using UnityEngine.Graphing;
using System.Collections.Generic;
using System.Linq;

namespace UnityEngine.MaterialGraph
{
    [Title("UV/Tri-Planar Mapping")]
    public class UVTriPlanar : FunctionNInNOut, IGeneratesFunction, IMayRequireNormal, IMayRequireWorldPosition
    {
        private int slot0, slot1, slot2, slot3, slot4, slot5, slot6 = 0;

        private string slot0Name = "texRef";
        private string slot1Name = "tileFactor";
        private string slot2Name = "blendFactor";
        private string slot4Name = "normalRef";
        private string slot5Name = "posRef";
        private string slot6Name = "outputRef";

        protected override string GetFunctionName()
        {
            return "unity_triplanar_" + precision;
        }

        public UVTriPlanar()
        {
            name = "UVTriPlanar";

            slot0 = AddSlot("Texture", slot0Name, Graphing.SlotType.Input, SlotValueType.Sampler2D, Vector4.zero);
            slot1 = AddSlot("Tile", slot1Name, Graphing.SlotType.Input, SlotValueType.Vector1, Vector4.zero);
            slot2 = AddSlot("Blend", slot2Name, Graphing.SlotType.Input, SlotValueType.Vector1, Vector4.zero);
            slot4 = AddSlot("Normals", slot4Name, Graphing.SlotType.Input, SlotValueType.Vector3, Vector3.one);
            slot5 = AddSlot("Position", slot5Name, Graphing.SlotType.Input, SlotValueType.Vector3, Vector3.one);
            slot6 = AddSlot("RGBA ", slot6Name, Graphing.SlotType.Output, SlotValueType.Vector4, Vector4.zero);

            UpdateNodeAfterDeserialization();
        }

        public override bool hasPreview
        {
            get { return true; }
        }

        public override PreviewMode previewMode
        {
            get
            {
                return PreviewMode.Preview3D;
            }
        }



        //TODO:Externalize
        //Reference code from:http://www.chilliant.com/rgb2hsv.html
        public void GenerateNodeFunction(ShaderGenerator visitor, GenerationMode generationMode)
        {
            var outputString = new ShaderGenerator();

            // outputString.AddShaderChunk(GetFunctionPrototype("arg1", "arg2", "arg3", samplerName), false);
            outputString.AddShaderChunk(GetFunctionPrototype(), false);
            outputString.Indent();
            outputString.AddShaderChunk("{", false);
            // create UVs from position
            outputString.AddShaderChunk("float3 uvs = " + slot5Name + "*" + slot1Name + ";", false);

            // use absolute value of normal as texture weights
            outputString.AddShaderChunk("half3 blend = pow(abs(" + slot4Name + ")," + slot2Name + ");", false);

            // make sure the weights sum up to 1 (divide by sum of x+y+z)
            outputString.AddShaderChunk("blend /= dot(blend, 1.0);", false);

            // read the three texture projections, for x,y,z axes
            outputString.AddShaderChunk("float4 cx = " + "tex2D(" + slot0Name + ", uvs.yz);", false);
            outputString.AddShaderChunk("float4 cy = " + "tex2D(" + slot0Name + ", uvs.xz);", false);
            outputString.AddShaderChunk("float4 cz = " + "tex2D(" + slot0Name + ", uvs.xy);", false);

            // blend the textures based on weights
            outputString.AddShaderChunk(slot6Name + " = cx * blend.x + cy * blend.y + cz * blend.z;", false);

            outputString.Deindent();
            outputString.AddShaderChunk("}", false);
            visitor.AddShaderChunk(outputString.GetShaderString(0), true);
        }

      


        //prevent validation errors when a sampler2D input is missing
        //use on any input requiring a TextureAssetNode
        public override void ValidateNode()
        {
            base.ValidateNode();
            var slot = FindInputSlot<MaterialSlot>(0);
            if (slot == null)
                return;

            var edges = owner.GetEdges(slot.slotReference).ToList();
            hasError |= edges.Count == 0;
        }

        public bool RequiresNormal()
        {
            return true;
        }

        public bool RequiresWorldPosition()
        {
            return true;
        }
    }
}

///////////////// TEXTURE2D version below. Works fine, but the master nodes don't jive with it //////////////////////////


