using System;
using System.Drawing;
using System.Collections.Generic;
using System.Linq;
using OpenTK;
using OpenTK.Graphics.OpenGL;
using System.Windows.Forms;
using System.Drawing.Imaging;
using OpenTK.Mathematics;
using OpenTK.GLControl;
using System.Drawing.Text;
using System.Security.Policy;

namespace Yw.WinFrmUI.Test.Core
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            this.glControl1.Load += GlControl1_Load;
            this.glControl1.Paint += GlControl1_Paint;
            this.glControl1.Resize += GlControl1_Resize;
            this.glControl1.MouseDown += GlControl1_MouseDown;
            this.glControl1.MouseUp += GlControl1_MouseUp;
            this.glControl1.MouseWheel += GlControl1_MouseWheel;
            this.glControl1.MouseMove += GlControl1_MouseMove;
        }

        private void GlControl1_MouseMove(object sender, MouseEventArgs e)
        {
            HandleMouseMove(e);
        }

        private void GlControl1_MouseWheel(object sender, MouseEventArgs e)
        {
            HandleMouseWheel(e);
        }

        private void GlControl1_MouseUp(object sender, MouseEventArgs e)
        {
            HandleMouseUp(e);
        }

        private void GlControl1_MouseDown(object sender, MouseEventArgs e)
        {
            HandleMouseDown(e);
        }

        private void GlControl1_Resize(object sender, EventArgs e)
        {
            OnResize();
        }

        private void GlControl1_Paint(object sender, PaintEventArgs e)
        {
            OnRender();
        }

        private void GlControl1_Load(object sender, EventArgs e)
        {
            InitialGLState();
        }



        #region 字段声明

        private const float _size = 100f;
        private Matrix4 _modelMatrix = Matrix4.Identity;
        private Matrix4 _viewMatrix = Matrix4.Identity;
        private Matrix4 _projMatrix = Matrix4.Identity;
        private float _rotationX, _rotationY;
        private float _translationX, _translationY;
        private float _zoom = 1f;
        private bool _isDragging, _isRotating;
        private Point _lastMousePos;
        private float _radius = 100f;
        private float _pw, _ph;
        private Vector3 _mc = new Vector3(0f);
        private Vector3 _eye, _target, _up;
        private readonly int[] _textures = new int[6];
        private float _screenWidth, _screenHeight;
        public float Zoom
        {
            get => _zoom;
            set => _zoom = MathHelper.Clamp(value, 0.01f, 100.0f); // 限制缩放范围
        }


        #endregion

        #region OpenGL初始化

        //初始化GL状态
        private void InitialGLState()
        {
            GL.ClearColor(Color.Transparent);
            GL.Enable(EnableCap.DepthTest);
            GL.Enable(EnableCap.Texture2D);
            GL.Enable(EnableCap.Blend);
            GL.BlendFunc(BlendingFactor.SrcAlpha, BlendingFactor.OneMinusSrcAlpha);

            // 生成六个面的文字纹理
            _textures[0] = CreateTextTexture("前", 128, Color.White, Color.Red);
            _textures[1] = CreateTextTexture("后", 128, Color.White, Color.Green);
            _textures[2] = CreateTextTexture("左", 128, Color.White, Color.Blue);
            _textures[3] = CreateTextTexture("右", 128, Color.White, Color.Yellow);
            _textures[4] = CreateTextTexture("上", 128, Color.White, Color.Magenta);
            _textures[5] = CreateTextTexture("下", 128, Color.White, Color.Cyan);
        }


        #endregion

        #region 矩阵更新

        private void UpdateMatrices()
        {
            if (!this.glControl1.IsHandleCreated)
            {
                return;
            }
            UpdateViewport();
            UpdateProjection();
            UpdateView();
            UpdateModel();
        }

