/*
 * This file is part of CodeChickenLib.
 * Copyright (c) 2018, covers1624, All rights reserved.
 *
 * CodeChickenLib 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 2.1 of the License, or
 * (at your option) any later version.
 *
 * CodeChickenLib 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 CodeChickenLib. If not, see <http://www.gnu.org/licenses/lgpl>.
 */

package appeng.thirdparty.codechicken.lib.model;


import javax.vecmath.Vector3f;

import net.minecraft.client.renderer.block.model.BakedQuad;
import net.minecraft.client.renderer.texture.TextureAtlasSprite;
import net.minecraft.client.renderer.vertex.VertexFormat;
import net.minecraft.util.EnumFacing;
import net.minecraft.util.math.AxisAlignedBB;
import net.minecraft.util.math.MathHelper;
import net.minecraftforge.client.model.pipeline.IVertexConsumer;
import net.minecraftforge.client.model.pipeline.IVertexProducer;
import net.minecraftforge.client.model.pipeline.LightUtil;
import net.minecraftforge.client.model.pipeline.UnpackedBakedQuad;

import appeng.thirdparty.codechicken.lib.math.InterpHelper;


/**
 * A simple easy to manipulate quad format. Can be reset and then used on a different format.
 *
 * @author covers1624
 */
public class Quad implements IVertexProducer, ISmartVertexConsumer
{

	public CachedFormat format;

	public int tintIndex = -1;
	public EnumFacing orientation;
	public boolean diffuseLighting = true;
	public TextureAtlasSprite sprite;

	public Vertex[] vertices = new Vertex[4];
	public boolean full;

	// Not copied.
	private int vertexIndex = 0;
	// Cache for normal computation.
	private Vector3f v1 = new Vector3f();
	private Vector3f v2 = new Vector3f();
	private Vector3f t = new Vector3f();
	private Vector3f normal = new Vector3f();

	/**
	 * Use this if you reset the quad each time you use it.
	 */
	public Quad()
	{
	}

	/**
	 * use this if you want to initialize the quad with a format.
	 *
	 * @param format The format.
	 */
	public Quad( CachedFormat format )
	{
		this.format = format;
	}

	@Override
	public VertexFormat getVertexFormat()
	{
		return this.format.format;
	}

	@Override
	public void setQuadTint( int tint )
	{
		this.tintIndex = tint;
	}

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

	@Override
	public void setApplyDiffuseLighting( boolean diffuse )
	{
		this.diffuseLighting = diffuse;
	}

	@Override
	public void setTexture( TextureAtlasSprite texture )
	{
		this.sprite = texture;
	}

	@Override
	public void put( int element, float... data )
	{
		if( this.full )
		{
			throw new RuntimeException( "Unable to add data when full." );
		}
		Vertex v = this.vertices[this.vertexIndex];
		if( v == null )
		{
			v = new Vertex( this.format );
			this.vertices[this.vertexIndex] = v;
		}
		System.arraycopy( data, 0, v.raw[element], 0, data.length );
		if( element == ( this.format.elementCount - 1 ) )
		{
			this.vertexIndex++;
			if( this.vertexIndex == 4 )
			{
				this.vertexIndex = 0;
				this.full = true;
				if(orientation == null)
				{
				    calculateOrientation(false);
                }
			}
		}
	}

	@Override
	public void put( Quad quad )
	{
		this.copyFrom( quad );
	}

	@Override
	public void pipe( IVertexConsumer consumer )
	{
		if( consumer instanceof ISmartVertexConsumer )
		{
			( (ISmartVertexConsumer) consumer ).put( this );
		}
		else
		{
			consumer.setQuadTint( this.tintIndex );
			consumer.setQuadOrientation( this.orientation );
			consumer.setApplyDiffuseLighting( this.diffuseLighting );
			consumer.setTexture( this.sprite );
			for( Vertex v : this.vertices )
			{
				for( int e = 0; e < this.format.elementCount; e++ )
				{
					consumer.put( e, v.raw[e] );
				}
			}
		}
	}

	/**
	 * Used to reset the interpolation values inside the provided helper.
	 *
	 * @param helper The helper.
	 * @param s The axis. side >> 1;
	 *
	 * @return The same helper.
	 */
	public InterpHelper resetInterp( InterpHelper helper, int s )
	{
		helper.reset( //
				this.vertices[0].dx( s ), this.vertices[0].dy( s ), //
				this.vertices[1].dx( s ), this.vertices[1].dy( s ), //
				this.vertices[2].dx( s ), this.vertices[2].dy( s ), //
				this.vertices[3].dx( s ), this.vertices[3].dy( s ) );
		return helper;
	}

