//-----------------------------------------------------------------------
// -----------------------------------------------------------------------
// file="MatrixParallelThread"
// Project: StgSharp
// AuthorGroup: Nitload
// Copyright (c) Nitload. 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;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Diagnostics.CodeAnalysis;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;

namespace StgSharp.Mathematics.Numeric
{
    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 MatrixParallelWrap BindedWrap { get; set; }

        internal RoleType Role { 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()
        {
            if (Role == RoleType.Leader)
            {
                LeaderEvent?.Set();
            } else
            {
                _resetEvent.Set();
            }
        }

        internal void MatrixParallelLeader()
        {
            Thread current = Thread.CurrentThread;
            current.Priority = ThreadPriority.Highest;
            LeaderEvent?.Wait();
            LeaderEvent?.Reset();

            // Console.WriteLine("Leader is computing");
            BindedWrap.ReportThreadAccomplished();

            // Console.WriteLine("leader's computing is done");
            Role = RoleType.Worker;
            LeaderEvent = null;
            current.Priority = BindedWrap.AfterWork;
        }

        [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(0);

            while (true)
            {
                // Thread self = Thread.CurrentThread;
                _resetEvent.Wait();
                _resetEvent.Reset();
                AfterWork = BindedWrap.AfterWork;
                _managedThread.Priority = ThreadPriority.Highest;
                switch (Role)
                {
                    case RoleType.Worker://worker
                        // _ = Interlocked.Decrement(ref RemainThreadCount);
                        // Console.WriteLine($"worker {Environment.CurrentManagedThreadId} start");
                        ExecuteTaskPackage(BindedWrap.TaskQueue);
                        BindedWrap.ReportThreadAccomplished();

                        // Console.WriteLine($"worker {Environment.CurrentManagedThreadId} end");
                        break;
                    case RoleType.SingleExternal:

                        // TODO 将外部线程绑定到当前线程上，并执行任务包
                        break;
                    default:
                        break;
                }
                _managedThread.Priority = AfterWork;
            }
        }

        internal enum RoleType : int
        {

            Worker = 0,
            Leader = 1,
            SingleExternal = 2,

        }

    }
}