        //更新视口
        private void UpdateViewport()
        {
            if (!this.glControl1.IsHandleCreated)
            {
                return;
            }
            _screenWidth = this.glControl1.Width;
            _screenHeight = this.glControl1.Height;
            GL.Viewport(0, 0, this.glControl1.Width, this.glControl1.Height);
        }

        private void UpdateProjection()
        {
            if (!this.glControl1.IsHandleCreated)
            {
                return;
            }

            // 获取窗口尺寸
            int screenWidth = ClientSize.Width;
            int screenHeight = ClientSize.Height;

            // 设置中心对齐的正交投影
            Matrix4 projection = Matrix4.CreateOrthographicOffCenter(
                left: -screenWidth / 2f,
                right: screenWidth / 2f,
                bottom: -screenHeight / 2f,
                top: screenHeight / 2f,
                depthNear: -1,
                depthFar: 1
            );

            _projMatrix = projection;
            //var aspect = this.glControl1.AspectRatio;
            //var size = _radius * 2;
            //_pw = size;
            //_ph = size;

            //if (aspect > 1)
            //{
            //    _pw *= aspect;
            //}
            //else
            //{
            //    _ph /= aspect;
            //}
            //_projMatrix = Matrix4.CreateOrthographic(_pw * this.Zoom, _ph * this.Zoom, _radius, _radius * 3);
        }


        private void UpdateView()
        {
            _eye = new Vector3(_mc.X, _mc.Y, _mc.Z + 2 * _radius);
            _target = _mc;
            _up = Vector3.UnitY;
            //var rotation = Quaternion.Identity;
            //var rotationX = Quaternion.FromAxisAngle(Vector3.UnitX, _rotationX);
            //var rotationY = Quaternion.FromAxisAngle(Vector3.UnitY, _rotationY);
            // rotation = rotationY * rotationX * rotation;
            //rotation.Normalize();
            // var matrix = Matrix4.CreateFromQuaternion(rotation);
            // matrix.Invert();
            // eye = Vector3.TransformPosition(eye, matrix);
            // up = Vector3.TransformPosition(up, matrix);
            _viewMatrix = Matrix4.LookAt(_eye, _target, _up);
        }

        private void UpdateModel()
        {
            _modelMatrix = Matrix4.CreateTranslation(new Vector3(_pw / 2f * this.Zoom, _ph / 2f * this.Zoom, 0)) *
                Matrix4.CreateFromAxisAngle(Vector3.UnitX, _rotationX) *
                Matrix4.CreateFromAxisAngle(Vector3.UnitY, _rotationY) *
                Matrix4.CreateTranslation(-new Vector3(_pw / 2f * this.Zoom, _ph / 2f * this.Zoom, 0)) *
                Matrix4.CreateTranslation(_translationX * this.Zoom, _translationY * this.Zoom, 0f);
        }

        #endregion

        #region 渲染逻辑

        private void OnRender()
        {
            if (!this.glControl1.IsHandleCreated)
            {
                return;
            }
            GL.Clear(ClearBufferMask.ColorBufferBit);

            GL.MatrixMode(MatrixMode.Modelview);
            GL.LoadIdentity();

            DrawReferenceLines();
            DrawRotatingObject();

            //SwapBuffers();


            //this.glControl1.MakeCurrent();
            //GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
            //// 设置矩阵
            //GL.MatrixMode(MatrixMode.Projection);
            //GL.LoadMatrix(ref _projMatrix);

            //GL.MatrixMode(MatrixMode.Modelview);
            //Matrix4 modelView = _viewMatrix * _modelMatrix;
            //GL.LoadMatrix(ref modelView);

            //// 绘制立方体
            ////DrawCube();

            //// 绘制立方体
            //DrawTexturedCube();

            //var error = GL.GetError();

            //// 绘制标签
            ////DrawLabels();

            //this.glControl1.SwapBuffers();
        }

        float rotationAngle = 45; // 测试角度

        void DrawRotatingObject()
        {
            GL.PushMatrix();

