using StgSharp;
using StgSharp.Geometries;
using StgSharp.Graphics;
using StgSharp.Math;

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

namespace StgSharpDebug
{

    public sealed class MainRenderStream : glRenderStream
    {
        private Uniform<float, float, float, float> color;
        private ElementBuffer ebo;
        private Uniform<int> ourTexture;
        private Uniform<int> ourTexture2;
        private ShaderProgram shader;
        private Texture texture;
        private VertexArray vao;
        private VertexBuffer vbo;

        protected MainRenderStream(RenderStreamConstructArgs args) : base(args)
        {

        }

        protected override void Deinit()
        {
            /**/
            vao.Dispose();
            vbo.Dispose();
            ebo.Dispose();
            /**/
        }

        protected override void Init()
        {
            SetSizeLimit(800, 800, 800, 800);


            FrameSizeCallback =
                (IntPtr id, uint width, uint height) =>
                {
                    GL.Viewport(0, 0, width, height);
                };

            shader = CreateShaderProgram();
            var vertex = CreateShaderSegment(ShaderType.Vertex, 1);
            var fragment = CreateShaderSegment(ShaderType.Fragment, 1);
            vertex.Compile(0, File.ReadAllText("Shader\\vertex.vert"));
            vertex.AttachTo(0, shader);
            fragment.Compile(0, File.ReadAllText("Shader\\fragment.frag"));
            fragment.AttachTo(0, shader);
            shader.Link();
            Triangle tri = new Triangle(
                -0.5f, -0.3f, 0.0f,
                0.5f, -0.5f, 0.0f,
                0.0f, 0.5f, 0.0f
                );
            Rectangle rec = new Rectangle(
                -0.3f, 0.3f, 130.0f,
                0.3f, 0.3f, 130.0f,
                0.3f, -0.3f, 130.0f,
                -0.3f, -0.3f, 130.0f
                );
            Polygon5 polygon = new Polygon5(
                -0.4f, 0.5f, 0.0f,
                0.5f, 0.5f, 0.0f,
                0.6f, -0.5f, 0.0f,
                0, -1, 0,
                -0.7f, -0.5f, 0.0f
                );
            vao = CreateVertexArray(1);
            vbo = CreateVertexBuffer(2);
            ebo = CreateElementBuffer(1);
            texture = CreateTexture(2);
            float[] texCoord = {
                    0.0f, 0.0f,
                    1.0f, 0.0f,
                    1.0f, 1.0f,
                    0.0f, 1.0f };
            GL.BindVertexArray(vao[0]);
            ebo.SetValue(0, rec.Indices, BufferUsage.STATIC_DRAW);
            vbo.SetValue(0, rec.VertexBuffer, BufferUsage.STATIC_DRAW);
            GL.SetVertexAttribute(0, 3, TypeCode.Single, false, 4 * sizeof(float), 0);
            vbo.SetValueArray(1, texCoord, BufferUsage.STATIC_DRAW);
            GL.SetVertexAttribute(2, 2, TypeCode.Single, false, 2 * sizeof(float), 0);
            /**/
            GL.BindBuffer(BufferType.ARRAY_BUFFER, glHandle.Zero);
            vao.BindNull();
            /**/
            texture.Bind2D(0);
            texture.Set2dWrapProperty(Wrap.Repeat, Wrap.Repeat);
            texture.Set2dFilterProperty(Filter.Nearest, Filter.Nearest);
            texture.LoadTexture(0, "Shader\\Image1.png", null);

            texture.Bind2D(1);
            texture.Set2dWrapProperty(Wrap.Repeat, Wrap.Repeat);
            texture.Set2dFilterProperty(Filter.Nearest, Filter.Nearest);
            texture.LoadTexture(1, "Shader\\awesomeface.png", null);

            shader.Use();
            /**/
            color = shader.GetUniform<float, float, float, float>("color");
            ourTexture = shader.GetUniform<int>("ourTexture");
            GL.SetValue(ourTexture, 0);
            ourTexture2 = shader.GetUniform<int>("ourTexture2");
            GL.SetValue(ourTexture2, 1);
            /**/

            NativeCameraViewTarget(
                new vec3d(0, 0, 200),
                new vec3d(0, 0, 100),
                new vec3d(0, 1, 0)
                );
            NativeCameraViewRange(new Degree(5),(0, 0), (50f, 50f));
            NativeCameraUniform(shader, "NativeCamera");
            
        }

        protected override void Main()
        {
            GL.ClearColor(0.333f, 0.555f, 0.555f, 1.0f);

            GL.Clear(MaskBufferBit.COLOR | MaskBufferBit.DEPTH);

            /**/
            vao.Bind(0);
            shader.Use();
            /**/
            /**/
            texture.Activate(TextureUnit.Unit0);
            texture.Bind2D(0);
            texture.Activate(TextureUnit.Unit1);
            texture.Bind2D(1);
            /**/

            /**/
            float time = /* CurrentFrameCount / /**/ 60.0f;

            

            GL.SetValue(color,
                0.5f + MathF.Cos(time),
                0.5f + MathF.Sin(time * 0.66667f + (2 * Scaler.Pi / 3)),
                0.5f + MathF.Sin(time * 0.33333f + (Scaler.Pi / 3)),
                time
                );

            NativeCamera.SetAllUniforms();
            /**/

            GL.DrawElements(GepmetryType.TRIANGLES, 6, TypeCode.UInt32, IntPtr.Zero);

            //vao.BindNull();
            /**/
        }

        protected override void ProcessInput()
        {
            float movement = 0.005f;
            if (InternalIO.glfwGetKey(CanvasHandle, (int)KeyboardKey.ESCAPE)
                == KeyStatus.PRESS)
            {
                InternalIO.glfwSetWindowShouldClose(CanvasHandle, 1);
            }
            if (InternalIO.glfwGetKey(this.CanvasHandle, GLconst.GLFW_KEY_UP) == KeyStatus.PRESS)
            {
                NativeCamera.Pitch(new Radius(movement));
            }
            else if (InternalIO.glfwGetKey(this.CanvasHandle, GLconst.GLFW_KEY_DOWN) == KeyStatus.PRESS)
            {
                NativeCamera.Pitch(new Radius(-movement));
            }
            if (InternalIO.glfwGetKey(CanvasHandle, GLconst.GLFW_KEY_LEFT) == KeyStatus.PRESS)
            {
                NativeCamera.Yaw(new Radius(-movement));
            }
            else if (InternalIO.glfwGetKey(CanvasHandle, GLconst.GLFW_KEY_RIGHT) == KeyStatus.PRESS)
            {
                NativeCamera.Yaw(new Radius(movement));
            }
        }
    }
}