using StgSharp.Logic;
using StgSharp.Math;
using System;

using System.Runtime.CompilerServices;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace StgSharp.Graphics
{
    internal sealed class FrameOperationBuffer
    {
        private readonly unsafe GLcontext* currentContext;
        private IntPtr _func;
        private ConcurrentQueue<IntPtr> _funcQueue;

        public unsafe bool CallNext()
        {
            if (_funcQueue.TryDequeue(out _func))
            {
                ((delegate*<FrameOperationBuffer, GLcontext*, void>)_func)(this, currentContext);
                return true;
            }
            else
            {
                return false;
            }
        }

        #region gl param queue

        private ConcurrentQueue<M128> paramQueue = new ConcurrentQueue<M128>();
        private ConcurrentQueue<glArrayHandle> streamQueue = new ConcurrentQueue<glArrayHandle>();

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void MethodEnqueue(IntPtr p)
        {
            _funcQueue.Enqueue(p);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void ParamEnqueue(Vec4d v)
        {
            paramQueue.Enqueue(v);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void ParamEnqueue(M128 m)
        {
            paramQueue.Enqueue(m);
            Console.WriteLine(paramQueue.Count + streamQueue.Count);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void ParamEnqueue(uint u0)
        {
            M128 m = default;
            m.Write<uint>(0, u0);
            this.ParamEnqueue(m);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void ParamEnqueue(uint u0, uint u1)
        {
            M128 m = default;
            m.Write<uint>(0, u0);
            m.Write<uint>(1, u1);
            this.ParamEnqueue(m);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void ParamEnqueue(ulong u0, ulong u1)
        {
            M128 m = default;
            m.Write<ulong>(0, u0);
            m.Write<ulong>(1, u1);
            this.ParamEnqueue(m);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void ParamEnqueue(uint u0, uint u1, uint u2)
        {
            M128 m = default;
            m.Write<uint>(0, u0);
            m.Write<uint>(1, u1);
            m.Write<uint>(2, u2);
            this.ParamEnqueue(m);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void ParamEnqueue(float f0, float f1, float f2)
        {
            M128 m = default;
            m.Write<float>(0, f0);
            m.Write<float>(1, f1);
            this.ParamEnqueue(m);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void ParamEnqueue(float f0, float f1, float f2, float f3)
        {
            M128 m = default;
            m.Write<float>(0, f0);
            m.Write<float>(1, f1);
            m.Write<float>(2, f2);
            m.Write<float>(3, f3);
            this.ParamEnqueue(m);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void ParamEnqueue(IntPtr p0, IntPtr p1)
        {
            M128 m = default;
            m.Write<ulong>(0, (ulong)p0);
            m.Write<ulong>(1, (ulong)p1);
            this.ParamEnqueue(m);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void ParamEnqueue(IntPtr p)
        {
            M128 m = default;
            m.Write<ulong>(0, (ulong)p);
            this.ParamEnqueue(m);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public unsafe void ParamEnqueue(glHandle handle)
        {
            M128 m = default;
            m.Write<ulong>(0, (ulong)handle.valuePtr);
            this.ParamEnqueue(m);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public unsafe void ParamEnqueue(glHandle handle, glHandle handle1)
        {
            M128 m = default;
            m.Write<ulong>(0, (ulong)handle.valuePtr);
            m.Write<ulong>(1, (ulong)handle1.valuePtr);
            this.ParamEnqueue(m);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void ParamEnqueue(int i0)
        {
            M128 m = default;
            m.Write<int>(0, i0);
            this.ParamEnqueue(m);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void ParamEnqueue(int i0, int i1)
        {
            M128 m = default;
            m.Write<int>(0, i0);
            m.Write<int>(1, i1);
            this.ParamEnqueue(m);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void ParamEnqueue(int i0, int i1, int i2)
        {
            M128 m = default;
            m.Write<int>(0, i0);
            m.Write<int>(1, i1);
            m.Write<int>(2, i2);
            this.ParamEnqueue(m);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void ParamEnqueue(int i0, int i1, int i2, int i3)
        {
            M128 m = default;
            m.Write<int>(0, i0);