            // 关键变换顺序
            GL.Translate(100, 50, 0);    // 将物体移动到屏幕坐标系中的(100,50)
            GL.Rotate(rotationAngle, Vector3.UnitZ); // 绕当前原点（屏幕中心）旋转

            // 绘制以原点为中心的物体
            GL.Color3(Color.Red);
            GL.Begin(PrimitiveType.Quads);
            GL.Vertex2(-25, -25);
            GL.Vertex2(25, -25);
            GL.Vertex2(25, 25);
            GL.Vertex2(-25, 25);
            GL.End();

            GL.PopMatrix();
        }

        void DrawReferenceLines()
        {
            //// 绘制屏幕中心十字
            //GL.Color3(Color.White);
            //GL.LineWidth(2);
            //GL.Begin(PrimitiveType.Lines);
            //// 水平线
            //GL.Vertex2(-1000, 0); GL.Vertex2(1000, 0);
            //// 垂直线
            //GL.Vertex2(0, -1000); GL.Vertex2(0, 1000);
            //GL.End();

            //// 绘制屏幕边框
            //GL.Color3(Color.Gray);
            //GL.Begin(PrimitiveType.LineLoop);
            //GL.Vertex2(-screenWidth / 2, -screenHeight / 2);
            //GL.Vertex2(screenWidth / 2, -screenHeight / 2);
            //GL.Vertex2(screenWidth / 2, screenHeight / 2);
            //GL.Vertex2(-screenWidth / 2, screenHeight / 2);
            //GL.End();
        }

        //改变
        private void OnResize()
        {
            if (!this.glControl1.IsHandleCreated)
            {
                return;
            }

            this.glControl1.MakeCurrent();

            // 防止OpenGL错误
            if (this.glControl1.Width == 0)
            {
                this.glControl1.Width = 1;
            }
            if (this.glControl1.Height == 0)
            {
                this.glControl1.Height = 1;
            }

            // 更新所有矩阵
            UpdateMatrices();

            // 请求重绘
            this.glControl1.Invalidate();
        }


        private void DrawCube()
        {
            GL.Begin(PrimitiveType.Quads);

            // 前面（Z+）
            //GL.Color3(Color.Purple);
            GL.Color4((float)Color.Purple.R, (float)Color.Purple.G, (float)Color.Purple.B, 1f);
            GL.Vertex3(-50f, -50f, 50f);
            GL.Vertex3(50f, -50f, 50f);
            GL.Vertex3(50f, 50f, 50f);
            //GL.Vertex3(50f, 50f, 50f);
            GL.Vertex3(-50f, 50f, 50f);
            // GL.Vertex3(-50f, -50f, 50f);



            // 后面（Z-）
            //GL.Color3(Color.Cyan);
            GL.Color4((float)Color.Cyan.R, (float)Color.Cyan.G, (float)Color.Cyan.B, 1f);
            GL.Vertex3(-50f, -50f, -50f);
            GL.Vertex3(-50f, 50f, -50f);
            GL.Vertex3(50f, 50f, -50f);
            //GL.Vertex3(50f, 50f, -50f);
            GL.Vertex3(50f, -50f, -50f);
            //GL.Vertex3(-50f, -50f, -50f);



            // 顶面（Y+）
            //GL.Color3(Color.Lime);
            GL.Color4((float)Color.Lime.R, (float)Color.Lime.G, (float)Color.Lime.B, 1f);
            GL.Vertex3(-50f, 50f, -50f);
            GL.Vertex3(50f, 50f, -50f);
            GL.Vertex3(50f, 50f, 50f);
            //GL.Vertex3(50f, 50f, 50f);
            GL.Vertex3(-50f, 50f, 50f);
            //GL.Vertex3(-50f, 50f, -50f);
            DrawTextOnFace("上", new Vector3(0, 50f, 0), new Vector3(0, 0, 100f));



