using OpenTK;
using System;
using OpenTK.Graphics;
using Labs.Utility;
using OpenTK.Graphics.OpenGL;

namespace Labs.ACW
{
    class cube
    {
        public enum cubeType
        {
            Bottom,
            Middle,
            Top
        };

        Matrix4 Position;
        cubeType cubeStructure;

        public cube(string inCubeStructure, Matrix4 inPosition)
        {
            switch (inCubeStructure)
            {
                case "Top":
                    cubeStructure = cubeType.Top;
                    break;
                case "Middle":
                    cubeStructure = cubeType.Middle;
                    break;
                case "Bottom":
                    cubeStructure = cubeType.Bottom;
                    break;
            }

            Position = inPosition;
        }

        public void OnLoad(EventArgs e)
        {
            float[] cubeVertices = new float[] {
                 // Top
                0, 1, 0, 0, 1, 0,
                1, 1, 0, 0, 1, 0,
                1, 1, 1, 0, 1, 0,

                0, 1, 0, 0, 1, 0,
                1, 1, 1, 0, 1, 0,
                0, 1, 1, 0, 1, 0,

                // Side 1 - Front Side
                0, 1, 1, 0, 1, 0,
                1, 1, 1, 0, 1, 0,
                1, 0, 1, 0, 1, 0,

                0, 1, 1, 0, 1, 0,
                1, 0, 1, 0, 1, 0,
                0, 0, 1, 0, 1, 0,

                // Side 2 - Left Side
                0, 1, 0, 0, 1, 0,
                0, 0, 1, 0, 1, 0,
                0, 0, 0, 0, 1, 0,

                0, 1, 0, 0, 1, 0,
                0, 1, 1, 0, 1, 0,
                0, 0, 1, 0, 1, 0,

                // Side 3 - Back Side
                1, 1, 0, 0, 1, 0,
                0, 0, 0, 0, 1, 0,
                1, 0, 0, 0, 1, 0,

                1, 1, 0, 0, 1, 0,
                0, 1, 0, 0, 1, 0,
                0, 0, 0, 0, 1, 0,

                // Side 4 - Right Side
                1, 1, 1, 0, 1, 0,
                1, 0, 0, 0, 1, 0,
                1, 0, 1, 0, 1, 0,

                1, 1, 1, 0, 1, 0,
                1, 1, 0, 0, 1, 0,
                1, 0, 0, 0, 1, 0,

                // Bottom
                0, 0, 0, 0, 1, 0,
                0, 0, 1, 0, 1, 0,
                1, 0, 1, 0, 1, 0,

                0, 0, 0, 0, 1, 0,
                1, 0, 1, 0, 1, 0,
                1, 0, 0, 0, 1, 0
            };

            // Bind Vertex Array
            GL.BindVertexArray(ACWWindow.mVertexArrayObjectIDArray[0]);

            // Bind Vertex Buffer
            GL.BindBuffer(BufferTarget.ArrayBuffer, ACWWindow.mVertexBufferObjectIDArray[0]);
            GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(cubeVertices.Length * sizeof(float)), cubeVertices, BufferUsageHint.StaticDraw);

            // Ensure Cube is loaded correctly
            int size;
            GL.GetBufferParameter(BufferTarget.ArrayBuffer, BufferParameterName.BufferSize, out size);
            if (cubeVertices.Length * sizeof(float) != size)
            {
                throw new ApplicationException("Vertex data not loaded onto graphics card correctly");
            }

            int vPositionLocation = GL.GetAttribLocation(ACWWindow.mShader.ShaderProgramID, "vPosition");
            int vNormalLocation = GL.GetAttribLocation(ACWWindow.mShader.ShaderProgramID, "vNormal");

            // Position and Normal
            GL.EnableVertexAttribArray(vPositionLocation);
            GL.VertexAttribPointer(vPositionLocation, 3, VertexAttribPointerType.Float, false, 6 * sizeof(float), 0);
            GL.EnableVertexAttribArray(vNormalLocation);
            GL.VertexAttribPointer(vNormalLocation, 3, VertexAttribPointerType.Float, true, 6 * sizeof(float), 3 * sizeof(float));
        }

        public void OnRenderFrame(FrameEventArgs e)
        {
            // Draw Cube
            int uModel = GL.GetUniformLocation(ACWWindow.mShader.ShaderProgramID, "uModel");
            GL.UniformMatrix4(uModel, true, ref Position);
            GL.BindVertexArray(ACWWindow.mVertexArrayObjectIDArray[0]);

            switch (cubeStructure)
            {
                case cubeType.Top:
                    GL.DrawArrays(PrimitiveType.Triangles, 0, 30);
                    break;
                case cubeType.Middle:
                    GL.DrawArrays(PrimitiveType.Triangles, 6, 30);
                    break;
                case cubeType.Bottom:
                    GL.DrawArrays(PrimitiveType.Triangles, 6, 36);
                    break;
            }
        }
    }
}