            m.Write<int>(1, i1);
            m.Write<int>(2, i2);
            m.Write<int>(3, i3);
            this.ParamEnqueue(m);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void ParamEnqueue(string str)
        {
            byte[] code = Encoding.UTF8.GetBytes(str);
            streamQueue.Enqueue(glArrayHandle.Alloc<byte>(code));
            Console.WriteLine(paramQueue.Count + streamQueue.Count);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void ParamEnqueue<T>(T[] array) where T : struct
        {
            streamQueue.Enqueue(glArrayHandle.Alloc<T>(array));
            Console.WriteLine(paramQueue.Count + streamQueue.Count);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void TryDequeue(out glArrayHandle arrayHandle)
        {
            if (!streamQueue.TryDequeue(out arrayHandle))
            {
                InternalIO.InternalWriteLog("No param in buffer when calling gl function:", LogType.Error);
                throw new Exception();
            }
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public bool TryDequeue(out M128 m)
        {
            bool ret = paramQueue.TryDequeue(out m);
            return ret;
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public unsafe void TryDequeue(out Vec4d v)
        {
            M128 m;
            if (this.TryDequeue(out m))
            {
                v = *(Vec4d*)&m;
            }
            else
            {
                InternalIO.InternalWriteLog("No param in buffer when calling gl function.", LogType.Error);
                throw new Exception();
            }
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void TryDequeue<T>(out T[] array)
        {
            glArrayHandle output = default;
            if (streamQueue.TryDequeue(out output))
            {
                array = output.a as T[];
            }
            else
            {
                InternalIO.InternalWriteLog("No param in buffer when calling gl function.", LogType.Error);
                throw new Exception();
            }
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void TryDequeue(out int i0)
        {
            M128 ret;
            if (this.TryDequeue(out ret))
            {
                i0 = ret.Read<int>(0);
            }
            else
            {
                InternalIO.InternalWriteLog("No param in buffer when calling gl function.", LogType.Error);
                throw new Exception();
            }
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void TryDequeue(out int i0, out int i1)
        {
            M128 ret;
            if (this.TryDequeue(out ret))
            {
                i0 = ret.Read<int>(0);
                i1 = ret.Read<int>(1);
            }
            else
            {
                InternalIO.InternalWriteLog("No param in buffer when calling gl function.", LogType.Error);
                throw new Exception();
            }
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void TryDequeue(out int i0, out int i1, out int i2)
        {
            M128 ret;
            if (this.TryDequeue(out ret))
            {
                i0 = ret.Read<int>(0);
                i1 = ret.Read<int>(1);
                i2 = ret.Read<int>(2);
            }
            else
            {
                InternalIO.InternalWriteLog("No param in buffer when calling gl function.", LogType.Error);
                throw new Exception();
            }
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void TryDequeue(out int i0, out int i1, out int i2, out int i3)
        {
            M128 ret;
            if (this.TryDequeue(out ret))
            {
                i0 = ret.Read<int>(0);
                i1 = ret.Read<int>(1);
                i2 = ret.Read<int>(2);
                i3 = ret.Read<int>(3);
            }
            else
            {
                InternalIO.InternalWriteLog("No param in buffer when calling gl function.", LogType.Error);
                throw new Exception();
            }
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void TryDequeue(out IntPtr p)
        {
            M128 ret;
            if (this.TryDequeue(out ret))
            {
                p = (IntPtr)ret.Read<ulong>(0);
            }
            else
            {
                InternalIO.InternalWriteLog("No param in buffer when calling gl function.", LogType.Error);
                throw new Exception();
            }
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void TryDequeue(out IntPtr p0, out IntPtr p1)
        {
            M128 ret;
            if (this.TryDequeue(out ret))
            {
                p0 = (IntPtr)ret.Read<ulong>(0);
