/**
 * @author sunag / http://www.sunag.com.br/
 */

import { TempNode } from '../core/TempNode.js';
import { FloatNode } from '../inputs/FloatNode.js';
import { ExpressionNode } from '../core/ExpressionNode.js';
import { TextureCubeUVNode } from './TextureCubeUVNode.js';
import { ReflectNode } from '../accessors/ReflectNode.js';
import { NormalNode } from '../accessors/NormalNode.js';
import { ColorSpaceNode } from '../utils/ColorSpaceNode.js';
import { BlinnExponentToRoughnessNode } from '../bsdfs/BlinnExponentToRoughnessNode.js';

function TextureCubeNode( value, textureSize ) {

	TempNode.call( this, 'v4' );

	this.value = value;
	this.textureSize = textureSize || new FloatNode( 1024 );

	this.radianceCache = { uv: new TextureCubeUVNode( 
		new ReflectNode( ReflectNode.VECTOR ), 
		this.textureSize, 
		new BlinnExponentToRoughnessNode() 
	) };

	this.irradianceCache = { uv: new TextureCubeUVNode( 
		new NormalNode( NormalNode.WORLD ), 
		this.textureSize, 
		new FloatNode( 1 ).setReadonly( true ) 
	) };

}

TextureCubeNode.prototype = Object.create( TempNode.prototype );
TextureCubeNode.prototype.constructor = TextureCubeNode;
TextureCubeNode.prototype.nodeType = "TextureCube";

TextureCubeNode.prototype.generateTextureCubeUV = function ( builder, cache ) {

	var uv_10 = cache.uv.build( builder ) + '.uv_10',
		uv_20 = cache.uv.build( builder ) + '.uv_20',
		t = cache.uv.build( builder ) + '.t';

	var color10 = 'texture2D( ' + this.value.build( builder, 'sampler2D' ) + ', ' + uv_10 + ' )',
		color20 = 'texture2D( ' + this.value.build( builder, 'sampler2D' ) + ', ' + uv_20 + ' )';

	// add a custom context for fix incompatibility with the core
	// include ColorSpace function only for vertex shader (in fragment shader color space functions is added automatically by core)
	// this should be removed in the future
	// context.include =: is used to include or not functions if used FunctionNode
	// context.ignoreCache =: not create temp variables nodeT0..9 to optimize the code
	var context = { include: builder.isShader( 'vertex' ), ignoreCache: true };
	var outputType = this.getType( builder );

	builder.addContext( context );

	cache.colorSpace10 = cache.colorSpace10 || new ColorSpaceNode( new ExpressionNode('', outputType ) );
	cache.colorSpace10.fromDecoding( builder.getTextureEncodingFromMap( this.value.value ) );
	cache.colorSpace10.input.parse( color10 );

	color10 = cache.colorSpace10.build( builder, outputType );

	cache.colorSpace20 = cache.colorSpace20 || new ColorSpaceNode( new ExpressionNode('', outputType ) );
	cache.colorSpace20.fromDecoding( builder.getTextureEncodingFromMap( this.value.value ) );
	cache.colorSpace20.input.parse( color20 );

	color20 = cache.colorSpace20.build( builder, outputType );

	// end custom context

	builder.removeContext();

	return 'mix( ' + color10 + ', ' + color20 + ', ' + t + ' ).rgb';

};

TextureCubeNode.prototype.generate = function ( builder, output ) {

	if ( builder.isShader( 'fragment' ) ) {

		var radiance = this.generateTextureCubeUV( builder, this.radianceCache );
		var irradiance = this.generateTextureCubeUV( builder, this.irradianceCache );

		builder.context.extra.irradiance = irradiance;

		return builder.format( 'vec4( ' + radiance + ', 1.0 )', this.getType( builder ), output );

	} else {

		console.warn( "THREE.TextureCubeNode is not compatible with " + builder.shader + " shader." );

		return builder.format( 'vec4( 0.0 )', this.getType( builder ), output );

	}

};

TextureCubeNode.prototype.toJSON = function ( meta ) {

	var data = this.getJSONNode( meta );

	if ( ! data ) {

		data = this.createJSONNode( meta );

		data.value = this.value.toJSON( meta ).uuid;

	}

	return data;

};

export { TextureCubeNode };