            // 底面（Y-）
            //GL.Color3(Color.Yellow);
            GL.Color4((float)Color.Yellow.R, (float)Color.Yellow.G, (float)Color.Yellow.B, 1f);
            GL.Vertex3(-50f, -50f, -50f);
            GL.Vertex3(50f, -50f, -50f);
            GL.Vertex3(50f, -50f, 50f);
            //GL.Vertex3(50f, -50f, 50f);
            GL.Vertex3(-50f, -50f, 50f);
            //GL.Vertex3(-50f, -50f, -50f);


            // 右面（X+）
            //GL.Color3(Color.Red);
            GL.Color4((float)Color.Red.R, (float)Color.Red.G, (float)Color.Red.B, 1f);
            GL.Vertex3(50f, -50f, -50f);
            GL.Vertex3(50f, 50f, -50f);
            GL.Vertex3(50f, 50f, 50f);
            // GL.Vertex3(50f, 50f, 50f);
            GL.Vertex3(50f, -50f, 50f);
            //GL.Vertex3(50f, -50f, -50f);


            // 左面（X-）
            GL.Color4((float)Color.Blue.R, (float)Color.Blue.G, (float)Color.Blue.B, 1f);
            //GL.Color3(Color.Blue);
            GL.Vertex3(-50f, -50f, -50f);
            GL.Vertex3(-50f, 50f, -50f);
            GL.Vertex3(-50f, 50f, 50f);
            //GL.Vertex3(-50f, 50f, 50f);
            GL.Vertex3(-50f, -50f, 50f);
            //GL.Vertex3(-50f, -50f, -50f);
            GL.End();

            GL.End();
        }

        private void DrawFace(Vector3 v1, Vector3 v2, Vector3 v3, Vector3 v4, Color4 color, string text)
        {
            GL.Begin(PrimitiveType.Quads);
            GL.Color4(color);
            GL.Vertex3(v1);
            GL.Vertex3(v2);
            GL.Vertex3(v3);
            GL.Vertex3(v4);
            GL.End();
            Vector3 center = (v1 + v2 + v3 + v4) / 4;
            Vector3 normal = Vector3.Cross(v2 - v1, v3 - v1);
            DrawTextOnFace(text, center, normal);
        }


        private void DrawTextOnFace(string text, Vector3 position, Vector3 normal)
        {
            //GL.PushMatrix();
            //GL.Translate(position);

            //Vector3 up = Vector3.UnitY;
            //Vector3 right = Vector3.Cross(normal, up);
            // up = Vector3.Cross(right, normal);

            // Matrix4 rotation = new Matrix4(
            //    new Vector4(right, 0),
            //    new Vector4(up, 0),
            //    new Vector4(-normal, 0),
            //    new Vector4(0, 0, 0, 1));

            //GL.MultMatrix(ref rotation);

            using (Bitmap bmp = new Bitmap(100, 100))
            using (Graphics g = Graphics.FromImage(bmp))
            {
                g.TextRenderingHint = TextRenderingHint.AntiAlias;
                Font font = new Font("Arial", 12);
                SizeF textSize = g.MeasureString(text, font);

                float xOffset = (bmp.Width - textSize.Width) / 2;
                float yOffset = (bmp.Height - textSize.Height) / 2;

                g.DrawString(text, font, Brushes.Black, new PointF(xOffset, yOffset));

                int textureId = GL.GenTexture();
                GL.BindTexture(TextureTarget.Texture2D, textureId);

                BitmapData data = bmp.LockBits(new Rectangle(0, 0, bmp.Width, bmp.Height),
                    ImageLockMode.ReadOnly, System.Drawing.Imaging.PixelFormat.Format32bppArgb);

                GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.Rgba, data.Width, data.Height,
                    0, OpenTK.Graphics.OpenGL.PixelFormat.Bgra, PixelType.UnsignedByte, data.Scan0);

                bmp.UnlockBits(data);

                GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMinFilter, (int)TextureMinFilter.Linear);
                GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMagFilter, (int)TextureMagFilter.Linear);

                GL.Enable(EnableCap.Texture2D);
                GL.Begin(PrimitiveType.Quads);
                GL.TexCoord2(0, 0); GL.Vertex3(-10, -10, 0);
                GL.TexCoord2(100, 0); GL.Vertex3(10, -10, 0);
                GL.TexCoord2(100, 100); GL.Vertex3(10, 10, 0);
                GL.TexCoord2(0, 100); GL.Vertex3(-10, 10, 0);
                GL.End();
                GL.Disable(EnableCap.Texture2D);

                GL.DeleteTexture(textureId);
            }

            // GL.PopMatrix();
        }


        private int CreateTextTexture(string text, int size, Color textColor, Color bgColor)
        {
            // 创建位图并绘制文字
            using (var bmp = new Bitmap(size, size))
            using (var gfx = Graphics.FromImage(bmp))
            {

                gfx.Clear(bgColor);
                var font = new Font("宋体", 32, FontStyle.Bold);
                var format = new StringFormat
                {
                    Alignment = StringAlignment.Center,
                    LineAlignment = StringAlignment.Center
                };

                gfx.DrawString(text, font, new SolidBrush(textColor),
                    new RectangleF(0, 0, size, size), format);
                bmp.RotateFlip(RotateFlipType.RotateNoneFlipY);

                // 转换位图为OpenGL纹理
                var data = bmp.LockBits(
                    new Rectangle(0, 0, bmp.Width, bmp.Height),
                    ImageLockMode.ReadOnly,
                    System.Drawing.Imaging.PixelFormat.Format32bppArgb);

                int texId = GL.GenTexture();
                GL.BindTexture(TextureTarget.Texture2D, texId);
                GL.TexImage2D(TextureTarget.Texture2D, 0,
                    PixelInternalFormat.Rgba,
                    data.Width, data.Height, 0,
                    OpenTK.Graphics.OpenGL.PixelFormat.Bgra,
                    PixelType.UnsignedByte, data.Scan0);

                // 设置纹理参数
                GL.TexParameter(TextureTarget.Texture2D,
                    TextureParameterName.TextureMinFilter,
                    (int)TextureMinFilter.Linear);
                GL.TexParameter(TextureTarget.Texture2D,
                    TextureParameterName.TextureMagFilter,
                    (int)TextureMagFilter.Linear);

                bmp.UnlockBits(data);

                return texId;
            }
        }

        private void DrawTexturedCube()
        {
            // 前面 (Z+)
            DrawFace(_textures[0], new[]
            {
                new Vector3(-50, -50, 50),
                new Vector3(50, -50, 50),
                new Vector3(50, 50, 50),
                new Vector3(-50, 50, 50)
            });

            // 后面 (Z-)
            DrawFace(_textures[1], new[]
            {
                new Vector3(50, -50, -50),
                new Vector3(-50, -50, -50),
                new Vector3(-50, 50, -50),
                new Vector3(50, 50, -50)
            });

            // 左面 (X-)
            DrawFace(_textures[2], new[]
            {
                new Vector3(-50, -50, -50),
                new Vector3(-50, -50, 50),
                new Vector3(-50, 50, 50),
                new Vector3(-50, 50, -50)
            });

            // 右面 (X+)
            DrawFace(_textures[3], new[]
            {
                new Vector3(50, -50, 50),
                new Vector3(50, -50, -50),
                new Vector3(50, 50, -50),
                new Vector3(50, 50, 50)
            });

            // 顶面 (Y+)
            DrawFace(_textures[4], new[]
            {
                new Vector3(-50, 50, 50),
                new Vector3(50, 50, 50),
                new Vector3(50, 50, -50),
                new Vector3(-50, 50, -50)
            });