                p1 = (IntPtr)ret.Read<ulong>(1);
            }
            else
            {
                InternalIO.InternalWriteLog("No param in buffer when calling gl function.", LogType.Error);
                throw new Exception();
            }
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void TryDequeue(out float f0, out float f1, out float f2, out float f3)
        {
            M128 ret;
            if (this.TryDequeue(out ret))
            {
                f0 = ret.Read<uint>(0);
                f1 = ret.Read<uint>(1);
                f2 = ret.Read<uint>(2);
                f3 = ret.Read<uint>(3);
            }
            else
            {
                InternalIO.InternalWriteLog("No param in buffer when calling gl function.", LogType.Error);
                throw new Exception();
            }
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void TryDequeue(out float f0, out float f1, out float f2)
        {
            M128 ret;
            if (this.TryDequeue(out ret))
            {
                f0 = ret.Read<uint>(0);
                f1 = ret.Read<uint>(1);
                f2 = ret.Read<uint>(2);
            }
            else
            {
                InternalIO.InternalWriteLog("No param in buffer when calling gl function.", LogType.Error);
                throw new Exception();
            }
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void TryDequeue(out uint u0)
        {
            M128 ret;
            if (this.TryDequeue(out ret))
            {
                u0 = ret.Read<uint>(0);
            }
            else
            {
                InternalIO.InternalWriteLog("No param in buffer when calling gl function.", LogType.Error);
                throw new Exception();
            }
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void TryDequeue(out uint u0, out uint u1)
        {
            M128 ret;
            if (this.TryDequeue(out ret))
            {
                u0 = ret.Read<uint>(0);
                u1 = ret.Read<uint>(1);
            }
            else
            {
                InternalIO.InternalWriteLog("No param in buffer when calling gl function.", LogType.Error);
                throw new Exception();
            }
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void TryDequeue(out uint u0, out uint u1, out uint u2)
        {
            M128 ret;
            if (this.TryDequeue(out ret))
            {
                u0 = ret.Read<uint>(0);
                u1 = ret.Read<uint>(1);
                u2 = ret.Read<uint>(2);
            }
            else
            {
                InternalIO.InternalWriteLog("No param in buffer when calling gl function.", LogType.Error);
                throw new Exception();
            }
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void TryDequeue(out uint u0, out uint u1, out uint u2, out uint u3)
        {
            M128 ret;
            if (this.TryDequeue(out ret))
            {
                u0 = ret.Read<uint>(0);
                u1 = ret.Read<uint>(1);
                u2 = ret.Read<uint>(2);
                u3 = ret.Read<uint>(3);
            }
            else
            {
                InternalIO.InternalWriteLog("No param in buffer when calling gl function.", LogType.Error);
                throw new Exception();
            }
        }

        /*
        internal void SetContext(GLcontext* p)
        {
            context = p;
        }
        /**/

        #endregion gl param queue
    }

    internal sealed class FrameThread
    {
        private Thread _thread;
        private FrameOperationBuffer renderBuffer;
        private SemaphoreSlim renderCompleteSemaphore = new SemaphoreSlim(1, 1);
        private SemaphoreSlim renderStartSemaphore;
        private bool shouldTerminate;
        private FrameOperationBuffer updateBuffer;

        internal FrameThread(GLonUpdate gl)
        {
            updateBuffer = gl.ActivatedOperationBuffer;
            _thread = new Thread(new ThreadStart(PrivateMain));
        }

        public bool IsRunning
        {
            get { return _thread.IsAlive; }
        }

        public void Start()
        {
            _thread.Start();
        }

        public void Terminate()
        {
            shouldTerminate = true;
        }

        private void PrivateMain()
        {
            renderStartSemaphore.Wait();
            while (shouldTerminate && renderBuffer.CallNext())
            { }
            renderCompleteSemaphore.Release();
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void SetNext(FrameThread thread)
        {
            renderStartSemaphore = thread.renderCompleteSemaphore;
        }
    }
}