using OpenTK.Mathematics;
using System.Security.Cryptography;

namespace Voxel
{
    static class Camera
    {
        public static Vector3 Position;

        public static float Pitch = 0f;
        public static float Yaw = -90f;
        public static float FOV = 70f;
        public static float Speed = 0.5f;

        public static Matrix4 view =>
            Matrix4.LookAt(Position, Position + Front, Vector3.UnitY);

        public static Matrix4 projection;

        public static Vector3 Front
        {
            get
            {
                Vector3 front;
                front.X = MathF.Cos(MathHelper.DegreesToRadians(Yaw)) * MathF.Cos(MathHelper.DegreesToRadians(Pitch));
                front.Y = MathF.Sin(MathHelper.DegreesToRadians(Pitch));
                front.Z = MathF.Sin(MathHelper.DegreesToRadians(Yaw)) * MathF.Cos(MathHelper.DegreesToRadians(Pitch));
                return front.Normalized();
            }
        }

        public static void Update(float time)
        {
            float moveSpeed = Speed * time;
            if (Input.GetKey(OpenTK.Windowing.GraphicsLibraryFramework.Keys.LeftShift))
            {
                moveSpeed *= 10;
            }
            if (Input.GetKey(OpenTK.Windowing.GraphicsLibraryFramework.Keys.W))
            {
                Position += Front * moveSpeed;
            }
            if (Input.GetKey(OpenTK.Windowing.GraphicsLibraryFramework.Keys.S))
            {
                Position += Front * -moveSpeed;
            }
            if (Input.GetKey(OpenTK.Windowing.GraphicsLibraryFramework.Keys.A))
            {
                Position += Vector3.Cross(Front, Vector3.UnitY).Normalized() * -moveSpeed;
            }
            if (Input.GetKey(OpenTK.Windowing.GraphicsLibraryFramework.Keys.D))
            {
                Position += Vector3.Cross(Front, Vector3.UnitY).Normalized() * moveSpeed;
            }
        }

        public static void UpdateMouse(Vector2 delta)
        {
            float fov = MathHelper.DegreesToRadians(60f);
            float aspectRatio = 800f / 600f;
            float near = 0.1f;
            float far = 100f;

            projection = Matrix4.CreatePerspectiveFieldOfView(fov, aspectRatio, near, far);

            float sensitivity = 0.1f;
            Yaw += delta.X * sensitivity;
            Pitch -= delta.Y * sensitivity;

            Pitch = MathHelper.Clamp(Pitch, -89f, 89f);
        }
    }
}