/*
 * This file is part of Applied Energistics 2.
 * Copyright (c) 2013 - 2014, 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.client.render.model;


import java.util.ArrayList;
import java.util.List;

import javax.vecmath.Vector3f;
import javax.vecmath.Vector4f;

import com.google.common.base.Objects;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;

import net.minecraft.block.state.IBlockState;
import net.minecraft.client.renderer.block.model.BakedQuad;
import net.minecraft.client.renderer.block.model.IBakedModel;
import net.minecraft.client.renderer.block.model.ItemCameraTransforms;
import net.minecraft.client.renderer.block.model.ItemOverrideList;
import net.minecraft.client.renderer.texture.TextureAtlasSprite;
import net.minecraft.client.renderer.vertex.VertexFormat;
import net.minecraft.client.renderer.vertex.VertexFormatElement;
import net.minecraft.util.EnumFacing;
import net.minecraft.util.math.Vec3i;
import net.minecraftforge.client.model.pipeline.IVertexConsumer;
import net.minecraftforge.client.model.pipeline.QuadGatheringTransformer;
import net.minecraftforge.client.model.pipeline.UnpackedBakedQuad;
import net.minecraftforge.common.property.IExtendedBlockState;

import appeng.block.AEBaseTileBlock;
import appeng.client.render.FacingToRotation;


public class AutoRotatingModel implements IBakedModel
{

	private final IBakedModel parent;
	private final LoadingCache<AutoRotatingCacheKey, List<BakedQuad>> quadCache;

	public AutoRotatingModel( IBakedModel parent )
	{
		this.parent = parent;
		// 6 (DUNSWE) * 6 (DUNSWE) * 7 (DUNSWE + null) = 252
		this.quadCache = CacheBuilder.newBuilder().maximumSize( 252 ).build( new CacheLoader<AutoRotatingCacheKey, List<BakedQuad>>(){
			@Override
			public List<BakedQuad> load( AutoRotatingCacheKey key ) throws Exception
			{
				return getRotatedModel( key.getBlockState(), key.getSide(), key.getForward(), key.getUp() );
			}
		} );
	}

	private List<BakedQuad> getRotatedModel( IBlockState state, EnumFacing side, EnumFacing forward, EnumFacing up )
	{
		FacingToRotation f2r = FacingToRotation.get( forward, up );
		List<BakedQuad> original = AutoRotatingModel.this.parent.getQuads( state, f2r.resultingRotate( side ), 0 );
		List<BakedQuad> rotated = new ArrayList<>( original.size() );
		for( BakedQuad quad : original )
		{
			VertexFormat format = quad.getFormat();
			UnpackedBakedQuad.Builder builder = new UnpackedBakedQuad.Builder( format );
			VertexRotator rot = new VertexRotator( f2r, quad.getFace() );
			rot.setParent( builder );
			quad.pipe( rot );
			if( quad.getFace() != null )
			{
				builder.setQuadOrientation( f2r.rotate( quad.getFace() ) );
			}
			else
			{
				builder.setQuadOrientation( null );

			}
			BakedQuad unpackedQuad = builder.build();

			// Make a copy of it to resolve the vertex data and throw away the unpacked stuff
			// This also fixes a bug in Forge's UnpackedBakedQuad, which unpacks a byte-based normal like 0,0,-1
			// to 0,0,-0.99607843. We replace these normals with the proper 0,0,-1 when rotation, which
			// causes a bug in the AO lighter, if an unpacked quad pipes this value back to it.
			// Packing it back to the vanilla vertex format will fix this inconsistency because it converts
			// the normal back to a byte-based format, which then re-applies Forge's own bug when piping it
			// to the AO lighter, thus fixing our problem.
			BakedQuad packedQuad = new BakedQuad( unpackedQuad.getVertexData(),
					quad.getTintIndex(),
					unpackedQuad.getFace(),
					quad.getSprite(),
					quad.shouldApplyDiffuseLighting(),
					quad.getFormat()
			);
			rotated.add( packedQuad );
		}
		return rotated;
	}

	@Override
	public boolean isAmbientOcclusion()
	{
		return parent.isAmbientOcclusion();
	}

	@Override
	public boolean isGui3d()
	{
		return parent.isGui3d();
	}

	@Override
	public boolean isBuiltInRenderer()
	{
		return parent.isBuiltInRenderer();
	}

	@Override
	public TextureAtlasSprite getParticleTexture()
	{
		return parent.getParticleTexture();
	}

	@Override
	public ItemCameraTransforms getItemCameraTransforms()
	{
		return parent.getItemCameraTransforms();
	}

	@Override
	public ItemOverrideList getOverrides()
	{
		return parent.getOverrides();
	}

	@Override
	public List<BakedQuad> getQuads( IBlockState state, EnumFacing side, long rand )
	{
		if( !( state instanceof IExtendedBlockState ) )
		{
			return parent.getQuads( state, side, rand );
		}