	/**
	 * Clamps the Quad inside the box.
	 *
	 * @param bb The box.
	 */
	public void clamp( AxisAlignedBB bb )
	{
		for( Vertex vertex : this.vertices )
		{
			float[] vec = vertex.vec;
			vec[0] = (float) MathHelper.clamp( vec[0], bb.minX, bb.maxX );
			vec[1] = (float) MathHelper.clamp( vec[1], bb.minY, bb.maxY );
			vec[2] = (float) MathHelper.clamp( vec[2], bb.minZ, bb.maxZ );
		}
		calculateOrientation(true);
	}

    /**
     * Re-calculates the Orientation of this quad,
     * optionally the normal vector.
     *
     * @param setNormal If the normal vector should be updated.
     */
	public void calculateOrientation( boolean setNormal )
    {
        this.v1.set( this.vertices[3].vec );
        this.t.set( this.vertices[1].vec );
        this.v1.sub( this.t );

        this.v2.set( this.vertices[2].vec );
        this.t.set( this.vertices[0].vec );
        this.v2.sub( this.t );

        this.normal.cross( this.v2, this.v1 );
        this.normal.normalize();

        if( this.format.hasNormal && setNormal)
        {
            for( Vertex vertex : this.vertices )
            {
                vertex.normal[0] = this.normal.x;
                vertex.normal[1] = this.normal.y;
                vertex.normal[2] = this.normal.z;
                vertex.normal[3] = 0;
            }
        }
        this.orientation = EnumFacing.getFacingFromVector( this.normal.x, this.normal.y, this.normal.z );
    }

	/**
	 * Used to create a new quad complete copy of this one.
	 *
	 * @return The new quad.
	 */
	public Quad copy()
	{
		if( !this.full )
		{
			throw new RuntimeException( "Only copying full quads is supported." );
		}
		Quad quad = new Quad( this.format );
		quad.tintIndex = this.tintIndex;
		quad.orientation = this.orientation;
		quad.diffuseLighting = this.diffuseLighting;
		quad.sprite = this.sprite;
		quad.full = true;
		for( int i = 0; i < 4; i++ )
		{
			quad.vertices[i] = this.vertices[i].copy();
		}
		return quad;
	}

	/**
	 * Copies the data inside the given quad to this one. This ignores VertexFormat, please make sure your quads are in
	 * the same format.
	 *
	 * @param quad The Quad to copy from.
	 *
	 * @return This quad.
	 */
	public Quad copyFrom( Quad quad )
	{
		this.tintIndex = quad.tintIndex;
		this.orientation = quad.orientation;
		this.diffuseLighting = quad.diffuseLighting;
		this.sprite = quad.sprite;
		this.full = quad.full;
		for( int v = 0; v < 4; v++ )
		{
			for( int e = 0; e < this.format.elementCount; e++ )
			{
				System.arraycopy( quad.vertices[v].raw[e], 0, this.vertices[v].raw[e], 0, 4 );
			}
		}
		return this;
	}

	/**
	 * Reset the quad to the new format.
	 *
	 * @param format The new format.
	 */
	public void reset( CachedFormat format )
	{
		this.format = format;
		this.tintIndex = -1;
		this.orientation = null;
		this.diffuseLighting = true;
		this.sprite = null;
		for( int i = 0; i < this.vertices.length; i++ )
		{
			Vertex v = this.vertices[i];
			if( v == null )
			{
				this.vertices[i] = v = new Vertex( format );
			}
			v.reset( format );
		}
		this.vertexIndex = 0;
		this.full = false;
	}

	/**
	 * Bakes this Quad to a BakedQuad.
	 *
	 * @return The BakedQuad.
	 */
	public BakedQuad bake()
	{
		int[] packedData = new int[this.format.format.getNextOffset()];
		for( int v = 0; v < 4; v++ )
		{
			for( int e = 0; e < this.format.elementCount; e++ )
			{
				LightUtil.pack( this.vertices[v].raw[e], packedData, this.format.format, v, e );
			}
		}
		return new BakedQuad( packedData, this.tintIndex, this.orientation, this.sprite, this.diffuseLighting, this.format.format );
	}

	/**
	 * Bakes this quad to an UnpackedBakedQuad.
	 *
	 * @return The UnpackedBakedQuad.
	 */
	public UnpackedBakedQuad bakeUnpacked()
	{
		UnpackedBakedQuad.Builder quad = new UnpackedBakedQuad.Builder( this.format.format );
		this.pipe( quad );
		return quad.build();
	}

	/**
	 * A simple vertex format.
	 */
	public static class Vertex
	{

		public CachedFormat format;

		/**
		 * The raw data.
		 */
		public float[][] raw;

		// References to the arrays inside raw.
		public float[] vec;
		public float[] normal;
		public float[] color;
		public float[] uv;
		public float[] lightmap;

		/**
		 * Create a new Vertex.
		 *
		 * @param format The format for the vertex.
		 */
		public Vertex( CachedFormat format )
		{
			this.format = format;
			this.raw = new float[format.elementCount][4];
			this.preProcess();
		}

