//-----------------------------------------------------------------------
//-----------------------------------------------------------------------
//     file="CollisionTexture.cs"
//     Project: StgSharp
//     AuthorGroup: Nitload Space
//     Copyright (c) Nitload Space. All rights reserved.
//     
//     Permission is hereby granted, free of charge, to any person 
//     obtaining a copy of this software and associated documentation 
//     files (the “Software”), to deal in the Software without restriction, 
//     including without limitation the rights to use, copy, modify, merge,
//     publish, distribute, sublicense, and/or sell copies of the Software, 
//     and to permit persons to whom the Software is furnished to do so, 
//     subject to the following conditions:
//     
//     The above copyright notice and 
//     this permission notice shall be included in all copies 
//     or substantial portions of the Software.
//     
//     THE SOFTWARE IS PROVIDED “AS IS”, 
//     WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, 
//     INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
//     FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 
//     IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
//     DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 
//     ARISING FROM, OUT OF OR IN CONNECTION WITH 
//     THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//     
//-----------------------------------------------------------------------
//-----------------------------------------------------------------------
using StgSharp.Data;
using StgSharp.Geometries;
using StgSharp.Graphics;
using StgSharp.Graphics.GL;
using StgSharp.Logic;
using StgSharp.Math;

using System;
using System.Buffers;
using System.Collections.Generic;
using System.Linq;
using System.Resources;
using System.Text;
using System.Threading.Tasks;

namespace StgSharp.Stg
{
    public class CollisionTextureInput : BlueprintPipelineArgs
    {

#pragma warning disable CS8618 
        public CollisionTextureInput()
#pragma warning restore CS8618 
        {
        }

        public new List<IInstancingBuffer> Value
        {
            get; set;
        }

    }

    public class OneDimensionalCollisionTexture2D : glRenderStream
    {

        private const string inputName = "InstanceBufferList";
        private const string outputName = "CollisionTextureOutput";

        private FrameBuffer fbo;

        ShaderProgram generatingShader;

        VertexArray vao;
        VertexBuffer vbo;
        ElementBuffer ebo;

        public OneDimensionalCollisionTexture2D(RenderStreamConstructArgs args) : base(args)
        {
            throw new InvalidOperationException(
                $"Collision TextureGL unit cannot share context with other render stream or set as mainstream of a form,{($"and cannot be inited by {typeof(RenderStreamConstructArgs).Name} as well.")}"
                );
        }

#pragma warning disable CS8618 
        public OneDimensionalCollisionTexture2D(Radius angleStride, string name) :
#pragma warning restore CS8618 
            base(new RenderStreamConstructArgs
            {
                Height = 1,
                Width = (int)((new Radius(Scaler.Pi)) / angleStride),
                UnitCubeSize = (1, 1, 1),
                Name = name
            })
        {
            InternalInit();
        }

        protected override string[] InputPortsName =>
            [
            inputName,
            ];

        protected override string[] OutputPortsName =>
            [
            outputName,
            ];


        protected override void Deinit()
        {
            throw new NotImplementedException();
        }

        protected override void Init()
        {
            generatingShader = CreateShaderProgram();

            Shader vertexShader = CreateShaderSegment(ShaderType.Vertex, 1);
            Shader fragmentShader = CreateShaderSegment(ShaderType.Fragment, 1);

            vertexShader.Compile(0, InternalIO.CollisionTextureVertexShader);
            fragmentShader.Compile(0, InternalIO.CollisionTextureFragmentShader);
            vertexShader.AttachTo(0, generatingShader);
            fragmentShader.AttachTo(0, generatingShader);

            generatingShader.Link();
            generatingShader.Use();

            vbo = CreateVertexBuffer(3);
            vao = CreateVertexArray(1);
            ebo = CreateElementBuffer(1);


            fbo = CreateFrameBuffer(1);
            RenderBuffer rbo = CreateRenderBuffer(1);
            glFunc.SetRenderBufferStorage(
                RenderBufferInternalFormat.Depth24_Stencil8, this.Size);


            t = CreateTexture(1);
            t.Bind2D(0);
            glFunc.TextureImage2d(Texture2DTarget.Texture2D, 0, (int)ImageChannel.WithAlphaChannel,
                (uint)Width, (uint)Height, (int)ImageChannel.WithAlphaChannel, ImageChannelLayout.Byte, glHandle.ZeroHandle);

            t.Set2dWrapProperty(Wrap.Repeat, Wrap.Repeat);
            t.Set2dFilterProperty(Filter.Nearest, Filter.Nearest);

            glFunc.FrameBufferTexture2d(FrameBufferTarget.All, glAttachment.Color(0),
        Texture2DTarget.Texture2D, t[0], 0);

            glFunc.CombineFrameBufferRenderBuffer(fbo[0], rbo[0]);

            textureOutput = new float[this.Width];
        }

        TextureGL t;
        float[] textureOutput;

        protected override void Main(
            in Dictionary<string, BlueprintPipeline> input,
            in Dictionary<string, BlueprintPipeline> output)
        {
            if (input == null)
            {
                throw new InvalidOperationException($"Unknown operation lead to null ref of {nameof(input)}");
            }
            if (input[inputName].Args is not CollisionTextureInput inpipeline || inpipeline.Value == null || inpipeline.Value.Count == 0)
            {
                throw new InvalidOperationException();
            }
            List<IInstancingBuffer> bufferList = inpipeline.Value;
            
            fbo.Bind(0);
            glFunc.ClearColor(0, 0, 0, 1);
            glFunc.Clear(MaskBufferBit.DEPTH|MaskBufferBit.COLOR);
            generatingShader.Use();
            vao.Bind(0);

            foreach (IInstancingBuffer item in bufferList)
            {
                IGeometry g = item.TypicalShape;

                if (!(g is PlainGeometry))
                {
                    throw new InvalidOperationException("The current particle buffer contains non-planar geometry,");
                }

                ebo.Bind(0);
                ebo.SetValue<int>(0,g.VertexIndices,BufferUsage.StreamDraw);

                vbo.WriteVectorData<vec4d>(0,item.CoordAndRotationSpan,BufferUsage.StreamDraw);
                VertexArray.SetVertexAttribute(1,3,TypeCode.Single,false, 4 * sizeof(float), 0);
                VertexArray.SetVertexAttribute(2,1, TypeCode.Single,false,4*sizeof(float), 3 * sizeof(float));

                vbo.WriteScalerData<float>(2, item.ScalingSpan, BufferUsage.StreamDraw);
                VertexArray.SetVertexAttribute(3, 1, TypeCode.Single, false, sizeof(float), 0);

                vbo.WriteVectorData(1,g.VertexStream,BufferUsage.StreamDraw);
                VertexArray.SetVertexAttribute(0,3,TypeCode.Single,false,4*sizeof(float),0);

                glFunc.DrawElementsInstanced(GeometryType.TRIANGLES,(uint)g.VertexIndices.Length / 3,
                    TypeCode.UInt32,IntPtr.Zero,(uint)item.ScalingSpan.Length);
            }

            t.Bind2D(0);
            glFunc.GetTextureImage(Texture2DTarget.Texture2D,0,ImageChannel.SingleColor,ImageChannelLayout.Float,ref textureOutput);
            VertexArray.BindNull();
        }

        protected override void ProcessInput()
        {
            throw new NotImplementedException();
        }

    }
}