using Mirle.Component.MPLC.DataBlocks.DeviceRange.Interfaces;
using Mirle.Component.MPLC.DataBlocks.Interfaces;
using System;
using System.Collections;
using System.Diagnostics;
using System.IO;
using System.IO.MemoryMappedFiles;
using System.Threading;

namespace Mirle.Component.MPLC.DataBlocks
{
    /// <summary>
    /// 共享記憶體資料區塊
    /// </summary>
    public class SMDataBlock : IDataBlock, IDisposable
    {
        /// <summary>
        /// 建構式
        /// </summary>
        /// <param name="deviceRange">設備範圍介面</param>
        /// <param name="sharedMemoryName">共享記憶體名稱</param>
        public SMDataBlock(ITypeDeviceRange deviceRange, string sharedMemoryName)
        {
            DeviceRange = deviceRange;
            _mmfName = sharedMemoryName;
            Initial();
        }
        /// <summary>
        /// 原始資料物件鎖定
        /// </summary>
        protected readonly ReaderWriterLockSlim _rwLock = new ReaderWriterLockSlim();
        /// <summary>
        /// 共享記憶體名稱
        /// </summary>
        protected string _mmfName;
        /// <summary>
        /// 共享記憶體長度
        /// </summary>
        protected long _mmfLength;
        /// <summary>
        /// 共享記憶體對應檔案
        /// </summary>
        protected MemoryMappedFile _mmf;
        /// <summary>
        /// 設備範圍介面
        /// </summary>
        public ITypeDeviceRange DeviceRange { get; }
        /// <summary>
        /// 共享記憶體對應名稱
        /// </summary>
        public string MemoryMappedName => _mmfName;
        /// <summary>
        /// 初始化
        /// </summary>
        protected virtual void Initial()
        {
            _mmfLength = DeviceRange.ByteArrayLength;

            #if NET5_0 || NET6_0
            if (OperatingSystem.IsWindows())
            {
                _mmf = MemoryMappedFile.CreateOrOpen(_mmfName, _mmfLength);
            }
            else
            {
                _mmf = MemoryMappedFile.CreateFromFile(_mmfName);
            }
            #elif NETFRAMEWORK
            _mmf = MemoryMappedFile.CreateOrOpen(_mmfName, _mmfLength);
            #else
            _mmf = MemoryMappedFile.CreateFromFile(_mmfName);
            #endif
        }
        /// <summary>
        /// 設置原始資料
        /// </summary>
        /// <param name="newRawData">原始資料</param>
        public virtual void SetRawData(byte[] newRawData)
        {
            try
            {
                _rwLock.EnterWriteLock();
                MemoryMappedViewStream stream = _mmf.CreateViewStream();
                using BinaryWriter writer = new BinaryWriter(stream);
                stream.Seek(0, SeekOrigin.Begin);
                for (int i = 0; i < Math.Min(newRawData.Length, _mmfLength); i++)
                {
                    writer.Write(newRawData[i]);
                }
            }
            catch (Exception ex)
            {
                Debug.WriteLine($"{ex}");
            }
            finally
            {
                _rwLock.ExitWriteLock();
            }
        }
        /// <summary>
        /// 取得原始資料
        /// </summary>
        /// <returns>原始資料</returns>
        public virtual byte[] GetRawData()
        {
            byte[] data = new byte[_mmfLength];
            try
            {
                _rwLock.EnterReadLock();
                MemoryMappedViewStream stream = _mmf.CreateViewStream();
                using BinaryReader reader = new BinaryReader(stream);
                stream.Seek(0, SeekOrigin.Begin);
                for (int i = 0; i < _mmfLength; i++)
                {
                    data[i] = reader.ReadByte();
                }
            }
            catch (Exception ex)
            {
                Debug.WriteLine($"{ex}");
            }
            finally
            {
                _rwLock.ExitReadLock();
            }
            return data;
        }
        /// <summary>
        /// 取得位元
        /// </summary>
        /// <param name="address">位置</param>
        /// <param name="value">是否成功取得</param>
        /// <returns>True/False</returns>
        public virtual bool TryGetBit(string address, out bool value)
        {
            value = false;
            try
            {
                _rwLock.EnterReadLock();
                if (DeviceRange.TryGetByteArrayOffset(address, out int offset) && DeviceRange.TryGetByteArrayBitIndex(address, out int index))
                {
                    MemoryMappedViewStream stream = _mmf.CreateViewStream();
                    using BinaryReader reader = new BinaryReader(stream);
                    stream.Seek(offset, SeekOrigin.Begin);
                    ushort word = reader.ReadUInt16();
                    BitArray bitArray = new BitArray(BitConverter.GetBytes(word));
                    value = bitArray.Get(index);
                    return true;
                }
            }
            catch (Exception ex)
            {
                Debug.WriteLine($"{ex}");
            }
            finally
            {
                _rwLock.ExitReadLock();
            }
            return false;
        }
        /// <summary>
        /// 設置位元開啟
        /// </summary>
        /// <param name="address">位置</param>
        /// <returns>True/False</returns>
        public bool TrySetBitOn(string address)
        {
            return SetBit(address, true);
        }
        /// <summary>
        /// 設置位元
        /// </summary>
        /// <param name="address">位置</param>
        /// <param name="isOn">是否開啟</param>
        /// <returns>True/False</returns>
        protected virtual bool SetBit(string address, bool isOn)
        {
            try
            {
                _rwLock.EnterWriteLock();
                if (DeviceRange.TryGetByteArrayOffset(address, out int offset) && DeviceRange.TryGetByteArrayBitIndex(address, out int index))
                {
                    MemoryMappedViewStream stream = _mmf.CreateViewStream();