		/**
		 * Creates a new Vertex using the data inside the other. A copy!
		 *
		 * @param other The other.
		 */
		public Vertex( Vertex other )
		{
			this.format = other.format;
			this.raw = other.raw.clone();
			for( int v = 0; v < this.format.elementCount; v++ )
			{
				this.raw[v] = other.raw[v].clone();
			}
			this.preProcess();
		}

		/**
		 * Pulls references to the individual element's arrays inside raw. Modifying the individual element arrays will
		 * update raw.
		 */
		public void preProcess()
		{
			if( this.format.hasPosition )
			{
				this.vec = this.raw[this.format.positionIndex];
			}
			if( this.format.hasNormal )
			{
				this.normal = this.raw[this.format.normalIndex];
			}
			if( this.format.hasColor )
			{
				this.color = this.raw[this.format.colorIndex];
			}
			if( this.format.hasUV )
			{
				this.uv = this.raw[this.format.uvIndex];
			}
			if( this.format.hasLightMap )
			{
				this.lightmap = this.raw[this.format.lightMapIndex];
			}
		}

		/**
		 * Gets the 2d X coord for the given axis.
		 *
		 * @param s The axis. side >> 1
		 *
		 * @return The x coord.
		 */
		public float dx( int s )
		{
			if( s <= 1 )
			{
				return this.vec[0];
			}
			else
			{
				return this.vec[2];
			}
		}

		/**
		 * Gets the 2d Y coord for the given axis.
		 *
		 * @param s The axis. side >> 1
		 *
		 * @return The y coord.
		 */
		public float dy( int s )
		{
			if( s > 0 )
			{
				return this.vec[1];
			}
			else
			{
				return this.vec[2];
			}
		}

		/**
		 * Interpolates the new color values for this Vertex using the others as a reference.
		 *
		 * @param interpHelper The InterpHelper to use.
		 * @param others The other Vertices to use as a template.
		 *
		 * @return The same Vertex.
		 */
		public Vertex interpColorFrom( InterpHelper interpHelper, Vertex[] others )
		{
			for( int e = 0; e < 4; e++ )
			{
				float p1 = others[0].color[e];
				float p2 = others[1].color[e];
				float p3 = others[2].color[e];
				float p4 = others[3].color[e];
				// Only interpolate if colors are different.
				if( p1 != p2 || p2 != p3 || p3 != p4 )
				{
					this.color[e] = interpHelper.interpolate( p1, p2, p3, p4 );
				}
			}
			return this;
		}

		/**
		 * Interpolates the new UV values for this Vertex using the others as a reference.
		 *
		 * @param interpHelper The InterpHelper to use.
		 * @param others The other Vertices to use as a template.
		 *
		 * @return The same Vertex.
		 */
		public Vertex interpUVFrom( InterpHelper interpHelper, Vertex[] others )
		{
			for( int e = 0; e < 2; e++ )
			{
				float p1 = others[0].uv[e];
				float p2 = others[1].uv[e];
				float p3 = others[2].uv[e];
				float p4 = others[3].uv[e];
				if( p1 != p2 || p2 != p3 || p3 != p4 )
				{
					this.uv[e] = interpHelper.interpolate( p1, p2, p3, p4 );
				}
			}
			return this;
		}

		/**
		 * Interpolates the new LightMap values for this Vertex using the others as a reference.
		 *
		 * @param interpHelper The InterpHelper to use.
		 * @param others The other Vertices to use as a template.
		 *
		 * @return The same Vertex.
		 */
		public Vertex interpLightMapFrom( InterpHelper interpHelper, Vertex[] others )
		{
			for( int e = 0; e < 2; e++ )
			{
				float p1 = others[0].lightmap[e];
				float p2 = others[1].lightmap[e];
				float p3 = others[2].lightmap[e];
				float p4 = others[3].lightmap[e];
				if( p1 != p2 || p2 != p3 || p3 != p4 )
				{
					this.lightmap[e] = interpHelper.interpolate( p1, p2, p3, p4 );
				}
			}
			return this;
		}

		/**
		 * Copies this Vertex to a new one.
		 *
		 * @return The new Vertex.
		 */
		public Vertex copy()
		{
			return new Vertex( this );
		}

		/**
		 * Resets the Vertex to a new format. Expands the raw array if needed.
		 *
		 * @param format The format to reset to.
		 */
		public void reset( CachedFormat format )
		{
			// If the format is different and our raw array is smaller, then expand it.
			if( !this.format.equals( format ) && format.elementCount > this.raw.length )
			{
				this.raw = new float[format.elementCount][4];
			}
			this.format = format;

			this.vec = null;
			this.normal = null;
			this.color = null;
			this.uv = null;
			this.lightmap = null;

			// for (float[] f : raw) {
			// Arrays.fill(f, 0F);
			// }

			this.preProcess();
		}
	}
}