/*

namespace UnityEngine.MaterialGraph
{
    [Title("UV/Tri-Planar Mapping")]
    public class UVTriPlanar : FunctionNInNOut, IGeneratesFunction, IMayRequireNormal, IMayRequireWorldPosition
    {
        private int slot0, slot1, slot2, slot3, slot4, slot5, slot6 = 0;

        private string slot0Name = "texRef";
        private string slot1Name = "tileFactor";
        private string slot2Name = "blendFactor";
        private string slot3Name = "samplerRef";
        private string slot4Name = "normalRef";
        private string slot5Name = "posRef";
        private string slot6Name = "outputRef";

        protected override string GetFunctionName()
        {
            return "unity_triplanar_" + precision;
        }

        public UVTriPlanar()
        {
            name = "UVTriPlanar";

            slot0 = AddSlot("Texture", slot0Name, Graphing.SlotType.Input, SlotValueType.Texture2D, Vector4.zero);
            slot1 = AddSlot("Tile", slot1Name, Graphing.SlotType.Input, SlotValueType.Vector1, Vector4.zero);
            slot2 = AddSlot("Blend", slot2Name, Graphing.SlotType.Input, SlotValueType.Vector1, Vector4.zero);
            slot3 = AddSlot("Sampler", slot3Name, Graphing.SlotType.Input, SlotValueType.SamplerState, Vector4.zero);
            slot4 = AddSlot("Normals", slot4Name, Graphing.SlotType.Input, SlotValueType.Vector3, Vector3.one);
            slot5 = AddSlot("Position", slot5Name, Graphing.SlotType.Input, SlotValueType.Vector3, Vector3.one);
            slot6 = AddSlot("RGBA ", slot6Name, Graphing.SlotType.Output, SlotValueType.Vector4, Vector4.zero);

            UpdateNodeAfterDeserialization();
        }

		public override bool hasPreview
		{
			get { return true; }
		}

		public override PreviewMode previewMode
		{
			get
			{
				return PreviewMode.Preview3D;
			}
		}



        //TODO:Externalize
        //Reference code from:http://www.chilliant.com/rgb2hsv.html
        public void GenerateNodeFunction(ShaderGenerator visitor, GenerationMode generationMode)
        {
            var outputString = new ShaderGenerator();
            //Sampler input
            var samplerName = GetSamplerInput(3);
            outputString.AddShaderChunk("#ifdef UNITY_COMPILER_HLSL", false);

           // outputString.AddShaderChunk(GetFunctionPrototype("arg1", "arg2", "arg3", samplerName), false);
            outputString.AddShaderChunk(GetFunctionPrototype(), false);
            outputString.Indent();
            outputString.AddShaderChunk("{", false);
            // create UVs from position
            outputString.AddShaderChunk("float3 uvs = " + slot5Name + "*" + slot1Name + ";", false);

            // use absolute value of normal as texture weights
            outputString.AddShaderChunk("half3 blend = pow(abs(" + slot4Name + ")," + slot2Name + ");", false);

            // make sure the weights sum up to 1 (divide by sum of x+y+z)
            outputString.AddShaderChunk("blend /= dot(blend, 1.0);", false);

            // read the three texture projections, for x,y,z axes
            outputString.AddShaderChunk("float4 cx = " + slot0Name + ".Sample(" + slot3Name + ", uvs.yz);", false);
            outputString.AddShaderChunk("float4 cy = " + slot0Name + ".Sample(" + slot3Name + ", uvs.xz);", false);
            outputString.AddShaderChunk("float4 cz = " + slot0Name + ".Sample(" + slot3Name + ", uvs.xy);", false);


            // blend the textures based on weights
            outputString.AddShaderChunk(slot6Name + " = cx * blend.x + cy * blend.y + cz * blend.z;", false);

            //outputString.AddShaderChunk("return " + "c;", false);
            outputString.Deindent();
            outputString.AddShaderChunk("}", false);
            outputString.AddShaderChunk("#endif", true);
            visitor.AddShaderChunk(outputString.GetShaderString(0), true);
        }

        public override void GeneratePropertyUsages(ShaderGenerator visitor, GenerationMode generationMode)
        {
            
    //Sampler input slot
            
            base.GeneratePropertyUsages(visitor, generationMode);
            var samplerSlot = FindInputSlot<MaterialSlot>(slot3);

            if (samplerSlot != null)
            {
                var samplerName = GetSamplerInput(slot3);

                visitor.AddShaderChunk("#ifdef UNITY_COMPILER_HLSL", false);
                visitor.AddShaderChunk("SamplerState " + samplerName + ";", true);
                visitor.AddShaderChunk("#endif", false);
            }
        }


        //prevent validation errors when a sampler2D input is missing
        //use on any input requiring a TextureAssetNode
        public override void ValidateNode()
        {
            base.ValidateNode();
            var slot = FindInputSlot<MaterialSlot>(0);
            if (slot == null)
                return;

            var edges = owner.GetEdges(slot.slotReference).ToList();
            hasError |= edges.Count == 0;
        }

        public bool RequiresNormal()
        {
            return true;
        }

        public bool RequiresWorldPosition()
        {
            return true;
        }
    }
}
 
*/