		IExtendedBlockState extState = (IExtendedBlockState) state;

		EnumFacing forward = extState.getValue( AEBaseTileBlock.FORWARD );
		EnumFacing up = extState.getValue( AEBaseTileBlock.UP );

		if( forward == null || up == null )
		{
			return parent.getQuads( state, side, rand );
		}

		// The model has other properties than just forward/up, so it would cause our cache to inadvertendly also cache
		// these
		// additional states, possibly leading to huge isseus if the other extended state properties do not implement
		// equals/hashCode correctly
		if( extState.getUnlistedProperties().size() != 2 )
		{
			return getRotatedModel( extState, side, forward, up );
		}

		AutoRotatingCacheKey key = new AutoRotatingCacheKey( extState.getClean(), forward, up, side );

		return quadCache.getUnchecked( key );
	}

	public static class VertexRotator extends QuadGatheringTransformer
	{
		private final FacingToRotation f2r;
		private final EnumFacing face;

		public VertexRotator( FacingToRotation f2r, EnumFacing face )
		{
			this.f2r = f2r;
			this.face = face;
		}

		@Override
		public void setParent( IVertexConsumer parent )
		{
			super.setParent( parent );
			if( Objects.equal( getVertexFormat(), parent.getVertexFormat() ) )
			{
				return;
			}
			setVertexFormat( parent.getVertexFormat() );
		}

		@Override
		protected void processQuad()
		{
			VertexFormat format = parent.getVertexFormat();
			int count = format.getElementCount();

			for( int v = 0; v < 4; v++ )
			{
				for( int e = 0; e < count; e++ )
				{
					VertexFormatElement element = format.getElement( e );
					if( element.getUsage() == VertexFormatElement.EnumUsage.POSITION )
					{
						parent.put( e, transform( quadData[e][v] ) );
					}
					else if( element.getUsage() == VertexFormatElement.EnumUsage.NORMAL )
					{
						parent.put( e, transformNormal( quadData[e][v] ) );
					}
					else
					{
						parent.put( e, quadData[e][v] );
					}
				}
			}
		}

		private float[] transform( float[] fs )
		{
			switch( fs.length )
			{
				case 3:
					Vector3f vec = new Vector3f( fs[0], fs[1], fs[2] );
					vec.x -= 0.5f;
					vec.y -= 0.5f;
					vec.z -= 0.5f;
					f2r.getMat().transform( vec );
					vec.x += 0.5f;
					vec.y += 0.5f;
					vec.z += 0.5f;
					return new float[] { vec.x, vec.y, vec.z
					};
				case 4:
					Vector4f vecc = new Vector4f( fs[0], fs[1], fs[2], fs[3] );
					vecc.x -= 0.5f;
					vecc.y -= 0.5f;
					vecc.z -= 0.5f;
					f2r.getMat().transform( vecc );
					vecc.x += 0.5f;
					vecc.y += 0.5f;
					vecc.z += 0.5f;
					return new float[] { vecc.x, vecc.y, vecc.z, vecc.w
					};

				default:
					return fs;
			}
		}

		private float[] transformNormal( float[] fs )
		{
			if( face == null )
			{
				switch( fs.length )
				{
					case 3:
						Vector3f vec = new Vector3f( fs );
						f2r.getMat().transform( vec );
						return new float[] {
								vec.getX(),
								vec.getY(),
								vec.getZ()
						};
					case 4:
						Vector4f vec4 = new Vector4f( fs );
						f2r.getMat().transform( vec4 );
						return new float[] {
								vec4.getX(),
								vec4.getY(),
								vec4.getZ(),
								0
						};

					default:
						return fs;
				}
			}
			else
			{
				switch( fs.length )
				{
					case 3:
						Vec3i vec = f2r.rotate( face ).getDirectionVec();
						return new float[] {
								vec.getX(),
								vec.getY(),
								vec.getZ()
						};
					case 4:
						Vector4f veccc = new Vector4f( fs[0], fs[1], fs[2], fs[3] );
						Vec3i vecc = f2r.rotate( face ).getDirectionVec();
						return new float[] {
								vecc.getX(),
								vecc.getY(),
								vecc.getZ(),
								veccc.w
						};

					default:
						return fs;
				}
			}
		}

		@Override
		public void setQuadTint( int tint )
		{
			parent.setQuadTint( tint );
		}

		@Override
		public void setQuadOrientation( EnumFacing orientation )
		{
			parent.setQuadOrientation( orientation );
		}

		@Override
		public void setApplyDiffuseLighting( boolean diffuse )
		{
			parent.setApplyDiffuseLighting( diffuse );
		}

		@Override
		public void setTexture( TextureAtlasSprite texture )
		{
			parent.setTexture( texture );
		}
	}
}