z + this.z_offset ) );
				}
				catch( final Throwable e )
				{
					AELog.debug( e );

					final BlockPos pos = new BlockPos( x, y, z );

					// attempt recovery...
					te.setWorldObj( this.world );
					te.setPos( pos );
					c.c.addTileEntity( new BlockPos( c.x, y + y, c.z ), te );
					// c.c.setChunkTileEntity( c.x, y + y, c.z, te );

					if( c.c.isLoaded() )
					{
						this.world.addTileEntity( te );
						this.world.notifyBlockUpdate( pos, this.world.getBlockState( pos ), this.world.getBlockState( pos ), z );
					}
				}

				mr.doneMoving( te );
			}
			else
			{
				alternateDestination.addTile( x, y, z, te, null, mr );
			}
		}
		catch( final Throwable e )
		{
			AELog.debug( e );
		}
	}

	private void updateChunks()
	{

		// update shit..
		for( int x = 0; x < this.cx_size; x++ )
		{
			for( int z = 0; z < this.cz_size; z++ )
			{
				final Chunk c = this.myChunks[x][z];
				c.resetRelightChecks();
				c.generateSkylightMap();
				c.setModified( true );
			}
		}

		// send shit...
		for( int x = 0; x < this.cx_size; x++ )
		{
			for( int z = 0; z < this.cz_size; z++ )
			{

				final Chunk c = this.myChunks[x][z];

				for( int y = 1; y < 255; y += 32 )
				{
					WorldData.instance().compassData().service().updateArea( this.getWorld(), c.xPosition << 4, y, c.zPosition << 4 );
				}

				Platform.sendChunk( c, this.verticalBits );
			}
		}
	}

	LinkedList<WorldCoord> getUpdates()
	{
		return this.updates;
	}

	World getWorld()
	{
		return this.world;
	}

	private class Column
	{

		private final int x;
		private final int z;
		private final Chunk c;
		private final Object[] ch = { 0, 0 };
		private final ExtendedBlockStorage[] storage;
		private List<Integer> skipThese = null;

		public Column( final Chunk chunk, final int x, final int z, final int chunkY, final int chunkHeight )
		{
			this.x = x;
			this.z = z;
			this.c = chunk;
			this.storage = this.c.getBlockStorageArray();

			// make sure storage exists before hand...
			for( int ay = 0; ay < chunkHeight; ay++ )
			{
				final int by = ( ay + chunkY );
				ExtendedBlockStorage extendedblockstorage = this.storage[by];
				if( extendedblockstorage == null )
				{
					extendedblockstorage = this.storage[by] = new ExtendedBlockStorage( by << 4, !this.c.getWorld().provider.getHasNoSky() );
				}
			}
		}

		private void setBlockIDWithMetadata( final int y, final Object[] blk )
		{
			if( blk[0] == matrixBlockState )
			{
				blk[0] = Platform.AIR_BLOCK.getDefaultState();
			}

			final ExtendedBlockStorage extendedBlockStorage = this.storage[y >> 4];
			extendedBlockStorage.set( this.x, y & 15, this.z, (IBlockState) blk[0] );
			// extendedBlockStorage.setExtBlockID( x, y & 15, z, blk[0] );
			extendedBlockStorage.setExtBlocklightValue( this.x, y & 15, this.z, (Integer) blk[1] );
		}

		private Object[] getDetails( final int y )
		{
			final ExtendedBlockStorage extendedblockstorage = this.storage[y >> 4];
			this.ch[0] = extendedblockstorage.get( this.x, y & 15, this.z );
			this.ch[1] = extendedblockstorage.getExtBlocklightValue( this.x, y & 15, this.z );
			return this.ch;
		}

		private boolean doNotSkip( final int y )
		{
			final ExtendedBlockStorage extendedblockstorage = this.storage[y >> 4];
			if( CachedPlane.this.reg.isBlacklisted( extendedblockstorage.get( this.x, y & 15, this.z ).getBlock() ) )
			{
				return false;
			}

			return this.skipThese == null || !this.skipThese.contains( y );
		}

		private void setSkip( final int yCoord )
		{
			if( this.skipThese == null )
			{
				this.skipThese = new LinkedList<Integer>();
			}
			this.skipThese.add( yCoord );
		}
	}
}