            // 底面 (Y-)
            DrawFace(_textures[5], new[]
            {
                new Vector3(-50, -50, -50),
                new Vector3(50, -50, -50),
                new Vector3(50, -50, 50),
                new Vector3(-50, -50, 50)
            });
        }


        private void DrawFace(int textureId, Vector3[] vertices)
        {
            GL.BindTexture(TextureTarget.Texture2D, textureId);
            GL.Begin(PrimitiveType.Quads);

            GL.TexCoord2(0, 0); GL.Vertex3(vertices[0]);
            GL.TexCoord2(1, 0); GL.Vertex3(vertices[1]);
            GL.TexCoord2(1, 1); GL.Vertex3(vertices[2]);
            GL.TexCoord2(0, 1); GL.Vertex3(vertices[3]);

            // 修正后的纹理坐标（翻转Y方向）
            //GL.TexCoord2(0, 1); GL.Vertex3(vertices[0]); // 左上→左下
            //GL.TexCoord2(1, 1); GL.Vertex3(vertices[1]); // 右上→右下
            //GL.TexCoord2(1, 0); GL.Vertex3(vertices[2]); // 右下→右上
            //GL.TexCoord2(0, 0); GL.Vertex3(vertices[3]); // 左下→左上

            GL.End();
        }




        #endregion

        #region 交互处理

        /// <summary>
        /// 处理鼠标滚轮
        /// </summary>
        public void HandleMouseWheel(MouseEventArgs e)
        {
            if (!this.glControl1.IsHandleCreated)
            {
                return;
            }
            this.Zoom *= e.Delta > 0 ? 0.9f : 1.1f;
            UpdateMatrices();
            this.glControl1.Invalidate();
        }

        /// <summary>
        /// 处理鼠标按下
        /// </summary>
        public void HandleMouseDown(MouseEventArgs e)
        {
            if (!this.glControl1.IsHandleCreated)
            {
                return;
            }
            _lastMousePos = e.Location;
            if (e.Button == MouseButtons.Right)
            {
                _isDragging = true;
                this.glControl1.Cursor = Cursors.SizeAll; // 修改光标样式
            }
            else if (e.Button == MouseButtons.Left)
            {
                _isRotating = true;
                this.glControl1.Cursor = Cursors.SizeAll; // 修改光标样式
            }
        }

        /// <summary>
        /// 处理鼠标弹起
        /// </summary>
        public void HandleMouseUp(MouseEventArgs e)
        {
            if (!this.glControl1.IsHandleCreated)
            {
                return;
            }
            _lastMousePos = e.Location;
            if (e.Button == MouseButtons.Right)
            {
                _isDragging = false;
                this.glControl1.Cursor = Cursors.Default;
            }
            else if (e.Button == MouseButtons.Left)
            {
                _isRotating = false;
                this.glControl1.Cursor = Cursors.Default;
            }
            this.glControl1.Invalidate();
        }

        /// <summary>
        /// 处理鼠标移动
        /// </summary>
        public void HandleMouseMove(MouseEventArgs e)
        {
            if (!this.glControl1.IsHandleCreated)
            {
                return;
            }
            float dx = e.X - _lastMousePos.X;
            float dy = e.Y - _lastMousePos.Y;

            if (_isRotating)
            {
                // 根据鼠标移动量计算旋转角度
                var roation_dx = dy / _radius;
                var rotaion_dy = dx / _radius;
                _rotationX += roation_dx;
                _rotationY += rotaion_dy;
                UpdateMatrices();
            }
            else if (_isDragging)
            {
                float xratio = _pw / this.glControl1.Width;
                float yratio = _ph / this.glControl1.Height;
                _translationX += dx * xratio;
                _translationY -= dy * yratio;
                UpdateMatrices();
            }

            _lastMousePos = e.Location;
            this.glControl1.Invalidate();
        }

        #endregion




    }
}