                    using BinaryReader reader = new BinaryReader(stream);
                    stream.Seek(offset, SeekOrigin.Begin);
                    ushort word = reader.ReadUInt16();
                    BitArray bitArray = new BitArray(BitConverter.GetBytes(word));
                    bitArray.Set(index, isOn);
                    byte[] tmpBytes = new byte[2];
                    bitArray.CopyTo(tmpBytes, 0);
                    stream = _mmf.CreateViewStream();

                    using BinaryWriter writer = new BinaryWriter(stream);
                    stream.Seek(offset, SeekOrigin.Begin);
                    writer.Write(tmpBytes[0]);
                    writer.Write(tmpBytes[1]);
                    return true;
                }
            }
            catch (Exception ex)
            {
                Debug.WriteLine($"{ex}");
            }
            finally
            {
                _rwLock.ExitWriteLock();
            }
            return false;
        }
        /// <summary>
        /// 設置位元關閉
        /// </summary>
        /// <param name="address">位置</param>
        /// <returns>True/False</returns>
        public bool TrySetBitOff(string address)
        {
            return SetBit(address, false);
        }
        /// <summary>
        /// 取得字元
        /// </summary>
        /// <param name="address">位置</param>
        /// <param name="value">值</param>
        /// <returns>True/False</returns>
        public virtual bool TryGetWord(string address, out int value)
        {
            value = 0;
            try
            {
                _rwLock.EnterReadLock();
                if (DeviceRange.TryGetByteArrayOffset(address, out int offset))
                {
                    MemoryMappedViewStream stream = _mmf.CreateViewStream();
                    using BinaryReader reader = new BinaryReader(stream);
                    stream.Seek(offset, SeekOrigin.Begin);
                    value = reader.ReadUInt16();
                    return true;
                }
            }
            catch (Exception ex)
            {
                Debug.WriteLine($"{ex}");
            }
            finally
            {
                _rwLock.ExitReadLock();
            }
            return false;
        }
        /// <summary>
        /// 設置字元
        /// </summary>
        /// <param name="address">位置</param>
        /// <param name="value">值</param>
        /// <returns>True/False</returns>
        public virtual bool TrySetWord(string address, int value)
        {
            try
            {
                _rwLock.EnterWriteLock();
                if (DeviceRange.TryGetByteArrayOffset(address, out int offset))
                {
                    MemoryMappedViewStream stream = _mmf.CreateViewStream();
                    using BinaryWriter writer = new BinaryWriter(stream);
                    stream.Seek(offset, SeekOrigin.Begin);
                    byte[] tmpBytes = BitConverter.GetBytes(value);
                    writer.Write(tmpBytes[0]);
                    writer.Write(tmpBytes[1]);
                    return true;
                }
            }
            catch (Exception ex)
            {
                Debug.WriteLine($"{ex}");
            }
            finally
            {
                _rwLock.ExitWriteLock();
            }
            return false;
        }
        /// <summary>
        /// 取得多個字元
        /// </summary>
        /// <param name="address">位置</param>
        /// <param name="data">資料集</param>
        /// <param name="length">長度</param>
        /// <returns>True/False</returns>
        public virtual bool TryGetWords(string address, out int[] data, int length)
        {
            data = new int[length];
            try
            {
                _rwLock.EnterReadLock();
                if (DeviceRange.TryGetByteArrayOffset(address, out int offset))
                {
                    MemoryMappedViewStream stream = _mmf.CreateViewStream();
                    using BinaryReader reader = new BinaryReader(stream);
                    stream.Seek(offset, SeekOrigin.Begin);
                    for (int i = 0; i < length; i++)
                    {
                        data[i] = reader.ReadUInt16();
                    }
                    return true;
                }
            }
            catch (Exception ex)
            {
                Debug.WriteLine($"{ex}");
            }
            finally
            {
                _rwLock.ExitReadLock();
            }
            return false;
        }
        /// <summary>
        /// 取得多個字元
        /// </summary>
        /// <param name="address">位置</param>
        /// <param name="data">資料集</param>
        /// <returns>True/False</returns>
        public virtual bool TrySetWords(string address, int[] data)
        {
            try
            {
                _rwLock.EnterWriteLock();
                if (DeviceRange.TryGetByteArrayOffset(address, out int offset))
                {
                    MemoryMappedViewStream stream = _mmf.CreateViewStream();
                    using BinaryWriter writer = new BinaryWriter(stream);
                    stream.Seek(offset, SeekOrigin.Begin);
                    for (int i = 0; i < data.Length; i++)
                    {
                        byte[] tmpBytes = BitConverter.GetBytes(data[i]);
                        writer.Write(tmpBytes[0]);
                        writer.Write(tmpBytes[1]);
                    }
                    return true;
                }
            }
            catch (Exception ex)
            {
                Debug.WriteLine($"{ex}");
            }
            finally
            {
                _rwLock.ExitWriteLock();
            }
            return false;
        }

        #region IDisposable Support

        private bool disposedValue = false;
        /// <summary>
        /// 釋放資源
        /// </summary>
        /// <param name="disposing"></param>
        protected virtual void Dispose(bool disposing)
        {
            if (!disposedValue)
            {
                if (disposing)
                {
                    _mmf?.Dispose();
                    _rwLock?.Dispose();
                }
                disposedValue = true;
            }
        }
        /// <summary>
        /// 解構式
        /// </summary>
        ~SMDataBlock()
        {
            Dispose(false);
        }
        /// <summary>
        /// 釋放資源
        /// </summary>
        public void Dispose()
        {
            Dispose(true);
            GC.SuppressFinalize(this);
        }

        #endregion
    }
}