//-----------------------------------------------------------------------
// -----------------------------------------------------------------------
// file="MatrixParallelThread"
// Project: StgSharp
// AuthorGroup: Nitload Space
// Copyright (c) Nitload Space. All rights reserved.
//     
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
//     
// -----------------------------------------------------------------------
// -----------------------------------------------------------------------
using StgSharp.Internal;
using StgSharp.Internal.Intrinsic;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;

namespace StgSharp.Mathematics.Numeric
{
    internal enum MatrixThreadState : int
    {

        Ready = 0,
        Running = 1,
        Idle = 2,

    }

    public unsafe partial class MatrixParallelThread : IDisposable
    {

        private IntPtr* _context;
        private bool disposedValue;
        private readonly ManualResetEventSlim _resetEvent;
        private readonly Thread _managedThread;

        internal MatrixParallelThread(int poolId)
        {
            _resetEvent = new ManualResetEventSlim(false);
            _managedThread = new Thread(MatrixParallelWorkLoad);
            _managedThread.Start();
            PoolId = poolId;
        }

        public int PoolId { get; init; }

        public ThreadPriority AfterWork { get; set; }

        internal ManualResetEventSlim? LeaderEvent { get; set; }

        internal IntrinsicContext* Intrinsic { get; set; }

        internal bool IsSingle { get; set; }

        internal MatrixParallelWrap BindedWrap { get; set; }

        internal MatrixThreadState state { get; set; }

        internal SIMDID Simd { get; set; }

        public void Dispose()
        {
            Dispose(disposing:true);
            GC.SuppressFinalize(this);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static unsafe void ExecuteTaskPackage(MatrixParallelQueue taskQueue)
        {
            MatrixParallelTaskPackage* p = taskQueue.Package;
            switch (p->ComputeMode.OperationStyle)
            {
                case MatrixIndexStyle.BUFFER_INDEX:
                    switch (p->ComputeMode.ParameterStyle)
                    {
                        case MatrixOperationParam.RIGHT_ANS_PARAM:
                            BufferComputeUnary(p);
                            break;
                        case MatrixOperationParam.LEFT_RIGHT_ANS_PARAM:
                            BufferComputeBinary(p);
                            break;
                        case MatrixOperationParam.RIGHT_ANS_SCALAR_PARAM:
                            BufferComputeUnaryScalar(p);
                            break;
                        case MatrixOperationParam.LEFT_RIGHT_ANS_SCALAR_PARAM:
                            BufferComputeBinaryScalar(p);
                            break;
                        case MatrixOperationParam.ANS_SCALAR_PARAM:
                            BufferComputeNoOperatorScalar(p);
                            break;
                        default:
                            break;
                    }
                    break;
                case MatrixIndexStyle.SPECIAL:
                    SpecialBufferCompute(p);
                    break;
                default:
                    break;
            }
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void Restart()
        {
            _resetEvent.Set();
        }

        [DllImport(
                dllName: Native.LibName,
                EntryPoint = "sn_get_simd_level_local",
                CallingConvention = CallingConvention.Cdecl)]
        internal static extern ulong GetSimdId();

        [DllImport(
                dllName:Native.LibName,
                EntryPoint = "sn_set_thread_affinity",
                CallingConvention = CallingConvention.Cdecl)]
        internal static extern void SetThreadAffinity(int coreId);

        protected virtual void Dispose(bool disposing)
        {
            if (!disposedValue)
            {
                if (disposing)
                {
                    _resetEvent.Dispose();
                    _managedThread.Join();
                }
                disposedValue = true;
            }
        }

        private unsafe void MatrixParallelWorkLoad()
        {
            // Bind OS-thread affinity once when the worker starts running
            SetThreadAffinity(PoolId);
            Thread.Sleep(1);
            SIMDID feature = new();
            feature.Mask = GetSimdId();
            _context = (nint*)MatrixParallel.GetContext(feature);
            while (true)
            {
                // Thread self = Thread.CurrentThread;
                _resetEvent.Wait();
                _resetEvent.Reset();
                AfterWork = BindedWrap.AfterWork;
                _managedThread.Priority = ThreadPriority.Highest;
                if (IsSingle)
                {
                    // TODO 将外部线程绑定到当前线程上，并执行任务包
                } else
                {
                    ExecuteTaskPackage(BindedWrap.TaskQueue);
                    BindedWrap.ReportThreadAccomplished();
                }
                _managedThread.Priority = AfterWork;
            }
        }

    }
}